diff --git a/xfa/fwl/cfwl_barcode.cpp b/xfa/fwl/cfwl_barcode.cpp
index edd3512..f59b441 100644
--- a/xfa/fwl/cfwl_barcode.cpp
+++ b/xfa/fwl/cfwl_barcode.cpp
@@ -163,12 +163,12 @@
   if (pTheme) {
     CFWL_ThemePart part;
     part.m_pWidget = this;
-    if (RetainPtr<CFGAS_GEFont> pFont = pTheme->GetFont(&part)) {
+    if (RetainPtr<CFGAS_GEFont> pFont = pTheme->GetFont(part)) {
       if (CFX_Font* pCXFont = pFont->GetDevFont())
         m_pBarcodeEngine->SetFont(pCXFont);
     }
-    m_pBarcodeEngine->SetFontSize(pTheme->GetFontSize(&part));
-    m_pBarcodeEngine->SetFontColor(pTheme->GetTextColor(&part));
+    m_pBarcodeEngine->SetFontSize(pTheme->GetFontSize(part));
+    m_pBarcodeEngine->SetFontColor(pTheme->GetTextColor(part));
   } else {
     m_pBarcodeEngine->SetFontSize(FWLTHEME_CAPACITY_FontSize);
   }
diff --git a/xfa/fwl/cfwl_caret.cpp b/xfa/fwl/cfwl_caret.cpp
index b2efba4..9380f9e 100644
--- a/xfa/fwl/cfwl_caret.cpp
+++ b/xfa/fwl/cfwl_caret.cpp
@@ -91,7 +91,7 @@
   param.m_dwStates = CFWL_PartState_HightLight;
   if (pMatrix)
     param.m_matrix.Concat(*pMatrix);
-  pTheme->DrawBackground(&param);
+  pTheme->DrawBackground(param);
 }
 
 void CFWL_Caret::OnProcessMessage(CFWL_Message* pMessage) {}
diff --git a/xfa/fwl/cfwl_checkbox.cpp b/xfa/fwl/cfwl_checkbox.cpp
index 35445a9..d627043 100644
--- a/xfa/fwl/cfwl_checkbox.cpp
+++ b/xfa/fwl/cfwl_checkbox.cpp
@@ -76,12 +76,13 @@
   param.m_matrix.Concat(matrix);
   param.m_rtPart = m_rtClient;
   if (m_pProperties->m_dwStates & FWL_WGTSTATE_Focused)
+
     param.m_pRtData = &m_rtFocus;
-  pTheme->DrawBackground(&param);
+  pTheme->DrawBackground(param);
 
   param.m_iPart = CFWL_Part::CheckBox;
   param.m_rtPart = m_rtBox;
-  pTheme->DrawBackground(&param);
+  pTheme->DrawBackground(param);
 
   CFWL_ThemeText textParam;
   textParam.m_pWidget = this;
@@ -93,7 +94,7 @@
   textParam.m_wsText = L"Check box";
   textParam.m_dwTTOStyles = m_TTOStyles;
   textParam.m_iTTOAlign = m_iTTOAlign;
-  pTheme->DrawText(&textParam);
+  pTheme->DrawText(textParam);
 }
 
 void CFWL_CheckBox::SetCheckState(int32_t iCheck) {
diff --git a/xfa/fwl/cfwl_combobox.cpp b/xfa/fwl/cfwl_combobox.cpp
index a835528..84f1be3 100644
--- a/xfa/fwl/cfwl_combobox.cpp
+++ b/xfa/fwl/cfwl_combobox.cpp
@@ -108,7 +108,7 @@
     param.m_dwStates = m_iBtnState;
     param.m_pGraphics = pGraphics;
     param.m_rtPart = m_rtBtn;
-    pTheme->DrawBackground(&param);
+    pTheme->DrawBackground(param);
   }
   pGraphics->RestoreGraphState();
 
@@ -222,7 +222,7 @@
   param.m_pWidget = this;
   if (pMatrix)
     param.m_matrix.Concat(*pMatrix);
-  m_pProperties->m_pThemeProvider->DrawBackground(&param);
+  m_pProperties->m_pThemeProvider->DrawBackground(param);
 }
 
 void CFWL_ComboBox::ShowDropList(bool bActivate) {
@@ -305,7 +305,7 @@
 
   CFWL_ThemePart part;
   part.m_pWidget = this;
-  CFX_RectF pUIMargin = theme->GetUIMargin(&part);
+  CFX_RectF pUIMargin = theme->GetUIMargin(part);
   m_rtContent.Deflate(pUIMargin.left, pUIMargin.top, pUIMargin.width,
                       pUIMargin.height);
 
diff --git a/xfa/fwl/cfwl_datetimepicker.cpp b/xfa/fwl/cfwl_datetimepicker.cpp
index 51727f1..a3fbc9c 100644
--- a/xfa/fwl/cfwl_datetimepicker.cpp
+++ b/xfa/fwl/cfwl_datetimepicker.cpp
@@ -211,7 +211,7 @@
   param.m_rtPart = m_rtBtn;
   if (pMatrix)
     param.m_matrix.Concat(*pMatrix);
-  pTheme->DrawBackground(&param);
+  pTheme->DrawBackground(param);
 }
 
 WideString CFWL_DateTimePicker::FormatDateString(int32_t iYear,
diff --git a/xfa/fwl/cfwl_edit.cpp b/xfa/fwl/cfwl_edit.cpp
index 0c28a18..c5aac8a 100644
--- a/xfa/fwl/cfwl_edit.cpp
+++ b/xfa/fwl/cfwl_edit.cpp
@@ -342,7 +342,7 @@
   param.m_pGraphics = pGraphics;
   param.m_matrix = *pMatrix;
   param.m_rtPart = m_rtClient;
-  pTheme->DrawBackground(&param);
+  pTheme->DrawBackground(param);
 
   if (!IsShowScrollBar(true) || !IsShowScrollBar(false))
     return;
@@ -355,7 +355,7 @@
   param.m_bStaticBackground = true;
   param.m_bMaximize = true;
   param.m_rtPart = rtStatic;
-  pTheme->DrawBackground(&param);
+  pTheme->DrawBackground(param);
 }
 
 void CFWL_Edit::DrawContent(CXFA_Graphics* pGraphics,
@@ -398,7 +398,7 @@
     param.m_pWidget = this;
     param.m_iPart = CFWL_Part::Background;
     param.m_pPath = &path;
-    pTheme->DrawBackground(&param);
+    pTheme->DrawBackground(param);
   }
 
   CFX_RenderDevice* pRenderDev = pGraphics->GetRenderDevice();
@@ -426,7 +426,7 @@
     param.m_pWidget = this;
     param.m_iPart = CFWL_Part::CombTextLine;
     param.m_pPath = &path;
-    pTheme->DrawBackground(&param);
+    pTheme->DrawBackground(param);
   }
   pGraphics->RestoreGraphState();
 }
@@ -530,19 +530,19 @@
     m_fFontSize = FWLTHEME_CAPACITY_FontSize;
     return;
   }
-  m_fFontSize = theme->GetFontSize(&part);
+  m_fFontSize = theme->GetFontSize(part);
 
-  RetainPtr<CFGAS_GEFont> pFont = theme->GetFont(&part);
+  RetainPtr<CFGAS_GEFont> pFont = theme->GetFont(part);
   if (!pFont)
     return;
 
   m_EdtEngine.SetFont(pFont);
-  m_EdtEngine.SetFontColor(theme->GetTextColor(&part));
+  m_EdtEngine.SetFontColor(theme->GetTextColor(part));
   m_EdtEngine.SetFontSize(m_fFontSize);
-  m_EdtEngine.SetLineSpace(theme->GetLineHeight(&part));
+  m_EdtEngine.SetLineSpace(theme->GetLineHeight(part));
   m_EdtEngine.SetTabWidth(m_fFontSize);
   m_EdtEngine.SetVisibleLineCount(m_rtEngine.height /
-                                  theme->GetLineHeight(&part));
+                                  theme->GetLineHeight(part));
 }
 
 void CFWL_Edit::UpdateEditLayout() {
@@ -607,7 +607,7 @@
     CFWL_ThemePart part;
     part.m_pWidget = this;
 
-    CFX_SizeF pSpace = theme->GetSpaceAboveBelow(&part);
+    CFX_SizeF pSpace = theme->GetSpaceAboveBelow(part);
     fSpaceAbove = pSpace.width >= 0.1f ? pSpace.width : 0.0f;
     fSpaceBelow = pSpace.height >= 0.1f ? pSpace.height : 0.0f;
   }
@@ -741,12 +741,12 @@
   CFWL_ThemePart part;
   if (!m_pOuter) {
     part.m_pWidget = this;
-    CFX_RectF pUIMargin = theme->GetUIMargin(&part);
+    CFX_RectF pUIMargin = theme->GetUIMargin(part);
     m_rtEngine.Deflate(pUIMargin.left, pUIMargin.top, pUIMargin.width,
                        pUIMargin.height);
   } else if (m_pOuter->GetClassID() == FWL_Type::DateTimePicker) {
     part.m_pWidget = m_pOuter;
-    CFX_RectF pUIMargin = theme->GetUIMargin(&part);
+    CFX_RectF pUIMargin = theme->GetUIMargin(part);
     m_rtEngine.Deflate(pUIMargin.left, pUIMargin.top, pUIMargin.width,
                        pUIMargin.height);
   }
diff --git a/xfa/fwl/cfwl_listbox.cpp b/xfa/fwl/cfwl_listbox.cpp
index 9e718fe..9d84649 100644
--- a/xfa/fwl/cfwl_listbox.cpp
+++ b/xfa/fwl/cfwl_listbox.cpp
@@ -361,7 +361,7 @@
   if (!IsEnabled())
     param.m_dwStates = CFWL_PartState_Disabled;
 
-  pTheme->DrawBackground(&param);
+  pTheme->DrawBackground(param);
 }
 
 void CFWL_ListBox::DrawItems(CXFA_Graphics* pGraphics,
@@ -431,7 +431,7 @@
     bg_param.m_rtPart.width -= (m_fScorllBarWidth + 1);
     rtFocus.Deflate(0.5, 0.5, 1 + m_fScorllBarWidth, 1);
   }
-  pTheme->DrawBackground(&bg_param);
+  pTheme->DrawBackground(bg_param);
 
   if (!pItem)
     return;
@@ -454,7 +454,7 @@
   textParam.m_dwTTOStyles = m_TTOStyles;
   textParam.m_iTTOAlign = m_iTTOAligns;
   textParam.m_bMaximize = true;
-  pTheme->DrawText(&textParam);
+  pTheme->DrawText(textParam);
 }
 
 CFX_SizeF CFWL_ListBox::CalcSize(bool bAutoSize) {
@@ -468,7 +468,7 @@
     CFWL_ThemePart part;
     part.m_pWidget = this;
     IFWL_ThemeProvider* theme = GetAvailableTheme();
-    CFX_RectF pUIMargin = theme ? theme->GetUIMargin(&part) : CFX_RectF();
+    CFX_RectF pUIMargin = theme ? theme->GetUIMargin(part) : CFX_RectF();
     m_rtConent.Deflate(pUIMargin.left, pUIMargin.top, pUIMargin.width,
                        pUIMargin.height);
   }
@@ -607,7 +607,7 @@
   IFWL_ThemeProvider* theme = GetAvailableTheme();
   CFWL_ThemePart part;
   part.m_pWidget = this;
-  return (theme ? theme->GetFontSize(&part) : 20.0f) + 2 * kItemTextMargin;
+  return (theme ? theme->GetFontSize(part) : 20.0f) + 2 * kItemTextMargin;
 }
 
 void CFWL_ListBox::InitVerticalScrollBar() {
diff --git a/xfa/fwl/cfwl_monthcalendar.cpp b/xfa/fwl/cfwl_monthcalendar.cpp
index dc8328b..548b27f 100644
--- a/xfa/fwl/cfwl_monthcalendar.cpp
+++ b/xfa/fwl/cfwl_monthcalendar.cpp
@@ -162,7 +162,7 @@
   params.m_rtPart = m_rtClient;
   if (pMatrix)
     params.m_matrix.Concat(*pMatrix);
-  pTheme->DrawBackground(&params);
+  pTheme->DrawBackground(params);
 }
 
 void CFWL_MonthCalendar::DrawHeadBK(CXFA_Graphics* pGraphics,
@@ -176,7 +176,7 @@
   params.m_rtPart = m_rtHead;
   if (pMatrix)
     params.m_matrix.Concat(*pMatrix);
-  pTheme->DrawBackground(&params);
+  pTheme->DrawBackground(params);
 }
 
 void CFWL_MonthCalendar::DrawLButton(CXFA_Graphics* pGraphics,
@@ -190,7 +190,7 @@
   params.m_rtPart = m_rtLBtn;
   if (pMatrix)
     params.m_matrix.Concat(*pMatrix);
-  pTheme->DrawBackground(&params);
+  pTheme->DrawBackground(params);
 }
 
 void CFWL_MonthCalendar::DrawRButton(CXFA_Graphics* pGraphics,
@@ -204,7 +204,7 @@
   params.m_rtPart = m_rtRBtn;
   if (pMatrix)
     params.m_matrix.Concat(*pMatrix);
-  pTheme->DrawBackground(&params);
+  pTheme->DrawBackground(params);
 }
 
 void CFWL_MonthCalendar::DrawCaption(CXFA_Graphics* pGraphics,
@@ -224,7 +224,7 @@
   textParam.m_iTTOAlign = FDE_TextAlignment::kCenter;
   if (pMatrix)
     textParam.m_matrix.Concat(*pMatrix);
-  pTheme->DrawText(&textParam);
+  pTheme->DrawText(textParam);
 }
 
 void CFWL_MonthCalendar::DrawSeperator(CXFA_Graphics* pGraphics,
@@ -238,7 +238,7 @@
   params.m_rtPart = m_rtHSep;
   if (pMatrix)
     params.m_matrix.Concat(*pMatrix);
-  pTheme->DrawBackground(&params);
+  pTheme->DrawBackground(params);
 }
 
 void CFWL_MonthCalendar::DrawDatesInBK(CXFA_Graphics* pGraphics,
@@ -263,10 +263,10 @@
       params.m_dwStates |= CFWL_PartState_Hovered;
     } else if (pDataInfo->dwStates & FWL_ITEMSTATE_MCD_Flag) {
       params.m_dwStates = CFWL_PartState_Flagged;
-      pTheme->DrawBackground(&params);
+      pTheme->DrawBackground(params);
     }
     params.m_rtPart = pDataInfo->rect;
-    pTheme->DrawBackground(&params);
+    pTheme->DrawBackground(params);
     params.m_dwStates = 0;
   }
 }
@@ -293,7 +293,7 @@
 
     params.m_rtPart = rtDayOfWeek;
     params.m_wsText = GetCapacityForDay(pTheme, params, i);
-    pTheme->DrawText(&params);
+    pTheme->DrawText(params);
   }
 }
 
