pdfviewer: All NulCanvas (does not draw operations), TrackDevice (trackes what pixels have been cha…

experimental/PdfViewer/SkTrackDevice.h

Index: experimental/PdfViewer/SkTrackDevice.h
===================================================================
--- experimental/PdfViewer/SkTrackDevice.h	(revision 0)
+++ experimental/PdfViewer/SkTrackDevice.h	(revision 0)
@@ -0,0 +1,177 @@
+#ifndef EXPERIMENTAL_PDFVIEWER_SKTRACKDEVICE_H_
+#define EXPERIMENTAL_PDFVIEWER_SKTRACKDEVICE_H_
+
+#include "SkDevice.h"
+#include "SkTracker.h"
+
+class SkTrackDevice : public SkDevice {
+public:
+    SK_DECLARE_INST_COUNT(SkTrackDevice)
+
+    SkTrackDevice(const SkBitmap& bitmap) : SkDevice(bitmap)
+                                          , fTracker(NULL) {}
+
+    SkTrackDevice(const SkBitmap& bitmap, const SkDeviceProperties& deviceProperties)
+        : SkDevice(bitmap, deviceProperties)
+        , fTracker(NULL) {}
+
+    SkTrackDevice(SkBitmap::Config config, int width, int height, bool isOpaque = false)
+        : SkDevice(config, width, height, isOpaque)
+        , fTracker(NULL) {}
+
+    SkTrackDevice(SkBitmap::Config config, int width, int height, bool isOpaque,
+                  const SkDeviceProperties& deviceProperties)
+        : SkDevice(config, width, height, isOpaque, deviceProperties)
+        , fTracker(NULL) {}
+
+    virtual ~SkTrackDevice() {}
+
+    void installTracker(SkTracker* tracker) {
+        fTracker = tracker;
+        fTracker->newFrame();
+    }
+
+protected:
+    virtual void clear(SkColor color) {
+        before();
+        INHERITED::clear(color);
+        after();
+    }
+
+    virtual void drawPaint(const SkDraw& dummy1, const SkPaint& paint) {
+        before();
+        INHERITED::drawPaint(dummy1, paint);
+        after();
+    }
+
+    virtual void drawPoints(const SkDraw& dummy1, SkCanvas::PointMode mode, size_t count,
+                            const SkPoint dummy2[], const SkPaint& paint) {
+        before();
+        INHERITED::drawPoints(dummy1, mode, count, dummy2, paint);
+        after();
+    }
+
+    virtual void drawRect(const SkDraw& dummy1, const SkRect& r,
+                          const SkPaint& paint) {
+        before();
+        INHERITED::drawRect(dummy1, r, paint);
+        after();
+    }
+
+
+    virtual void drawOval(const SkDraw& dummy1, const SkRect& oval,
+                          const SkPaint& paint) {
+        before();
+        INHERITED::drawOval(dummy1, oval, paint);
+        after();
+    }
+
+    virtual void drawRRect(const SkDraw& dummy1, const SkRRect& rr,
+                           const SkPaint& paint) {
+        before();
+        INHERITED::drawRRect(dummy1, rr, paint);
+        after();
+    }
+
+    virtual void drawPath(const SkDraw& dummy1, const SkPath& path,
+                          const SkPaint& paint,
+                          const SkMatrix* prePathMatrix = NULL,
+                          bool pathIsMutable = false) {
+        before();
+        INHERITED::drawPath(dummy1, path, paint, prePathMatrix, pathIsMutable);
+        after();
+    }
+
+    virtual void drawBitmap(const SkDraw& dummy1, const SkBitmap& bitmap,
+                            const SkIRect* srcRectOrNull,
+                            const SkMatrix& matrix, const SkPaint& paint) {
+        before();
+        INHERITED::drawBitmap(dummy1, bitmap, srcRectOrNull, matrix, paint);
+        after();
+    }
+
+    virtual void drawSprite(const SkDraw& dummy1, const SkBitmap& bitmap,
+                            int x, int y, const SkPaint& paint) {
+        before();
+        INHERITED::drawSprite(dummy1, bitmap, x, y, paint);
+        after();
+    }
+
+    virtual void drawBitmapRect(const SkDraw& dummy1, const SkBitmap& dummy2,
+                                const SkRect* srcOrNull, const SkRect& dst,
+                                const SkPaint& paint) {
+        before();
+        INHERITED::drawBitmapRect(dummy1, dummy2, srcOrNull, dst, paint);
+        after();
+    }
+
+    virtual void drawText(const SkDraw& dummy1, const void* text, size_t len,
+                          SkScalar x, SkScalar y, const SkPaint& paint) {
+        before();
+        INHERITED::drawText(dummy1, text, len, x, y, paint);
+        after();
+    }
+
+    virtual void drawPosText(const SkDraw& dummy1, const void* text, size_t len,
+                             const SkScalar pos[], SkScalar constY,
+                             int scalarsPerPos, const SkPaint& paint) {
+        before();
+        INHERITED::drawPosText(dummy1, text, len, pos, constY, scalarsPerPos, paint);
+        after();
+    }
+
+    virtual void drawTextOnPath(const SkDraw& dummy1, const void* text, size_t len,
+                                const SkPath& path, const SkMatrix* matrix,
+                                const SkPaint& paint)  {
+        before();
+        INHERITED::drawTextOnPath(dummy1, text, len, path, matrix, paint);
+        after();
+    }
+
+#ifdef SK_BUILD_FOR_ANDROID
+    virtual void drawPosTextOnPath(const SkDraw& draw, const void* text, size_t len,
+                                   const SkPoint pos[], const SkPaint& paint,
+                                   const SkPath& path, const SkMatrix* matrix)  {
+        before();
+        INHERITED::drawPosTextOnPath(draw, text, len, pos, paint, path, matrix);
+        after();
+    }
+#endif
+    virtual void drawVertices(const SkDraw& dummy1, SkCanvas::VertexMode dummy2, int vertexCount,
+                              const SkPoint verts[], const SkPoint texs[],
+                              const SkColor colors[], SkXfermode* xmode,
+                              const uint16_t indices[], int indexCount,
+                              const SkPaint& paint) {
+        before();
+        INHERITED::drawVertices(dummy1, dummy2, vertexCount,verts, texs,colors, xmode, indices, indexCount, paint);
+        after();
+    }
+
+    virtual void drawDevice(const SkDraw& dummy1, SkDevice* dummy2, int x, int y,
+                            const SkPaint& dummy3) {
+        before();
+        INHERITED::drawDevice(dummy1, dummy2, x, y, dummy3);
+        after();
+    }
+
+private:
+    void before() {
+        if (fTracker) {
+            fTracker->before(accessBitmap(false));
+        }
+    }
+
+    // any/all of the expected touched has to be changed, and all expected untouched must be intact
+    void after() {
+        if (fTracker) {
+            fTracker->after(accessBitmap(false));
+        }
+    }
+
+private:
+    SkTracker* fTracker;
+
+    typedef SkDevice INHERITED;
+};
+
+#endif  // EXPERIMENTAL_PDFVIEWER_SKTRACKDEVICE_H_