widget/ScrollbarDrawing.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_widget_ScrollbarDrawing_h
   8 #define mozilla_widget_ScrollbarDrawing_h
   9
  10 #include "mozilla/dom/RustTypes.h"
  11 #include "mozilla/gfx/2D.h"
  12 #include "nsColor.h"
  13 #include "nsITheme.h"
  14 #include "ThemeColors.h"
  15 #include "ThemeDrawing.h"
  16 #include "Units.h"
  17
  18 namespace mozilla::widget {
  19
  20 class ScrollbarDrawing {
  21  protected:
  22   using DPIRatio = mozilla::CSSToLayoutDeviceScale;
  23   using ElementState = dom::ElementState;
  24   using DocumentState = dom::DocumentState;
  25   using DrawTarget = mozilla::gfx::DrawTarget;
  26   using sRGBColor = mozilla::gfx::sRGBColor;
  27   using Colors = ThemeColors;
  28   using ScrollbarSizes = nsITheme::ScrollbarSizes;
  29   using Overlay = nsITheme::Overlay;
  30   using WebRenderBackendData = mozilla::widget::WebRenderBackendData;
  31
  32   enum class Kind : uint8_t {
  33     Android,
  34     Cocoa,
  35     Gtk,
  36     Win10,
  37     Win11,
  38   };
  39
  40   explicit ScrollbarDrawing(Kind aKind) : mKind(aKind) {}
  41
  42  public:
  43   virtual ~ScrollbarDrawing() = default;
  44
  45   enum class ScrollbarKind : uint8_t {
  46     Horizontal,
  47     VerticalLeft,
  48     VerticalRight,
  49   };
  50
  51   static DPIRatio GetDPIRatioForScrollbarPart(nsPresContext*);
  52
  53   static nsIFrame* GetParentScrollbarFrame(nsIFrame* aFrame);
  54   static bool IsParentScrollbarRolledOver(nsIFrame* aFrame);
  55   static bool IsParentScrollbarHoveredOrActive(nsIFrame* aFrame);
  56
  57   static bool IsScrollbarWidthThin(const ComputedStyle& aStyle);
  58   static bool IsScrollbarWidthThin(nsIFrame* aFrame);
  59
  60   virtual ScrollbarSizes GetScrollbarSizes(nsPresContext*, StyleScrollbarWidth,
  61                                            Overlay);
  62   ScrollbarSizes GetScrollbarSizes(nsPresContext*, nsIFrame*);
  63   virtual LayoutDeviceIntSize GetMinimumWidgetSize(nsPresContext*,
  64                                                    StyleAppearance aAppearance,
  65                                                    nsIFrame* aFrame) = 0;
  66   virtual Maybe<nsITheme::Transparency> GetScrollbarPartTransparency(
  67       nsIFrame* aFrame, StyleAppearance aAppearance) {
  68     return Nothing();
  69   }
  70
  71   bool IsScrollbarTrackOpaque(nsIFrame*);
  72   virtual sRGBColor ComputeScrollbarTrackColor(nsIFrame*, const ComputedStyle&,
  73                                                const DocumentState&,
  74                                                const Colors&);
  75   virtual sRGBColor ComputeScrollbarThumbColor(nsIFrame*, const ComputedStyle&,
  76                                                const ElementState&,
  77                                                const DocumentState&,
  78                                                const Colors&);
  79
  80   nscolor GetScrollbarButtonColor(nscolor aTrackColor, ElementState);
  81   Maybe<nscolor> GetScrollbarArrowColor(nscolor aButtonColor);
  82
  83   // Returned colors are button, arrow.