@@ -316,7 +316,7 @@
 
   if (pMatrix)
     params.m_matrix.Concat(*pMatrix);
-  pTheme->DrawText(&params);
+  pTheme->DrawText(params);
 }
 
 void CFWL_MonthCalendar::DrawDatesIn(CXFA_Graphics* pGraphics,
@@ -341,7 +341,7 @@
       params.m_dwStates |= CFWL_PartState_Hovered;
 
     params.m_dwTTOStyles.single_line_ = true;
-    pTheme->DrawText(&params);
+    pTheme->DrawText(params);
   }
 }
 
@@ -356,7 +356,7 @@
   params.m_iTTOAlign = FDE_TextAlignment::kCenter;
   if (pMatrix)
     params.m_matrix.Concat(*pMatrix);
-  pTheme->DrawText(&params);
+  pTheme->DrawText(params);
 }
 
 void CFWL_MonthCalendar::DrawDatesInCircle(CXFA_Graphics* pGraphics,
@@ -380,7 +380,7 @@
   params.m_dwStates = CFWL_PartState_Normal;
   if (pMatrix)
     params.m_matrix.Concat(*pMatrix);
-  pTheme->DrawBackground(&params);
+  pTheme->DrawBackground(params);
 }
 
 CFX_SizeF CFWL_MonthCalendar::CalcSize() {
diff --git a/xfa/fwl/cfwl_pushbutton.cpp b/xfa/fwl/cfwl_pushbutton.cpp
index a977a7b..4737f9e 100644
--- a/xfa/fwl/cfwl_pushbutton.cpp
+++ b/xfa/fwl/cfwl_pushbutton.cpp
@@ -75,7 +75,7 @@
   param.m_rtPart = m_rtClient;
   if (m_pProperties->m_dwStates & FWL_WGTSTATE_Focused)
     param.m_pRtData = &m_rtCaption;
-  pTheme->DrawBackground(&param);
+  pTheme->DrawBackground(param);
 }
 
 uint32_t CFWL_PushButton::GetPartStates() {
diff --git a/xfa/fwl/cfwl_scrollbar.cpp b/xfa/fwl/cfwl_scrollbar.cpp
index 9a762a5..9c9eec1 100644
--- a/xfa/fwl/cfwl_scrollbar.cpp
+++ b/xfa/fwl/cfwl_scrollbar.cpp
@@ -93,7 +93,7 @@
   param.m_pGraphics = pGraphics;
   param.m_matrix.Concat(*pMatrix);
   param.m_rtPart = bLower ? m_rtMinTrack : m_rtMaxTrack;
-  pTheme->DrawBackground(&param);
+  pTheme->DrawBackground(param);
 }
 
 void CFWL_ScrollBar::DrawArrowBtn(CXFA_Graphics* pGraphics,
@@ -110,7 +110,7 @@
   param.m_matrix.Concat(*pMatrix);
   param.m_rtPart = bMinBtn ? m_rtMinBtn : m_rtMaxBtn;
   if (param.m_rtPart.height > 0 && param.m_rtPart.width > 0)
-    pTheme->DrawBackground(&param);
+    pTheme->DrawBackground(param);
 }
 
 void CFWL_ScrollBar::DrawThumb(CXFA_Graphics* pGraphics,
@@ -125,7 +125,7 @@
   param.m_pGraphics = pGraphics;
   param.m_matrix.Concat(*pMatrix);
   param.m_rtPart = m_rtThumb;
-  pTheme->DrawBackground(&param);
+  pTheme->DrawBackground(param);
 }
 
 void CFWL_ScrollBar::Layout() {
diff --git a/xfa/fwl/cfwl_widget.cpp b/xfa/fwl/cfwl_widget.cpp
index 1fb0855..027dfc4 100644
--- a/xfa/fwl/cfwl_widget.cpp
+++ b/xfa/fwl/cfwl_widget.cpp
@@ -274,7 +274,7 @@
   calPart.m_iTTOAlign = FDE_TextAlignment::kTopLeft;
   float fWidth = bMultiLine ? FWL_WGT_CalcMultiLineDefWidth : FWL_WGT_CalcWidth;
   CFX_RectF rect(0, 0, fWidth, FWL_WGT_CalcHeight);
-  pTheme->CalcTextRect(&calPart, &rect);
+  pTheme->CalcTextRect(calPart, &rect);
   return CFX_SizeF(rect.width, rect.height);
 }
 
@@ -288,7 +288,7 @@
   calPart.m_wsText = wsText;
   calPart.m_dwTTOStyles = dwTTOStyles;
   calPart.m_iTTOAlign = iTTOAlign;
-  pTheme->CalcTextRect(&calPart, pRect);
+  pTheme->CalcTextRect(calPart, pRect);
 }
 
 void CFWL_Widget::SetGrab(bool bSet) {
@@ -330,7 +330,7 @@
   if (pMatrix)
     param.m_matrix = *pMatrix;
   param.m_rtPart = GetRelativeRect();
-  pTheme->DrawBackground(&param);
+  pTheme->DrawBackground(param);
 }
 
 void CFWL_Widget::DrawBorder(CXFA_Graphics* pGraphics,
@@ -343,7 +343,7 @@
   param.m_pGraphics = pGraphics;
   param.m_matrix = matrix;
   param.m_rtPart = GetRelativeRect();
-  pTheme->DrawBackground(&param);
+  pTheme->DrawBackground(param);
 }
 
 void CFWL_Widget::NotifyDriver() {
diff --git a/xfa/fwl/ifwl_themeprovider.h b/xfa/fwl/ifwl_themeprovider.h
index 1996768..5700d34 100644
--- a/xfa/fwl/ifwl_themeprovider.h
+++ b/xfa/fwl/ifwl_themeprovider.h
@@ -21,18 +21,21 @@
  public:
   virtual ~IFWL_ThemeProvider() = default;
 
-  virtual void DrawBackground(CFWL_ThemeBackground* pParams) = 0;
-  virtual void DrawText(CFWL_ThemeText* pParams) = 0;
-  virtual void CalcTextRect(CFWL_ThemeText* pParams, CFX_RectF* pRect) = 0;
+  virtual void DrawBackground(const CFWL_ThemeBackground& pParams) = 0;
+  virtual void DrawText(const CFWL_ThemeText& pParams) = 0;
+  virtual void CalcTextRect(const CFWL_ThemeText& pParams,
+                            CFX_RectF* pRect) = 0;
   virtual float GetCXBorderSize() const = 0;
   virtual float GetCYBorderSize() const = 0;
-  virtual CFX_RectF GetUIMargin(CFWL_ThemePart* pThemePart) const = 0;
-  virtual float GetFontSize(CFWL_ThemePart* pThemePart) const = 0;
-  virtual RetainPtr<CFGAS_GEFont> GetFont(CFWL_ThemePart* pThemePart) const = 0;
-  virtual float GetLineHeight(CFWL_ThemePart* pThemePart) const = 0;
+  virtual CFX_RectF GetUIMargin(const CFWL_ThemePart& pThemePart) const = 0;
+  virtual float GetFontSize(const CFWL_ThemePart& pThemePart) const = 0;
+  virtual RetainPtr<CFGAS_GEFont> GetFont(
+      const CFWL_ThemePart& pThemePart) const = 0;
+  virtual float GetLineHeight(const CFWL_ThemePart& pThemePart) const = 0;
   virtual float GetScrollBarWidth() const = 0;
-  virtual FX_COLORREF GetTextColor(CFWL_ThemePart* pThemePart) const = 0;
-  virtual CFX_SizeF GetSpaceAboveBelow(CFWL_ThemePart* pThemePart) const = 0;
+  virtual FX_COLORREF GetTextColor(const CFWL_ThemePart& pThemePart) const = 0;
+  virtual CFX_SizeF GetSpaceAboveBelow(
+      const CFWL_ThemePart& pThemePart) const = 0;
 };
 
 #endif  // XFA_FWL_IFWL_THEMEPROVIDER_H_
diff --git a/xfa/fwl/theme/cfwl_barcodetp.cpp b/xfa/fwl/theme/cfwl_barcodetp.cpp
index 52e0c9f..c1baf9b 100644
--- a/xfa/fwl/theme/cfwl_barcodetp.cpp
+++ b/xfa/fwl/theme/cfwl_barcodetp.cpp
@@ -14,18 +14,15 @@
 
 CFWL_BarcodeTP::~CFWL_BarcodeTP() {}
 
-void CFWL_BarcodeTP::DrawBackground(CFWL_ThemeBackground* pParams) {
-  if (!pParams)
-    return;
-
-  switch (pParams->m_iPart) {
+void CFWL_BarcodeTP::DrawBackground(const CFWL_ThemeBackground& pParams) {
+  switch (pParams.m_iPart) {
     case CFWL_Part::Border:
-      DrawBorder(pParams->m_pGraphics.Get(), &pParams->m_rtPart,
-                 &pParams->m_matrix);
+      DrawBorder(pParams.m_pGraphics.Get(), &pParams.m_rtPart,
+                 &pParams.m_matrix);
       break;
     case CFWL_Part::Background:
-      FillBackground(pParams->m_pGraphics.Get(), &pParams->m_rtPart,
-                     &pParams->m_matrix);
+      FillBackground(pParams.m_pGraphics.Get(), &pParams.m_rtPart,
+                     &pParams.m_matrix);
       break;
     default:
       break;
diff --git a/xfa/fwl/theme/cfwl_barcodetp.h b/xfa/fwl/theme/cfwl_barcodetp.h
index 3fb9d3d..8b88fcd 100644
--- a/xfa/fwl/theme/cfwl_barcodetp.h
+++ b/xfa/fwl/theme/cfwl_barcodetp.h
@@ -16,7 +16,7 @@
   ~CFWL_BarcodeTP() override;
 
   // CFWL_WidgetTP
-  void DrawBackground(CFWL_ThemeBackground* pParams) override;
+  void DrawBackground(const CFWL_ThemeBackground& pParams) override;
 };
 
 #endif  // XFA_FWL_THEME_CFWL_BARCODETP_H_
diff --git a/xfa/fwl/theme/cfwl_carettp.cpp b/xfa/fwl/theme/cfwl_carettp.cpp
index 3cc8355..4d95034 100644
--- a/xfa/fwl/theme/cfwl_carettp.cpp
+++ b/xfa/fwl/theme/cfwl_carettp.cpp
@@ -15,17 +15,14 @@
 CFWL_CaretTP::CFWL_CaretTP() {}
 CFWL_CaretTP::~CFWL_CaretTP() {}
 
-void CFWL_CaretTP::DrawBackground(CFWL_ThemeBackground* pParams) {
-  if (!pParams)
-    return;
-
-  switch (pParams->m_iPart) {
+void CFWL_CaretTP::DrawBackground(const CFWL_ThemeBackground& pParams) {
+  switch (pParams.m_iPart) {
     case CFWL_Part::Background: {
-      if (!(pParams->m_dwStates & CFWL_PartState_HightLight))
+      if (!(pParams.m_dwStates & CFWL_PartState_HightLight))
         return;
 
-      DrawCaretBK(pParams->m_pGraphics.Get(), pParams->m_dwStates,
-                  &pParams->m_rtPart, &pParams->m_matrix);
+      DrawCaretBK(pParams.m_pGraphics.Get(), pParams.m_dwStates,
+                  &pParams.m_rtPart, &pParams.m_matrix);
       break;
     }
     default:
@@ -36,7 +33,7 @@
 void CFWL_CaretTP::DrawCaretBK(CXFA_Graphics* pGraphics,
                                uint32_t dwStates,
                                const CFX_RectF* pRect,
-                               CFX_Matrix* pMatrix) {
+                               const CFX_Matrix* pMatrix) {
   CXFA_GEPath path;
   CFX_RectF rect = *pRect;
   path.AddRectangle(rect.left, rect.top, rect.width, rect.height);
diff --git a/xfa/fwl/theme/cfwl_carettp.h b/xfa/fwl/theme/cfwl_carettp.h
index 633abf0..096ed7a 100644
--- a/xfa/fwl/theme/cfwl_carettp.h
+++ b/xfa/fwl/theme/cfwl_carettp.h
@@ -15,13 +15,13 @@
   ~CFWL_CaretTP() override;
 
   // CFWL_WidgetTP
-  void DrawBackground(CFWL_ThemeBackground* pParams) override;
+  void DrawBackground(const CFWL_ThemeBackground& pParams) override;
 
  private:
   void DrawCaretBK(CXFA_Graphics* pGraphics,
                    uint32_t dwStates,
                    const CFX_RectF* pRect,
-                   CFX_Matrix* pMatrix);
+                   const CFX_Matrix* pMatrix);
 };
 
 #endif  // XFA_FWL_THEME_CFWL_CARETTP_H_
diff --git a/xfa/fwl/theme/cfwl_checkboxtp.cpp b/xfa/fwl/theme/cfwl_checkboxtp.cpp
index f54f93f..c97bc91 100644
--- a/xfa/fwl/theme/cfwl_checkboxtp.cpp
+++ b/xfa/fwl/theme/cfwl_checkboxtp.cpp
@@ -48,11 +48,11 @@
   CFWL_WidgetTP::Finalize();
 }
 
-void CFWL_CheckBoxTP::DrawText(CFWL_ThemeText* pParams) {
+void CFWL_CheckBoxTP::DrawText(const CFWL_ThemeText& pParams) {
   if (!m_pTextOut)
     return;
 
