Don't pass pictures with no content to UI thread

bug:5748182

Adjusted text detection logic to also simply detect content, and moved to a
separate class. No content means a picture is not attached to the layer, and a PaintedSurface isn't allocated to the layer on the UI side.

Most commonly, this avoids allocating textures for the clipping element for an
overscroll div, but only if it has nothing to paint.

Change-Id: I5e57d497780c0532e0f28ac94b7ced3de9718e92

6 files changed, 266 insertions, 89 deletions

diff --git a/Source/WebCore/Android.mk b/Source/WebCore/Android.mk
index aa8ffe6..d731082 100644
--- a/Source/WebCore/Android.mk
+++ b/Source/WebCore/Android.mk
@@ -659,6 +659,7 @@ LOCAL_SRC_FILES := $(LOCAL_SRC_FILES) \
 	platform/graphics/android/ImageSourceAndroid.cpp \
 	platform/graphics/android/ImagesManager.cpp \
 	platform/graphics/android/ImageTexture.cpp \
+	platform/graphics/android/InspectorCanvas.cpp \
 	platform/graphics/android/Layer.cpp \
 	platform/graphics/android/LayerAndroid.cpp \
 	platform/graphics/android/MediaLayer.cpp \
diff --git a/Source/WebCore/platform/graphics/android/GraphicsLayerAndroid.cpp b/Source/WebCore/platform/graphics/android/GraphicsLayerAndroid.cpp
index ef74521..80819cc 100644
--- a/Source/WebCore/platform/graphics/android/GraphicsLayerAndroid.cpp
+++ b/Source/WebCore/platform/graphics/android/GraphicsLayerAndroid.cpp
@@ -573,7 +573,7 @@ bool GraphicsLayerAndroid::repaint()
             phase.set(GraphicsLayerPaintBackground);
             if (!paintContext(m_contentLayer->recordContext(), layerBounds))
                 return false;
-            m_contentLayer->checkTextPresence();
+            m_contentLayer->checkForPictureOptimizations();
 
             // Construct the foreground layer and draw.
             RenderBox* box = layer->renderBox();
@@ -592,7 +592,7 @@ bool GraphicsLayerAndroid::repaint()
             layer->scrollToOffset(0, 0);
             // At this point, it doesn't matter if painting failed.
             (void) paintContext(m_foregroundLayer->recordContext(), contentsRect);
-            m_foregroundLayer->checkTextPresence();
+            m_foregroundLayer->checkForPictureOptimizations();
             layer->scrollToOffset(scroll.width(), scroll.height());
 
