render_widget_host.h revision 58537e28ecd584eab876aee8be7156509866d23a
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#ifndef CONTENT_PUBLIC_BROWSER_RENDER_WIDGET_HOST_H_ 6#define CONTENT_PUBLIC_BROWSER_RENDER_WIDGET_HOST_H_ 7 8#include "base/callback.h" 9#include "content/common/content_export.h" 10#include "content/public/browser/native_web_keyboard_event.h" 11#include "ipc/ipc_channel.h" 12#include "ipc/ipc_sender.h" 13#include "third_party/WebKit/public/web/WebInputEvent.h" 14#include "third_party/WebKit/public/web/WebTextDirection.h" 15#include "ui/gfx/size.h" 16#include "ui/surface/transport_dib.h" 17 18#if defined(TOOLKIT_GTK) 19#include "ui/base/x/x11_util.h" 20#elif defined(OS_MACOSX) 21#include "skia/ext/platform_device.h" 22#endif 23 24class SkBitmap; 25 26namespace gfx { 27class Rect; 28} 29 30namespace WebKit { 31class WebMouseEvent; 32struct WebScreenInfo; 33} 34 35namespace content { 36 37class RenderProcessHost; 38class RenderWidgetHostImpl; 39class RenderWidgetHostIterator; 40class RenderWidgetHostView; 41 42// A RenderWidgetHost manages the browser side of a browser<->renderer 43// HWND connection. The HWND lives in the browser process, and 44// windows events are sent over IPC to the corresponding object in the 45// renderer. The renderer paints into shared memory, which we 46// transfer to a backing store and blit to the screen when Windows 47// sends us a WM_PAINT message. 48// 49// How Shutdown Works 50// 51// There are two situations in which this object, a RenderWidgetHost, can be 52// instantiated: 53// 54// 1. By a WebContents as the communication conduit for a rendered web page. 55// The WebContents instantiates a derived class: RenderViewHost. 56// 2. By a WebContents as the communication conduit for a select widget. The 57// WebContents instantiates the RenderWidgetHost directly. 58// 59// For every WebContents there are several objects in play that need to be 60// properly destroyed or cleaned up when certain events occur. 61// 62// - WebContents - the WebContents itself, and its associated HWND. 63// - RenderViewHost - representing the communication conduit with the child 64// process. 65// - RenderWidgetHostView - the view of the web page content, message handler, 66// and plugin root. 67// 68// Normally, the WebContents contains a child RenderWidgetHostView that renders 69// the contents of the loaded page. It has a WS_CLIPCHILDREN style so that it 70// does no painting of its own. 71// 72// The lifetime of the RenderWidgetHostView is tied to the render process. If 73// the render process dies, the RenderWidgetHostView goes away and all 74// references to it must become NULL. 75// 76// RenderViewHost (a RenderWidgetHost subclass) is the conduit used to 77// communicate with the RenderView and is owned by the WebContents. If the 78// render process crashes, the RenderViewHost remains and restarts the render 79// process if needed to continue navigation. 80// 81// Some examples of how shutdown works: 82// 83// For a WebContents, its Destroy method tells the RenderViewHost to 84// shut down the render process and die. 85// 86// When the render process is destroyed it destroys the View: the 87// RenderWidgetHostView, which destroys its HWND and deletes that object. 88// 89// For select popups, the situation is a little different. The RenderWidgetHost 90// associated with the select popup owns the view and itself (is responsible 91// for destroying itself when the view is closed). The WebContents's only 92// responsibility is to select popups is to create them when it is told to. When 93// the View is destroyed via an IPC message (for when WebCore destroys the 94// popup, e.g. if the user selects one of the options), or because 95// WM_CANCELMODE is received by the view, the View schedules the destruction of 96// the render process. However in this case since there's no WebContents 97// container, when the render process is destroyed, the RenderWidgetHost just 98// deletes itself, which is safe because no one else should have any references 99// to it (the WebContents does not). 100// 101// It should be noted that the RenderViewHost, not the RenderWidgetHost, 102// handles IPC messages relating to the render process going away, since the 103// way a RenderViewHost (WebContents) handles the process dying is different to 104// the way a select popup does. As such the RenderWidgetHostView handles these 105// messages for select popups. This placement is more out of convenience than 106// anything else. When the view is live, these messages are forwarded to it by 107// the RenderWidgetHost's IPC message map. 108class CONTENT_EXPORT RenderWidgetHost : public IPC::Sender { 109 public: 110 // Free all backing stores used for rendering to drop memory usage. 111 static void RemoveAllBackingStores(); 112 113 // Returns the size of all the backing stores used for rendering 114 static size_t BackingStoreMemorySize(); 115 116 // Adds/removes a callback called on creation of each new RenderWidgetHost. 