-  m_pTextOut->SetTextColor(pParams->m_dwStates & CFWL_PartState_Disabled
+  m_pTextOut->SetTextColor(pParams.m_dwStates & CFWL_PartState_Disabled
                                ? FWLTHEME_CAPACITY_TextDisColor
                                : FWLTHEME_CAPACITY_TextColor);
   CFWL_WidgetTP::DrawText(pParams);
@@ -61,7 +61,7 @@
 void CFWL_CheckBoxTP::DrawSignCheck(CXFA_Graphics* pGraphics,
                                     const CFX_RectF* pRtSign,
                                     FX_ARGB argbFill,
-                                    CFX_Matrix* pMatrix) {
+                                    const CFX_Matrix* pMatrix) {
   if (!m_pCheckPath)
     InitCheckPath(pRtSign->width);
 
@@ -77,7 +77,7 @@
 void CFWL_CheckBoxTP::DrawSignCircle(CXFA_Graphics* pGraphics,
                                      const CFX_RectF* pRtSign,
                                      FX_ARGB argbFill,
-                                     CFX_Matrix* pMatrix) {
+                                     const CFX_Matrix* pMatrix) {
   CXFA_GEPath path;
   path.AddEllipse(*pRtSign);
   pGraphics->SaveGraphState();
@@ -89,7 +89,7 @@
 void CFWL_CheckBoxTP::DrawSignCross(CXFA_Graphics* pGraphics,
                                     const CFX_RectF* pRtSign,
                                     FX_ARGB argbFill,
-                                    CFX_Matrix* pMatrix) {
+                                    const CFX_Matrix* pMatrix) {
   CXFA_GEPath path;
   float fRight = pRtSign->right();
   float fBottom = pRtSign->bottom();
@@ -107,7 +107,7 @@
 void CFWL_CheckBoxTP::DrawSignDiamond(CXFA_Graphics* pGraphics,
                                       const CFX_RectF* pRtSign,
                                       FX_ARGB argbFill,
-                                      CFX_Matrix* pMatrix) {
+                                      const CFX_Matrix* pMatrix) {
   CXFA_GEPath path;
   float fWidth = pRtSign->width;
   float fHeight = pRtSign->height;
@@ -127,7 +127,7 @@
 void CFWL_CheckBoxTP::DrawSignSquare(CXFA_Graphics* pGraphics,
                                      const CFX_RectF* pRtSign,
                                      FX_ARGB argbFill,
-                                     CFX_Matrix* pMatrix) {
+                                     const CFX_Matrix* pMatrix) {
   CXFA_GEPath path;
   path.AddRectangle(pRtSign->left, pRtSign->top, pRtSign->width,
                     pRtSign->height);
@@ -140,7 +140,7 @@
 void CFWL_CheckBoxTP::DrawSignStar(CXFA_Graphics* pGraphics,
                                    const CFX_RectF* pRtSign,
                                    FX_ARGB argbFill,
-                                   CFX_Matrix* pMatrix) {
+                                   const CFX_Matrix* pMatrix) {
   CXFA_GEPath path;
   float fBottom = pRtSign->bottom();
   float fRadius =
@@ -264,14 +264,14 @@
   }
 }
 
-void CFWL_CheckBoxTP::DrawBackground(CFWL_ThemeBackground* pParams) {
-  if (pParams->m_iPart != CFWL_Part::CheckBox)
+void CFWL_CheckBoxTP::DrawBackground(const CFWL_ThemeBackground& pParams) {
+  if (pParams.m_iPart != CFWL_Part::CheckBox)
     return;
 
-  if ((pParams->m_dwStates & CFWL_PartState_Checked) ||
-      (pParams->m_dwStates & CFWL_PartState_Neutral)) {
-    DrawCheckSign(pParams->m_pWidget, pParams->m_pGraphics.Get(),
-                  pParams->m_rtPart, pParams->m_dwStates, &pParams->m_matrix);
+  if ((pParams.m_dwStates & CFWL_PartState_Checked) ||
+      (pParams.m_dwStates & CFWL_PartState_Neutral)) {
+    DrawCheckSign(pParams.m_pWidget, pParams.m_pGraphics.Get(),
+                  pParams.m_rtPart, pParams.m_dwStates, &pParams.m_matrix);
   }
 }
 
@@ -279,7 +279,7 @@
                                     CXFA_Graphics* pGraphics,
                                     const CFX_RectF& pRtBox,
                                     int32_t iState,
-                                    CFX_Matrix* pMatrix) {
+                                    const CFX_Matrix* pMatrix) {
   CFX_RectF rtSign(pRtBox);
   uint32_t dwColor = iState & CFWL_PartState_Neutral ? 0xFFA9A9A9 : 0xFF000000;
 
diff --git a/xfa/fwl/theme/cfwl_checkboxtp.h b/xfa/fwl/theme/cfwl_checkboxtp.h
index 3898648..f10f4be 100644
--- a/xfa/fwl/theme/cfwl_checkboxtp.h
+++ b/xfa/fwl/theme/cfwl_checkboxtp.h
@@ -19,11 +19,11 @@
   CFWL_CheckBoxTP();
   ~CFWL_CheckBoxTP() override;
 
-  // CFWL_WidgeTP
+  // CFWL_WidgetTP
   void Initialize() override;
   void Finalize() override;
-  void DrawText(CFWL_ThemeText* pParams) override;
-  void DrawBackground(CFWL_ThemeBackground* pParams) override;
+  void DrawBackground(const CFWL_ThemeBackground& pParams) override;
+  void DrawText(const CFWL_ThemeText& pParams) override;
 
  private:
   struct CKBThemeData {
@@ -41,31 +41,31 @@
                      CXFA_Graphics* pGraphics,
                      const CFX_RectF& pRtBox,
                      int32_t iState,
-                     CFX_Matrix* pMatrix);
+                     const CFX_Matrix* pMatrix);
   void DrawSignCheck(CXFA_Graphics* pGraphics,
                      const CFX_RectF* pRtSign,
                      FX_ARGB argbFill,
-                     CFX_Matrix* pMatrix);
+                     const CFX_Matrix* pMatrix);
   void DrawSignCircle(CXFA_Graphics* pGraphics,
                       const CFX_RectF* pRtSign,
                       FX_ARGB argbFill,
-                      CFX_Matrix* pMatrix);
+                      const CFX_Matrix* pMatrix);
   void DrawSignCross(CXFA_Graphics* pGraphics,
                      const CFX_RectF* pRtSign,
                      FX_ARGB argbFill,
-                     CFX_Matrix* pMatrix);
+                     const CFX_Matrix* pMatrix);
   void DrawSignDiamond(CXFA_Graphics* pGraphics,
                        const CFX_RectF* pRtSign,
                        FX_ARGB argbFill,
-                       CFX_Matrix* pMatrix);
+                       const CFX_Matrix* pMatrix);
   void DrawSignSquare(CXFA_Graphics* pGraphics,
                       const CFX_RectF* pRtSign,
                       FX_ARGB argbFill,
-                      CFX_Matrix* pMatrix);
+                      const CFX_Matrix* pMatrix);
   void DrawSignStar(CXFA_Graphics* pGraphics,
                     const CFX_RectF* pRtSign,
                     FX_ARGB argbFill,
-                    CFX_Matrix* pMatrix);
+                    const CFX_Matrix* pMatrix);
 
   void InitCheckPath(float fCheckLen);
   void SetThemeData();
diff --git a/xfa/fwl/theme/cfwl_comboboxtp.cpp b/xfa/fwl/theme/cfwl_comboboxtp.cpp
index 8c35e56..f5cfeb5 100644
--- a/xfa/fwl/theme/cfwl_comboboxtp.cpp
+++ b/xfa/fwl/theme/cfwl_comboboxtp.cpp
@@ -17,22 +17,19 @@
 
 CFWL_ComboBoxTP::~CFWL_ComboBoxTP() {}
 
-void CFWL_ComboBoxTP::DrawBackground(CFWL_ThemeBackground* pParams) {
-  if (!pParams)
-    return;
-
-  switch (pParams->m_iPart) {
+void CFWL_ComboBoxTP::DrawBackground(const CFWL_ThemeBackground& pParams) {
+  switch (pParams.m_iPart) {
     case CFWL_Part::Border: {
-      DrawBorder(pParams->m_pGraphics.Get(), &pParams->m_rtPart,
-                 &pParams->m_matrix);
+      DrawBorder(pParams.m_pGraphics.Get(), &pParams.m_rtPart,
+                 &pParams.m_matrix);
       break;
     }
     case CFWL_Part::Background: {
       CXFA_GEPath path;
-      CFX_RectF& rect = pParams->m_rtPart;
+      const CFX_RectF& rect = pParams.m_rtPart;
       path.AddRectangle(rect.left, rect.top, rect.width, rect.height);
       FX_ARGB argb_color;
-      switch (pParams->m_dwStates) {
+      switch (pParams.m_dwStates) {
         case CFWL_PartState_Selected:
           argb_color = FWLTHEME_COLOR_BKSelected;
           break;
@@ -42,18 +39,18 @@
         default:
           argb_color = 0xFFFFFFFF;
       }
-      pParams->m_pGraphics->SaveGraphState();
-      pParams->m_pGraphics->SetFillColor(CXFA_GEColor(argb_color));
-      pParams->m_pGraphics->FillPath(&path, FXFILL_WINDING, &pParams->m_matrix);
-      pParams->m_pGraphics->RestoreGraphState();
+      pParams.m_pGraphics->SaveGraphState();
+      pParams.m_pGraphics->SetFillColor(CXFA_GEColor(argb_color));
+      pParams.m_pGraphics->FillPath(&path, FXFILL_WINDING, &pParams.m_matrix);
+      pParams.m_pGraphics->RestoreGraphState();
       break;
     }
     case CFWL_Part::DropDownButton: {
-      DrawDropDownButton(pParams, pParams->m_dwStates, &pParams->m_matrix);
+      DrawDropDownButton(pParams, pParams.m_dwStates, &pParams.m_matrix);
       break;
     }
     case CFWL_Part::StretchHandler: {
-      DrawStrethHandler(pParams, 0, &pParams->m_matrix);
+      DrawStretchHandler(pParams, 0, &pParams.m_matrix);
       break;
     }
     default:
@@ -61,20 +58,19 @@
   }
 }
 
-void CFWL_ComboBoxTP::DrawStrethHandler(CFWL_ThemeBackground* pParams,
-                                        uint32_t dwStates,
-                                        CFX_Matrix* pMatrix) {
+void CFWL_ComboBoxTP::DrawStretchHandler(const CFWL_ThemeBackground& pParams,
+                                         uint32_t dwStates,
+                                         const CFX_Matrix* pMatrix) {
   CXFA_GEPath path;
-  path.AddRectangle(pParams->m_rtPart.left, pParams->m_rtPart.top,
-                    pParams->m_rtPart.width - 1, pParams->m_rtPart.height);
-  pParams->m_pGraphics->SetFillColor(
-      CXFA_GEColor(ArgbEncode(0xff, 0xff, 0, 0)));
-  pParams->m_pGraphics->FillPath(&path, FXFILL_WINDING, &pParams->m_matrix);
+  path.AddRectangle(pParams.m_rtPart.left, pParams.m_rtPart.top,
+                    pParams.m_rtPart.width - 1, pParams.m_rtPart.height);
+  pParams.m_pGraphics->SetFillColor(CXFA_GEColor(ArgbEncode(0xff, 0xff, 0, 0)));
+  pParams.m_pGraphics->FillPath(&path, FXFILL_WINDING, &pParams.m_matrix);
 }
 
-void CFWL_ComboBoxTP::DrawDropDownButton(CFWL_ThemeBackground* pParams,
+void CFWL_ComboBoxTP::DrawDropDownButton(const CFWL_ThemeBackground& pParams,
                                          uint32_t dwStates,
-                                         CFX_Matrix* pMatrix) {
+                                         const CFX_Matrix* pMatrix) {
   FWLTHEME_STATE eState = FWLTHEME_STATE_Normal;
   switch (dwStates) {
     case CFWL_PartState_Normal: {
@@ -96,6 +92,6 @@
     default:
       break;
   }
-  DrawArrowBtn(pParams->m_pGraphics.Get(), &pParams->m_rtPart,
-               FWLTHEME_DIRECTION_Down, eState, &pParams->m_matrix);
+  DrawArrowBtn(pParams.m_pGraphics.Get(), &pParams.m_rtPart,
+               FWLTHEME_DIRECTION_Down, eState, &pParams.m_matrix);
 }
diff --git a/xfa/fwl/theme/cfwl_comboboxtp.h b/xfa/fwl/theme/cfwl_comboboxtp.h
index 1456143..11f23d8 100644
--- a/xfa/fwl/theme/cfwl_comboboxtp.h
+++ b/xfa/fwl/theme/cfwl_comboboxtp.h
@@ -15,15 +15,15 @@
   ~CFWL_ComboBoxTP() override;
 
   // CFWL_WidgetTP
-  void DrawBackground(CFWL_ThemeBackground* pParams) override;
+  void DrawBackground(const CFWL_ThemeBackground& pParams) override;
 
  private:
-  void DrawDropDownButton(CFWL_ThemeBackground* pParams,
+  void DrawDropDownButton(const CFWL_ThemeBackground& pParams,
                           uint32_t dwStates,
-                          CFX_Matrix* pMatrix);
-  void DrawStrethHandler(CFWL_ThemeBackground* pParams,
-                         uint32_t dwStates,
-                         CFX_Matrix* pMatrix);
+                          const CFX_Matrix* pMatrix);
+  void DrawStretchHandler(const CFWL_ThemeBackground& pParams,
+                          uint32_t dwStates,
+                          const CFX_Matrix* pMatrix);
 };
 
 #endif  // XFA_FWL_THEME_CFWL_COMBOBOXTP_H_
diff --git a/xfa/fwl/theme/cfwl_datetimepickertp.cpp b/xfa/fwl/theme/cfwl_datetimepickertp.cpp
index d13d4c7..b529575 100644
--- a/xfa/fwl/theme/cfwl_datetimepickertp.cpp
+++ b/xfa/fwl/theme/cfwl_datetimepickertp.cpp
@@ -13,26 +13,25 @@
 