             // Construct the clip layer for masking the contents.
@@ -625,7 +625,7 @@ bool GraphicsLayerAndroid::repaint()
             // picture.
             if (!paintContext(m_contentLayer->recordContext(), layerBounds))
                 return false;
-            m_contentLayer->checkTextPresence();
+            m_contentLayer->checkForPictureOptimizations();
             // Check for a scrollable iframe and report the scrolling
             // limits based on the view size.
             if (m_contentLayer->contentIsScrollable()) {
diff --git a/Source/WebCore/platform/graphics/android/InspectorCanvas.cpp b/Source/WebCore/platform/graphics/android/InspectorCanvas.cpp
new file mode 100644
index 0000000..0137cec
--- /dev/null
+++ b/Source/WebCore/platform/graphics/android/InspectorCanvas.cpp
@@ -0,0 +1,149 @@
+/*
+ * Copyright 2011, The Android Open Source Project
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (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 "config.h"
+#include "InspectorCanvas.h"
+
+#include "SkPicture.h"
+
+#include <cutils/log.h>
+#include <wtf/CurrentTime.h>
+#include <wtf/text/CString.h>
+
+#undef XLOGC
+#define XLOGC(...) android_printLog(ANDROID_LOG_DEBUG, "InspectorCanvas", __VA_ARGS__)
+
+#ifdef DEBUG
+
+#undef XLOG
+#define XLOG(...) android_printLog(ANDROID_LOG_DEBUG, "InspectorCanvas", __VA_ARGS__)
+
+#else
+
+#undef XLOG
+#define XLOG(...)
+
+#endif // DEBUG
+
+
+namespace WebCore {
+
+
+void InspectorCanvas::setHasText()
+{
+    m_hasText = true;
+    setHasContent();
+}
+
+void InspectorCanvas::setHasContent()
+{
+    m_hasContent = true;
+    if (m_hasText) {
+        // has text. Have to paint properly, so no further
+        // information is useful
+        m_picture->abortPlayback();
+    }
+}
+
+void InspectorCanvas::setIsBackground(const SkPaint& paint)
+{
+    // TODO: if the paint is a solid color, opaque, and the last instruction in
+    // the picture, replace the picture with simple draw rect info
+    setHasContent();
+}
+
+void InspectorCanvas::commonDrawBitmap(const SkBitmap& bitmap,
+                                       const SkIRect* rect,
+                                       const SkMatrix&,
+                                       const SkPaint&)
+{
+    setHasContent();
+}
+
+void InspectorCanvas::drawPaint(const SkPaint& paint)
+{
+    setHasContent();
+}
+
+void InspectorCanvas::drawPath(const SkPath&, const SkPaint& paint)
+{
+    setHasContent();
+}
+void InspectorCanvas::drawPoints(PointMode, size_t,
+                                 const SkPoint [], const SkPaint& paint)
+{
+    setHasContent();
+}
+
+void InspectorCanvas::drawRect(const SkRect& rect, const SkPaint& paint)
+{
+    if (rect.fLeft == 0
+            && rect.fTop == 0
+            && rect.width() >= m_picture->width()
+            && rect.height() >= m_picture->height()) {
+        // rect same size as canvas, treat layer as a single color rect until
+        // more content is drawn
+        setIsBackground(paint);
+    } else {
+        // regular rect drawing path
+        setHasContent();
+    }
+    XLOG("draw rect at %f %f, size %f %f, picture size %d %d",
+         rect.fLeft, rect.fTop, rect.width(), rect.height(),
+         m_picture->width(), m_picture->height());
+}
+void InspectorCanvas::drawSprite(const SkBitmap& , int , int ,
+                                 const SkPaint* paint)
+{
+    setHasContent();
+}
+
+void InspectorCanvas::drawText(const void*, size_t byteLength, SkScalar,
+                               SkScalar, const SkPaint& paint)
+{
+    setHasText();
+}
+
+void InspectorCanvas::drawPosText(const void* , size_t byteLength,
+                                  const SkPoint [], const SkPaint& paint)
+{
+    setHasText();
+}
+
+void InspectorCanvas::drawPosTextH(const void*, size_t byteLength,
+                                   const SkScalar [], SkScalar,
+                                   const SkPaint& paint)
+{
+    setHasText();
+}
+
+void InspectorCanvas::drawTextOnPath(const void*, size_t byteLength,
+                                     const SkPath&, const SkMatrix*,
+                                     const SkPaint& paint)
+{
+    setHasText();
+}
+
+} // namespace WebCore
diff --git a/Source/WebCore/platform/graphics/android/InspectorCanvas.h b/Source/WebCore/platform/graphics/android/InspectorCanvas.h
new file mode 100644
index 0000000..415a579
--- /dev/null
+++ b/Source/WebCore/platform/graphics/android/InspectorCanvas.h
@@ -0,0 +1,102 @@
+/*
+ * Copyright 2011, The Android Open Source Project
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef InspectorCanvas_h
+#define InspectorCanvas_h
+
+#include "SkBounder.h"
+#include "SkCanvas.h"
+
+namespace WebCore {
+
+class InspectorBounder : public SkBounder {
+    virtual bool onIRect(const SkIRect& rect)
+    {
+        return false;
+    }
+};
+
+class InspectorCanvas : public SkCanvas {
+public:
+    InspectorCanvas(SkBounder* bounder, SkPicture* picture)
+        : m_picture(picture)
+        , m_hasText(false)
+        , m_hasContent(false)
+    {
+        setBounder(bounder);
+    }
+
+    bool hasText() {return m_hasText;}
+    bool hasContent() {return m_hasContent;}
+
+    virtual bool clipPath(const SkPath&, SkRegion::Op) {
+        return true;
+    }
+
+    virtual void commonDrawBitmap(const SkBitmap& bitmap,
+                                  const SkIRect* rect,
+                                  const SkMatrix&,
+                                  const SkPaint&);
+
+    virtual void drawPaint(const SkPaint& paint);
+    virtual void drawPath(const SkPath&, const SkPaint& paint);
+    virtual void drawPoints(PointMode, size_t,
+                            const SkPoint [], const SkPaint& paint);
+
+    virtual void drawRect(const SkRect& , const SkPaint& paint);
+    virtual void drawSprite(const SkBitmap& , int , int ,
+                            const SkPaint* paint = NULL);
+
+    virtual void drawText(const void*, size_t byteLength, SkScalar,
+                          SkScalar, const SkPaint& paint);
+    virtual void drawPosText(const void* , size_t byteLength,
+                             const SkPoint [], const SkPaint& paint);
+    virtual void drawPosTextH(const void*, size_t byteLength,
+                              const SkScalar [], SkScalar,
+                              const SkPaint& paint);
+    virtual void drawTextOnPath(const void*, size_t byteLength,
+                                const SkPath&, const SkMatrix*,
+                                const SkPaint& paint);
+
+private:
+
+    // vector instructions exist, must repaint at any scale
+    void setHasText();
+
+    // painting is required
+    void setHasContent();
+
+    // rect covering entire content, don't need to use a texture if nothing else
+    // is painted
+    void setIsBackground(const SkPaint& paint);
+
+    SkPicture* m_picture;
+    bool m_hasText;
+    bool m_hasContent;
+};
+
+} // namespace WebCore
+
+#endif // InspectorCanvas_h
diff --git a/Source/WebCore/platform/graphics/android/LayerAndroid.cpp b/Source/WebCore/platform/graphics/android/LayerAndroid.cpp
index 962bcdf..25c5e7b 100644
--- a/Source/WebCore/platform/graphics/android/LayerAndroid.cpp
+++ b/Source/WebCore/platform/graphics/android/LayerAndroid.cpp
@@ -8,11 +8,11 @@
 #include "DrawExtra.h"
 #include "GLUtils.h"
 #include "ImagesManager.h"
+#include "InspectorCanvas.h"
 #include "MediaLayer.h"
 #include "PaintedSurface.h"
 #include "ParseCanvas.h"
 #include "SkBitmapRef.h"
-#include "SkBounder.h"
 #include "SkDrawFilter.h"
 #include "SkPaint.h"
 #include "SkPicture.h"
@@ -55,87 +55,6 @@ private:
     int m_opacity;
 };
 
