CEF3 笔记三(常用类的介绍)

接上文《CEF3 笔记二(常用的类介绍)》

CefBrowserHost 类介绍

CefBrowserHost: 该类在浏览器窗口来看代表了 browser 进程，同时也暴露了与浏览器窗口相关的接口，该类的方法只能在 browser 进程中调用，但可以在 browser 进程的任意线程中被调用。该类的主要方法如下：

• 创建浏览器对象。

需要传入的参数包括 CefWindowInfo 对象，CefClient 对象，默认的 URL， 以及浏览器启动时参数设置。

public static bool CreateBrowser(const CefWindowInfo& windowInfo,
                       CefRefPtr<CefClient> client, const CefString& url,
                       const CefBrowserSettings& settings);

public static CefRefPtr<CefBrowser> CreateBrowserSync(
                  const CefWindowInfo& windowInfo,
                  CefRefPtr< CefClient > client,
                  const CefString& url, const CefBrowserSettings& settings);

• 请求关闭浏览器对象。该函数被调用是会触发 JS 'onbeforeunload' 事件，如果参数 force_close为 false，并且提供了 onbeforeunload 事件的回调函数，则提示用户是否关闭浏览器，此时用户可以选取取消操作。如果 force_close为 true，则直接关闭浏览器。

public virtual void CloseBrowser(bool force_close)= 0;

• 获取浏览器对象(在 CefBrowser 类中可以通过调用 GetHost() 获取与之对应的 CefBrowserHost)

public virtual CefRefPtr< CefBrowser > GetBrowser()= 0;

• 获取 CefClient 对象

public virtual CefRefPtr< CefClient > GetClient()= 0;

• 获取该浏览器对象的窗口句柄，如果是弹出窗口，则返回 NULL。

public virtual CefWindowHandle GetOpenerWindowHandle()= 0;

CefBrowser 类介绍

CefBrowser: 该类代表一个浏览器对象，在 browser 进程中该类的方法可以被任意线程调用。在 render 进程中只能在主线程被调用。该类的主要方法包括：

  // Returns the browser host object. This method can only be called in the
  // browser process.
  virtual CefRefPtr<CefBrowserHost> GetHost() =0;

  // Returns true if the browser can navigate backwards.
  virtual bool CanGoBack() =0;

  // Navigate backwards.
  virtual void GoBack() =0;

  // Returns true if the browser can navigate forwards.
  virtual bool CanGoForward() =0;

  // Navigate forwards.
  virtual void GoForward() =0;

  // Returns true if the browser is currently loading.
  virtual bool IsLoading() =0;

  // Reload the current page.
  virtual void Reload() =0;

  // Reload the current page ignoring any cached data.
  virtual void ReloadIgnoreCache() =0;

  // Stop loading the page.
  virtual void StopLoad() =0;

  // Returns the globally unique identifier for this browser.
  virtual int GetIdentifier() =0;

  // Returns true if this object is pointing to the same handle as |that|
  // object.
  virtual bool IsSame(CefRefPtr<CefBrowser> that) =0;

  // Returns true if the window is a popup window.
  virtual bool IsPopup() =0;

  // Returns true if a document has been loaded in the browser.
  virtual bool HasDocument() =0;

  // Returns the main (top-level) frame for the browser window.
  virtual CefRefPtr<CefFrame> GetMainFrame() =0;

  // Returns the focused frame for the browser window.
  virtual CefRefPtr<CefFrame> GetFocusedFrame() =0;

  // Returns the frame with the specified identifier, or NULL if not found.
  virtual CefRefPtr<CefFrame> GetFrame(int64 identifier) =0;

  // Returns the frame with the specified name, or NULL if not found.
  virtual CefRefPtr<CefFrame> GetFrame(const CefString& name) =0;

  // Returns the number of frames that currently exist.
  virtual size_t GetFrameCount() =0;

