Perform check for text/content on recording context PicturePiles

Only implemented for now when USE_RECORDING_CONTEXT is enabled.  Standard
SkPicture PicturePile implementation defaults to hasText = hasContent = true.

Change-Id: I535b53151963bf8c415e420c1d5a789954e98cbf

2 files changed, 36 insertions, 2 deletions

diff --git a/Source/WebKit/android/jni/PicturePile.cpp b/Source/WebKit/android/jni/PicturePile.cpp
index b69c131..554bd1b 100644
--- a/Source/WebKit/android/jni/PicturePile.cpp
+++ b/Source/WebKit/android/jni/PicturePile.cpp
@@ -277,6 +277,24 @@ PrerenderedInval* PicturePile::prerenderedInvalForArea(const IntRect& area)
     return 0;
 }
 
+bool PicturePile::hasText() const
+{
+    for (size_t i = 0; i < m_pile.size(); i++) {
+        if (m_pile[i].hasText)
+            return true;
+    }
+    return false;
+}
+
+bool PicturePile::isEmpty() const
+{
+    for (size_t i = 0; i < m_pile.size(); i++) {
+        if (m_pile[i].picture)
+            return false;
+    }
+    return true;
+}
+
 #if USE_RECORDING_CONTEXT
 void PicturePile::drawPicture(SkCanvas* canvas, PictureContainer& pc)
 {
@@ -286,12 +304,18 @@ void PicturePile::drawPicture(SkCanvas* canvas, PictureContainer& pc)
 
 Picture* PicturePile::recordPicture(PicturePainter* painter, PictureContainer& pc)
 {
-    // TODO: Support? Not needed?
-    pc.prerendered.clear();
+    pc.prerendered.clear(); // TODO: Support? Not needed?
+
     Recording* picture = new Recording();
     WebCore::PlatformGraphicsContextRecording pgc(picture);
     WebCore::GraphicsContext gc(&pgc);
     painter->paintContents(&gc, pc.area);
+    pc.hasText = pgc.hasText();
+    if (pgc.isEmpty()) {
+        SkSafeUnref(picture);
+        picture = 0;
+    }
+
     return picture;
 }
 #else
@@ -336,6 +360,10 @@ Picture* PicturePile::recordPicture(PicturePainter* painter, PictureContainer& p
     WebCore::GraphicsContext gc(&pgc);
     ALOGV("painting picture: " INT_RECT_FORMAT, INT_RECT_ARGS(drawArea));
     painter->paintContents(&gc, drawArea);
+
+    // TODO: consider paint-time checking for these with SkPicture painting?
+    pc.hasText = true;
+
     SkSafeUnref(canvas);
     picture->endRecording();
     return picture;
diff --git a/Source/WebKit/android/jni/PicturePile.h b/Source/WebKit/android/jni/PicturePile.h
index a8175d9..f60a4b6 100644
--- a/Source/WebKit/android/jni/PicturePile.h
+++ b/Source/WebKit/android/jni/PicturePile.h
@@ -71,11 +71,13 @@ public:
     IntRect area;
     bool dirty;
     RefPtr<PrerenderedInval> prerendered;
+    bool hasText;
 
     PictureContainer(const IntRect& area)
         : picture(0)
         , area(area)
         , dirty(true)
+        , hasText(false)
     {}
 
     PictureContainer(const PictureContainer& other);
@@ -102,6 +104,10 @@ public:
     SkRegion& dirtyRegion() { return m_dirtyRegion; }
     PrerenderedInval* prerenderedInvalForArea(const IntRect& area);
 
+    // UI-side methods used to check content, after construction/updates are complete
+    bool hasText() const;
+    bool isEmpty() const;
+
 private:
     void applyWebkitInvals();
     void updatePicture(PicturePainter* painter, PictureContainer& container);