-class HasTextBounder : public SkBounder {
-    virtual bool onIRect(const SkIRect& rect)
-    {
-        return false;
-    }
-};
-
-class HasTextCanvas : public SkCanvas {
-public:
-    HasTextCanvas(SkBounder* bounder, SkPicture* picture)
-        : m_picture(picture)
-        , m_hasText(false)
-    {
-        setBounder(bounder);
-    }
-
-    void setHasText()
-    {
-        m_hasText = true;
-        m_picture->abortPlayback();
-    }
-
-    bool hasText()
-    {
-        return m_hasText;
-    }
-
-    virtual bool clipPath(const SkPath&, SkRegion::Op) {
-        return true;
-    }
-
-    virtual void commonDrawBitmap(const SkBitmap& bitmap,
-                                  const SkIRect* rect,
-                                  const SkMatrix&,
-                                  const SkPaint&) {}
-
-    virtual void drawPaint(const SkPaint& paint) {}
-    virtual void drawPath(const SkPath&, const SkPaint& paint) {}
-    virtual void drawPoints(PointMode, size_t,
-                            const SkPoint [], const SkPaint& paint) {}
-
-    virtual void drawRect(const SkRect& , const SkPaint& paint) {}
-    virtual void drawSprite(const SkBitmap& , int , int ,
-                            const SkPaint* paint = NULL) {}
-
-    virtual void drawText(const void*, size_t byteLength, SkScalar,
-                          SkScalar, const SkPaint& paint)
-    {
-        setHasText();
-    }
-
-    virtual void drawPosText(const void* , size_t byteLength,
-                             const SkPoint [], const SkPaint& paint)
-    {
-        setHasText();
-    }
-
-    virtual void drawPosTextH(const void*, size_t byteLength,
-                              const SkScalar [], SkScalar,
-                              const SkPaint& paint)
-    {
-        setHasText();
-    }
-
-    virtual void drawTextOnPath(const void*, size_t byteLength,
-                                const SkPath&, const SkMatrix*,
-                                const SkPaint& paint)
-    {
-        setHasText();
-    }
-
-    virtual void drawPicture(SkPicture& picture) {
-        SkCanvas::drawPicture(picture);
-    }
-
-private:
-
-    SkPicture* m_picture;
-    bool m_hasText;
-};
-
 ///////////////////////////////////////////////////////////////////////////////
 
 LayerAndroid::LayerAndroid(RenderLayer* owner) : Layer(),
@@ -226,13 +145,13 @@ LayerAndroid::LayerAndroid(const LayerAndroid& layer) : Layer(layer),
 #endif
 }
 
-void LayerAndroid::checkTextPresence()
+void LayerAndroid::checkForPictureOptimizations()
 {
     if (m_recordingPicture) {
         // Let's check if we have text or not. If we don't, we can limit
         // ourselves to scale 1!
-        HasTextBounder hasTextBounder;
-        HasTextCanvas checker(&hasTextBounder, m_recordingPicture);
+        InspectorBounder inspectorBounder;
+        InspectorCanvas checker(&inspectorBounder, m_recordingPicture);
         SkBitmap bitmap;
         bitmap.setConfig(SkBitmap::kARGB_8888_Config,
                          m_recordingPicture->width(),
@@ -240,6 +159,12 @@ void LayerAndroid::checkTextPresence()
         checker.setBitmapDevice(bitmap);
         checker.drawPicture(*m_recordingPicture);
         m_hasText = checker.hasText();
+        if (!checker.hasContent()) {
+            // no content to draw, discard picture so UI / tile generation
+            // doesn't bother with it
+            SkSafeUnref(m_recordingPicture);
+            m_recordingPicture = 0;
+        }
     }
 }
 
diff --git a/Source/WebCore/platform/graphics/android/LayerAndroid.h b/Source/WebCore/platform/graphics/android/LayerAndroid.h
index c1f1bc9..d6e1e9a 100644
--- a/Source/WebCore/platform/graphics/android/LayerAndroid.h
+++ b/Source/WebCore/platform/graphics/android/LayerAndroid.h
@@ -302,7 +302,7 @@ public:
     int type() { return m_type; }
 
     bool hasText() { return m_hasText; }
-    void checkTextPresence();
+    void checkForPictureOptimizations();
 
     void copyAnimationStartTimesRecursive(LayerAndroid* oldTree);