1 2 /* 3 * Copyright 2011 Google Inc. 4 * 5 * Use of this source code is governed by a BSD-style license that can be 6 * found in the LICENSE file. 7 */ 8 #ifndef SkTouchGesture_DEFINED 9 #define SkTouchGesture_DEFINED 10 11 #include "SkTDArray.h" 12 #include "SkMatrix.h" 13 14 struct SkFlingState { 15 SkFlingState() : fActive(false) {} 16 17 bool isActive() const { return fActive; } 18 void stop() { fActive = false; } 19 20 void reset(float sx, float sy); 21 bool evaluateMatrix(SkMatrix* matrix); 22 23 private: 24 SkPoint fDirection; 25 SkScalar fSpeed0; 26 double fTime0; 27 bool fActive; 28 }; 29 30 class SkTouchGesture { 31 public: 32 SkTouchGesture(); 33 ~SkTouchGesture(); 34 35 void touchBegin(void* owner, float x, float y); 36 void touchMoved(void* owner, float x, float y); 37 void touchEnd(void* owner); 38 void reset(); 39 40 bool isActive() { return fFlinger.isActive(); } 41 void stop() { fFlinger.stop(); } 42 43 const SkMatrix& localM(); 44 const SkMatrix& globalM() const { return fGlobalM; } 45 46 private: 47 enum State { 48 kEmpty_State, 49 kTranslate_State, 50 kZoom_State, 51 }; 52 53 struct Rec { 54 void* fOwner; 55 float fStartX, fStartY; 56 float fPrevX, fPrevY; 57 float fLastX, fLastY; 58 SkMSec fPrevT, fLastT; 59 }; 60 SkTDArray<Rec> fTouches; 61 62 State fState; 63 SkMatrix fLocalM, fGlobalM; 64 SkFlingState fFlinger; 65 SkMSec fLastUpT; 66 SkPoint fLastUpP; 67 68 69 void flushLocalM(); 70 int findRec(void* owner) const; 71 void appendNewRec(void* owner, float x, float y); 72 float computePinch(const Rec&, const Rec&); 73 float limitTotalZoom(float scale) const; 74 bool handleDblTap(float, float); 75 }; 76 77 #endif 78
