Fix find-in-page to scroll scrollable layers

This requires the addition of the following methods ...
- Layer::contentIsScrollable()
- Layer::localToParent()
- ScrollableLayerAndroid::scrollRectIntoView()

Bug: 5262656
Change-Id: I2f1cf3342f73890f98a172f1b4e3f440c02dd9f4

1 files changed, 29 insertions, 0 deletions

diff --git a/Source/WebCore/platform/graphics/android/ScrollableLayerAndroid.cpp b/Source/WebCore/platform/graphics/android/ScrollableLayerAndroid.cpp
index 2bb8b5c..bca2fd4 100644
--- a/Source/WebCore/platform/graphics/android/ScrollableLayerAndroid.cpp
+++ b/Source/WebCore/platform/graphics/android/ScrollableLayerAndroid.cpp
@@ -31,6 +31,35 @@ void ScrollableLayerAndroid::getScrollRect(SkIRect* out) const
     out->fBottom = getSize().height() - m_scrollLimits.height();
 }
 
+bool ScrollableLayerAndroid::scrollRectIntoView(const SkIRect& rect)
+{
+    // Apply the local transform to the rect to get it relative to the parent
+    // layer.
+    SkMatrix localTransform;
+    getLocalTransform(&localTransform);
+    SkRect transformedRect;
+    transformedRect.set(rect);
+    localTransform.mapRect(&transformedRect);
+
+    // Test left before right to prioritize left alignment if transformedRect is wider than
+    // visible area.
+    int x = m_scrollLimits.fLeft;
+    if (transformedRect.fLeft < m_scrollLimits.fLeft)
+        x = transformedRect.fLeft;
+    else if (transformedRect.fRight > m_scrollLimits.fRight)
+        x = transformedRect.fRight - std::max(m_scrollLimits.width(), transformedRect.width());
+
+    // Test top before bottom to prioritize top alignment if transformedRect is taller than
+    // visible area.
+    int y = m_scrollLimits.fTop;
+    if (transformedRect.fTop < m_scrollLimits.fTop)
+        y = transformedRect.fTop;
+    else if (transformedRect.fBottom > m_scrollLimits.fBottom)
+        y = transformedRect.fBottom - std::max(m_scrollLimits.height(), transformedRect.height());
+
+    return scrollTo(x - getPosition().fX, y - getPosition().fY);
+}
+
 } // namespace WebCore
 
 #endif // USE(ACCELERATED_COMPOSITING)