Implement touch control

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1982643004

Review-Url: https://codereview.chromium.org/1982643004

1 files changed, 4 insertions, 2 deletions

diff --git a/tools/viewer/Viewer.h b/tools/viewer/Viewer.h
index 3579e4d296..c785cff78e 100644
--- a/tools/viewer/Viewer.h
+++ b/tools/viewer/Viewer.h
@@ -24,6 +24,7 @@ public:
 
     void onPaint(SkCanvas* canvas);
     void onIdle(double ms) override;
+    bool onTouch(int owner, sk_app::Window::InputState state, float x, float y);
 
 private:
     void initSlides();
@@ -33,7 +34,7 @@ private:
     void drawStats(SkCanvas* canvas);
 
     void changeZoomLevel(float delta);
-    void updateMatrix();
+    SkMatrix computeMatrix();
 
     sk_app::Window*        fWindow;
 
@@ -50,13 +51,14 @@ private:
     sk_app::Window::BackendType fBackendType;
 
     // transform data
-    SkMatrix               fLocalMatrix;
     SkScalar               fZoomCenterX;
     SkScalar               fZoomCenterY;
     SkScalar               fZoomLevel;
     SkScalar               fZoomScale;
 
     sk_app::CommandSet     fCommands;
+
+    SkTouchGesture         fGesture;
 };