  84   virtual std::pair<sRGBColor, sRGBColor> ComputeScrollbarButtonColors(
  85       nsIFrame*, StyleAppearance, const ComputedStyle&, const ElementState&,
  86       const DocumentState&, const Colors&);
  87
  88   virtual bool PaintScrollbarButton(DrawTarget&, StyleAppearance,
  89                                     const LayoutDeviceRect&, ScrollbarKind,
  90                                     nsIFrame*, const ComputedStyle&,
  91                                     const ElementState&, const DocumentState&,
  92                                     const Colors&, const DPIRatio&);
  93
  94   virtual bool PaintScrollbarThumb(DrawTarget&, const LayoutDeviceRect&,
  95                                    ScrollbarKind, nsIFrame*,
  96                                    const ComputedStyle&, const ElementState&,
  97                                    const DocumentState&, const Colors&,
  98                                    const DPIRatio&) = 0;
  99   virtual bool PaintScrollbarThumb(WebRenderBackendData&,
 100                                    const LayoutDeviceRect&, ScrollbarKind,
 101                                    nsIFrame*, const ComputedStyle&,
 102                                    const ElementState&, const DocumentState&,
 103                                    const Colors&, const DPIRatio&) = 0;
 104
 105   template <typename PaintBackendData>
 106   bool DoPaintDefaultScrollbar(PaintBackendData&, const LayoutDeviceRect&,
 107                                ScrollbarKind, nsIFrame*, const ComputedStyle&,
 108                                const ElementState&, const DocumentState&,
 109                                const Colors&, const DPIRatio&);
 110   bool PaintScrollbar(DrawTarget&, const LayoutDeviceRect&, ScrollbarKind,
 111                       nsIFrame*, const ComputedStyle&, const ElementState&,
 112                       const DocumentState&, const Colors&, const DPIRatio&);
 113   bool PaintScrollbar(WebRenderBackendData&, const LayoutDeviceRect&,
 114                       ScrollbarKind, nsIFrame*, const ComputedStyle&,
 115                       const ElementState&, const DocumentState&, const Colors&,
 116                       const DPIRatio&);
 117
 118   virtual bool PaintScrollbarTrack(DrawTarget&, const LayoutDeviceRect&,
 119                                    ScrollbarKind, nsIFrame*,
 120                                    const ComputedStyle&, const DocumentState&,
 121                                    const Colors&, const DPIRatio&) {
 122     // Draw nothing by default. Subclasses can override this.
 123     return true;
 124   }
 125   virtual bool PaintScrollbarTrack(WebRenderBackendData&,
 126                                    const LayoutDeviceRect&, ScrollbarKind,
 127                                    nsIFrame*, const ComputedStyle&,
 128                                    const DocumentState&, const Colors&,
 129                                    const DPIRatio&) {
 130     // Draw nothing by default. Subclasses can override this.
 131     return true;
 132   }
 133
 134   template <typename PaintBackendData>
 135   bool DoPaintDefaultScrollCorner(PaintBackendData&, const LayoutDeviceRect&,
 136                                   ScrollbarKind, nsIFrame*,
 137                                   const ComputedStyle&, const DocumentState&,
 138                                   const Colors&, const DPIRatio&);
 139   virtual bool PaintScrollCorner(DrawTarget&, const LayoutDeviceRect&,
 140                                  ScrollbarKind, nsIFrame*, const ComputedStyle&,
 141                                  const DocumentState&, const Colors&,
 142                                  const DPIRatio&);
 143   virtual bool PaintScrollCorner(WebRenderBackendData&, const LayoutDeviceRect&,
 144                                  ScrollbarKind, nsIFrame*, const ComputedStyle&,
 145                                  const DocumentState&, const Colors&,
 146                                  const DPIRatio&);
 147
 148   virtual void RecomputeScrollbarParams() = 0;
 149
 150   virtual bool ShouldDrawScrollbarButtons() { return true; }
 151
 152   uint32_t GetHorizontalScrollbarHeight() const {
 153     return mHorizontalScrollbarHeight;
 154   }
 155   uint32_t GetVerticalScrollbarWidth() const { return mVerticalScrollbarWidth; }
 156
 157  protected:
 158   // For some kind of style differences a full virtual method is overkill, so we
 159   // store the kind here so we can branch on it if necessary.
 160   Kind mKind;
 161   uint32_t mHorizontalScrollbarHeight = 0;
 162   uint32_t mVerticalScrollbarWidth = 0;
 163 };
 164
 165 }  // namespace mozilla::widget
 166
 167 #endif