widget/ScrollbarDrawingGTK.cpp

   1 /* -*- Mode: C++; tab-width: 40; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "ScrollbarDrawingGTK.h"
   7
   8 #include "mozilla/gfx/Helpers.h"
   9 #include "mozilla/StaticPrefs_widget.h"
  10 #include "nsLayoutUtils.h"
  11 #include "nsNativeTheme.h"
  12
  13 using namespace mozilla;
  14 using namespace mozilla::gfx;
  15 using namespace mozilla::widget;
  16
  17 LayoutDeviceIntSize ScrollbarDrawingGTK::GetMinimumWidgetSize(
  18     nsPresContext* aPresContext, StyleAppearance aAppearance,
  19     nsIFrame* aFrame) {
  20   MOZ_ASSERT(nsNativeTheme::IsWidgetScrollbarPart(aAppearance));
  21   auto scrollbarSize = GetScrollbarSize(aPresContext, aFrame);
  22   LayoutDeviceIntSize size{scrollbarSize, scrollbarSize};
  23   if (aAppearance == StyleAppearance::ScrollbarHorizontal ||
  24       aAppearance == StyleAppearance::ScrollbarVertical ||
  25       aAppearance == StyleAppearance::ScrollbarthumbHorizontal ||
  26       aAppearance == StyleAppearance::ScrollbarthumbVertical) {
  27     CSSCoord thumbSize(
  28         StaticPrefs::widget_non_native_theme_gtk_scrollbar_thumb_cross_size());
  29     const bool isVertical =
  30         aAppearance == StyleAppearance::ScrollbarVertical ||
  31         aAppearance == StyleAppearance::ScrollbarthumbVertical;
  32     auto dpi = GetDPIRatioForScrollbarPart(aPresContext);
  33     if (isVertical) {
  34       size.height = thumbSize * dpi;
  35     } else {
  36       size.width = thumbSize * dpi;
  37     }
  38   }
  39   return size;
  40 }
  41
  42 Maybe<nsITheme::Transparency> ScrollbarDrawingGTK::GetScrollbarPartTransparency(
  43     nsIFrame* aFrame, StyleAppearance aAppearance) {
  44   if (!aFrame->PresContext()->UseOverlayScrollbars() &&
  45       (aAppearance == StyleAppearance::ScrollbarVertical ||
  46        aAppearance == StyleAppearance::ScrollbarHorizontal) &&
  47       IsScrollbarTrackOpaque(aFrame)) {
  48     return Some(nsITheme::eOpaque);
  49   }
  50
  51   return Nothing();
  52 }
  53
  54 template <typename PaintBackendData>
  55 bool ScrollbarDrawingGTK::DoPaintScrollbarThumb(
  56     PaintBackendData& aPaintData, const LayoutDeviceRect& aRect,
  57     ScrollbarKind aScrollbarKind, nsIFrame* aFrame, const ComputedStyle& aStyle,
  58     const ElementState& aElementState, const DocumentState& aDocumentState,
  59     const Colors& aColors, const DPIRatio& aDpiRatio) {
  60   sRGBColor thumbColor = ComputeScrollbarThumbColor(
  61       aFrame, aStyle, aElementState, aDocumentState, aColors);
  62
  63   LayoutDeviceRect thumbRect(aRect);
  64
  65   const bool horizontal = aScrollbarKind == ScrollbarKind::Horizontal;
  66   if (aFrame->PresContext()->UseOverlayScrollbars() &&
  67       !ScrollbarDrawing::IsParentScrollbarHoveredOrActive(aFrame)) {
  68     if (horizontal) {
  69       thumbRect.height *= 0.5;
  70       thumbRect.y += thumbRect.height;
  71     } else {
  72       thumbRect.width *= 0.5;
  73       if (aScrollbarKind == ScrollbarKind::VerticalRight) {
  74         thumbRect.x += thumbRect.width;
  75       }
  76     }
  77   }
  78
  79   {
  80     float factor = std::max(
  81         0.0f,
  82         1.0f - StaticPrefs::widget_non_native_theme_gtk_scrollbar_thumb_size());
  83     thumbRect.Deflate((horizontal ? thumbRect.height : thumbRect.width) *
  84                       factor);
  85   }
  86
  87   LayoutDeviceCoord radius =
  88       StaticPrefs::widget_non_native_theme_gtk_scrollbar_round_thumb()
  89           ? (horizontal ? thumbRect.height : thumbRect.width) / 2.0f
  90           : 0.0f;
  91
  92   ThemeDrawing::PaintRoundedRectWithRadius(aPaintData, thumbRect, thumbColor,
  93                                            sRGBColor(), 0, radius / aDpiRatio,
  94                                            aDpiRatio);
  95   return true;
  96 }
  97
  98 bool ScrollbarDrawingGTK::PaintScrollbarThumb(
  99     DrawTarget& aDrawTarget, const LayoutDeviceRect& aRect,
 100     ScrollbarKind aScrollbarKind, nsIFrame* aFrame, const ComputedStyle& aStyle,
 101     const ElementState& aElementState, const DocumentState& aDocumentState,
 102     const Colors& aColors, const DPIRatio& aDpiRatio) {
 103   return DoPaintScrollbarThumb(aDrawTarget, aRect, aScrollbarKind, aFrame,
 104                                aStyle, aElementState, aDocumentState, aColors,
 105                                aDpiRatio);
 106 }
 107
 108 bool ScrollbarDrawingGTK::PaintScrollbarThumb(
 109     WebRenderBackendData& aWrData, const LayoutDeviceRect& aRect,
 110     ScrollbarKind aScrollbarKind, nsIFrame* aFrame, const ComputedStyle& aStyle,
 111     const ElementState& aElementState, const DocumentState& aDocumentState,
 112     const Colors& aColors, const DPIRatio& aDpiRatio) {
 113   return DoPaintScrollbarThumb(aWrData, aRect, aScrollbarKind, aFrame, aStyle,
 114                                aElementState, aDocumentState, aColors,
 115                                aDpiRatio);
 116 }
 117
 118 bool ScrollbarDrawingGTK::ShouldDrawScrollbarButtons() {
 119   if (StaticPrefs::widget_non_native_theme_enabled()) {
 120     return StaticPrefs::widget_non_native_theme_gtk_scrollbar_allow_buttons();
 121   }
 122   return true;
 123 }
 124
 125 void ScrollbarDrawingGTK::RecomputeScrollbarParams() {
 126   uint32_t defaultSize = 12;
 127   uint32_t overrideSize =
 128       StaticPrefs::widget_non_native_theme_scrollbar_size_override();
 129   if (overrideSize > 0) {
 130     defaultSize = overrideSize;
 131   }
 132   ConfigureScrollbarSize(defaultSize);
 133 }