 CFWL_DateTimePickerTP::~CFWL_DateTimePickerTP() {}
 
-void CFWL_DateTimePickerTP::DrawBackground(CFWL_ThemeBackground* pParams) {
-  if (!pParams)
-    return;
-
-  switch (pParams->m_iPart) {
+void CFWL_DateTimePickerTP::DrawBackground(
+    const CFWL_ThemeBackground& pParams) {
+  switch (pParams.m_iPart) {
     case CFWL_Part::Border:
-      DrawBorder(pParams->m_pGraphics.Get(), &pParams->m_rtPart,
-                 &pParams->m_matrix);
+      DrawBorder(pParams.m_pGraphics.Get(), &pParams.m_rtPart,
+                 &pParams.m_matrix);
       break;
     case CFWL_Part::DropDownButton:
-      DrawDropDownButton(pParams, &pParams->m_matrix);
+      DrawDropDownButton(pParams, &pParams.m_matrix);
       break;
     default:
       break;
   }
 }
 
-void CFWL_DateTimePickerTP::DrawDropDownButton(CFWL_ThemeBackground* pParams,
-                                               CFX_Matrix* pMatrix) {
-  uint32_t dwStates = pParams->m_dwStates;
+void CFWL_DateTimePickerTP::DrawDropDownButton(
+    const CFWL_ThemeBackground& pParams,
+    const CFX_Matrix* pMatrix) {
+  uint32_t dwStates = pParams.m_dwStates;
   dwStates &= 0x03;
   FWLTHEME_STATE eState = FWLTHEME_STATE_Normal;
   switch (eState & dwStates) {
@@ -55,7 +54,6 @@
     default:
       break;
   }
-  DrawArrowBtn(pParams->m_pGraphics.Get(), &pParams->m_rtPart,
+  DrawArrowBtn(pParams.m_pGraphics.Get(), &pParams.m_rtPart,
                FWLTHEME_DIRECTION_Down, eState, pMatrix);
 }
-
diff --git a/xfa/fwl/theme/cfwl_datetimepickertp.h b/xfa/fwl/theme/cfwl_datetimepickertp.h
index e7a7239..b74600f 100644
--- a/xfa/fwl/theme/cfwl_datetimepickertp.h
+++ b/xfa/fwl/theme/cfwl_datetimepickertp.h
@@ -15,10 +15,11 @@
   ~CFWL_DateTimePickerTP() override;
 
   // CFWL_WidgetTP
-  void DrawBackground(CFWL_ThemeBackground* pParams) override;
+  void DrawBackground(const CFWL_ThemeBackground& pParams) override;
 
  private:
-  void DrawDropDownButton(CFWL_ThemeBackground* pParams, CFX_Matrix* pMatrix);
+  void DrawDropDownButton(const CFWL_ThemeBackground& pParams,
+                          const CFX_Matrix* pMatrix);
 };
 
 #endif  // XFA_FWL_THEME_CFWL_DATETIMEPICKERTP_H_
diff --git a/xfa/fwl/theme/cfwl_edittp.cpp b/xfa/fwl/theme/cfwl_edittp.cpp
index eb1f24e..16d3f79 100644
--- a/xfa/fwl/theme/cfwl_edittp.cpp
+++ b/xfa/fwl/theme/cfwl_edittp.cpp
@@ -20,9 +20,9 @@
 
 CFWL_EditTP::~CFWL_EditTP() {}
 
-void CFWL_EditTP::DrawBackground(CFWL_ThemeBackground* pParams) {
-  if (CFWL_Part::CombTextLine == pParams->m_iPart) {
-    CXFA_FFWidget* pWidget = XFA_ThemeGetOuterWidget(pParams->m_pWidget);
+void CFWL_EditTP::DrawBackground(const CFWL_ThemeBackground& pParams) {
+  if (CFWL_Part::CombTextLine == pParams.m_iPart) {
+    CXFA_FFWidget* pWidget = XFA_ThemeGetOuterWidget(pParams.m_pWidget);
     ASSERT(pWidget->GetNode()->IsWidgetReady());
 
     CXFA_Border* borderUI = pWidget->GetNode()->GetUIBorder();
@@ -35,53 +35,50 @@
         fWidth = edge->GetThickness();
       }
     }
-    pParams->m_pGraphics->SetStrokeColor(CXFA_GEColor(cr));
-    pParams->m_pGraphics->SetLineWidth(fWidth);
-    pParams->m_pGraphics->StrokePath(pParams->m_pPath.Get(),
-                                     &pParams->m_matrix);
+    pParams.m_pGraphics->SetStrokeColor(CXFA_GEColor(cr));
+    pParams.m_pGraphics->SetLineWidth(fWidth);
+    pParams.m_pGraphics->StrokePath(pParams.m_pPath.Get(), &pParams.m_matrix);
     return;
   }
 
-  switch (pParams->m_iPart) {
+  switch (pParams.m_iPart) {
     case CFWL_Part::Border: {
-      DrawBorder(pParams->m_pGraphics.Get(), &pParams->m_rtPart,
-                 &pParams->m_matrix);
+      DrawBorder(pParams.m_pGraphics.Get(), &pParams.m_rtPart,
+                 &pParams.m_matrix);
       break;
     }
     case CFWL_Part::Background: {
-      if (pParams->m_pPath) {
-        CXFA_Graphics* pGraphics = pParams->m_pGraphics.Get();
+      if (pParams.m_pPath) {
+        CXFA_Graphics* pGraphics = pParams.m_pGraphics.Get();
         pGraphics->SaveGraphState();
         pGraphics->SetFillColor(CXFA_GEColor(FWLTHEME_COLOR_BKSelected));
-        pGraphics->FillPath(pParams->m_pPath.Get(), FXFILL_WINDING,
-                            &pParams->m_matrix);
+        pGraphics->FillPath(pParams.m_pPath.Get(), FXFILL_WINDING,
+                            &pParams.m_matrix);
         pGraphics->RestoreGraphState();
       } else {
         CXFA_GEPath path;
-        path.AddRectangle(pParams->m_rtPart.left, pParams->m_rtPart.top,
-                          pParams->m_rtPart.width, pParams->m_rtPart.height);
+        path.AddRectangle(pParams.m_rtPart.left, pParams.m_rtPart.top,
+                          pParams.m_rtPart.width, pParams.m_rtPart.height);
         CXFA_GEColor cr(FWLTHEME_COLOR_Background);
-        if (!pParams->m_bStaticBackground) {
-          if (pParams->m_dwStates & CFWL_PartState_Disabled)
+        if (!pParams.m_bStaticBackground) {
+          if (pParams.m_dwStates & CFWL_PartState_Disabled)
             cr = CXFA_GEColor(FWLTHEME_COLOR_EDGERB1);
-          else if (pParams->m_dwStates & CFWL_PartState_ReadOnly)
+          else if (pParams.m_dwStates & CFWL_PartState_ReadOnly)
             cr = CXFA_GEColor(ArgbEncode(255, 236, 233, 216));
           else
             cr = CXFA_GEColor(0xFFFFFFFF);
         }
-        pParams->m_pGraphics->SaveGraphState();
-        pParams->m_pGraphics->SetFillColor(cr);
-        pParams->m_pGraphics->FillPath(&path, FXFILL_WINDING,
-                                       &pParams->m_matrix);
-        pParams->m_pGraphics->RestoreGraphState();
+        pParams.m_pGraphics->SaveGraphState();
+        pParams.m_pGraphics->SetFillColor(cr);
+        pParams.m_pGraphics->FillPath(&path, FXFILL_WINDING, &pParams.m_matrix);
+        pParams.m_pGraphics->RestoreGraphState();
       }
       break;
     }
     case CFWL_Part::CombTextLine: {
-      pParams->m_pGraphics->SetStrokeColor(CXFA_GEColor(0xFF000000));
-      pParams->m_pGraphics->SetLineWidth(1.0f);
-      pParams->m_pGraphics->StrokePath(pParams->m_pPath.Get(),
-                                       &pParams->m_matrix);
+      pParams.m_pGraphics->SetStrokeColor(CXFA_GEColor(0xFF000000));
+      pParams.m_pGraphics->SetLineWidth(1.0f);
+      pParams.m_pGraphics->StrokePath(pParams.m_pPath.Get(), &pParams.m_matrix);
       break;
     }
     default:
diff --git a/xfa/fwl/theme/cfwl_edittp.h b/xfa/fwl/theme/cfwl_edittp.h
index 7d00560..b5b58f3 100644
--- a/xfa/fwl/theme/cfwl_edittp.h
+++ b/xfa/fwl/theme/cfwl_edittp.h
@@ -14,8 +14,8 @@
   CFWL_EditTP();
   ~CFWL_EditTP() override;
 
-  // CFWL_WidgeTTP
-  void DrawBackground(CFWL_ThemeBackground* pParams) override;
+  // CFWL_WidgetTP
+  void DrawBackground(const CFWL_ThemeBackground& pParams) override;
 };
 
 #endif  // XFA_FWL_THEME_CFWL_EDITTP_H_
diff --git a/xfa/fwl/theme/cfwl_listboxtp.cpp b/xfa/fwl/theme/cfwl_listboxtp.cpp
index fc0f54e..b98890a 100644
--- a/xfa/fwl/theme/cfwl_listboxtp.cpp
+++ b/xfa/fwl/theme/cfwl_listboxtp.cpp
@@ -16,40 +16,36 @@
 
 CFWL_ListBoxTP::~CFWL_ListBoxTP() {}
 
-void CFWL_ListBoxTP::DrawBackground(CFWL_ThemeBackground* pParams) {
-  if (!pParams)
-    return;
-
-  switch (pParams->m_iPart) {
+void CFWL_ListBoxTP::DrawBackground(const CFWL_ThemeBackground& pParams) {
+  switch (pParams.m_iPart) {
     case CFWL_Part::Border: {
-      DrawBorder(pParams->m_pGraphics.Get(), &pParams->m_rtPart,
-                 &pParams->m_matrix);
+      DrawBorder(pParams.m_pGraphics.Get(), &pParams.m_rtPart,
+                 &pParams.m_matrix);
       break;
     }
     case CFWL_Part::Background: {
-      FillSolidRect(pParams->m_pGraphics.Get(), ArgbEncode(255, 255, 255, 255),
-                    &pParams->m_rtPart, &pParams->m_matrix);
-      if (pParams->m_pRtData) {
-        FillSolidRect(pParams->m_pGraphics.Get(), FWLTHEME_COLOR_Background,
-                      pParams->m_pRtData, &pParams->m_matrix);
+      FillSolidRect(pParams.m_pGraphics.Get(), ArgbEncode(255, 255, 255, 255),
+                    &pParams.m_rtPart, &pParams.m_matrix);
+      if (pParams.m_pRtData) {
+        FillSolidRect(pParams.m_pGraphics.Get(), FWLTHEME_COLOR_Background,
+                      pParams.m_pRtData, &pParams.m_matrix);
       }
       break;
     }
     case CFWL_Part::ListItem: {
-      DrawListBoxItem(pParams->m_pGraphics.Get(), pParams->m_dwStates,
-                      &pParams->m_rtPart, pParams->m_pRtData,
-                      &pParams->m_matrix);
+      DrawListBoxItem(pParams.m_pGraphics.Get(), pParams.m_dwStates,
+                      &pParams.m_rtPart, pParams.m_pRtData, &pParams.m_matrix);
       break;
     }
     case CFWL_Part::Check: {
       uint32_t color = 0xFF000000;
-      if (pParams->m_dwStates == CFWL_PartState_Checked) {
+      if (pParams.m_dwStates == CFWL_PartState_Checked) {
         color = 0xFFFF0000;
-      } else if (pParams->m_dwStates == CFWL_PartState_Normal) {
+      } else if (pParams.m_dwStates == CFWL_PartState_Normal) {
         color = 0xFF0000FF;
       }
-      FillSolidRect(pParams->m_pGraphics.Get(), color, &pParams->m_rtPart,
-                    &pParams->m_matrix);
+      FillSolidRect(pParams.m_pGraphics.Get(), color, &pParams.m_rtPart,
+                    &pParams.m_matrix);
       break;
     }
     default:
@@ -61,7 +57,7 @@
                                      uint32_t dwStates,
                                      const CFX_RectF* prtItem,
                                      void* pData,
-                                     CFX_Matrix* pMatrix) {
+                                     const CFX_Matrix* pMatrix) {
   if (dwStates & CFWL_PartState_Selected) {
     pGraphics->SaveGraphState();
     pGraphics->SetFillColor(CXFA_GEColor(FWLTHEME_COLOR_BKSelected));
diff --git a/xfa/fwl/theme/cfwl_listboxtp.h b/xfa/fwl/theme/cfwl_listboxtp.h
index e87ac6f..03cc905 100644
--- a/xfa/fwl/theme/cfwl_listboxtp.h
+++ b/xfa/fwl/theme/cfwl_listboxtp.h
@@ -15,14 +15,14 @@
   ~CFWL_ListBoxTP() override;
 
   // CFWL_WidgetTP
-  void DrawBackground(CFWL_ThemeBackground* pParams) override;
+  void DrawBackground(const CFWL_ThemeBackground& pParams) override;
 
  private:
   void DrawListBoxItem(CXFA_Graphics* pGraphics,
                        uint32_t dwStates,
                        const CFX_RectF* prtItem,
                        void* pData,
-                       CFX_Matrix* pMatrix);
+                       const CFX_Matrix* pMatrix);
 };
 
 #endif  // XFA_FWL_THEME_CFWL_LISTBOXTP_H_
diff --git a/xfa/fwl/theme/cfwl_monthcalendartp.cpp b/xfa/fwl/theme/cfwl_monthcalendartp.cpp
index c17451d..cb0fe98 100644
--- a/xfa/fwl/theme/cfwl_monthcalendartp.cpp
+++ b/xfa/fwl/theme/cfwl_monthcalendartp.cpp
@@ -31,54 +31,51 @@
   CFWL_WidgetTP::Finalize();
 }
 
