add Tickmarks to aura overlay scrollbar

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

 /*
  * Copyright (C) 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 11 matching lines @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "platform/scroll/ScrollbarTheme.h"
 
 #include "platform/PlatformMouseEvent.h"
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/graphics/Color.h"
 #include "platform/graphics/GraphicsContext.h"
+#include "platform/graphics/GraphicsContextStateSaver.h"
 #include "platform/graphics/paint/CompositingRecorder.h"
 #include "platform/graphics/paint/CullRect.h"
 #include "platform/graphics/paint/DrawingDisplayItem.h"
 #include "platform/graphics/paint/DrawingRecorder.h"
 #include "platform/graphics/paint/PaintController.h"
 #include "platform/scroll/Scrollbar.h"
 #include "platform/scroll/ScrollbarThemeMock.h"
 #include "platform/scroll/ScrollbarThemeOverlayMock.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebPoint.h"
@@ skipping 174 matching lines @@
       WebThemeEngine::StateNormal, WebRect(cornerRect), 0);
 #endif
 }
 
 bool ScrollbarTheme::shouldCenterOnThumb(const ScrollbarThemeClient& scrollbar,
                                          const PlatformMouseEvent& evt) {
   return Platform::current()->scrollbarBehavior()->shouldCenterOnThumb(
       evt.pointerProperties().button, evt.shiftKey(), evt.altKey());
 }
 
+// Only ScrollbarThemeAura and ScrollbarThemeOverlay are using this method.
+void ScrollbarTheme::paintTickmarks(GraphicsContext& context,
+                                    const Scrollbar& scrollbar,
+                                    const IntRect& rect) {
+  if (scrollbar.orientation() != VerticalScrollbar)
+    return;
+
+  if (rect.height() <= 0 || rect.width() <= 0)
+    return;
+
+  // Get the tickmarks for the frameview.
+  Vector<IntRect> tickmarks;
+  scrollbar.getTickmarks(tickmarks);
+  if (!tickmarks.size())
+    return;
+
+  if (DrawingRecorder::useCachedDrawingIfPossible(
+          context, scrollbar, DisplayItem::kScrollbarTickmarks))
+    return;
+
+  DrawingRecorder recorder(context, scrollbar, DisplayItem::kScrollbarTickmarks,
+                           rect);
+  GraphicsContextStateSaver stateSaver(context);
+  context.setShouldAntialias(false);
+
+  for (Vector<IntRect>::const_iterator i = tickmarks.begin();
+       i != tickmarks.end(); ++i) {
+    // Calculate how far down (in %) the tick-mark should appear.
+    const float percent = static_cast<float>(i->y()) / scrollbar.totalSize();
+
+    // Calculate how far down (in pixels) the tick-mark should appear.
+    const int yPos = rect.y() + (rect.height() * percent);
+
+    FloatRect tickRect(rect.x(), yPos, rect.width(), 3);
+    context.fillRect(tickRect, Color(0xCC, 0xAA, 0x00, 0xFF));
+
+    FloatRect tickStroke(rect.x(), yPos + 1, rect.width(), 1);
+    context.fillRect(tickStroke, Color(0xFF, 0xDD, 0x00, 0xFF));
+  }
+}
+
 bool ScrollbarTheme::shouldSnapBackToDragOrigin(
     const ScrollbarThemeClient& scrollbar,
     const PlatformMouseEvent& evt) {
   IntPoint mousePosition = scrollbar.convertFromRootFrame(evt.position());
   mousePosition.move(scrollbar.x(), scrollbar.y());
   return Platform::current()->scrollbarBehavior()->shouldSnapBackToDragOrigin(
       mousePosition, trackRect(scrollbar),
       scrollbar.orientation() == HorizontalScrollbar);
 }
 
@@ skipping 155 matching lines @@
       return DisplayItem::kScrollbarBackTrack;
     case ForwardTrackPart:
       return DisplayItem::kScrollbarForwardTrack;
     default:
       ASSERT_NOT_REACHED();
       return DisplayItem::kScrollbarBackTrack;
   }
 }
 
 }  // namespace blink