1 files changed, 134 insertions, 0 deletions
diff --git a/widget/ScrollbarDrawingGTK.cpp b/widget/ScrollbarDrawingGTK.cpp
new file mode 100644
index 0000000000..15556cad35
--- /dev/null
+++ b/widget/ScrollbarDrawingGTK.cpp
@@ -0,0 +1,134 @@
+/* -*- Mode: C++; tab-width: 40; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "ScrollbarDrawingGTK.h"
+
+#include "mozilla/gfx/Helpers.h"
+#include "mozilla/StaticPrefs_widget.h"
+#include "nsLayoutUtils.h"
+#include "nsNativeTheme.h"
+
+using namespace mozilla;
+using namespace mozilla::gfx;
+using namespace mozilla::widget;
+
+LayoutDeviceIntSize ScrollbarDrawingGTK::GetMinimumWidgetSize(
+    nsPresContext* aPresContext, StyleAppearance aAppearance,
+    nsIFrame* aFrame) {
+  MOZ_ASSERT(nsNativeTheme::IsWidgetScrollbarPart(aAppearance));
+  auto sizes = GetScrollbarSizes(aPresContext, aFrame);
+  MOZ_ASSERT(sizes.mHorizontal == sizes.mVertical);
+  LayoutDeviceIntSize size{sizes.mHorizontal, sizes.mVertical};
+  if (aAppearance == StyleAppearance::ScrollbarHorizontal ||
+      aAppearance == StyleAppearance::ScrollbarVertical ||
+      aAppearance == StyleAppearance::ScrollbarthumbHorizontal ||
+      aAppearance == StyleAppearance::ScrollbarthumbVertical) {
+    CSSCoord thumbSize(
+        StaticPrefs::widget_non_native_theme_gtk_scrollbar_thumb_cross_size());
+    const bool isVertical =
+        aAppearance == StyleAppearance::ScrollbarVertical ||
+        aAppearance == StyleAppearance::ScrollbarthumbVertical;
+    auto dpi = GetDPIRatioForScrollbarPart(aPresContext);
+    if (isVertical) {
+      size.height = thumbSize * dpi;
+    } else {
+      size.width = thumbSize * dpi;
+    }
+  }
+  return size;
+}
+
+Maybe<nsITheme::Transparency> ScrollbarDrawingGTK::GetScrollbarPartTransparency(
+    nsIFrame* aFrame, StyleAppearance aAppearance) {
+  if (!aFrame->PresContext()->UseOverlayScrollbars() &&
+      (aAppearance == StyleAppearance::ScrollbarVertical ||
+       aAppearance == StyleAppearance::ScrollbarHorizontal) &&
+      IsScrollbarTrackOpaque(aFrame)) {
+    return Some(nsITheme::eOpaque);
+  }
+
+  return Nothing();
+}
+
+template <typename PaintBackendData>
+bool ScrollbarDrawingGTK::DoPaintScrollbarThumb(
+    PaintBackendData& aPaintData, const LayoutDeviceRect& aRect,
+    ScrollbarKind aScrollbarKind, nsIFrame* aFrame, const ComputedStyle& aStyle,
+    const ElementState& aElementState, const DocumentState& aDocumentState,
+    const Colors& aColors, const DPIRatio& aDpiRatio) {
+  sRGBColor thumbColor = ComputeScrollbarThumbColor(
+      aFrame, aStyle, aElementState, aDocumentState, aColors);
+
+  LayoutDeviceRect thumbRect(aRect);
+
+  const bool horizontal = aScrollbarKind == ScrollbarKind::Horizontal;
+  if (aFrame->PresContext()->UseOverlayScrollbars() &&
+      !ScrollbarDrawing::IsParentScrollbarHoveredOrActive(aFrame)) {
+    if (horizontal) {
+      thumbRect.height *= 0.5;
+      thumbRect.y += thumbRect.height;
+    } else {
+      thumbRect.width *= 0.5;
+      if (aScrollbarKind == ScrollbarKind::VerticalRight) {
+        thumbRect.x += thumbRect.width;
+      }
+    }
+  }
+
+  {
+    float factor = std::max(
+        0.0f,
+        1.0f - StaticPrefs::widget_non_native_theme_gtk_scrollbar_thumb_size());
+    thumbRect.Deflate((horizontal ? thumbRect.height : thumbRect.width) *
+                      factor);
+  }
+
+  LayoutDeviceCoord radius =
+      StaticPrefs::widget_non_native_theme_gtk_scrollbar_round_thumb()
+          ? (horizontal ? thumbRect.height : thumbRect.width) / 2.0f
+          : 0.0f;
+
+  ThemeDrawing::PaintRoundedRectWithRadius(aPaintData, thumbRect, thumbColor,
+                                           sRGBColor(), 0, radius / aDpiRatio,
+                                           aDpiRatio);
+  return true;
+}
+
+bool ScrollbarDrawingGTK::PaintScrollbarThumb(
+    DrawTarget& aDrawTarget, const LayoutDeviceRect& aRect,
+    ScrollbarKind aScrollbarKind, nsIFrame* aFrame, const ComputedStyle& aStyle,
+    const ElementState& aElementState, const DocumentState& aDocumentState,
+    const Colors& aColors, const DPIRatio& aDpiRatio) {
+  return DoPaintScrollbarThumb(aDrawTarget, aRect, aScrollbarKind, aFrame,
+                               aStyle, aElementState, aDocumentState, aColors,
+                               aDpiRatio);
+}
+
+bool ScrollbarDrawingGTK::PaintScrollbarThumb(
+    WebRenderBackendData& aWrData, const LayoutDeviceRect& aRect,
+    ScrollbarKind aScrollbarKind, nsIFrame* aFrame, const ComputedStyle& aStyle,
+    const ElementState& aElementState, const DocumentState& aDocumentState,
+    const Colors& aColors, const DPIRatio& aDpiRatio) {
+  return DoPaintScrollbarThumb(aWrData, aRect, aScrollbarKind, aFrame, aStyle,
+                               aElementState, aDocumentState, aColors,
+                               aDpiRatio);
+}
+
+bool ScrollbarDrawingGTK::ShouldDrawScrollbarButtons() {
+  if (StaticPrefs::widget_non_native_theme_enabled()) {
+    return StaticPrefs::widget_non_native_theme_gtk_scrollbar_allow_buttons();
+  }
+  return true;
+}
+
+void ScrollbarDrawingGTK::RecomputeScrollbarParams() {
+  uint32_t defaultSize = 12;
+  uint32_t overrideSize =
+      StaticPrefs::widget_non_native_theme_scrollbar_size_override();
+  if (overrideSize > 0) {
+    defaultSize = overrideSize;
+  }
+  mHorizontalScrollbarHeight = mVerticalScrollbarWidth = defaultSize;
+}