1 files changed, 125 insertions, 0 deletions
diff --git a/widget/gtk/nsNativeBasicThemeGTK.cpp b/widget/gtk/nsNativeBasicThemeGTK.cpp
new file mode 100644
index 0000000000..cf32161c40
--- /dev/null
+++ b/widget/gtk/nsNativeBasicThemeGTK.cpp
@@ -0,0 +1,125 @@
+/* -*- 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 "nsNativeBasicThemeGTK.h"
+
+#include "nsLayoutUtils.h"
+
+using namespace mozilla;
+
+static constexpr CSSCoord kGtkMinimumScrollbarSize = 12;
+static constexpr CSSCoord kGtkMinimumThinScrollbarSize = 6;
+static constexpr CSSCoord kGtkMinimumScrollbarThumbSize = 40;
+
+already_AddRefed<nsITheme> do_GetBasicNativeThemeDoNotUseDirectly() {
+  static mozilla::StaticRefPtr<nsITheme> gInstance;
+  if (MOZ_UNLIKELY(!gInstance)) {
+    gInstance = new nsNativeBasicThemeGTK();
+    ClearOnShutdown(&gInstance);
+  }
+  return do_AddRef(gInstance);
+}
+
+nsITheme::Transparency nsNativeBasicThemeGTK::GetWidgetTransparency(
+    nsIFrame* aFrame, StyleAppearance aAppearance) {
+  switch (aAppearance) {
+    case StyleAppearance::ScrollbarVertical:
+    case StyleAppearance::ScrollbarHorizontal:
+      // Make scrollbar tracks opaque on the window's scroll frame to prevent
+      // leaf layers from overlapping. See bug 1179780.
+      return IsRootScrollbar(aFrame) ? eOpaque : eTransparent;
+    default:
+      return nsNativeBasicTheme::GetWidgetTransparency(aFrame, aAppearance);
+  }
+}
+
+NS_IMETHODIMP
+nsNativeBasicThemeGTK::GetMinimumWidgetSize(nsPresContext* aPresContext,
+                                            nsIFrame* aFrame,
+                                            StyleAppearance aAppearance,
+                                            LayoutDeviceIntSize* aResult,
+                                            bool* aIsOverridable) {
+  DPIRatio dpiRatio = GetDPIRatio(aFrame);
+
+  switch (aAppearance) {
+    case StyleAppearance::ScrollbarVertical:
+    case StyleAppearance::ScrollbarHorizontal:
+    case StyleAppearance::ScrollbarbuttonUp:
+    case StyleAppearance::ScrollbarbuttonDown:
+    case StyleAppearance::ScrollbarbuttonLeft:
+    case StyleAppearance::ScrollbarbuttonRight:
+    case StyleAppearance::ScrollbarthumbVertical:
+    case StyleAppearance::ScrollbarthumbHorizontal:
+    case StyleAppearance::ScrollbartrackHorizontal:
+    case StyleAppearance::ScrollbartrackVertical:
+    case StyleAppearance::Scrollcorner: {
+      ComputedStyle* style = nsLayoutUtils::StyleForScrollbar(aFrame);
+      if (style->StyleUIReset()->mScrollbarWidth == StyleScrollbarWidth::Thin) {
+        aResult->SizeTo(kGtkMinimumThinScrollbarSize * dpiRatio,
+                        kGtkMinimumThinScrollbarSize * dpiRatio);
+      } else {
+        aResult->SizeTo(kGtkMinimumScrollbarSize * dpiRatio,
+                        kGtkMinimumScrollbarSize * dpiRatio);
+      }
+      break;
+    }
+    default:
+      return nsNativeBasicTheme::GetMinimumWidgetSize(
+          aPresContext, aFrame, aAppearance, aResult, aIsOverridable);
+  }
+
+  switch (aAppearance) {
+    case StyleAppearance::ScrollbarthumbHorizontal:
+      aResult->width = kGtkMinimumScrollbarThumbSize * dpiRatio;
+      break;
+    case StyleAppearance::ScrollbarthumbVertical:
+      aResult->height = kGtkMinimumScrollbarThumbSize * dpiRatio;
+      break;
+    default:
+      break;
+  }
+
+  *aIsOverridable = true;
+  return NS_OK;
+}
+
+void nsNativeBasicThemeGTK::PaintScrollbarThumb(
+    DrawTarget* aDrawTarget, const LayoutDeviceRect& aRect, bool aHorizontal,
+    nsIFrame* aFrame, const ComputedStyle& aStyle,
+    const EventStates& aElementState, const EventStates& aDocumentState,
+    DPIRatio aDpiRatio) {
+  sRGBColor thumbColor =
+      ComputeScrollbarThumbColor(aFrame, aStyle, aElementState, aDocumentState);
+  LayoutDeviceRect thumbRect(aRect);
+  thumbRect.Deflate(floorf((aHorizontal ? aRect.height : aRect.width) / 4.0f));
+  LayoutDeviceCoord radius =
+      (aHorizontal ? thumbRect.height : thumbRect.width) / 2.0f;
+  PaintRoundedRectWithRadius(aDrawTarget, thumbRect, thumbColor, sRGBColor(), 0,
+                             radius / aDpiRatio, aDpiRatio);
+}
+
+void nsNativeBasicThemeGTK::PaintScrollbar(DrawTarget* aDrawTarget,
+                                           const LayoutDeviceRect& aRect,
+                                           bool aHorizontal, nsIFrame* aFrame,
+                                           const ComputedStyle& aStyle,
+                                           const EventStates& aDocumentState,
+                                           DPIRatio aDpiRatio, bool aIsRoot) {
+  auto [trackColor, borderColor] =
+      ComputeScrollbarColors(aFrame, aStyle, aDocumentState, aIsRoot);
+  Unused << borderColor;
+  aDrawTarget->FillRect(aRect.ToUnknownRect(),
+                        gfx::ColorPattern(ToDeviceColor(trackColor)));
+}
+
+void nsNativeBasicThemeGTK::PaintScrollCorner(
+    DrawTarget* aDrawTarget, const LayoutDeviceRect& aRect, nsIFrame* aFrame,
+    const ComputedStyle& aStyle, const EventStates& aDocumentState,
+    DPIRatio aDpiRatio, bool aIsRoot) {
+  auto [trackColor, borderColor] =
+      ComputeScrollbarColors(aFrame, aStyle, aDocumentState, aIsRoot);
+  Unused << borderColor;
+  aDrawTarget->FillRect(aRect.ToUnknownRect(),
+                        gfx::ColorPattern(ToDeviceColor(trackColor)));
+}