Web Animations CSS: Support animation of background-position and background-image

Source/core/css/resolver/AnimatedStyleBuilder.cpp

Index: Source/core/css/resolver/AnimatedStyleBuilder.cpp
diff --git a/Source/core/css/resolver/AnimatedStyleBuilder.cpp b/Source/core/css/resolver/AnimatedStyleBuilder.cpp
index 012e38707eb0adc708a814a1165207c686a119ce..9280bf72be1527775d8af67ae9f4c18ca9e28d74 100644
--- a/Source/core/css/resolver/AnimatedStyleBuilder.cpp
+++ b/Source/core/css/resolver/AnimatedStyleBuilder.cpp
@@ -38,6 +38,7 @@
 #include "core/animation/AnimatableLength.h"
 #include "core/animation/AnimatableLengthBox.h"
 #include "core/animation/AnimatableLengthSize.h"
+#include "core/animation/AnimatableRepeatable.h"
 #include "core/animation/AnimatableSVGLength.h"
 #include "core/animation/AnimatableSVGPaint.h"
 #include "core/animation/AnimatableShapeValue.h"
@@ -91,6 +92,47 @@ LengthSize animatableValueToLengthSize(const AnimatableValue* value, const Style
         animatableValueToLength(animatableLengthSize->height(), state, range));
 }
 
+void setLengthOnFillLayers(void (FillLayer::*setter)(Length), void (FillLayer::*clear)(), const AnimatableValue* value, StyleResolverState& state)
+{
+    FillLayer* fillLayer = state.style()->accessBackgroundLayers();
+    const Vector<RefPtr<AnimatableValue> >& values = toAnimatableRepeatable(value)->values();
+    ASSERT(!values.isEmpty());

[dstockwell, 2013/10/08 22:57:31]

I didn't see this assertion in the factory.

[alancutter (OOO until 2018), 2013/10/09 07:20:55]

Added assertion to factory.

+    FillLayer* prev = 0;
+    for (size_t i = 0; i < values.size(); ++i) {
+        if (!fillLayer) {
+            fillLayer = new FillLayer(BackgroundFillLayer);
+            prev->setNext(fillLayer);
+        }
+        (fillLayer->*setter)(animatableValueToLength(values[i].get(), state));
+        prev = fillLayer;
+        fillLayer = fillLayer->next();
+    }
+    while (fillLayer) {
+        (fillLayer->*clear)();
+        fillLayer = fillLayer->next();
+    }
+}
+
+void setImageOnFillLayers(FillLayer* fillLayer, const AnimatableValue* value)

[dstockwell, 2013/10/08 23:02:46]

and here, if we template on CSSPropertyID we should only need one method

[alancutter (OOO until 2018), 2013/10/09 07:20:55]

Done.

+{
+    const Vector<RefPtr<AnimatableValue> >& values = toAnimatableRepeatable(value)->values();
+    ASSERT(!values.isEmpty());
+    FillLayer* prev = 0;
+    for (size_t i = 0; i < values.size(); ++i) {
+        if (!fillLayer) {
+            fillLayer = new FillLayer(BackgroundFillLayer);
+            prev->setNext(fillLayer);
+        }
+        fillLayer->setImage(toAnimatableImage(values[i].get())->toStyleImage());
+        prev = fillLayer;
+        fillLayer = fillLayer->next();
+    }
+    while (fillLayer) {
+        fillLayer->clearImage();
+        fillLayer = fillLayer->next();
+    }
+}
+
 } // namespace
 
 // FIXME: Generate this function.
@@ -106,6 +148,15 @@ void AnimatedStyleBuilder::applyProperty(CSSPropertyID property, StyleResolverSt
         style->setBackgroundColor(toAnimatableColor(value)->color());
         style->setVisitedLinkBackgroundColor(toAnimatableColor(value)->visitedLinkColor());
         return;
+    case CSSPropertyBackgroundImage:
+        setImageOnFillLayers(style->accessBackgroundLayers(), value);
+        return;
+    case CSSPropertyBackgroundPositionX:
+        setLengthOnFillLayers(&FillLayer::setXPosition, &FillLayer::clearXPosition, value, state);
+        return;
+    case CSSPropertyBackgroundPositionY:
+        setLengthOnFillLayers(&FillLayer::setYPosition, &FillLayer::clearYPosition, value, state);
+        return;
     case CSSPropertyBaselineShift:
         style->setBaselineShiftValue(toAnimatableSVGLength(value)->toSVGLength());
         return;