-void CFWL_MonthCalendarTP::DrawBackground(CFWL_ThemeBackground* pParams) {
-  if (!pParams)
-    return;
-
-  switch (pParams->m_iPart) {
+void CFWL_MonthCalendarTP::DrawBackground(const CFWL_ThemeBackground& pParams) {
+  switch (pParams.m_iPart) {
     case CFWL_Part::Border: {
-      DrawBorder(pParams->m_pGraphics.Get(), &pParams->m_rtPart,
-                 &pParams->m_matrix);
+      DrawBorder(pParams.m_pGraphics.Get(), &pParams.m_rtPart,
+                 &pParams.m_matrix);
       break;
     }
     case CFWL_Part::Background: {
-      DrawTotalBK(pParams, &pParams->m_matrix);
+      DrawTotalBK(pParams, &pParams.m_matrix);
       break;
     }
     case CFWL_Part::Header: {
-      DrawHeadBk(pParams, &pParams->m_matrix);
+      DrawHeadBk(pParams, &pParams.m_matrix);
       break;
     }
     case CFWL_Part::LBtn: {
-      FWLTHEME_STATE eState = GetState(pParams->m_dwStates);
-      DrawArrowBtn(pParams->m_pGraphics.Get(), &pParams->m_rtPart,
-                   FWLTHEME_DIRECTION_Left, eState, &pParams->m_matrix);
+      FWLTHEME_STATE eState = GetState(pParams.m_dwStates);
+      DrawArrowBtn(pParams.m_pGraphics.Get(), &pParams.m_rtPart,
+                   FWLTHEME_DIRECTION_Left, eState, &pParams.m_matrix);
       break;
     }
     case CFWL_Part::RBtn: {
-      FWLTHEME_STATE eState = GetState(pParams->m_dwStates);
-      DrawArrowBtn(pParams->m_pGraphics.Get(), &pParams->m_rtPart,
-                   FWLTHEME_DIRECTION_Right, eState, &pParams->m_matrix);
+      FWLTHEME_STATE eState = GetState(pParams.m_dwStates);
+      DrawArrowBtn(pParams.m_pGraphics.Get(), &pParams.m_rtPart,
+                   FWLTHEME_DIRECTION_Right, eState, &pParams.m_matrix);
       break;
     }
     case CFWL_Part::HSeparator: {
-      DrawHSeperator(pParams, &pParams->m_matrix);
+      DrawHSeperator(pParams, &pParams.m_matrix);
       break;
     }
     case CFWL_Part::DatesIn: {
-      DrawDatesInBK(pParams, &pParams->m_matrix);
+      DrawDatesInBK(pParams, &pParams.m_matrix);
       break;
     }
     case CFWL_Part::TodayCircle: {
-      DrawTodayCircle(pParams, &pParams->m_matrix);
+      DrawTodayCircle(pParams, &pParams.m_matrix);
       break;
     }
     case CFWL_Part::DateInCircle: {
-      DrawDatesInCircle(pParams, &pParams->m_matrix);
+      DrawDatesInCircle(pParams, &pParams.m_matrix);
       break;
     }
     case CFWL_Part::WeekNumSep: {
-      DrawWeekNumSep(pParams, &pParams->m_matrix);
+      DrawWeekNumSep(pParams, &pParams.m_matrix);
       break;
     }
     default:
@@ -86,16 +83,16 @@
   }
 }
 
-void CFWL_MonthCalendarTP::DrawText(CFWL_ThemeText* pParams) {
+void CFWL_MonthCalendarTP::DrawText(const CFWL_ThemeText& pParams) {
   if (!m_pTextOut)
     return;
 
-  if ((pParams->m_iPart == CFWL_Part::DatesIn) &&
-      !(pParams->m_dwStates & FWL_ITEMSTATE_MCD_Flag) &&
-      (pParams->m_dwStates &
+  if ((pParams.m_iPart == CFWL_Part::DatesIn) &&
+      !(pParams.m_dwStates & FWL_ITEMSTATE_MCD_Flag) &&
+      (pParams.m_dwStates &
        (CFWL_PartState_Hovered | CFWL_PartState_Selected))) {
     m_pTextOut->SetTextColor(0xFFFFFFFF);
-  } else if (pParams->m_iPart == CFWL_Part::Caption) {
+  } else if (pParams.m_iPart == CFWL_Part::Caption) {
     m_pTextOut->SetTextColor(m_pThemeData->clrCaption);
   } else {
     m_pTextOut->SetTextColor(0xFF000000);
@@ -103,45 +100,45 @@
   CFWL_WidgetTP::DrawText(pParams);
 }
 
-void CFWL_MonthCalendarTP::DrawTotalBK(CFWL_ThemeBackground* pParams,
-                                       CFX_Matrix* pMatrix) {
+void CFWL_MonthCalendarTP::DrawTotalBK(const CFWL_ThemeBackground& pParams,
+                                       const CFX_Matrix* pMatrix) {
   CXFA_GEPath path;
-  CFX_RectF rtTotal(pParams->m_rtPart);
+  CFX_RectF rtTotal(pParams.m_rtPart);
   path.AddRectangle(rtTotal.left, rtTotal.top, rtTotal.width, rtTotal.height);
-  pParams->m_pGraphics->SaveGraphState();
-  pParams->m_pGraphics->SetFillColor(CXFA_GEColor(m_pThemeData->clrBK));
-  pParams->m_pGraphics->FillPath(&path, FXFILL_WINDING, pMatrix);
-  pParams->m_pGraphics->RestoreGraphState();
+  pParams.m_pGraphics->SaveGraphState();
+  pParams.m_pGraphics->SetFillColor(CXFA_GEColor(m_pThemeData->clrBK));
+  pParams.m_pGraphics->FillPath(&path, FXFILL_WINDING, pMatrix);
+  pParams.m_pGraphics->RestoreGraphState();
 }
 
-void CFWL_MonthCalendarTP::DrawHeadBk(CFWL_ThemeBackground* pParams,
-                                      CFX_Matrix* pMatrix) {
+void CFWL_MonthCalendarTP::DrawHeadBk(const CFWL_ThemeBackground& pParams,
+                                      const CFX_Matrix* pMatrix) {
   CXFA_GEPath path;
-  CFX_RectF rtHead = pParams->m_rtPart;
+  CFX_RectF rtHead = pParams.m_rtPart;
   path.AddRectangle(rtHead.left, rtHead.top, rtHead.width, rtHead.height);
-  pParams->m_pGraphics->SaveGraphState();
-  pParams->m_pGraphics->SetFillColor(CXFA_GEColor(m_pThemeData->clrBK));
-  pParams->m_pGraphics->FillPath(&path, FXFILL_WINDING, pMatrix);
-  pParams->m_pGraphics->RestoreGraphState();
+  pParams.m_pGraphics->SaveGraphState();
+  pParams.m_pGraphics->SetFillColor(CXFA_GEColor(m_pThemeData->clrBK));
+  pParams.m_pGraphics->FillPath(&path, FXFILL_WINDING, pMatrix);
+  pParams.m_pGraphics->RestoreGraphState();
 }
 
-void CFWL_MonthCalendarTP::DrawLButton(CFWL_ThemeBackground* pParams,
-                                       CFX_Matrix* pMatrix) {
+void CFWL_MonthCalendarTP::DrawLButton(const CFWL_ThemeBackground& pParams,
+                                       const CFX_Matrix* pMatrix) {
   CXFA_GEPath path;
-  CFX_RectF rtLBtn = pParams->m_rtPart;
+  CFX_RectF rtLBtn = pParams.m_rtPart;
   path.AddRectangle(rtLBtn.left, rtLBtn.top, rtLBtn.width, rtLBtn.height);
-  pParams->m_pGraphics->SaveGraphState();
-  pParams->m_pGraphics->SetStrokeColor(
+  pParams.m_pGraphics->SaveGraphState();
+  pParams.m_pGraphics->SetStrokeColor(
       CXFA_GEColor(ArgbEncode(0xff, 205, 219, 243)));
-  pParams->m_pGraphics->StrokePath(&path, pMatrix);
-  if (pParams->m_dwStates & CFWL_PartState_Pressed) {
-    pParams->m_pGraphics->SetFillColor(
+  pParams.m_pGraphics->StrokePath(&path, pMatrix);
+  if (pParams.m_dwStates & CFWL_PartState_Pressed) {
+    pParams.m_pGraphics->SetFillColor(
         CXFA_GEColor(ArgbEncode(0xff, 174, 198, 242)));
-    pParams->m_pGraphics->FillPath(&path, FXFILL_WINDING, pMatrix);
+    pParams.m_pGraphics->FillPath(&path, FXFILL_WINDING, pMatrix);
   } else {
-    pParams->m_pGraphics->SetFillColor(
+    pParams.m_pGraphics->SetFillColor(
         CXFA_GEColor(ArgbEncode(0xff, 227, 235, 249)));
-    pParams->m_pGraphics->FillPath(&path, FXFILL_WINDING, pMatrix);
+    pParams.m_pGraphics->FillPath(&path, FXFILL_WINDING, pMatrix);
   }
 
   path.Clear();
@@ -152,29 +149,29 @@
   path.LineTo(CFX_PointF(rtLBtn.left + rtLBtn.Width() / 3 * 2,
                          rtLBtn.bottom() - rtLBtn.height / 4));
 
-  pParams->m_pGraphics->SetStrokeColor(
+  pParams.m_pGraphics->SetStrokeColor(
       CXFA_GEColor(ArgbEncode(0xff, 50, 104, 205)));
-  pParams->m_pGraphics->StrokePath(&path, pMatrix);
-  pParams->m_pGraphics->RestoreGraphState();
+  pParams.m_pGraphics->StrokePath(&path, pMatrix);
+  pParams.m_pGraphics->RestoreGraphState();
 }
 
-void CFWL_MonthCalendarTP::DrawRButton(CFWL_ThemeBackground* pParams,
-                                       CFX_Matrix* pMatrix) {
+void CFWL_MonthCalendarTP::DrawRButton(const CFWL_ThemeBackground& pParams,
+                                       const CFX_Matrix* pMatrix) {
   CXFA_GEPath path;
-  CFX_RectF rtRBtn = pParams->m_rtPart;
+  CFX_RectF rtRBtn = pParams.m_rtPart;
   path.AddRectangle(rtRBtn.left, rtRBtn.top, rtRBtn.width, rtRBtn.height);
-  pParams->m_pGraphics->SaveGraphState();
-  pParams->m_pGraphics->SetStrokeColor(
+  pParams.m_pGraphics->SaveGraphState();
+  pParams.m_pGraphics->SetStrokeColor(
       CXFA_GEColor(ArgbEncode(0xff, 205, 219, 243)));
-  pParams->m_pGraphics->StrokePath(&path, pMatrix);
-  if (pParams->m_dwStates & CFWL_PartState_Pressed) {
-    pParams->m_pGraphics->SetFillColor(
+  pParams.m_pGraphics->StrokePath(&path, pMatrix);
+  if (pParams.m_dwStates & CFWL_PartState_Pressed) {
+    pParams.m_pGraphics->SetFillColor(
         CXFA_GEColor(ArgbEncode(0xff, 174, 198, 242)));
-    pParams->m_pGraphics->FillPath(&path, FXFILL_WINDING, pMatrix);
+    pParams.m_pGraphics->FillPath(&path, FXFILL_WINDING, pMatrix);
   } else {
-    pParams->m_pGraphics->SetFillColor(
+    pParams.m_pGraphics->SetFillColor(
         CXFA_GEColor(ArgbEncode(0xff, 227, 235, 249)));
-    pParams->m_pGraphics->FillPath(&path, FXFILL_WINDING, pMatrix);
+    pParams.m_pGraphics->FillPath(&path, FXFILL_WINDING, pMatrix);
   }
 
   path.Clear();
@@ -185,85 +182,84 @@
   path.LineTo(CFX_PointF(rtRBtn.left + rtRBtn.Width() / 3,
                          rtRBtn.bottom() - rtRBtn.height / 4));
 
-  pParams->m_pGraphics->SetStrokeColor(
+  pParams.m_pGraphics->SetStrokeColor(
       CXFA_GEColor(ArgbEncode(0xff, 50, 104, 205)));
-  pParams->m_pGraphics->StrokePath(&path, pMatrix);
-  pParams->m_pGraphics->RestoreGraphState();
+  pParams.m_pGraphics->StrokePath(&path, pMatrix);
+  pParams.m_pGraphics->RestoreGraphState();
 }
 
-void CFWL_MonthCalendarTP::DrawHSeperator(CFWL_ThemeBackground* pParams,
-                                          CFX_Matrix* pMatrix) {
+void CFWL_MonthCalendarTP::DrawHSeperator(const CFWL_ThemeBackground& pParams,
+                                          const CFX_Matrix* pMatrix) {
   CXFA_GEPath path;
-  CFX_RectF rtHSep = pParams->m_rtPart;
+  CFX_RectF rtHSep = pParams.m_rtPart;
   path.MoveTo(CFX_PointF(rtHSep.left, rtHSep.top + rtHSep.height / 2));
   path.LineTo(CFX_PointF(rtHSep.right(), rtHSep.top + rtHSep.height / 2));
-  pParams->m_pGraphics->SaveGraphState();
-  pParams->m_pGraphics->SetStrokeColor(
-      CXFA_GEColor(m_pThemeData->clrSeperator));
-  pParams->m_pGraphics->StrokePath(&path, pMatrix);
-  pParams->m_pGraphics->RestoreGraphState();
+  pParams.m_pGraphics->SaveGraphState();
+  pParams.m_pGraphics->SetStrokeColor(CXFA_GEColor(m_pThemeData->clrSeperator));
+  pParams.m_pGraphics->StrokePath(&path, pMatrix);
+  pParams.m_pGraphics->RestoreGraphState();
 }
 
-void CFWL_MonthCalendarTP::DrawWeekNumSep(CFWL_ThemeBackground* pParams,
-                                          CFX_Matrix* pMatrix) {
+void CFWL_MonthCalendarTP::DrawWeekNumSep(const CFWL_ThemeBackground& pParams,
+                                          const CFX_Matrix* pMatrix) {
   CXFA_GEPath path;
-  CFX_RectF rtWeekSep = pParams->m_rtPart;
+  CFX_RectF rtWeekSep = pParams.m_rtPart;
   path.MoveTo(rtWeekSep.TopLeft());
   path.LineTo(rtWeekSep.BottomLeft());
-  pParams->m_pGraphics->SaveGraphState();
-  pParams->m_pGraphics->SetStrokeColor(
-      CXFA_GEColor(m_pThemeData->clrSeperator));
-  pParams->m_pGraphics->StrokePath(&path, pMatrix);
-  pParams->m_pGraphics->RestoreGraphState();
+  pParams.m_pGraphics->SaveGraphState();
+  pParams.m_pGraphics->SetStrokeColor(CXFA_GEColor(m_pThemeData->clrSeperator));
+  pParams.m_pGraphics->StrokePath(&path, pMatrix);
+  pParams.m_pGraphics->RestoreGraphState();
 }
 
