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 "../private/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 void setTransLimit(const SkRect& contentRect, const SkRect& windowRect); 47 48 private: 49 enum State { 50 kEmpty_State, 51 kTranslate_State, 52 kZoom_State, 53 }; 54 55 struct Rec { 56 void* fOwner; 57 float fStartX, fStartY; 58 float fPrevX, fPrevY; 59 float fLastX, fLastY; 60 float fPrevT, fLastT; 61 }; 62 SkTDArray<Rec> fTouches; 63 64 State fState; 65 SkMatrix fLocalM, fGlobalM; 66 SkFlingState fFlinger; 67 double fLastUpMillis; 68 SkPoint fLastUpP; 69 70 // The following rects are used to limit the translation so the content never leaves the window 71 SkRect fContentRect, fWindowRect; 72 bool fIsTransLimited = false; 73 74 void limitTrans(); // here we only limit the translation with respect to globalM 75 void flushLocalM(); 76 int findRec(void* owner) const; 77 void appendNewRec(void* owner, float x, float y); 78 float computePinch(const Rec&, const Rec&); 79 float limitTotalZoom(float scale) const; 80 bool handleDblTap(float, float); 81 }; 82 83 #endif 84