117 typedef base::Callback<void(RenderWidgetHost*)> CreatedCallback; 118 static void AddCreatedCallback(const CreatedCallback& callback); 119 static void RemoveCreatedCallback(const CreatedCallback& callback); 120 121 // Returns the RenderWidgetHost given its ID and the ID of its render process. 122 // Returns NULL if the IDs do not correspond to a live RenderWidgetHost. 123 static RenderWidgetHost* FromID(int32 process_id, int32 routing_id); 124 125 // Returns an iterator to iterate over the global list of active render widget 126 // hosts. 127 static scoped_ptr<RenderWidgetHostIterator> GetRenderWidgetHosts(); 128 129 virtual ~RenderWidgetHost() {} 130 131 // Edit operations. 132 virtual void Undo() = 0; 133 virtual void Redo() = 0; 134 virtual void Cut() = 0; 135 virtual void Copy() = 0; 136 virtual void CopyToFindPboard() = 0; 137 virtual void Paste() = 0; 138 virtual void PasteAndMatchStyle() = 0; 139 virtual void Delete() = 0; 140 virtual void SelectAll() = 0; 141 virtual void Unselect() = 0; 142 143 // Update the text direction of the focused input element and notify it to a 144 // renderer process. 145 // These functions have two usage scenarios: changing the text direction 146 // from a menu (as Safari does), and; changing the text direction when a user 147 // presses a set of keys (as IE and Firefox do). 148 // 1. Change the text direction from a menu. 149 // In this scenario, we receive a menu event only once and we should update 150 // the text direction immediately when a user chooses a menu item. So, we 151 // should call both functions at once as listed in the following snippet. 152 // void RenderViewHost::SetTextDirection(WebTextDirection direction) { 153 // UpdateTextDirection(direction); 154 // NotifyTextDirection(); 155 // } 156 // 2. Change the text direction when pressing a set of keys. 157 // Because of auto-repeat, we may receive the same key-press event many 158 // times while we presses the keys and it is nonsense to send the same IPC 159 // message every time when we receive a key-press event. 160 // To suppress the number of IPC messages, we just update the text direction 161 // when receiving a key-press event and send an IPC message when we release 162 // the keys as listed in the following snippet. 163 // if (key_event.type == WebKeyboardEvent::KEY_DOWN) { 164 // if (key_event.windows_key_code == 'A' && 165 // key_event.modifiers == WebKeyboardEvent::CTRL_KEY) { 166 // UpdateTextDirection(dir); 167 // } else { 168 // CancelUpdateTextDirection(); 169 // } 170 // } else if (key_event.type == WebKeyboardEvent::KEY_UP) { 171 // NotifyTextDirection(); 172 // } 173 // Once we cancel updating the text direction, we have to ignore all 174 // succeeding UpdateTextDirection() requests until calling 175 // NotifyTextDirection(). (We may receive keydown events even after we 176 // canceled updating the text direction because of auto-repeat.) 177 // Note: we cannot undo this change for compatibility with Firefox and IE. 178 virtual void UpdateTextDirection(WebKit::WebTextDirection direction) = 0; 179 virtual void NotifyTextDirection() = 0; 180 181 virtual void Focus() = 0; 182 virtual void Blur() = 0; 183 184 // Sets whether the renderer should show controls in an active state. On all 185 // platforms except mac, that's the same as focused. On mac, the frontmost 186 // window will show active controls even if the focus is not in the web 187 // contents, but e.g. in the omnibox. 188 virtual void SetActive(bool active) = 0; 189 190 // Copies the given subset of the backing store, and passes the result as a 191 // bitmap to a callback. 192 // 193 // If |src_rect| is empty, the whole contents is copied. If non empty 194 // |accelerated_dst_size| is given and accelerated compositing is active, the 195 // content is shrunk so that it fits in |accelerated_dst_size|. If 196 // |accelerated_dst_size| is larger than the content size, the content is not 197 // resized. If |accelerated_dst_size| is empty, the size copied from the 198 // source contents is used. |callback| is invoked with true on success, false 199 // otherwise, along with a SkBitmap containing the copied pixel data. 200 // 201 // NOTE: |callback| is called synchronously if the backing store is available. 202 // When accelerated compositing is active, |callback| may be called 203 // asynchronously. 204 virtual void CopyFromBackingStore( 205 const gfx::Rect& src_rect, 206 const gfx::Size& accelerated_dst_size, 207 const base::Callback<void(bool, const SkBitmap&)>& callback) = 0; 208#if defined(TOOLKIT_GTK) 209 // Paint the backing store into the target's |dest_rect|. 210 virtual bool CopyFromBackingStoreToGtkWindow(const gfx::Rect& dest_rect, 211 GdkWindow* target) = 0; 212#elif defined(OS_MACOSX) 213 virtual gfx::Size GetBackingStoreSize() = 0; 214 virtual bool CopyFromBackingStoreToCGContext(const CGRect& dest_rect, 215 CGContextRef target) = 0; 216#endif 217 218 // Send a command to the renderer to turn on full accessibility. 219 virtual void EnableFullAccessibilityMode() = 0; 220 221 // Forwards the given message to the renderer. These are called by 222 // the view when it has received a message. 