-void CFWL_MonthCalendarTP::DrawDatesInBK(CFWL_ThemeBackground* pParams,
-                                         CFX_Matrix* pMatrix) {
-  pParams->m_pGraphics->SaveGraphState();
-  if (pParams->m_dwStates & CFWL_PartState_Selected) {
+void CFWL_MonthCalendarTP::DrawDatesInBK(const CFWL_ThemeBackground& pParams,
+                                         const CFX_Matrix* pMatrix) {
+  pParams.m_pGraphics->SaveGraphState();
+  if (pParams.m_dwStates & CFWL_PartState_Selected) {
     CXFA_GEPath path;
-    CFX_RectF rtSelDay = pParams->m_rtPart;
+    CFX_RectF rtSelDay = pParams.m_rtPart;
     path.AddRectangle(rtSelDay.left, rtSelDay.top, rtSelDay.width,
                       rtSelDay.height);
-    pParams->m_pGraphics->SetFillColor(
+    pParams.m_pGraphics->SetFillColor(
         CXFA_GEColor(m_pThemeData->clrDatesSelectedBK));
-    pParams->m_pGraphics->FillPath(&path, FXFILL_WINDING, pMatrix);
-  } else if (pParams->m_dwStates & CFWL_PartState_Hovered) {
+    pParams.m_pGraphics->FillPath(&path, FXFILL_WINDING, pMatrix);
+  } else if (pParams.m_dwStates & CFWL_PartState_Hovered) {
     CXFA_GEPath path;
-    CFX_RectF rtSelDay = pParams->m_rtPart;
+    CFX_RectF rtSelDay = pParams.m_rtPart;
     path.AddRectangle(rtSelDay.left, rtSelDay.top, rtSelDay.width,
                       rtSelDay.height);
-    pParams->m_pGraphics->SetFillColor(
+    pParams.m_pGraphics->SetFillColor(
         CXFA_GEColor(m_pThemeData->clrDatesHoverBK));
-    pParams->m_pGraphics->FillPath(&path, FXFILL_WINDING, pMatrix);
+    pParams.m_pGraphics->FillPath(&path, FXFILL_WINDING, pMatrix);
   }
-  pParams->m_pGraphics->RestoreGraphState();
+  pParams.m_pGraphics->RestoreGraphState();
 }
 
-void CFWL_MonthCalendarTP::DrawDatesInCircle(CFWL_ThemeBackground* pParams,
-                                             CFX_Matrix* pMatrix) {
+void CFWL_MonthCalendarTP::DrawDatesInCircle(
+    const CFWL_ThemeBackground& pParams,
+    const CFX_Matrix* pMatrix) {
   CXFA_GEPath path;
-  CFX_RectF rtSelDay = pParams->m_rtPart;
+  CFX_RectF rtSelDay = pParams.m_rtPart;
   path.AddRectangle(rtSelDay.left, rtSelDay.top, rtSelDay.width,
                     rtSelDay.height);
-  pParams->m_pGraphics->SaveGraphState();
-  pParams->m_pGraphics->SetStrokeColor(
+  pParams.m_pGraphics->SaveGraphState();
+  pParams.m_pGraphics->SetStrokeColor(
       CXFA_GEColor(m_pThemeData->clrDatesCircle));
-  pParams->m_pGraphics->StrokePath(&path, pMatrix);
-  pParams->m_pGraphics->RestoreGraphState();
+  pParams.m_pGraphics->StrokePath(&path, pMatrix);
+  pParams.m_pGraphics->RestoreGraphState();
 }
 
-void CFWL_MonthCalendarTP::DrawTodayCircle(CFWL_ThemeBackground* pParams,
-                                           CFX_Matrix* pMatrix) {
+void CFWL_MonthCalendarTP::DrawTodayCircle(const CFWL_ThemeBackground& pParams,
+                                           const CFX_Matrix* pMatrix) {
   CXFA_GEPath path;
-  CFX_RectF rtTodayCircle = pParams->m_rtPart;
+  CFX_RectF rtTodayCircle = pParams.m_rtPart;
   path.AddRectangle(rtTodayCircle.left, rtTodayCircle.top, rtTodayCircle.width,
                     rtTodayCircle.height);
-  pParams->m_pGraphics->SaveGraphState();
-  pParams->m_pGraphics->SetStrokeColor(
+  pParams.m_pGraphics->SaveGraphState();
+  pParams.m_pGraphics->SetStrokeColor(
       CXFA_GEColor(m_pThemeData->clrDatesCircle));
-  pParams->m_pGraphics->StrokePath(&path, pMatrix);
-  pParams->m_pGraphics->RestoreGraphState();
+  pParams.m_pGraphics->StrokePath(&path, pMatrix);
+  pParams.m_pGraphics->RestoreGraphState();
 }
 
 FWLTHEME_STATE CFWL_MonthCalendarTP::GetState(uint32_t dwFWLStates) {
diff --git a/xfa/fwl/theme/cfwl_monthcalendartp.h b/xfa/fwl/theme/cfwl_monthcalendartp.h
index 4dd08b4..ee6661a 100644
--- a/xfa/fwl/theme/cfwl_monthcalendartp.h
+++ b/xfa/fwl/theme/cfwl_monthcalendartp.h
@@ -19,8 +19,8 @@
   // CFWL_WidgetTP
   void Initialize() override;
   void Finalize() override;
-  void DrawBackground(CFWL_ThemeBackground* pParams) override;
-  void DrawText(CFWL_ThemeText* pParams) override;
+  void DrawBackground(const CFWL_ThemeBackground& pParams) override;
+  void DrawText(const CFWL_ThemeText& pParams) override;
 
  private:
   struct MCThemeData {
@@ -33,15 +33,24 @@
     FX_ARGB clrBK;
   };
 
-  void DrawTotalBK(CFWL_ThemeBackground* pParams, CFX_Matrix* pMatrix);
-  void DrawHeadBk(CFWL_ThemeBackground* pParams, CFX_Matrix* pMatrix);
-  void DrawLButton(CFWL_ThemeBackground* pParams, CFX_Matrix* pMatrix);
-  void DrawRButton(CFWL_ThemeBackground* pParams, CFX_Matrix* pMatrix);
-  void DrawDatesInBK(CFWL_ThemeBackground* pParams, CFX_Matrix* pMatrix);
-  void DrawDatesInCircle(CFWL_ThemeBackground* pParams, CFX_Matrix* pMatrix);
-  void DrawTodayCircle(CFWL_ThemeBackground* pParams, CFX_Matrix* pMatrix);
-  void DrawHSeperator(CFWL_ThemeBackground* pParams, CFX_Matrix* pMatrix);
-  void DrawWeekNumSep(CFWL_ThemeBackground* pParams, CFX_Matrix* pMatrix);
+  void DrawTotalBK(const CFWL_ThemeBackground& pParams,
+                   const CFX_Matrix* pMatrix);
+  void DrawHeadBk(const CFWL_ThemeBackground& pParams,
+                  const CFX_Matrix* pMatrix);
+  void DrawLButton(const CFWL_ThemeBackground& pParams,
+                   const CFX_Matrix* pMatrix);
+  void DrawRButton(const CFWL_ThemeBackground& pParams,
+                   const CFX_Matrix* pMatrix);
+  void DrawDatesInBK(const CFWL_ThemeBackground& pParams,
+                     const CFX_Matrix* pMatrix);
+  void DrawDatesInCircle(const CFWL_ThemeBackground& pParams,
+                         const CFX_Matrix* pMatrix);
+  void DrawTodayCircle(const CFWL_ThemeBackground& pParams,
+                       const CFX_Matrix* pMatrix);
+  void DrawHSeperator(const CFWL_ThemeBackground& pParams,
+                      const CFX_Matrix* pMatrix);
+  void DrawWeekNumSep(const CFWL_ThemeBackground& pParams,
+                      const CFX_Matrix* pMatrix);
   FWLTHEME_STATE GetState(uint32_t dwFWLStates);
   void SetThemeData();
 
diff --git a/xfa/fwl/theme/cfwl_pictureboxtp.cpp b/xfa/fwl/theme/cfwl_pictureboxtp.cpp
index 6a30113..851eb74 100644
--- a/xfa/fwl/theme/cfwl_pictureboxtp.cpp
+++ b/xfa/fwl/theme/cfwl_pictureboxtp.cpp
@@ -14,14 +14,11 @@
 
 CFWL_PictureBoxTP::~CFWL_PictureBoxTP() {}
 
-void CFWL_PictureBoxTP::DrawBackground(CFWL_ThemeBackground* pParams) {
-  if (!pParams)
-    return;
-
-  switch (pParams->m_iPart) {
+void CFWL_PictureBoxTP::DrawBackground(const CFWL_ThemeBackground& pParams) {
+  switch (pParams.m_iPart) {
     case CFWL_Part::Border:
-      DrawBorder(pParams->m_pGraphics.Get(), &pParams->m_rtPart,
-                 &pParams->m_matrix);
+      DrawBorder(pParams.m_pGraphics.Get(), &pParams.m_rtPart,
+                 &pParams.m_matrix);
       break;
     default:
       break;
diff --git a/xfa/fwl/theme/cfwl_pictureboxtp.h b/xfa/fwl/theme/cfwl_pictureboxtp.h
index 1bb3486..4bb295a 100644
--- a/xfa/fwl/theme/cfwl_pictureboxtp.h
+++ b/xfa/fwl/theme/cfwl_pictureboxtp.h
@@ -15,7 +15,7 @@
   ~CFWL_PictureBoxTP() override;
 
   // CFWL_WidgetTP
-  void DrawBackground(CFWL_ThemeBackground* pParams) override;
+  void DrawBackground(const CFWL_ThemeBackground& pParams) override;
 };
 
 #endif  // XFA_FWL_THEME_CFWL_PICTUREBOXTP_H_
diff --git a/xfa/fwl/theme/cfwl_pushbuttontp.cpp b/xfa/fwl/theme/cfwl_pushbuttontp.cpp
index dbd6800..9b5d416 100644
--- a/xfa/fwl/theme/cfwl_pushbuttontp.cpp
+++ b/xfa/fwl/theme/cfwl_pushbuttontp.cpp
@@ -21,15 +21,15 @@
 
 CFWL_PushButtonTP::~CFWL_PushButtonTP() {}
 
-void CFWL_PushButtonTP::DrawBackground(CFWL_ThemeBackground* pParams) {
-  switch (pParams->m_iPart) {
+void CFWL_PushButtonTP::DrawBackground(const CFWL_ThemeBackground& pParams) {
+  switch (pParams.m_iPart) {
     case CFWL_Part::Border: {
-      DrawBorder(pParams->m_pGraphics.Get(), &pParams->m_rtPart,
-                 &pParams->m_matrix);
+      DrawBorder(pParams.m_pGraphics.Get(), &pParams.m_rtPart,
+                 &pParams.m_matrix);
       break;
     }
     case CFWL_Part::Background: {
-      CFX_RectF& rect = pParams->m_rtPart;
+      const CFX_RectF& rect = pParams.m_rtPart;
       float fRight = rect.right();
       float fBottom = rect.bottom();
 
@@ -52,7 +52,7 @@
       CXFA_GEPath fillPath;
       fillPath.AddSubpath(&strokePath);
 
-      CXFA_Graphics* pGraphics = pParams->m_pGraphics.Get();
+      CXFA_Graphics* pGraphics = pParams.m_pGraphics.Get();
       pGraphics->SaveGraphState();
 
       CFX_RectF rtInner(rect);
@@ -61,22 +61,22 @@
       fillPath.AddRectangle(rtInner.left, rtInner.top, rtInner.width,
                             rtInner.height);
 
-      int32_t iColor = GetColorID(pParams->m_dwStates);
+      int32_t iColor = GetColorID(pParams.m_dwStates);
       FillSolidRect(pGraphics, m_pThemeData->clrEnd[iColor], &rect,
-                    &pParams->m_matrix);
+                    &pParams.m_matrix);
 
       pGraphics->SetStrokeColor(CXFA_GEColor(m_pThemeData->clrBorder[iColor]));
-      pGraphics->StrokePath(&strokePath, &pParams->m_matrix);
+      pGraphics->StrokePath(&strokePath, &pParams.m_matrix);
 
       fillPath.Clear();
       fillPath.AddRectangle(rtInner.left, rtInner.top, rtInner.width,
                             rtInner.height);
 
       pGraphics->SetFillColor(CXFA_GEColor(m_pThemeData->clrFill[iColor]));
-      pGraphics->FillPath(&fillPath, FXFILL_WINDING, &pParams->m_matrix);
-      if (pParams->m_dwStates & CFWL_PartState_Focused) {
+      pGraphics->FillPath(&fillPath, FXFILL_WINDING, &pParams.m_matrix);
+      if (pParams.m_dwStates & CFWL_PartState_Focused) {
         rtInner.Inflate(1, 1, 0, 0);
-        DrawFocus(pGraphics, &rtInner, &pParams->m_matrix);
+        DrawFocus(pGraphics, &rtInner, &pParams.m_matrix);
       }
       pGraphics->RestoreGraphState();
       break;
diff --git a/xfa/fwl/theme/cfwl_pushbuttontp.h b/xfa/fwl/theme/cfwl_pushbuttontp.h
index 6b49ba6..c3079dd 100644
--- a/xfa/fwl/theme/cfwl_pushbuttontp.h
+++ b/xfa/fwl/theme/cfwl_pushbuttontp.h
@@ -17,7 +17,7 @@
   ~CFWL_PushButtonTP() override;
 
   // CFWL_WidgetTP
-  void DrawBackground(CFWL_ThemeBackground* pParams) override;
+  void DrawBackground(const CFWL_ThemeBackground& pParams) override;
 
  private:
   struct PBThemeData {
diff --git a/xfa/fwl/theme/cfwl_scrollbartp.cpp b/xfa/fwl/theme/cfwl_scrollbartp.cpp
index 0f383e6..e46675e 100644
--- a/xfa/fwl/theme/cfwl_scrollbartp.cpp
+++ b/xfa/fwl/theme/cfwl_scrollbartp.cpp
@@ -25,45 +25,42 @@
 
