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_BROWSER_MAIN_PARTS_H_ 6#define CONTENT_PUBLIC_BROWSER_BROWSER_MAIN_PARTS_H_ 7 8#include "base/basictypes.h" 9#include "content/common/content_export.h" 10 11namespace content { 12 13// This class contains different "stages" to be executed by |BrowserMain()|, 14// Each stage is represented by a single BrowserMainParts method, called from 15// the corresponding method in |BrowserMainLoop| (e.g., EarlyInitialization()) 16// which does the following: 17// - calls a method (e.g., "PreEarlyInitialization()") which implements 18// platform / tookit specific code for that stage. 19// - calls various methods for things common to all platforms (for that stage). 20// - calls a method (e.g., "PostEarlyInitialization()") for platform-specific 21// code to be called after the common code. 22// 23// Stages: 24// - EarlyInitialization: things which should be done as soon as possible on 25// program start (such as setting up signal handlers) and things to be done 26// at some generic time before the start of the main message loop. 27// - MainMessageLoopStart: things beginning with the start of the main message 28// loop and ending with initialization of the main thread; platform-specific 29// things which should be done immediately before the start of the main 30// message loop should go in |PreMainMessageLoopStart()|. 31// - RunMainMessageLoopParts: things to be done before and after invoking the 32// main message loop run method (e.g. MessageLoopForUI::current()->Run()). 33// 34// How to add stuff (to existing parts): 35// - Figure out when your new code should be executed. What must happen 36// before/after your code is executed? Are there performance reasons for 37// running your code at a particular time? Document these things! 38// - Split out any platform-specific bits. Please avoid #ifdefs it at all 39// possible. You have two choices for platform-specific code: (1) Execute it 40// from one of the platform-specific |Pre/Post...()| methods; do this if the 41// code is unique to a platform type. Or (2) execute it from one of the 42// "parts" (e.g., |EarlyInitialization()|) and provide platform-specific 43// implementations of your code (in a virtual method); do this if you need to 44// provide different implementations across most/all platforms. 45// - Unless your new code is just one or two lines, put it into a separate 46// method with a well-defined purpose. (Likewise, if you're adding to an 47// existing chunk which makes it longer than one or two lines, please move 48// the code out into a separate method.) 49// 50class CONTENT_EXPORT BrowserMainParts { 51 public: 52 BrowserMainParts() {} 53 virtual ~BrowserMainParts() {} 54 55 virtual void PreEarlyInitialization() {} 56 57 virtual void PostEarlyInitialization() {} 58 59 virtual void PreMainMessageLoopStart() {} 60 61 virtual void PostMainMessageLoopStart() {} 62 63 // Allows an embedder to do any extra toolkit initialization. 64 virtual void ToolkitInitialized() {} 65 66 // Called just before any child threads owned by the content 67 // framework are created. 68 // 69 // The main message loop has been started at this point (but has not 70 // been run), and the toolkit has been initialized. Returns the error code 71 // (or 0 if no error). 72 virtual int PreCreateThreads(); 73 74 // This is called just before the main message loop is run. The 75 // various browser threads have all been created at this point 76 virtual void PreMainMessageLoopRun() {} 77 78 // Returns true if the message loop was run, false otherwise. 79 // If this returns false, the default implementation will be run. 80 // May set |result_code|, which will be returned by |BrowserMain()|. 81 virtual bool MainMessageLoopRun(int* result_code); 82 83 // This happens after the main message loop has stopped, but before 84 // threads are stopped. 85 virtual void PostMainMessageLoopRun() {} 86 87 // Called as the very last part of shutdown, after threads have been 88 // stopped and destroyed. 89 virtual void PostDestroyThreads() {} 90}; 91 92} // namespace content 93 94#endif // CONTENT_PUBLIC_BROWSER_BROWSER_MAIN_PARTS_H_ 95