223 virtual void ForwardMouseEvent( 224 const WebKit::WebMouseEvent& mouse_event) = 0; 225 virtual void ForwardWheelEvent( 226 const WebKit::WebMouseWheelEvent& wheel_event) = 0; 227 virtual void ForwardKeyboardEvent( 228 const NativeWebKeyboardEvent& key_event) = 0; 229 230 virtual const gfx::Vector2d& GetLastScrollOffset() const = 0; 231 232 virtual RenderProcessHost* GetProcess() const = 0; 233 234 virtual int GetRoutingID() const = 0; 235 236 // Gets the View of this RenderWidgetHost. Can be NULL, e.g. if the 237 // RenderWidget is being destroyed or the render process crashed. You should 238 // never cache this pointer since it can become NULL if the renderer crashes, 239 // instead you should always ask for it using the accessor. 240 virtual RenderWidgetHostView* GetView() const = 0; 241 242 // Returns true if the renderer is loading, false if not. 243 virtual bool IsLoading() const = 0; 244 245 // Returns true if this is a RenderViewHost, false if not. 246 virtual bool IsRenderView() const = 0; 247 248 // This tells the renderer to paint into a bitmap and return it, 249 // regardless of whether the tab is hidden or not. It resizes the 250 // web widget to match the |page_size| and then returns the bitmap 251 // scaled so it matches the |desired_size|, so that the scaling 252 // happens on the rendering thread. When the bitmap is ready, the 253 // renderer sends a PaintAtSizeACK to this host, and a 254 // RENDER_WIDGET_HOST_DID_RECEIVE_PAINT_AT_SIZE_ACK notification is issued. 255 // Note that this bypasses most of the update logic that is normally invoked, 256 // and doesn't put the results into the backing store. 257 virtual void PaintAtSize(TransportDIB::Handle dib_handle, 258 int tag, 259 const gfx::Size& page_size, 260 const gfx::Size& desired_size) = 0; 261 262 // Makes an IPC call to tell webkit to replace the currently selected word 263 // or a word around the cursor. 264 virtual void Replace(const string16& word) = 0; 265 266 // Makes an IPC call to tell webkit to replace the misspelling in the current 267 // selection. 268 virtual void ReplaceMisspelling(const string16& word) = 0; 269 270 // Called to notify the RenderWidget that the resize rect has changed without 271 // the size of the RenderWidget itself changing. 272 virtual void ResizeRectChanged(const gfx::Rect& new_rect) = 0; 273 274 // Restart the active hang monitor timeout. Clears all existing timeouts and 275 // starts with a new one. This can be because the renderer has become 276 // active, the tab is being hidden, or the user has chosen to wait some more 277 // to give the tab a chance to become active and we don't want to display a 278 // warning too soon. 279 virtual void RestartHangMonitorTimeout() = 0; 280 281 virtual void SetIgnoreInputEvents(bool ignore_input_events) = 0; 282 283 // Stops loading the page. 284 virtual void Stop() = 0; 285 286 // Called to notify the RenderWidget that it has been resized. 287 virtual void WasResized() = 0; 288 289 // Access to the implementation's IPC::Listener::OnMessageReceived. Intended 290 // only for test code. 291 292 // Add/remove a callback that can handle key presses without requiring focus. 293 typedef base::Callback<bool(const NativeWebKeyboardEvent&)> 294 KeyPressEventCallback; 295 virtual void AddKeyPressEventCallback( 296 const KeyPressEventCallback& callback) = 0; 297 virtual void RemoveKeyPressEventCallback( 298 const KeyPressEventCallback& callback) = 0; 299 300 // Add/remove a callback that can handle all kinds of mouse events. 301 typedef base::Callback<bool(const WebKit::WebMouseEvent&)> MouseEventCallback; 302 virtual void AddMouseEventCallback(const MouseEventCallback& callback) = 0; 303 virtual void RemoveMouseEventCallback(const MouseEventCallback& callback) = 0; 304 305 // Get the screen info corresponding to this render widget. 306 virtual void GetWebScreenInfo(WebKit::WebScreenInfo* result) = 0; 307 308 // Grabs snapshot from renderer side and returns the bitmap to a callback. 309 // If |src_rect| is empty, the whole contents is copied. This is an expensive 310 // operation due to the IPC, but it can be used as a fallback method when 311 // CopyFromBackingStore fails due to the backing store not being available or, 312 // in composited mode, when the accelerated surface is not available to the 313 // browser side. 314 virtual void GetSnapshotFromRenderer( 315 const gfx::Rect& src_subrect, 316 const base::Callback<void(bool, const SkBitmap&)>& callback) = 0; 317 318 protected: 319 friend class RenderWidgetHostImpl; 320 321 // Retrieves the implementation class. Intended only for code 322 // within content/. This method is necessary because 323 // RenderWidgetHost is the root of a diamond inheritance pattern, so 324 // subclasses inherit it virtually, which removes our ability to 325 // static_cast to the subclass. 326 virtual RenderWidgetHostImpl* AsRenderWidgetHostImpl() = 0; 327}; 328 329} // namespace content 330 331#endif // CONTENT_PUBLIC_BROWSER_RENDER_WIDGET_HOST_H_ 332