1 files changed, 72 insertions, 0 deletions
diff --git a/include/views/SkTouchGesture.h b/include/views/SkTouchGesture.h
new file mode 100644
index 0000000..79d4e28
--- /dev/null
+++ b/include/views/SkTouchGesture.h
@@ -0,0 +1,72 @@
+#ifndef SkTouchGesture_DEFINED
+#define SkTouchGesture_DEFINED
+
+#include "SkTDArray.h"
+#include "SkMatrix.h"
+
+struct SkFlingState {
+    SkFlingState() : fActive(false) {}
+    
+    bool isActive() const { return fActive; }
+    void stop() { fActive = false; }
+    
+    void reset(float sx, float sy);
+    bool evaluateMatrix(SkMatrix* matrix);
+    
+private:
+    SkPoint     fDirection;
+    SkScalar    fSpeed0;
+    double      fTime0;
+    bool        fActive;
+};
+
+class SkTouchGesture {
+public:
+    SkTouchGesture();
+    ~SkTouchGesture();
+
+    void touchBegin(void* owner, float x, float y);
+    void touchMoved(void* owner, float x, float y);
+    void touchEnd(void* owner);
+    void reset();
+
+    bool isActive() { return fFlinger.isActive(); }
+    void stop() { fFlinger.stop(); }
+
+    const SkMatrix& localM();
+    const SkMatrix& globalM() const { return fGlobalM; }
+
+private:
+    enum State {
+        kEmpty_State,
+        kTranslate_State,
+        kZoom_State,
+    };
+
+    struct Rec {
+        void*   fOwner;
+        float   fStartX, fStartY;
+        float   fPrevX, fPrevY;
+        float   fLastX, fLastY;
+        SkMSec  fPrevT, fLastT;
+    };
+    SkTDArray<Rec> fTouches;
+
+    State           fState;
+    SkMatrix        fLocalM, fGlobalM;
+    SkFlingState    fFlinger;
+    SkMSec          fLastUpT;
+    SkPoint         fLastUpP;
+
+
+    void flushLocalM();
+    int findRec(void* owner) const;
+    void appendNewRec(void* owner, float x, float y);
+    float computePinch(const Rec&, const Rec&);
+    float limitTotalZoom(float scale) const;
+    bool handleDblTap(float, float);
+};
+
+#endif
+
+