1 /* 2 * Copyright (C) 2008 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef SkDrawFilter_DEFINED 18 #define SkDrawFilter_DEFINED 19 20 #include "SkRefCnt.h" 21 22 ////////////////// EXPERIMENTAL ////////////////////////// 23 24 class SkCanvas; 25 class SkPaint; 26 27 /** Right before something is being draw, filter() is called with the 28 current canvas and paint. If it returns true, then drawing proceeds 29 with the (possibly modified) canvas/paint, and then restore() is called 30 to restore the canvas/paint to their state before filter() was called. 31 If filter returns false, canvas/paint should not have been changed, and 32 restore() will not be called. 33 */ 34 class SkDrawFilter : public SkRefCnt { 35 public: 36 enum Type { 37 kPaint_Type, 38 kPoint_Type, 39 kLine_Type, 40 kBitmap_Type, 41 kRect_Type, 42 kPath_Type, 43 kText_Type 44 }; 45 46 /** Return true to allow the draw to continue (with possibly modified 47 canvas/paint). If true is returned, then restore() will be called. 48 */ 49 virtual bool filter(SkCanvas*, SkPaint*, Type) = 0; 50 /** If filter() returned true, then restore() will be called to restore the 51 canvas/paint to their previous states 52 */ 53 virtual void restore(SkCanvas*, SkPaint*, Type) = 0; 54 }; 55 56 #endif 57
