Paint media element's play button using padding.

third_party/WebKit/Source/core/paint/MediaControlsPainter.cpp

 /*
  * Copyright (C) 2009 Apple Inc.
  * Copyright (C) 2009 Google 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.
@@ skipping 71 matching lines @@
     // Return currentName or newName based on current or new playback.
     return platformResource(RuntimeEnabledFeatures::newMediaPlaybackUiEnabled() ? newName : currentName);
 }
 
 static bool hasSource(const HTMLMediaElement* mediaElement)
 {
     return mediaElement->networkState() != HTMLMediaElement::NETWORK_EMPTY
         && mediaElement->networkState() != HTMLMediaElement::NETWORK_NO_SOURCE;
 }
 
-static bool paintMediaButton(GraphicsContext* context, const IntRect& rect, Image* image, bool isEnabled = true)
+static FloatRect adjustRectForPadding(IntRect rect, const LayoutObject* object)

[philipj_slow, 2015/10/28 12:38:07]

It's surprising that it would be necessary to write this manually. If you ask
someone on the layout (eae@) or paint teams (chrishtr@) perhaps they can suggest
a better way.

 {
-    if (!RuntimeEnabledFeatures::newMediaPlaybackUiEnabled())
-        isEnabled = true; // New UI only.
+    FloatRect adjustedRect(rect);
+
+    if (!object)
+        return adjustedRect;
+
+    if (const ComputedStyle* style = object->style()) {
+        const float paddingLeft = style->paddingLeft().getFloatValue();
+        const float paddingTop = style->paddingTop().getFloatValue();
+        const float paddingRight = style->paddingRight().getFloatValue();
+        const float paddingBottom = style->paddingBottom().getFloatValue();
+        adjustedRect = FloatRect(rect.x() + paddingLeft,
+            rect.y() + paddingTop,
+            rect.width() - paddingLeft - paddingRight,
+            rect.height() - paddingTop - paddingBottom);
+    }
+
+    return adjustedRect;
+}
+
+static bool paintMediaButton(GraphicsContext* context, const IntRect& rect, Image* image, const LayoutObject* object, bool isEnabled)
+{
+    if (!RuntimeEnabledFeatures::newMediaPlaybackUiEnabled()) {
+        context->drawImage(image, rect);
+        return true;
+    }
+
+    FloatRect drawRect = adjustRectForPadding(rect, object);
 
     if (!isEnabled)
         context->beginLayer(kDisabledAlpha);
 
-    context->drawImage(image, rect);
+    context->drawImage(image, drawRect, FloatRect(FloatPoint(), FloatSize(image->size())));
 
     if (!isEnabled)
         context->endLayer();
 
     return true;
 }
 
+static bool paintMediaButton(GraphicsContext* context, const IntRect& rect, Image* image, bool isEnabled = true)
+{
+    return paintMediaButton(context, rect, image, 0, isEnabled);
+}
+
 bool MediaControlsPainter::paintMediaMuteButton(const LayoutObject& object, const PaintInfo& paintInfo, const IntRect& rect)
 {
     const HTMLMediaElement* mediaElement = toParentMediaElement(object);
     if (!mediaElement)
         return false;
 
     // The new UI uses "muted" and "not muted" only.
     static Image* soundLevel3 = platformResource("mediaplayerSoundLevel3",
         "mediaplayerSoundLevel3New");
     static Image* soundLevel2 = platformResource("mediaplayerSoundLevel2",
@@ skipping 26 matching lines @@
     if (!mediaElement)
         return false;
 
     static Image* mediaPlay = platformResource("mediaplayerPlay", "mediaplayerPlayNew");
     static Image* mediaPause = platformResource("mediaplayerPause", "mediaplayerPauseNew");
     // For this case, the new UI draws the normal icon, but the entire panel
     // grays out.
     static Image* mediaPlayDisabled = platformResource("mediaplayerPlayDisabled", "mediaplayerPlayNew");
 
     if (!hasSource(mediaElement))
-        return paintMediaButton(paintInfo.context, rect, mediaPlayDisabled, false);
+        return paintMediaButton(paintInfo.context, rect, mediaPlayDisabled, &object, false);
 
     Image * image = !object.node()->isMediaControlElement() || mediaControlElementType(object.node()) == MediaPlayButton ? mediaPlay : mediaPause;
-    return paintMediaButton(paintInfo.context, rect, image);
+    return paintMediaButton(paintInfo.context, rect, image, &object, true);
 }
 
 bool MediaControlsPainter::paintMediaOverlayPlayButton(const LayoutObject& object, const PaintInfo& paintInfo, const IntRect& rect)
 {
     const HTMLMediaElement* mediaElement = toParentMediaElement(object);
     if (!mediaElement)
         return false;
 
     if (!hasSource(mediaElement) || !mediaElement->paused())
         return false;
@@ skipping 402 matching lines @@
     }
 
     float zoomLevel = style.effectiveZoom();
     if (thumbImage) {
         style.setWidth(Length(static_cast<int>(width * zoomLevel), Fixed));
         style.setHeight(Length(static_cast<int>(height * zoomLevel), Fixed));
     }
 }
 
 } // namespace blink