 CFWL_ScrollBarTP::~CFWL_ScrollBarTP() {}
 
-void CFWL_ScrollBarTP::DrawBackground(CFWL_ThemeBackground* pParams) {
-  if (!pParams)
-    return;
-
-  CFWL_Widget* pWidget = pParams->m_pWidget;
+void CFWL_ScrollBarTP::DrawBackground(const CFWL_ThemeBackground& pParams) {
+  CFWL_Widget* pWidget = pParams.m_pWidget;
   FWLTHEME_STATE eState = FWLTHEME_STATE_Normal;
-  if (pParams->m_dwStates & CFWL_PartState_Hovered)
+  if (pParams.m_dwStates & CFWL_PartState_Hovered)
     eState = FWLTHEME_STATE_Hover;
-  else if (pParams->m_dwStates & CFWL_PartState_Pressed)
+  else if (pParams.m_dwStates & CFWL_PartState_Pressed)
     eState = FWLTHEME_STATE_Pressed;
-  else if (pParams->m_dwStates & CFWL_PartState_Disabled)
+  else if (pParams.m_dwStates & CFWL_PartState_Disabled)
     eState = FWLTHEME_STATE_Disable;
 
-  CXFA_Graphics* pGraphics = pParams->m_pGraphics.Get();
-  CFX_RectF* pRect = &pParams->m_rtPart;
+  CXFA_Graphics* pGraphics = pParams.m_pGraphics.Get();
+  const CFX_RectF* pRect = &pParams.m_rtPart;
   bool bVert = !!pWidget->GetStylesEx();
-  switch (pParams->m_iPart) {
+  switch (pParams.m_iPart) {
     case CFWL_Part::ForeArrow: {
       DrawMaxMinBtn(pGraphics, pRect,
                     bVert ? FWLTHEME_DIRECTION_Up : FWLTHEME_DIRECTION_Left,
-                    eState, &pParams->m_matrix);
+                    eState, &pParams.m_matrix);
       break;
     }
     case CFWL_Part::BackArrow: {
       DrawMaxMinBtn(pGraphics, pRect,
                     bVert ? FWLTHEME_DIRECTION_Down : FWLTHEME_DIRECTION_Right,
-                    eState, &pParams->m_matrix);
+                    eState, &pParams.m_matrix);
       break;
     }
     case CFWL_Part::Thumb: {
-      DrawThumbBtn(pGraphics, pRect, bVert, eState, true, &pParams->m_matrix);
+      DrawThumbBtn(pGraphics, pRect, bVert, eState, true, &pParams.m_matrix);
       break;
     }
     case CFWL_Part::LowerTrack: {
-      DrawTrack(pGraphics, pRect, bVert, eState, true, &pParams->m_matrix);
+      DrawTrack(pGraphics, pRect, bVert, eState, true, &pParams.m_matrix);
       break;
     }
     case CFWL_Part::UpperTrack: {
-      DrawTrack(pGraphics, pRect, bVert, eState, false, &pParams->m_matrix);
+      DrawTrack(pGraphics, pRect, bVert, eState, false, &pParams.m_matrix);
       break;
     }
     default:
@@ -76,7 +73,7 @@
                                     bool bVert,
                                     FWLTHEME_STATE eState,
                                     bool bPawButton,
-                                    CFX_Matrix* pMatrix) {
+                                    const CFX_Matrix* pMatrix) {
   if (eState < FWLTHEME_STATE_Normal || eState > FWLTHEME_STATE_Disable)
     return;
 
@@ -106,7 +103,7 @@
                                const CFX_RectF* pRect,
                                bool bVert,
                                FWLTHEME_STATE eState,
-                               CFX_Matrix* pMatrix) {
+                               const CFX_Matrix* pMatrix) {
   CXFA_GEPath path;
   if (bVert) {
     float fPawLen = kPawLength;
@@ -190,7 +187,7 @@
                                  bool bVert,
                                  FWLTHEME_STATE eState,
                                  bool bLowerTrack,
-                                 CFX_Matrix* pMatrix) {
+                                 const CFX_Matrix* pMatrix) {
   if (eState < FWLTHEME_STATE_Normal || eState > FWLTHEME_STATE_Disable)
     return;
 
@@ -218,7 +215,7 @@
                                      const CFX_RectF* pRect,
                                      FWLTHEME_DIRECTION eDict,
                                      FWLTHEME_STATE eState,
-                                     CFX_Matrix* pMatrix) {
+                                     const CFX_Matrix* pMatrix) {
   DrawTrack(pGraphics, pRect,
             eDict == FWLTHEME_DIRECTION_Up || eDict == FWLTHEME_DIRECTION_Down,
             eState, true, pMatrix);
diff --git a/xfa/fwl/theme/cfwl_scrollbartp.h b/xfa/fwl/theme/cfwl_scrollbartp.h
index 2a202e1..2727a0b 100644
--- a/xfa/fwl/theme/cfwl_scrollbartp.h
+++ b/xfa/fwl/theme/cfwl_scrollbartp.h
@@ -17,7 +17,7 @@
   ~CFWL_ScrollBarTP() override;
 
   // CFWL_WidgetTP
-  void DrawBackground(CFWL_ThemeBackground* pParams) override;
+  void DrawBackground(const CFWL_ThemeBackground& pParams) override;
 
  private:
   struct SBThemeData {
@@ -34,23 +34,23 @@
                     bool bVert,
                     FWLTHEME_STATE eState,
                     bool bPawButton,
-                    CFX_Matrix* pMatrix);
+                    const CFX_Matrix* pMatrix);
   void DrawTrack(CXFA_Graphics* pGraphics,
                  const CFX_RectF* pRect,
                  bool bVert,
                  FWLTHEME_STATE eState,
                  bool bLowerTrack,
-                 CFX_Matrix* pMatrix);
+                 const CFX_Matrix* pMatrix);
   void DrawMaxMinBtn(CXFA_Graphics* pGraphics,
                      const CFX_RectF* pRect,
                      FWLTHEME_DIRECTION eDict,
                      FWLTHEME_STATE eState,
-                     CFX_Matrix* pMatrix);
+                     const CFX_Matrix* pMatrix);
   void DrawPaw(CXFA_Graphics* pGraphics,
                const CFX_RectF* pRect,
                bool bVert,
                FWLTHEME_STATE eState,
-               CFX_Matrix* pMatrix);
+               const CFX_Matrix* pMatrix);
   void SetThemeData();
 
   std::unique_ptr<SBThemeData> m_pThemeData;
diff --git a/xfa/fwl/theme/cfwl_widgettp.cpp b/xfa/fwl/theme/cfwl_widgettp.cpp
index bea8b3b..5c2bf22 100644
--- a/xfa/fwl/theme/cfwl_widgettp.cpp
+++ b/xfa/fwl/theme/cfwl_widgettp.cpp
@@ -35,26 +35,26 @@
     FinalizeTTO();
 }
 
-void CFWL_WidgetTP::DrawBackground(CFWL_ThemeBackground* pParams) {}
+void CFWL_WidgetTP::DrawBackground(const CFWL_ThemeBackground& pParams) {}
 
-void CFWL_WidgetTP::DrawText(CFWL_ThemeText* pParams) {
+void CFWL_WidgetTP::DrawText(const CFWL_ThemeText& pParams) {
   if (!m_pTextOut)
     InitTTO();
 
-  int32_t iLen = pParams->m_wsText.GetLength();
+  int32_t iLen = pParams.m_wsText.GetLength();
   if (iLen <= 0)
     return;
 
-  CXFA_Graphics* pGraphics = pParams->m_pGraphics;
-  m_pTextOut->SetStyles(pParams->m_dwTTOStyles);
-  m_pTextOut->SetAlignment(pParams->m_iTTOAlign);
+  CXFA_Graphics* pGraphics = pParams.m_pGraphics;
+  m_pTextOut->SetStyles(pParams.m_dwTTOStyles);
+  m_pTextOut->SetAlignment(pParams.m_iTTOAlign);
 
-  CFX_Matrix* pMatrix = &pParams->m_matrix;
-  pMatrix->Concat(*pGraphics->GetMatrix());
-  m_pTextOut->SetMatrix(*pMatrix);
+  CFX_Matrix matrix = pParams.m_matrix;
+  matrix.Concat(*pGraphics->GetMatrix());
+  m_pTextOut->SetMatrix(matrix);
   m_pTextOut->DrawLogicText(pGraphics->GetRenderDevice(),
-                            WideStringView(pParams->m_wsText.c_str(), iLen),
-                            pParams->m_rtPart);
+                            WideStringView(pParams.m_wsText.c_str(), iLen),
+                            pParams.m_rtPart);
 }
 
 const RetainPtr<CFGAS_GEFont>& CFWL_WidgetTP::GetFont() const {
@@ -102,7 +102,7 @@
 
 void CFWL_WidgetTP::DrawBorder(CXFA_Graphics* pGraphics,
                                const CFX_RectF* pRect,
-                               CFX_Matrix* pMatrix) {
+                               const CFX_Matrix* pMatrix) {
   if (!pGraphics || !pRect)
     return;
 
@@ -118,14 +118,14 @@
 
 void CFWL_WidgetTP::FillBackground(CXFA_Graphics* pGraphics,
                                    const CFX_RectF* pRect,
-                                   CFX_Matrix* pMatrix) {
+                                   const CFX_Matrix* pMatrix) {
   FillSolidRect(pGraphics, FWLTHEME_COLOR_Background, pRect, pMatrix);
 }
 
 void CFWL_WidgetTP::FillSolidRect(CXFA_Graphics* pGraphics,
                                   FX_ARGB fillColor,
                                   const CFX_RectF* pRect,
-                                  CFX_Matrix* pMatrix) {
+                                  const CFX_Matrix* pMatrix) {
   if (!pGraphics || !pRect)
     return;
 
@@ -139,7 +139,7 @@
 
 void CFWL_WidgetTP::DrawFocus(CXFA_Graphics* pGraphics,
                               const CFX_RectF* pRect,
-                              CFX_Matrix* pMatrix) {
+                              const CFX_Matrix* pMatrix) {
   if (!pGraphics || !pRect)
     return;
 
@@ -157,7 +157,7 @@
                               const CFX_RectF* pRect,
                               FWLTHEME_DIRECTION eDict,
                               FX_ARGB argSign,
-                              CFX_Matrix* pMatrix) {
+                              const CFX_Matrix* pMatrix) {
   bool bVert =
       (eDict == FWLTHEME_DIRECTION_Up || eDict == FWLTHEME_DIRECTION_Down);
   float fLeft =
@@ -210,9 +210,8 @@
 void CFWL_WidgetTP::DrawBtn(CXFA_Graphics* pGraphics,
                             const CFX_RectF* pRect,
                             FWLTHEME_STATE eState,
-                            CFX_Matrix* pMatrix) {
+                            const CFX_Matrix* pMatrix) {
   InitializeArrowColorData();
-
   FillSolidRect(pGraphics, m_pColorData->clrEnd[eState - 1], pRect, pMatrix);
 
   CXFA_GEPath path;
@@ -225,7 +224,7 @@
                                  const CFX_RectF* pRect,
                                  FWLTHEME_DIRECTION eDict,
                                  FWLTHEME_STATE eState,
-                                 CFX_Matrix* pMatrix) {
+                                 const CFX_Matrix* pMatrix) {
   DrawBtn(pGraphics, pRect, eState, pMatrix);
 
   InitializeArrowColorData();
diff --git a/xfa/fwl/theme/cfwl_widgettp.h b/xfa/fwl/theme/cfwl_widgettp.h
index 05f7174..732b510 100644
--- a/xfa/fwl/theme/cfwl_widgettp.h
+++ b/xfa/fwl/theme/cfwl_widgettp.h
@@ -29,8 +29,8 @@
   virtual void Initialize();
   virtual void Finalize();
 
-  virtual void DrawBackground(CFWL_ThemeBackground* pParams);
-  virtual void DrawText(CFWL_ThemeText* pParams);
+  virtual void DrawBackground(const CFWL_ThemeBackground& pParams);
+  virtual void DrawText(const CFWL_ThemeText& pParams);
 
   const RetainPtr<CFGAS_GEFont>& GetFont() const;
 
@@ -50,31 +50,31 @@
 
   void DrawBorder(CXFA_Graphics* pGraphics,
                   const CFX_RectF* pRect,
-                  CFX_Matrix* pMatrix);
+                  const CFX_Matrix* pMatrix);
   void FillBackground(CXFA_Graphics* pGraphics,
                       const CFX_RectF* pRect,
-                      CFX_Matrix* pMatrix);
+                      const CFX_Matrix* pMatrix);
   void FillSolidRect(CXFA_Graphics* pGraphics,
                      FX_ARGB fillColor,
                      const CFX_RectF* pRect,
-                     CFX_Matrix* pMatrix);
+                     const CFX_Matrix* pMatrix);
   void DrawFocus(CXFA_Graphics* pGraphics,
                  const CFX_RectF* pRect,
-                 CFX_Matrix* pMatrix);
+                 const CFX_Matrix* pMatrix);
   void DrawArrow(CXFA_Graphics* pGraphics,
                  const CFX_RectF* pRect,
                  FWLTHEME_DIRECTION eDict,
                  FX_ARGB argSign,
-                 CFX_Matrix* pMatrix);
+                 const CFX_Matrix* pMatrix);
   void DrawBtn(CXFA_Graphics* pGraphics,
                const CFX_RectF* pRect,
                FWLTHEME_STATE eState,
-               CFX_Matrix* pMatrix);
+               const CFX_Matrix* pMatrix);
   void DrawArrowBtn(CXFA_Graphics* pGraphics,
                     const CFX_RectF* pRect,
                     FWLTHEME_DIRECTION eDict,
                     FWLTHEME_STATE eState,
-                    CFX_Matrix* pMatrix);
+                    const CFX_Matrix* pMatrix);
 
   uint32_t m_dwRefCount;
   std::unique_ptr<CFDE_TextOut> m_pTextOut;
diff --git a/xfa/fxfa/cxfa_fwltheme.cpp b/xfa/fxfa/cxfa_fwltheme.cpp
index 820b294..1270025 100644
--- a/xfa/fxfa/cxfa_fwltheme.cpp
+++ b/xfa/fxfa/cxfa_fwltheme.cpp
@@ -84,75 +84,75 @@
   FWLTHEME_Release();
 }
 
