Aura overlay scrollbars adjust color for dark backgrounds

third_party/WebKit/Source/platform/scroll/ScrollableArea.cpp

 /*
  * Copyright (c) 2010, Google Inc. All rights reserved.
  * Copyright (C) 2008, 2011 Apple Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 56 matching lines @@
   return kMinFractionToStepWhenPaging;
 }
 
 int ScrollableArea::maxOverlapBetweenPages() {
   static int maxOverlapBetweenPages =
       ScrollbarTheme::theme().maxOverlapBetweenPages();
   return maxOverlapBetweenPages;
 }
 
 ScrollableArea::ScrollableArea()
-    : m_scrollbarOverlayStyle(ScrollbarOverlayStyleDefault),
+    : m_scrollbarOverlayColorTheme(ScrollbarOverlayColorThemeDark),
       m_scrollOriginChanged(false),
       m_horizontalScrollbarNeedsPaintInvalidation(false),
       m_verticalScrollbarNeedsPaintInvalidation(false),
       m_scrollCornerNeedsPaintInvalidation(false) {}
 
 ScrollableArea::~ScrollableArea() {}
 
 void ScrollableArea::clearScrollAnimators() {
 #if OS(MACOSX)
   if (m_scrollAnimator)
@@ skipping 268 matching lines @@
 
 void ScrollableArea::didAddScrollbar(Scrollbar& scrollbar,
                                      ScrollbarOrientation orientation) {
   if (orientation == VerticalScrollbar)
     scrollAnimator().didAddVerticalScrollbar(scrollbar);
   else
     scrollAnimator().didAddHorizontalScrollbar(scrollbar);
 
   // <rdar://problem/9797253> AppKit resets the scrollbar's style when you
   // attach a scrollbar
-  setScrollbarOverlayStyle(getScrollbarOverlayStyle());
+  setScrollbarOverlayColorTheme(getScrollbarOverlayColorTheme());
 }
 
 void ScrollableArea::willRemoveScrollbar(Scrollbar& scrollbar,
                                          ScrollbarOrientation orientation) {
   if (ScrollAnimatorBase* scrollAnimator = existingScrollAnimator()) {
     if (orientation == VerticalScrollbar)
       scrollAnimator->willRemoveVerticalScrollbar(scrollbar);
     else
       scrollAnimator->willRemoveHorizontalScrollbar(scrollbar);
   }
 }
 
 void ScrollableArea::contentsResized() {
   if (ScrollAnimatorBase* scrollAnimator = existingScrollAnimator())
     scrollAnimator->contentsResized();
 }
 
 bool ScrollableArea::hasOverlayScrollbars() const {
   Scrollbar* vScrollbar = verticalScrollbar();
   if (vScrollbar && vScrollbar->isOverlayScrollbar())
     return true;
   Scrollbar* hScrollbar = horizontalScrollbar();
   return hScrollbar && hScrollbar->isOverlayScrollbar();
 }
 
-void ScrollableArea::setScrollbarOverlayStyle(
-    ScrollbarOverlayStyle overlayStyle) {
-  m_scrollbarOverlayStyle = overlayStyle;
+void ScrollableArea::setScrollbarOverlayColorTheme(
+    ScrollbarOverlayColorTheme overlayTheme) {
+  m_scrollbarOverlayColorTheme = overlayTheme;
 
   if (Scrollbar* scrollbar = horizontalScrollbar()) {
-    ScrollbarTheme::theme().updateScrollbarOverlayStyle(*scrollbar);
+    ScrollbarTheme::theme().updateScrollbarOverlayColorTheme(*scrollbar);
     scrollbar->setNeedsPaintInvalidation(AllParts);
   }
 
   if (Scrollbar* scrollbar = verticalScrollbar()) {
-    ScrollbarTheme::theme().updateScrollbarOverlayStyle(*scrollbar);
+    ScrollbarTheme::theme().updateScrollbarOverlayColorTheme(*scrollbar);
     scrollbar->setNeedsPaintInvalidation(AllParts);
   }
 }
 
-void ScrollableArea::recalculateScrollbarOverlayStyle(Color backgroundColor) {
-  ScrollbarOverlayStyle oldOverlayStyle = getScrollbarOverlayStyle();
-  ScrollbarOverlayStyle overlayStyle = ScrollbarOverlayStyleDefault;
+void ScrollableArea::recalculateScrollbarOverlayColorTheme(
+    Color backgroundColor) {
+  ScrollbarOverlayColorTheme oldOverlayTheme = getScrollbarOverlayColorTheme();
+  ScrollbarOverlayColorTheme overlayTheme = ScrollbarOverlayColorThemeDark;
 
   // Reduce the background color from RGB to a lightness value
   // and determine which scrollbar style to use based on a lightness
   // heuristic.
   double hue, saturation, lightness;
   backgroundColor.getHSL(hue, saturation, lightness);
   if (lightness <= .5)
-    overlayStyle = ScrollbarOverlayStyleLight;
+    overlayTheme = ScrollbarOverlayColorThemeLight;
 
-  if (oldOverlayStyle != overlayStyle)
-    setScrollbarOverlayStyle(overlayStyle);
+  if (oldOverlayTheme != overlayTheme)
+    setScrollbarOverlayColorTheme(overlayTheme);
 }
 
 void ScrollableArea::setScrollbarNeedsPaintInvalidation(
     ScrollbarOrientation orientation) {
   if (orientation == HorizontalScrollbar) {
     if (GraphicsLayer* graphicsLayer = layerForHorizontalScrollbar()) {
       graphicsLayer->setNeedsDisplay();
       graphicsLayer->setContentsNeedsDisplay();
     }
     m_horizontalScrollbarNeedsPaintInvalidation = true;
@@ skipping 160 matching lines @@
   return IntSize(std::max(0, size.width() - verticalScrollbarWidth()),
                  std::max(0, size.height() - horizontalScrollbarHeight()));
 }
 
 DEFINE_TRACE(ScrollableArea) {
   visitor->trace(m_scrollAnimator);
   visitor->trace(m_programmaticScrollAnimator);
 }
 
 }  // namespace blink