1 // Copyright (c) 2011 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 <algorithm> 6 7 #include "ppapi/c/pp_input_event.h" 8 #include "ppapi/cpp/graphics_2d.h" 9 #include "ppapi/cpp/image_data.h" 10 #include "ppapi/cpp/input_event.h" 11 #include "ppapi/cpp/instance.h" 12 #include "ppapi/cpp/module.h" 13 #include "ppapi/cpp/size.h" 14 #include "ppapi/cpp/view.h" 15 #include "ppapi/utility/graphics/paint_manager.h" 16 17 // Number of pixels to each side of the center of the square that we draw. 18 static const int kSquareRadius = 2; 19 20 // We identify our square by the center point. This computes the rect for the 21 // square given that point. 22 pp::Rect SquareForPoint(int x, int y) { 23 return PP_MakeRectFromXYWH(x - kSquareRadius, y - kSquareRadius, 24 kSquareRadius * 2 + 1, kSquareRadius * 2 + 1); 25 } 26 27 static void FillRect(pp::ImageData* image, 28 int left, int top, int width, int height, 29 uint32_t color) { 30 for (int y = std::max(0, top); 31 y < std::min(image->size().height() - 1, top + height); 32 y++) { 33 for (int x = std::max(0, left); 34 x < std::min(image->size().width() - 1, left + width); 35 x++) 36 *image->GetAddr32(pp::Point(x, y)) = color; 37 } 38 } 39 40 class MyInstance : public pp::Instance, public pp::PaintManager::Client { 41 public: 42 MyInstance(PP_Instance instance) 43 : pp::Instance(instance), 44 paint_manager_(), 45 last_x_(0), 46 last_y_(0) { 47 paint_manager_.Initialize(this, this, false); 48 RequestInputEvents(PP_INPUTEVENT_CLASS_MOUSE); 49 } 50 51 virtual bool HandleInputEvent(const pp::InputEvent& event) { 52 switch (event.GetType()) { 53 case PP_INPUTEVENT_TYPE_MOUSEDOWN: { 54 pp::MouseInputEvent mouse_event(event); 55 // Update the square on a mouse down. 56 if (mouse_event.GetButton() == PP_INPUTEVENT_MOUSEBUTTON_LEFT) { 57 UpdateSquare(static_cast<int>(mouse_event.GetPosition().x()), 58 static_cast<int>(mouse_event.GetPosition().y())); 59 } 60 return true; 61 } 62 case PP_INPUTEVENT_TYPE_MOUSEMOVE: { 63 pp::MouseInputEvent mouse_event(event); 64 // Update the square on a drag. 65 if (mouse_event.GetButton() == PP_INPUTEVENT_MOUSEBUTTON_LEFT) { 66 UpdateSquare(static_cast<int>(mouse_event.GetPosition().x()), 67 static_cast<int>(mouse_event.GetPosition().y())); 68 } 69 return true; 70 } 71 default: 72 return false; 73 } 74 } 75 76 virtual void DidChangeView(const pp::View& view) { 77 paint_manager_.SetSize(view.GetRect().size()); 78 } 79 80 // PaintManager::Client implementation. 81 virtual bool OnPaint(pp::Graphics2D& graphics_2d, 82 const std::vector<pp::Rect>& paint_rects, 83 const pp::Rect& paint_bounds) { 84 // Make an image just large enough to hold all dirty rects. We won't 85 // actually paint all of these pixels below, but rather just the dirty 86 // ones. Since image allocation can be somewhat heavyweight, we wouldn't 87 // want to allocate separate images in the case of multiple dirty rects. 88 pp::ImageData updated_image(this, PP_IMAGEDATAFORMAT_BGRA_PREMUL, 89 paint_bounds.size(), false); 90 91 // We could repaint everything inside the image we made above. For this 92 // example, that would probably be the easiest thing since updates are 93 // small and typically close to each other. However, for the purposes of 94 // demonstration, here we only actually paint the pixels that changed, 95 // which may be the entire update region, or could be multiple discontigous 96 // regions inside the update region. 97 // 98 // Note that the aggregator used by the paint manager won't give us 99 // multiple regions that overlap, so we don't have to worry about double 100 // painting in this code. 101 for (size_t i = 0; i < paint_rects.size(); i++) { 102 // Since our image is just the invalid region, we need to offset the 103 // areas we paint by that much. This is just a light blue background. 104 FillRect(&updated_image, 105 paint_rects[i].x() - paint_bounds.x(), 106 paint_rects[i].y() - paint_bounds.y(), 107 paint_rects[i].width(), 108 paint_rects[i].height(), 109 0xFFAAAAFF); 110 } 111 112 // Paint the square black. Because we're lazy, we do this outside of the 113 // loop above. 114 pp::Rect square = SquareForPoint(last_x_, last_y_); 115 FillRect(&updated_image, 116 square.x() - paint_bounds.x(), 117 square.y() - paint_bounds.y(), 118 square.width(), 119 square.height(), 120 0xFF000000); 121 122 graphics_2d.PaintImageData(updated_image, paint_bounds.point()); 123 return true; 124 } 125 126 private: 127 void UpdateSquare(int x, int y) { 128 if (x == last_x_ && y == last_y_) 129 return; // Nothing changed. 130 131 // Invalidate the region around the old square which needs to be repainted 132 // because it's no longer there. 133 paint_manager_.InvalidateRect(SquareForPoint(last_x_, last_y_)); 134 135 // Update the current position. 136 last_x_ = x; 137 last_y_ = y; 138 139 // Also invalidate the region around the new square. 140 paint_manager_.InvalidateRect(SquareForPoint(last_x_, last_y_)); 141 } 142 143 pp::PaintManager paint_manager_; 144 145 int last_x_; 146 int last_y_; 147 }; 148 149 class MyModule : public pp::Module { 150 public: 151 virtual pp::Instance* CreateInstance(PP_Instance instance) { 152 return new MyInstance(instance); 153 } 154 }; 155 156 namespace pp { 157 158 // Factory function for your specialization of the Module object. 159 Module* CreateModule() { 160 return new MyModule(); 161 } 162 163 } // namespace pp 164