-void CXFA_FWLTheme::DrawBackground(CFWL_ThemeBackground* pParams) {
-  GetTheme(pParams->m_pWidget)->DrawBackground(pParams);
+void CXFA_FWLTheme::DrawBackground(const CFWL_ThemeBackground& pParams) {
+  GetTheme(pParams.m_pWidget)->DrawBackground(pParams);
 }
 
-void CXFA_FWLTheme::DrawText(CFWL_ThemeText* pParams) {
-  if (pParams->m_wsText.IsEmpty())
+void CXFA_FWLTheme::DrawText(const CFWL_ThemeText& pParams) {
+  if (pParams.m_wsText.IsEmpty())
     return;
 
-  if (pParams->m_pWidget->GetClassID() == FWL_Type::MonthCalendar) {
-    CXFA_FFWidget* pWidget = XFA_ThemeGetOuterWidget(pParams->m_pWidget);
+  if (pParams.m_pWidget->GetClassID() == FWL_Type::MonthCalendar) {
+    CXFA_FFWidget* pWidget = XFA_ThemeGetOuterWidget(pParams.m_pWidget);
     if (!pWidget)
       return;
 
-    m_pTextOut->SetStyles(pParams->m_dwTTOStyles);
-    m_pTextOut->SetAlignment(pParams->m_iTTOAlign);
+    m_pTextOut->SetStyles(pParams.m_dwTTOStyles);
+    m_pTextOut->SetAlignment(pParams.m_iTTOAlign);
     m_pTextOut->SetFont(m_pCalendarFont);
     m_pTextOut->SetFontSize(FWLTHEME_CAPACITY_FontSize);
     m_pTextOut->SetTextColor(FWLTHEME_CAPACITY_TextColor);
-    if ((pParams->m_iPart == CFWL_Part::DatesIn) &&
-        !(pParams->m_dwStates & FWL_ITEMSTATE_MCD_Flag) &&
-        (pParams->m_dwStates &
+    if ((pParams.m_iPart == CFWL_Part::DatesIn) &&
+        !(pParams.m_dwStates & FWL_ITEMSTATE_MCD_Flag) &&
+        (pParams.m_dwStates &
          (CFWL_PartState_Hovered | CFWL_PartState_Selected))) {
       m_pTextOut->SetTextColor(0xFF888888);
     }
-    if (pParams->m_iPart == CFWL_Part::Caption)
+    if (pParams.m_iPart == CFWL_Part::Caption)
       m_pTextOut->SetTextColor(ArgbEncode(0xff, 0, 153, 255));
 
-    CXFA_Graphics* pGraphics = pParams->m_pGraphics;
+    CXFA_Graphics* pGraphics = pParams.m_pGraphics;
     CFX_RenderDevice* pRenderDevice = pGraphics->GetRenderDevice();
     if (!pRenderDevice)
       return;
 
-    CFX_Matrix mtPart = pParams->m_matrix;
+    CFX_Matrix mtPart = pParams.m_matrix;
     const CFX_Matrix* pMatrix = pGraphics->GetMatrix();
     if (pMatrix)
       mtPart.Concat(*pMatrix);
 
     m_pTextOut->SetMatrix(mtPart);
-    m_pTextOut->DrawLogicText(pRenderDevice, pParams->m_wsText.AsStringView(),
-                              pParams->m_rtPart);
+    m_pTextOut->DrawLogicText(pRenderDevice, pParams.m_wsText.AsStringView(),
+                              pParams.m_rtPart);
     return;
   }
-  CXFA_FFWidget* pWidget = XFA_ThemeGetOuterWidget(pParams->m_pWidget);
+  CXFA_FFWidget* pWidget = XFA_ThemeGetOuterWidget(pParams.m_pWidget);
   if (!pWidget)
     return;
 
   CXFA_Node* pNode = pWidget->GetNode();
-  CXFA_Graphics* pGraphics = pParams->m_pGraphics;
+  CXFA_Graphics* pGraphics = pParams.m_pGraphics;
   CFX_RenderDevice* pRenderDevice = pGraphics->GetRenderDevice();
   if (!pRenderDevice)
     return;
 
-  m_pTextOut->SetStyles(pParams->m_dwTTOStyles);
-  m_pTextOut->SetAlignment(pParams->m_iTTOAlign);
+  m_pTextOut->SetStyles(pParams.m_dwTTOStyles);
+  m_pTextOut->SetAlignment(pParams.m_iTTOAlign);
   m_pTextOut->SetFont(pNode->GetFDEFont(pWidget->GetDoc()));
   m_pTextOut->SetFontSize(pNode->GetFontSize());
   m_pTextOut->SetTextColor(pNode->GetTextColor());
-  CFX_Matrix mtPart = pParams->m_matrix;
+  CFX_Matrix mtPart = pParams.m_matrix;
   const CFX_Matrix* pMatrix = pGraphics->GetMatrix();
   if (pMatrix)
     mtPart.Concat(*pMatrix);
 
   m_pTextOut->SetMatrix(mtPart);
-  m_pTextOut->DrawLogicText(pRenderDevice, pParams->m_wsText.AsStringView(),
-                            pParams->m_rtPart);
+  m_pTextOut->DrawLogicText(pRenderDevice, pParams.m_wsText.AsStringView(),
+                            pParams.m_rtPart);
 }
 
-CFX_RectF CXFA_FWLTheme::GetUIMargin(CFWL_ThemePart* pThemePart) const {
-  CXFA_FFWidget* pWidget = XFA_ThemeGetOuterWidget(pThemePart->m_pWidget);
+CFX_RectF CXFA_FWLTheme::GetUIMargin(const CFWL_ThemePart& pThemePart) const {
+  CXFA_FFWidget* pWidget = XFA_ThemeGetOuterWidget(pThemePart.m_pWidget);
   if (!pWidget)
     return CFX_RectF();
 
@@ -185,21 +185,21 @@
   return 1.0f;
 }
 
-float CXFA_FWLTheme::GetFontSize(CFWL_ThemePart* pThemePart) const {
-  if (CXFA_FFWidget* pWidget = XFA_ThemeGetOuterWidget(pThemePart->m_pWidget))
+float CXFA_FWLTheme::GetFontSize(const CFWL_ThemePart& pThemePart) const {
+  if (CXFA_FFWidget* pWidget = XFA_ThemeGetOuterWidget(pThemePart.m_pWidget))
     return pWidget->GetNode()->GetFontSize();
   return FWLTHEME_CAPACITY_FontSize;
 }
 
 RetainPtr<CFGAS_GEFont> CXFA_FWLTheme::GetFont(
-    CFWL_ThemePart* pThemePart) const {
-  if (CXFA_FFWidget* pWidget = XFA_ThemeGetOuterWidget(pThemePart->m_pWidget))
+    const CFWL_ThemePart& pThemePart) const {
+  if (CXFA_FFWidget* pWidget = XFA_ThemeGetOuterWidget(pThemePart.m_pWidget))
     return pWidget->GetNode()->GetFDEFont(pWidget->GetDoc());
-  return GetTheme(pThemePart->m_pWidget)->GetFont();
+  return GetTheme(pThemePart.m_pWidget)->GetFont();
 }
 
-float CXFA_FWLTheme::GetLineHeight(CFWL_ThemePart* pThemePart) const {
-  if (CXFA_FFWidget* pWidget = XFA_ThemeGetOuterWidget(pThemePart->m_pWidget))
+float CXFA_FWLTheme::GetLineHeight(const CFWL_ThemePart& pThemePart) const {
+  if (CXFA_FFWidget* pWidget = XFA_ThemeGetOuterWidget(pThemePart.m_pWidget))
     return pWidget->GetNode()->GetLineHeight();
   return kLineHeight;
 }
@@ -208,15 +208,17 @@
   return 9.0f;
 }
 
-FX_COLORREF CXFA_FWLTheme::GetTextColor(CFWL_ThemePart* pThemePart) const {
-  if (CXFA_FFWidget* pWidget = XFA_ThemeGetOuterWidget(pThemePart->m_pWidget))
+FX_COLORREF CXFA_FWLTheme::GetTextColor(
+    const CFWL_ThemePart& pThemePart) const {
+  if (CXFA_FFWidget* pWidget = XFA_ThemeGetOuterWidget(pThemePart.m_pWidget))
     return pWidget->GetNode()->GetTextColor();
   return FWLTHEME_CAPACITY_TextColor;
 }
 
-CFX_SizeF CXFA_FWLTheme::GetSpaceAboveBelow(CFWL_ThemePart* pThemePart) const {
+CFX_SizeF CXFA_FWLTheme::GetSpaceAboveBelow(
+    const CFWL_ThemePart& pThemePart) const {
   CFX_SizeF sizeAboveBelow;
-  if (CXFA_FFWidget* pWidget = XFA_ThemeGetOuterWidget(pThemePart->m_pWidget)) {
+  if (CXFA_FFWidget* pWidget = XFA_ThemeGetOuterWidget(pThemePart.m_pWidget)) {
     CXFA_Para* para = pWidget->GetNode()->GetParaIfExists();
     if (para) {
       sizeAboveBelow.width = para->GetSpaceAbove();
@@ -226,35 +228,32 @@
   return sizeAboveBelow;
 }
 
-void CXFA_FWLTheme::CalcTextRect(CFWL_ThemeText* pParams, CFX_RectF* pRect) {
-  if (pParams->m_pWidget->GetClassID() == FWL_Type::MonthCalendar) {
-    CXFA_FFWidget* pWidget = XFA_ThemeGetOuterWidget(pParams->m_pWidget);
-    if (!pWidget || !pParams || !m_pTextOut)
-      return;
+void CXFA_FWLTheme::CalcTextRect(const CFWL_ThemeText& pParams,
+                                 CFX_RectF* pRect) {
+  if (!m_pTextOut)
+    return;
 
+  CXFA_FFWidget* pWidget = XFA_ThemeGetOuterWidget(pParams.m_pWidget);
+  if (!pWidget)
+    return;
+
+  if (pParams.m_pWidget->GetClassID() == FWL_Type::MonthCalendar) {
     m_pTextOut->SetFont(m_pCalendarFont);
     m_pTextOut->SetFontSize(FWLTHEME_CAPACITY_FontSize);
     m_pTextOut->SetTextColor(FWLTHEME_CAPACITY_TextColor);
-    m_pTextOut->SetAlignment(pParams->m_iTTOAlign);
-    m_pTextOut->SetStyles(pParams->m_dwTTOStyles);
-    m_pTextOut->CalcLogicSize(pParams->m_wsText, pRect);
+    m_pTextOut->SetAlignment(pParams.m_iTTOAlign);
+    m_pTextOut->SetStyles(pParams.m_dwTTOStyles);
+    m_pTextOut->CalcLogicSize(pParams.m_wsText, pRect);
     return;
   }
 
-  CXFA_FFWidget* pWidget = XFA_ThemeGetOuterWidget(pParams->m_pWidget);
-  if (!pWidget)
-    return;
-
   CXFA_Node* pNode = pWidget->GetNode();
   m_pTextOut->SetFont(pNode->GetFDEFont(pWidget->GetDoc()));
   m_pTextOut->SetFontSize(pNode->GetFontSize());
   m_pTextOut->SetTextColor(pNode->GetTextColor());
-  if (!pParams)
-    return;
-
-  m_pTextOut->SetAlignment(pParams->m_iTTOAlign);
-  m_pTextOut->SetStyles(pParams->m_dwTTOStyles);
-  m_pTextOut->CalcLogicSize(pParams->m_wsText, pRect);
+  m_pTextOut->SetAlignment(pParams.m_iTTOAlign);
+  m_pTextOut->SetStyles(pParams.m_dwTTOStyles);
+  m_pTextOut->CalcLogicSize(pParams.m_wsText, pRect);
 }
 
 CFWL_WidgetTP* CXFA_FWLTheme::GetTheme(CFWL_Widget* pWidget) const {
diff --git a/xfa/fxfa/cxfa_fwltheme.h b/xfa/fxfa/cxfa_fwltheme.h
index 31e29bf..c52e962 100644
--- a/xfa/fxfa/cxfa_fwltheme.h
+++ b/xfa/fxfa/cxfa_fwltheme.h
@@ -32,18 +32,19 @@
   bool LoadCalendarFont(CXFA_FFDoc* doc);
 
   // IFWL_ThemeProvider:
-  void DrawBackground(CFWL_ThemeBackground* pParams) override;
-  void DrawText(CFWL_ThemeText* pParams) override;
-  void CalcTextRect(CFWL_ThemeText* pParams, CFX_RectF* pRect) override;
+  void DrawBackground(const CFWL_ThemeBackground& pParams) override;
+  void DrawText(const CFWL_ThemeText& pParams) override;
+  void CalcTextRect(const CFWL_ThemeText& pParams, CFX_RectF* pRect) override;
   float GetCXBorderSize() const override;
   float GetCYBorderSize() const override;
-  CFX_RectF GetUIMargin(CFWL_ThemePart* pThemePart) const override;
-  float GetFontSize(CFWL_ThemePart* pThemePart) const override;
-  RetainPtr<CFGAS_GEFont> GetFont(CFWL_ThemePart* pThemePart) const override;
-  float GetLineHeight(CFWL_ThemePart* pThemePart) const override;
+  CFX_RectF GetUIMargin(const CFWL_ThemePart& pThemePart) const override;
+  float GetFontSize(const CFWL_ThemePart& pThemePart) const override;
+  RetainPtr<CFGAS_GEFont> GetFont(
+      const CFWL_ThemePart& pThemePart) const override;
+  float GetLineHeight(const CFWL_ThemePart& pThemePart) const override;
   float GetScrollBarWidth() const override;
-  FX_COLORREF GetTextColor(CFWL_ThemePart* pThemePart) const override;
-  CFX_SizeF GetSpaceAboveBelow(CFWL_ThemePart* pThemePart) const override;
+  FX_COLORREF GetTextColor(const CFWL_ThemePart& pThemePart) const override;
+  CFX_SizeF GetSpaceAboveBelow(const CFWL_ThemePart& pThemePart) const override;
 
  private:
   CFWL_WidgetTP* GetTheme(CFWL_Widget* pWidget) const;