Implement touch control

tools/viewer/Viewer.cpp

Index: tools/viewer/Viewer.cpp
diff --git a/tools/viewer/Viewer.cpp b/tools/viewer/Viewer.cpp
index 7dd265e6e2183cd75c4e726410be8a845aa12d41..49fc6dccebf5b78fb11e5383cca54418a05ae4af 100644
--- a/tools/viewer/Viewer.cpp
+++ b/tools/viewer/Viewer.cpp
@@ -112,7 +112,6 @@ Viewer::Viewer(int argc, char** argv, void* platformData)
     // set up first frame
     fCurrentSlide = 0;
     setupCurrentSlide(-1);
-    updateMatrix();
 
     fWindow->show();
 }
@@ -205,10 +204,9 @@ void Viewer::changeZoomLevel(float delta) {
     } else {
         fZoomScale = SK_Scalar1;
     }
-    this->updateMatrix();
 }
 
-void Viewer::updateMatrix(){
+SkMatrix Viewer::computeMatrix() {
     SkMatrix m;
     m.reset();
 
@@ -224,12 +222,10 @@ void Viewer::updateMatrix(){
         m.postTranslate(cx, cy);
     }
 
-    // TODO: add gesture support
-    // Apply any gesture matrix
-    //m.preConcat(fGesture.localM());
-    //m.preConcat(fGesture.globalM());
+    m.preConcat(fWindow->getGestureLocalM());
+    m.preConcat(fWindow->getGestureGlobalM());
 
-    fLocalMatrix = m;
+    return m;
 }
 
 void Viewer::onPaint(SkCanvas* canvas) {
@@ -251,7 +247,7 @@ void Viewer::onPaint(SkCanvas* canvas) {
         matrix.setRectToRect(slideBounds, contentRect, SkMatrix::kCenter_ScaleToFit);
         canvas->concat(matrix);
     }
-    canvas->concat(fLocalMatrix);
+    canvas->concat(computeMatrix());
 
     fSlides[fCurrentSlide]->draw(canvas);
     canvas->restoreToCount(count);