text: // Copyright (c) 2012 The Chromium Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  #ifndef CONTENT_RENDERER_PEPPER_PEPPER_GRAPHICS_2D_HOST_H_
  #define CONTENT_RENDERER_PEPPER_PEPPER_GRAPHICS_2D_HOST_H_
  
  #include <vector>
  
  #include "base/basictypes.h"
  #include "base/compiler_specific.h"
  #include "base/memory/weak_ptr.h"
  #include "content/common/content_export.h"
  #include "ppapi/c/dev/ppb_graphics_2d_dev.h"
  #include "ppapi/c/ppb_graphics_2d.h"
  #include "ppapi/host/host_message_context.h"
  #include "ppapi/host/resource_host.h"
  #include "third_party/WebKit/public/platform/WebCanvas.h"
  #include "ui/gfx/point.h"
  #include "ui/gfx/size.h"
  
  namespace cc {
  class SingleReleaseCallback;
  class TextureMailbox;
  }
  
  namespace gfx {
  class Rect;
  }
  
  namespace ppapi {
  struct ViewData;
  }
  
  namespace content {
    
  class PepperPluginInstanceImpl;
  class PPB_ImageData_Impl;
  class RendererPpapiHost;
  
  class CONTENT_EXPORT PepperGraphics2DHost
      : public ppapi::host::ResourceHost,
        public base::SupportsWeakPtr<PepperGraphics2DHost> {
   public:
    static PepperGraphics2DHost* Create(
        RendererPpapiHost* host,
        PP_Instance instance,
        PP_Resource resource,
        const PP_Size& size,
        PP_Bool is_always_opaque,
        scoped_refptr<PPB_ImageData_Impl> backing_store);
  
    virtual ~PepperGraphics2DHost();
  
    // ppapi::host::ResourceHost override.
    virtual int32_t OnResourceMessageReceived(
        const IPC::Message& msg,
        ppapi::host::HostMessageContext* context) OVERRIDE;
    virtual bool IsGraphics2DHost() OVERRIDE;
  
    bool ReadImageData(PP_Resource image,
                       const PP_Point* top_left);
    // Assciates this device with the given plugin instance. You can pass NULL
    // to clear the existing device. Returns true on success. In this case, a
    // repaint of the page will also be scheduled. Failure means that the device
    // is already bound to a different instance, and nothing will happen.
    bool BindToInstance(PepperPluginInstanceImpl* new_instance);
    // Paints the current backing store to the web page.
    void Paint(blink::WebCanvas* canvas,
               const gfx::Rect& plugin_rect,
               const gfx::Rect& paint_rect);
  
    bool PrepareTextureMailbox(
        cc::TextureMailbox* mailbox,
        scoped_ptr<cc::SingleReleaseCallback>* release_callback);
    void AttachedToNewLayer();
  
    // Notifications about the view's progress painting.  See PluginInstance.
    // These messages are used to send Flush callbacks to the plugin.
    void ViewInitiatedPaint();
    void ViewFlushedPaint();
  
    void DidChangeView(const ppapi::ViewData& view_data);
  
    void SetScale(float scale);
    float GetScale() const;
    bool IsAlwaysOpaque() const;
    PPB_ImageData_Impl* ImageData();
    gfx::Size Size() const;
  
    // The amount to resize the backing store by when painting to the canvas.
    // This is used to stretch the backing store when resizing the plugin element.
    gfx::PointF GetResizeScale() const;
    // The offset of the backing store into the plugin element.
    gfx::Point plugin_offset() const { return plugin_offset_; }
  
   private:
    PepperGraphics2DHost(RendererPpapiHost* host,
                         PP_Instance instance,
                         PP_Resource resource);
  
    bool Init(int width,
              int height,
              bool is_always_opaque,
              scoped_refptr<PPB_ImageData_Impl> backing_store);
  
    int32_t OnHostMsgPaintImageData(ppapi::host::HostMessageContext* context,
                                    const ppapi::HostResource& image_data,
                                    const PP_Point& top_left,
                                    bool src_rect_specified,
                                    const PP_Rect& src_rect);
    int32_t OnHostMsgScroll(ppapi::host::HostMessageContext* context,
                            bool clip_specified,
                            const PP_Rect& clip,
                            const PP_Point& amount);
    int32_t OnHostMsgReplaceContents(ppapi::host::HostMessageContext* context,
                                     const ppapi::HostResource& image_data);
    int32_t OnHostMsgFlush(ppapi::host::HostMessageContext* context,
                           const ppapi::ViewData& view_data);
    int32_t OnHostMsgSetScale(ppapi::host::HostMessageContext* context,
                              float scale);
    int32_t OnHostMsgSetOffset(ppapi::host::HostMessageContext* context,
                               const PP_Point& offset);
    int32_t OnHostMsgSetResizeMode(ppapi::host::HostMessageContext* context,
                                   PP_Graphics2D_Dev_ResizeMode resize_mode);
    int32_t OnHostMsgReadImageData(ppapi::host::HostMessageContext* context,
                                   PP_Resource image,
                                   const PP_Point& top_left);
  
