ios/web/public/app/web_main_parts.h

   1 // Copyright 2014 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 IOS_WEB_PUBLIC_APP_WEB_MAIN_PARTS_H_
   6 #define IOS_WEB_PUBLIC_APP_WEB_MAIN_PARTS_H_
   7
   8 #include "base/basictypes.h"
   9
  10 namespace web {
  11
  12 // This class contains different "stages" to be executed by |WebMain()|.
  13 // Each stage is represented by a single WebMainParts method, called from
  14 // the corresponding method in |WebMainLoop| (e.g., EarlyInitialization())
  15 // which does the following:
  16 //  - calls a method (e.g., "PreEarlyInitialization()") which implements
  17 //    platform / tookit specific code for that stage.
  18 //  - calls various methods for things common to all platforms (for that stage).
  19 //  - calls a method (e.g., "PostEarlyInitialization()") for platform-specific
  20 //    code to be called after the common code.
  21 //
  22 // Stages:
  23 //  - EarlyInitialization: things which should be done as soon as possible on
  24 //    program start (such as setting up signal handlers) and things to be done
  25 //    at some generic time before the start of the main message loop.
  26 //  - MainMessageLoopStart: things beginning with the start of the main message
  27 //    loop and ending with initialization of the main thread; things which
  28 //    should be done immediately before the start of the main message loop
  29 //    should go in |PreMainMessageLoopStart()|.
  30 //  - RunMainMessageLoopParts:  things to be done before and after invoking the
  31 //    main message loop run method (e.g. MessageLoopForUI::current()->Run()).
  32 //
  33 // How to add stuff (to existing parts):
  34 //  - Figure out when your new code should be executed. What must happen
  35 //    before/after your code is executed? Are there performance reasons for
  36 //    running your code at a particular time? Document these things!
  37 //  - Unless your new code is just one or two lines, put it into a separate
  38 //    method with a well-defined purpose. (Likewise, if you're adding to an
  39 //    existing chunk which makes it longer than one or two lines, please move
  40 //    the code out into a separate method.)
  41 //
  42 class WebMainParts {
  43  public:
  44   WebMainParts() {}
  45   virtual ~WebMainParts() {}
  46
  47   virtual void PreEarlyInitialization() {}
  48
  49   virtual void PostEarlyInitialization() {}
  50
  51   virtual void PreMainMessageLoopStart() {}
  52
  53   virtual void PostMainMessageLoopStart() {}
  54
  55   // Called just before any child threads owned by the web
  56   // framework are created.
  57   //
  58   // The main message loop has been started at this point (but has not
  59   // been run), and the toolkit has been initialized. Returns the error code
  60   // (or 0 if no error).
  61   virtual int PreCreateThreads();
  62
  63   // This is called just before the main message loop is run.  The
  64   // various browser threads have all been created at this point
  65   virtual void PreMainMessageLoopRun() {}
  66
  67   // This happens after the main message loop has stopped, but before
  68   // threads are stopped.
  69   virtual void PostMainMessageLoopRun() {}
  70
  71   // Called as the very last part of shutdown, after threads have been
  72   // stopped and destroyed.
  73   virtual void PostDestroyThreads() {}
  74 };
  75
  76 }  // namespace web
  77
  78 #endif  // IOS_WEB_PUBLIC_APP_WEB_MAIN_PARTS_H_