michael@0: 
michael@0: /*
michael@0:  * Copyright 2011 Google Inc.
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: #ifndef SkTouchGesture_DEFINED
michael@0: #define SkTouchGesture_DEFINED
michael@0: 
michael@0: #include "SkTDArray.h"
michael@0: #include "SkMatrix.h"
michael@0: 
michael@0: struct SkFlingState {
michael@0:     SkFlingState() : fActive(false) {}
michael@0: 
michael@0:     bool isActive() const { return fActive; }
michael@0:     void stop() { fActive = false; }
michael@0: 
michael@0:     void reset(float sx, float sy);
michael@0:     bool evaluateMatrix(SkMatrix* matrix);
michael@0: 
michael@0: private:
michael@0:     SkPoint     fDirection;
michael@0:     SkScalar    fSpeed0;
michael@0:     double      fTime0;
michael@0:     bool        fActive;
michael@0: };
michael@0: 
michael@0: class SkTouchGesture {
michael@0: public:
michael@0:     SkTouchGesture();
michael@0:     ~SkTouchGesture();
michael@0: 
michael@0:     void touchBegin(void* owner, float x, float y);
michael@0:     void touchMoved(void* owner, float x, float y);
michael@0:     void touchEnd(void* owner);
michael@0:     void reset();
michael@0: 
michael@0:     bool isActive() { return fFlinger.isActive(); }
michael@0:     void stop() { fFlinger.stop(); }
michael@0: 
michael@0:     const SkMatrix& localM();
michael@0:     const SkMatrix& globalM() const { return fGlobalM; }
michael@0: 
michael@0: private:
michael@0:     enum State {
michael@0:         kEmpty_State,
michael@0:         kTranslate_State,
michael@0:         kZoom_State,
michael@0:     };
michael@0: 
michael@0:     struct Rec {
michael@0:         void*   fOwner;
michael@0:         float   fStartX, fStartY;
michael@0:         float   fPrevX, fPrevY;
michael@0:         float   fLastX, fLastY;
michael@0:         SkMSec  fPrevT, fLastT;
michael@0:     };
michael@0:     SkTDArray<Rec> fTouches;
michael@0: 
michael@0:     State           fState;
michael@0:     SkMatrix        fLocalM, fGlobalM;
michael@0:     SkFlingState    fFlinger;
michael@0:     SkMSec          fLastUpT;
michael@0:     SkPoint         fLastUpP;
michael@0: 
michael@0: 
michael@0:     void flushLocalM();
michael@0:     int findRec(void* owner) const;
michael@0:     void appendNewRec(void* owner, float x, float y);
michael@0:     float computePinch(const Rec&, const Rec&);
michael@0:     float limitTotalZoom(float scale) const;
michael@0:     bool handleDblTap(float, float);
michael@0: };
michael@0: 
michael@0: #endif