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/EventStates.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 EventStates = mozilla::EventStates;
  24   using DrawTarget = mozilla::gfx::DrawTarget;
  25   using sRGBColor = mozilla::gfx::sRGBColor;
  26   using Colors = ThemeColors;
  27   using ScrollbarSizes = nsITheme::ScrollbarSizes;
  28   using Overlay = nsITheme::Overlay;
  29   using WebRenderBackendData = mozilla::widget::WebRenderBackendData;
  30
  31   enum class Kind : uint8_t {
  32     Android,
  33     Cocoa,
  34     Gtk,
  35     Win10,
  36     Win11,
  37   };
  38
  39  public:
  40   explicit ScrollbarDrawing(Kind aKind) : mKind(aKind) {}
  41   virtual ~ScrollbarDrawing() = default;
  42
  43   static DPIRatio GetDPIRatioForScrollbarPart(nsPresContext*);
  44
  45   static nsIFrame* GetParentScrollbarFrame(nsIFrame* aFrame);
  46   static bool IsParentScrollbarRolledOver(nsIFrame* aFrame);
  47   static bool IsParentScrollbarHoveredOrActive(nsIFrame* aFrame);
  48
  49   static bool IsScrollbarWidthThin(const ComputedStyle& aStyle);
  50   static bool IsScrollbarWidthThin(nsIFrame* aFrame);
  51
  52   virtual ScrollbarSizes GetScrollbarSizes(nsPresContext*, StyleScrollbarWidth,
  53                                            Overlay);
  54   ScrollbarSizes GetScrollbarSizes(nsPresContext*, nsIFrame*);
  55   virtual LayoutDeviceIntSize GetMinimumWidgetSize(nsPresContext*,
  56                                                    StyleAppearance aAppearance,
  57                                                    nsIFrame* aFrame) = 0;
  58   virtual Maybe<nsITheme::Transparency> GetScrollbarPartTransparency(
  59       nsIFrame* aFrame, StyleAppearance aAppearance) {
  60     return Nothing();
  61   }
  62
  63   bool IsScrollbarTrackOpaque(nsIFrame*);
  64   virtual sRGBColor ComputeScrollbarTrackColor(
  65       nsIFrame*, const ComputedStyle&, const EventStates& aDocumentState,
  66       const Colors&);
  67   virtual sRGBColor ComputeScrollbarThumbColor(
  68       nsIFrame*, const ComputedStyle&, const EventStates& aElementState,
  69       const EventStates& aDocumentState, const Colors&);
  70
  71   nscolor GetScrollbarButtonColor(nscolor aTrackColor, EventStates);
  72   Maybe<nscolor> GetScrollbarArrowColor(nscolor aButtonColor);
  73
  74   // Returned colors are button, arrow.
  75   virtual std::pair<sRGBColor, sRGBColor> ComputeScrollbarButtonColors(
  76       nsIFrame*, StyleAppearance, const ComputedStyle&,
  77       const EventStates& aElementState, const EventStates& aDocumentState,
  78       const Colors&);
  79
  80   virtual bool PaintScrollbarButton(DrawTarget&, StyleAppearance,
  81                                     const LayoutDeviceRect&, nsIFrame*,
  82                                     const ComputedStyle&,
  83                                     const EventStates& aElementState,
  84                                     const EventStates& aDocumentState,
  85                                     const Colors&, const DPIRatio&);
  86
  87   virtual bool PaintScrollbarThumb(DrawTarget&, const LayoutDeviceRect&,
  88                                    bool aHorizontal, nsIFrame*,
  89                                    const ComputedStyle&,
  90                                    const EventStates& aElementState,
  91                                    const EventStates& aDocumentState,
  92                                    const Colors&, const DPIRatio&) = 0;
  93   virtual bool PaintScrollbarThumb(WebRenderBackendData&,
  94                                    const LayoutDeviceRect&, bool aHorizontal,
  95                                    nsIFrame*, const ComputedStyle&,
  96                                    const EventStates& aElementState,
  97                                    const EventStates& aDocumentState,
  98                                    const Colors&, const DPIRatio&) = 0;
  99
 100   template <typename PaintBackendData>
 101   bool DoPaintDefaultScrollbar(PaintBackendData&, const LayoutDeviceRect&,
 102                                bool aHorizontal, nsIFrame*,
 103                                const ComputedStyle&,
 104                                const EventStates& aElementState,
 105                                const EventStates& aDocumentState, const Colors&,
 106                                const DPIRatio&);
 107   bool PaintScrollbar(DrawTarget&, const LayoutDeviceRect&, bool aHorizontal,
 108                       nsIFrame*, const ComputedStyle&,
 109                       const EventStates& aElementState,
 110                       const EventStates& aDocumentState, const Colors&,
 111                       const DPIRatio&);
 112   bool PaintScrollbar(WebRenderBackendData&, const LayoutDeviceRect&,
 113                       bool aHorizontal, nsIFrame*, const ComputedStyle&,
 114                       const EventStates& aElementState,
 115                       const EventStates& aDocumentState, const Colors&,
 116                       const DPIRatio&);
 117
 118   virtual bool PaintScrollbarTrack(DrawTarget&, const LayoutDeviceRect&,
 119                                    bool aHorizontal, nsIFrame*,
 120                                    const ComputedStyle&,
 121                                    const EventStates& aDocumentState,
 122                                    const Colors&, const DPIRatio&) {
 123     // Draw nothing by default. Subclasses can override this.
 124     return true;
 125   }
 126   virtual bool PaintScrollbarTrack(WebRenderBackendData&,
 127                                    const LayoutDeviceRect&, bool aHorizontal,
 128                                    nsIFrame*, const ComputedStyle&,
 129                                    const EventStates& aDocumentState,
 130                                    const Colors&, const DPIRatio&) {
 131     // Draw nothing by default. Subclasses can override this.
 132     return true;
 133   }
 134
 135   template <typename PaintBackendData>
 136   bool DoPaintDefaultScrollCorner(PaintBackendData&, const LayoutDeviceRect&,
 137                                   nsIFrame*, const ComputedStyle&,
 138                                   const EventStates& aDocumentState,
 139                                   const Colors&, const DPIRatio&);
 140   virtual bool PaintScrollCorner(DrawTarget&, const LayoutDeviceRect&,
 141                                  nsIFrame*, const ComputedStyle&,
 142                                  const EventStates& aDocumentState,
 143                                  const Colors&, const DPIRatio&);
 144   virtual bool PaintScrollCorner(WebRenderBackendData&, const LayoutDeviceRect&,
 145                                  nsIFrame*, const ComputedStyle&,
 146                                  const EventStates& aDocumentState,
 147                                  const Colors&, const DPIRatio&);
 148
 149   virtual void RecomputeScrollbarParams() = 0;
 150
 151   virtual bool ShouldDrawScrollbarButtons() { return true; }
 152
 153   uint32_t GetHorizontalScrollbarHeight() const {
 154     return mHorizontalScrollbarHeight;
 155   }
 156   uint32_t GetVerticalScrollbarWidth() const { return mVerticalScrollbarWidth; }
 157
 158  protected:
 159   // For some kind of style differences a full virtual method is overkill, so we
 160   // store the kind here so we can branch on it if necessary.
 161   Kind mKind;
 162   uint32_t mHorizontalScrollbarHeight = 0;
 163   uint32_t mVerticalScrollbarWidth = 0;
 164 };
 165
 166 }  // namespace mozilla::widget
 167
 168 #endif