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      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_WEB_UI_H_
      6 #define CONTENT_PUBLIC_BROWSER_WEB_UI_H_
      7 
      8 #include <vector>
      9 
     10 #include "base/basictypes.h"
     11 #include "base/callback.h"
     12 #include "base/strings/string16.h"
     13 #include "content/common/content_export.h"
     14 #include "content/public/common/page_transition_types.h"
     15 #include "ui/base/layout.h"
     16 
     17 class GURL;
     18 
     19 namespace base {
     20 class ListValue;
     21 class Value;
     22 }
     23 
     24 namespace content {
     25 
     26 class WebContents;
     27 class WebUIController;
     28 class WebUIMessageHandler;
     29 
     30 // A WebUI sets up the datasources and message handlers for a given HTML-based
     31 // UI.
     32 class CONTENT_EXPORT WebUI {
     33  public:
     34   // An opaque identifier used to identify a WebUI. This can only be compared to
     35   // kNoWebUI or other WebUI types. See GetWebUIType.
     36   typedef void* TypeID;
     37 
     38   // A special WebUI type that signifies that a given page would not use the
     39   // Web UI system.
     40   static const TypeID kNoWebUI;
     41 
     42   // Returns JavaScript code that, when executed, calls the function specified
     43   // by |function_name| with the arguments specified in |arg_list|.
     44   static string16 GetJavascriptCall(
     45       const std::string& function_name,
     46       const std::vector<const base::Value*>& arg_list);
     47 
     48   virtual ~WebUI() {}
     49 
     50   virtual WebContents* GetWebContents() const = 0;
     51 
     52   virtual WebUIController* GetController() const = 0;
     53   virtual void SetController(WebUIController* controller) = 0;
     54 
     55   // Returns the device scale factor of the monitor that the renderer is on.
     56   // Whenever possible, WebUI should push resources with this scale factor to
     57   // Javascript.
     58   virtual ui::ScaleFactor GetDeviceScaleFactor() const = 0;
     59 
     60   // Gets a custom tab title provided by the Web UI. If there is no title
     61   // override, the string will be empty which should trigger the default title
     62   // behavior for the tab.
     63   virtual const string16& GetOverriddenTitle() const = 0;
     64   virtual void OverrideTitle(const string16& title) = 0;
     65 
     66   // Returns the transition type that should be used for link clicks on this
     67   // Web UI. This will default to LINK but may be overridden.
     68   virtual PageTransition GetLinkTransitionType() const = 0;
     69   virtual void SetLinkTransitionType(PageTransition type) = 0;
     70 
     71   // Allows a controller to override the BindingsPolicy that should be enabled
     72   // for this page.
     73   virtual int GetBindings() const = 0;
     74   virtual void SetBindings(int bindings) = 0;
     75 
     76   // Sets the path for the iframe if this WebUI is embedded in a page.
     77   virtual void SetFrameXPath(const std::string& xpath) = 0;
     78 
     79   // Takes ownership of |handler|, which will be destroyed when the WebUI is.
     80   virtual void AddMessageHandler(WebUIMessageHandler* handler) = 0;
     81 
     82   // Used by WebUIMessageHandlers. If the given message is already registered,
     83   // the call has no effect unless |register_callback_overwrites_| is set to
     84   // true.
     85   typedef base::Callback<void(const base::ListValue*)> MessageCallback;
     86   virtual void RegisterMessageCallback(const std::string& message,
     87                                        const MessageCallback& callback) = 0;
     88 
     89   // This is only needed if an embedder overrides handling of a WebUIMessage and
     90   // then later wants to undo that, or to route it to a different WebUI object.
     91   virtual void ProcessWebUIMessage(const GURL& source_url,
     92                                    const std::string& message,
     93                                    const base::ListValue& args) = 0;
     94 
     95   // Call a Javascript function by sending its name and arguments down to
     96   // the renderer.  This is asynchronous; there's no way to get the result
     97   // of the call, and should be thought of more like sending a message to
     98   // the page.
     99   // All function names in WebUI must consist of only ASCII characters.
    100   // There are variants for calls with more arguments.
    101   virtual void CallJavascriptFunction(const std::string& function_name) = 0;
    102   virtual void CallJavascriptFunction(const std::string& function_name,
    103                                       const base::Value& arg) = 0;
    104   virtual void CallJavascriptFunction(const std::string& function_name,
    105                                       const base::Value& arg1,
    106                                       const base::Value& arg2) = 0;
    107   virtual void CallJavascriptFunction(const std::string& function_name,
    108                                       const base::Value& arg1,
    109                                       const base::Value& arg2,
    110                                       const base::Value& arg3) = 0;
    111   virtual void CallJavascriptFunction(const std::string& function_name,
    112                                       const base::Value& arg1,
    113                                       const base::Value& arg2,
    114                                       const base::Value& arg3,
    115                                       const base::Value& arg4) = 0;
    116   virtual void CallJavascriptFunction(
    117       const std::string& function_name,
    118       const std::vector<const base::Value*>& args) = 0;
    119 };
    120 
    121 }  // namespace content
    122 
    123 #endif  // CONTENT_PUBLIC_BROWSER_WEB_UI_H_
    124