    // If |old_image_data| is not NULL, a previous used ImageData object will be
    // reused.  This is used by ReplaceContents.
    int32_t Flush(PP_Resource* old_image_data,
                  const gfx::Size& flushed_plugin_size);
  
    // Called internally to execute the different queued commands. The
    // parameters to these functions will have already been validated. The last
    // rect argument will be filled by each function with the area affected by
    // the update that requires invalidation. If there were no pixels changed,
    // this rect can be untouched.
    void ExecutePaintImageData(PPB_ImageData_Impl* image,
                               int x, int y,
                               const gfx::Rect& src_rect,
                               gfx::Rect* invalidated_rect);
    void ExecuteScroll(const gfx::Rect& clip, int dx, int dy,
                       gfx::Rect* invalidated_rect);
    void ExecuteReplaceContents(PPB_ImageData_Impl* image,
                                gfx::Rect* invalidated_rect,
                                PP_Resource* old_image_data);
  
    void SendFlushAck();
  
    // Function scheduled to execute by ScheduleOffscreenFlushAck that actually
    // issues the offscreen callbacks.
    void SendOffscreenFlushAck();
  
    // Schedules the offscreen flush ACK at a future time.
    void ScheduleOffscreenFlushAck();
  
    // Returns true if there is any type of flush callback pending.
    bool HasPendingFlush() const;
  
    // Scale |op_rect| to logical pixels, taking care to include partially-
    // covered logical pixels (aka DIPs). Also scale optional |delta| to logical
    // pixels as well for scrolling cases. Returns false for scrolling cases where
    // scaling either |op_rect| or |delta| would require scrolling to fall back to
    // invalidation due to rounding errors, true otherwise.
    static bool ConvertToLogicalPixels(float scale,
                                       gfx::Rect* op_rect,
                                       gfx::Point* delta);
  
    RendererPpapiHost* renderer_ppapi_host_;
  
    scoped_refptr<PPB_ImageData_Impl> image_data_;
  
    // Non-owning pointer to the plugin instance this context is currently bound
    // to, if any. If the context is currently unbound, this will be NULL.
    PepperPluginInstanceImpl* bound_instance_;
  
    // Keeps track of all drawing commands queued before a Flush call.
    struct QueuedOperation;
    typedef std::vector<QueuedOperation> OperationQueue;
    OperationQueue queued_operations_;
  
    // True if we need to send an ACK to plugin.
    bool need_flush_ack_;
  
    // When doing offscreen flushes, we issue a task that issues the callback
    // later. This is set when one of those tasks is pending so that we can
    // enforce the "only one pending flush at a time" constraint in the API.
    bool offscreen_flush_pending_;
  
    // Set to true if the plugin declares that this device will always be opaque.
    // This allows us to do more optimized painting in some cases.
    bool is_always_opaque_;
  
    // Set to the scale between what the plugin considers to be one pixel and one
    // DIP
    float scale_;
  
    ppapi::host::ReplyMessageContext flush_reply_context_;
  
    bool is_running_in_process_;
  
    bool texture_mailbox_modified_;
    bool is_using_texture_layer_;
  
    // The offset into the plugin area at which to draw the contents of the
    // graphics context.
    gfx::Point plugin_offset_;
  
    // The size of the plugin element from the plugin's perspective at the last
    // time Flush() was called. Because the plugin runs in a separate process and
    // the size of the plugin element in the renderer is updated asynchronously,
    // it may believe that the plugin element is a different size to what it
    // actually is.
    gfx::Size flushed_plugin_size_;
    // The current size of the plugin element.
    gfx::Size current_plugin_size_;
  
    PP_Graphics2D_Dev_ResizeMode resize_mode_;
  
    friend class PepperGraphics2DHostTest;
    DISALLOW_COPY_AND_ASSIGN(PepperGraphics2DHost);
  };
  
  }  // namespace content
  
  #endif  // CONTENT_RENDERER_PEPPER_PEPPER_GRAPHICS_2D_HOST_H_
  