1 /* 2 * Copyright (C) 2010 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 ScrollableLayerAndroid_h 18 #define ScrollableLayerAndroid_h 19 20 #if USE(ACCELERATED_COMPOSITING) 21 22 #include "LayerAndroid.h" 23 24 namespace WebCore { 25 26 class ScrollableLayerAndroid : public LayerAndroid { 27 28 public: ScrollableLayerAndroid(RenderLayer * owner)29 ScrollableLayerAndroid(RenderLayer* owner) 30 : LayerAndroid(owner) {} ScrollableLayerAndroid(const ScrollableLayerAndroid & layer)31 ScrollableLayerAndroid(const ScrollableLayerAndroid& layer) 32 : LayerAndroid(layer) 33 , m_scrollLimits(layer.m_scrollLimits) {} ScrollableLayerAndroid(const LayerAndroid & layer)34 ScrollableLayerAndroid(const LayerAndroid& layer) 35 : LayerAndroid(layer) 36 { 37 m_scrollLimits.setEmpty(); 38 } ~ScrollableLayerAndroid()39 virtual ~ScrollableLayerAndroid() {}; 40 contentIsScrollable()41 virtual bool contentIsScrollable() const { return true; } 42 copy()43 virtual LayerAndroid* copy() const { return new ScrollableLayerAndroid(*this); } subclassType()44 virtual SubclassType subclassType() const { return LayerAndroid::ScrollableLayer; } 45 46 // Scrolls to the given position in the layer. 47 // Returns whether or not any scrolling was required. 48 virtual bool scrollTo(int x, int y); 49 50 // Fills the rect with the current scroll offset and the maximum scroll offset. 51 // fLeft = scrollX 52 // fTop = scrollY 53 // fRight = maxScrollX 54 // fBottom = maxScrollY 55 virtual void getScrollRect(SkIRect*) const; 56 57 void setScrollLimits(float minX, float minY, float maxX, float maxY); 58 59 // Given a rect in the layer, scrolls to bring the rect into view. Uses a 60 // lazy approach, whereby we scroll as little as possible to bring the 61 // entire rect into view. If the size of the rect exceeds that of the 62 // visible area of the layer, we favor the top and left of the rect. 63 // Returns whether or not any scrolling was required. 64 bool scrollRectIntoView(const SkIRect&); 65 66 friend void android::serializeLayer(LayerAndroid* layer, SkWStream* stream); 67 friend LayerAndroid* android::deserializeLayer(int version, SkStream* stream); 68 69 protected: 70 71 void getScrollBounds(IntRect*) const; 72 73 // The position of the visible area of the layer, relative to the parent 74 // layer. This is fixed during scrolling. We acheive scrolling by modifying 75 // the position of the layer. 76 SkRect m_scrollLimits; 77 }; 78 79 } 80 81 #endif // USE(ACCELERATED_COMPOSITING) 82 83 #endif // LayerAndroid_h 84