  // Returns the identifiers of all existing frames.
  virtual void GetFrameIdentifiers(std::vector<int64>& identifiers) =0;

  // Returns the names of all existing frames.
  virtual void GetFrameNames(std::vector<CefString>& names) =0;

  // Send a message to the specified |target_process|. Returns true if the
  // message was sent successfully.
  virtual bool SendProcessMessage(CefProcessId target_process,
                                  CefRefPtr<CefProcessMessage> message) =0;

CefFrame 类介绍

CefFrame: 表示浏览器窗口中的一个 frame，在 browser 进程中该类的方法可以被任意线程调用（简单理解就是 Frame 标识一个页面，通过该类开发者可以加载某一URL 或者一段 HTML 代码，获取页面的源码和文本，URL，V8 执行上下文，访问页面中的 DOM）。该类的主要方法如下：

  // True if this object is currently attached to a valid frame.
  virtual bool IsValid() =0;

  // Execute undo in this frame.
  virtual void Undo() =0;

  // Execute redo in this frame.
  virtual void Redo() =0;

  // Execute cut in this frame.
  virtual void Cut() =0;

  // Execute copy in this frame.
  virtual void Copy() =0;

  // Execute paste in this frame.
  virtual void Paste() =0;

  // Execute delete in this frame.
  virtual void Delete() =0;

  // Execute select all in this frame.
  virtual void SelectAll() =0;

  // Save this frame's HTML source to a temporary file and open it in the
  // default text viewing application. This method can only be called from the
  // browser process.
  virtual void ViewSource() =0;

  // Retrieve this frame's HTML source as a string sent to the specified
  // visitor.
  virtual void GetSource(CefRefPtr<CefStringVisitor> visitor) =0;

  // Retrieve this frame's display text as a string sent to the specified
  // visitor.
  virtual void GetText(CefRefPtr<CefStringVisitor> visitor) =0;

  // Load the request represented by the |request| object.
  virtual void LoadRequest(CefRefPtr<CefRequest> request) =0;

  // Load the specified |url|.
  virtual void LoadURL(const CefString& url) =0;

  // Load the contents of |string_val| with the specified dummy |url|. |url|
  // should have a standard scheme (for example, http scheme) or behaviors like
  // link clicks and web security restrictions may not behave as expected.
  virtual void LoadString(const CefString& string_val,
                          const CefString& url) =0;

  // Execute a string of JavaScript code in this frame. The |script_url|
  // parameter is the URL where the script in question can be found, if any.
  // The renderer may request this URL to show the developer the source of the
  // error.  The |start_line| parameter is the base line number to use for error
  // reporting.
  virtual void ExecuteJavaScript(const CefString& code,
                                 const CefString& script_url,
                                 int start_line) =0;

  // Returns true if this is the main (top-level) frame.
  virtual bool IsMain() =0;

  // Returns true if this is the focused frame.
  virtual bool IsFocused() =0;

  // Returns the name for this frame. If the frame has an assigned name (for
  // example, set via the iframe "name" attribute) then that value will be
  // returned. Otherwise a unique name will be constructed based on the frame
  // parent hierarchy. The main (top-level) frame will always have an empty name
  // value.
  virtual CefString GetName() =0;

  // Returns the globally unique identifier for this frame.
  virtual int64 GetIdentifier() =0;

  // Returns the parent of this frame or NULL if this is the main (top-level)
  // frame.
  virtual CefRefPtr<CefFrame> GetParent() =0;

  // Returns the URL currently loaded in this frame.
  virtual CefString GetURL() =0;

  // Returns the browser that this frame belongs to.
  virtual CefRefPtr<CefBrowser> GetBrowser() =0;

  // Get the V8 context associated with the frame. This method can only be
  // called from the render process.
  virtual CefRefPtr<CefV8Context> GetV8Context() =0;
  
  // Visit the DOM document. This method can only be called from the render
  // process.
  virtual void VisitDOM(CefRefPtr<CefDOMVisitor> visitor) =0;