1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #include "ppapi/c/pp_input_event.h" 6 #include "ppapi/cpp/graphics_2d.h" 7 #include "ppapi/cpp/image_data.h" 8 #include "ppapi/cpp/input_event.h" 9 #include "ppapi/cpp/instance.h" 10 #include "ppapi/cpp/module.h" 11 #include "ppapi/cpp/size.h" 12 #include "ppapi/cpp/view.h" 13 #include "ppapi/utility/graphics/paint_manager.h" 14 15 // Number of pixels to each side of the center of the square that we draw. 16 static const int kSquareRadius = 2; 17 18 // We identify our square by the center point. This computes the rect for the 19 // square given that point. 20 pp::Rect SquareForPoint(int x, int y) { 21 return PP_MakeRectFromXYWH(x - kSquareRadius, y - kSquareRadius, 22 kSquareRadius * 2 + 1, kSquareRadius * 2 + 1); 23 } 24 25 static void FillRect(pp::ImageData* image, 26 int left, int top, int width, int height, 27 uint32_t color) { 28 for (int y = std::max(0, top); 29 y < std::min(image->size().height() - 1, top + height); 30 y++) { 31 for (int x = std::max(0, left); 32 x < std::min(image->size().width() - 1, left + width); 33 x++) 34 *image->GetAddr32(pp::Point(x, y)) = color; 35 } 36 } 37 38 class MyInstance : public pp::Instance, public pp::PaintManager::Client { 39 public: 40 MyInstance(PP_Instance instance) 41 : pp::Instance(instance), 42 paint_manager_(), 43 last_x_(0), 44 last_y_(0) { 45 paint_manager_.Initialize(this, this, false); 46 RequestInputEvents(PP_INPUTEVENT_CLASS_MOUSE | PP_INPUTEVENT_CLASS_TOUCH); 47 } 48 49 virtual bool HandleInputEvent(const pp::InputEvent& event) { 50 switch (event.GetType()) { 51 case PP_INPUTEVENT_TYPE_MOUSEDOWN: { 52 pp::MouseInputEvent mouse_event(event); 53 // Update the square on a mouse down. 54 if (mouse_event.GetButton() == PP_INPUTEVENT_MOUSEBUTTON_LEFT) { 55 UpdateSquare(static_cast<int>(mouse_event.GetPosition().x()), 56 static_cast<int>(mouse_event.GetPosition().y())); 57 } 58 return true; 59 } 60 case PP_INPUTEVENT_TYPE_MOUSEMOVE: { 61 pp::MouseInputEvent mouse_event(event); 62 // Update the square on a drag. 63 if (mouse_event.GetButton() == PP_INPUTEVENT_MOUSEBUTTON_LEFT) { 64 UpdateSquare(static_cast<int>(mouse_event.GetPosition().x()), 65 static_cast<int>(mouse_event.GetPosition().y())); 66 } 67 return true; 68 } 69 70 case PP_INPUTEVENT_TYPE_TOUCHSTART: { 71 pp::TouchInputEvent touch(event); 72 // Update the square on a touch down. 73 uint32_t count = touch.GetTouchCount(PP_TOUCHLIST_TYPE_CHANGEDTOUCHES); 74 for (uint32_t i = 0; i < count; ++i) { 75 pp::TouchPoint point = touch.GetTouchByIndex( 76 PP_TOUCHLIST_TYPE_CHANGEDTOUCHES, i); 77 UpdateSquare(static_cast<int>(point.position().x()), 78 static_cast<int>(point.position().y())); 79 } 80 return true; 81 } 82 case PP_INPUTEVENT_TYPE_TOUCHMOVE: 83 case PP_INPUTEVENT_TYPE_TOUCHEND: 84 case PP_INPUTEVENT_TYPE_TOUCHCANCEL: 85 return true; 86 87 default: 88 return false; 89 } 90 } 91 92 virtual void DidChangeView(const pp::View& view) { 93 paint_manager_.SetSize(view.GetRect().size()); 94 } 95 96 // PaintManager::Client implementation. 97 virtual bool OnPaint(pp::Graphics2D& graphics_2d, 98 const std::vector<pp::Rect>& paint_rects, 99 const pp::Rect& paint_bounds) { 100 // Make an image just large enough to hold all dirty rects. We won't 101 // actually paint all of these pixels below, but rather just the dirty 102 // ones. Since image allocation can be somewhat heavyweight, we wouldn't 103 // want to allocate separate images in the case of multiple dirty rects. 104 pp::ImageData updated_image(this, PP_IMAGEDATAFORMAT_BGRA_PREMUL, 105 paint_bounds.size(), false); 106 107 // We could repaint everything inside the image we made above. For this 108 // example, that would probably be the easiest thing since updates are 109 // small and typically close to each other. However, for the purposes of 110 // demonstration, here we only actually paint the pixels that changed, 111 // which may be the entire update region, or could be multiple discontigous 112 // regions inside the update region. 113 // 114 // Note that the aggregator used by the paint manager won't give us 115 // multiple regions that overlap, so we don't have to worry about double 116 // painting in this code. 117 for (size_t i = 0; i < paint_rects.size(); i++) { 118 // Since our image is just the invalid region, we need to offset the 119 // areas we paint by that much. This is just a light blue background. 120 FillRect(&updated_image, 121 paint_rects[i].x() - paint_bounds.x(), 122 paint_rects[i].y() - paint_bounds.y(), 123 paint_rects[i].width(), 124 paint_rects[i].height(), 125 0xFFAAAAFF); 126 } 127 128 // Paint the square black. Because we're lazy, we do this outside of the 129 // loop above. 130 pp::Rect square = SquareForPoint(last_x_, last_y_); 131 FillRect(&updated_image, 132 square.x() - paint_bounds.x(), 133 square.y() - paint_bounds.y(), 134 square.width(), 135 square.height(), 136 0xFF000000); 137 138 graphics_2d.PaintImageData(updated_image, paint_bounds.point()); 139 return true; 140 } 141 142 private: 143 void UpdateSquare(int x, int y) { 144 if (x == last_x_ && y == last_y_) 145 return; // Nothing changed. 146 147 // Invalidate the region around the old square which needs to be repainted 148 // because it's no longer there. 149 paint_manager_.InvalidateRect(SquareForPoint(last_x_, last_y_)); 150 151 // Update the current position. 152 last_x_ = x; 153 last_y_ = y; 154 155 // Also invalidate the region around the new square. 156 paint_manager_.InvalidateRect(SquareForPoint(last_x_, last_y_)); 157 } 158 159 pp::PaintManager paint_manager_; 160 161 int last_x_; 162 int last_y_; 163 }; 164 165 class MyModule : public pp::Module { 166 public: 167 virtual pp::Instance* CreateInstance(PP_Instance instance) { 168 return new MyInstance(instance); 169 } 170 }; 171 172 namespace pp { 173 174 // Factory function for your specialization of the Module object. 175 Module* CreateModule() { 176 return new MyModule(); 177 } 178 179 } // namespace pp 180
