一、浏览器事件监听类BrowserListObserver：
chrome\browser\ui\browser_list_observer.h
class Browser;enum class BrowserClosingStatus;class BrowserListObserver : public base::CheckedObserver {public:// Called immediately after a browser is added to the list.virtual void OnBrowserAdded(Browser* browser) {}// Called when code attempted to close `browser`, but failed due to `reason`.virtual void OnBrowserCloseCancelled(Browser* browser,BrowserClosingStatus reason) {}// Called when a Browser starts closing. This is called prior to// removing the tabs. Removing the tabs may delay or stop the close.virtual void OnBrowserClosing(Browser* browser) {}// Called immediately after a browser is removed from the list.virtual void OnBrowserRemoved(Browser* browser) {}// Called immediately after a browser is set active (SetLastActive).virtual void OnBrowserSetLastActive(Browser* browser) {}// Called immediately after a browser becomes not active.virtual void OnBrowserNoLongerActive(Browser* browser) {}
};
此类有browser添加 删除 关闭等回调。
二、浏览器browser全局列表BrowserList：
chrome\browser\ui\browser_list.h
class Browser;
class Profile;namespace base {
class FilePath;
}class BrowserListObserver;// Maintains a list of Browser objects.
class BrowserList {public:using BrowserSet = base::flat_set<Browser*>;using BrowserVector = std::vector<raw_ptr<Browser, VectorExperimental>>;using CloseCallback = base::RepeatingCallback<void(const base::FilePath&)>;using const_iterator = BrowserVector::const_iterator;using const_reverse_iterator = BrowserVector::const_reverse_iterator;struct BrowsersOrderedByActivationRange {const raw_ref<const BrowserList> browser_list;const_reverse_iterator begin() const {return browser_list->begin_browsers_ordered_by_activation();}const_reverse_iterator end() const {return browser_list->end_browsers_ordered_by_activation();}private:// Stack allocated only to reduce risk of out of bounds lifetime with// |browser_list|.STACK_ALLOCATED();};BrowserList(const BrowserList&) = delete;BrowserList& operator=(const BrowserList&) = delete;// Returns the last active browser for this list.Browser* GetLastActive() const;const_iterator begin() const { return browsers_.begin(); }const_iterator end() const { return browsers_.end(); }bool empty() const { return browsers_.empty(); }size_t size() const { return browsers_.size(); }Browser* get(size_t index) const { return browsers_[index]; }// Returns iterated access to list of open browsers ordered by activation. The// underlying data structure is a vector and we push_back on recent access so// a reverse iterator gives the latest accessed browser first.const_reverse_iterator begin_browsers_ordered_by_activation() const {return browsers_ordered_by_activation_.rbegin();}const_reverse_iterator end_browsers_ordered_by_activation() const {return browsers_ordered_by_activation_.rend();}// Convenience method for iterating over browsers in activation order.// Example:// for (Browser* browser : BrowserList::GetInstance()->OrderedByActivation())BrowsersOrderedByActivationRange OrderedByActivation() const {return {raw_ref(*this)};}// Returns the set of browsers that are currently in the closing state.const BrowserSet& currently_closing_browsers() const {return currently_closing_browsers_;}static BrowserList* GetInstance();// Adds or removes |browser| from the list it is associated with. The browser// object should be valid BEFORE these calls (for the benefit of observers),// so notify and THEN delete the object.static void AddBrowser(Browser* browser);static void RemoveBrowser(Browser* browser);// Appends active browser windows to |browsers_ordered_by_activation_|.// Prepends inactive browser windows to |browsers_ordered_by_activation_|.static void AddBrowserToActiveList(Browser* browser);// Adds and removes |observer| from the observer list for all desktops.// Observers are responsible for making sure the notifying browser is relevant// to them (e.g., on the specific desktop they care about if any).static void AddObserver(BrowserListObserver* observer);static void RemoveObserver(BrowserListObserver* observer);// Moves all the browsers that show on workspace |new_workspace| to the end of// the browser list (i.e. the browsers that were "activated" most recently).static void MoveBrowsersInWorkspaceToFront(const std::string& new_workspace);// Called by Browser objects when their window is activated (focused). This// allows us to determine what the last active Browser was on each desktop.static void SetLastActive(Browser* browser);// Notifies the observers when the current active browser becomes not active.static void NotifyBrowserNoLongerActive(Browser* browser);// Notifies the observers that the attempted closure of `browser` was// cancelled for a certain `reason`.static void NotifyBrowserCloseCancelled(Browser* browser,BrowserClosingStatus reason);// Notifies the observers when browser close was started. This may be called// more than once for a particular browser.static void NotifyBrowserCloseStarted(Browser* browser);// Closes all browsers for |profile| across all desktops.// TODO(mlerman): Move the Profile Deletion flow to use the overloaded// version of this method with a callback, then remove this method.static void CloseAllBrowsersWithProfile(Profile* profile);// Closes all browsers for |profile| across all desktops. Uses// TryToCloseBrowserList() to do the actual closing. Triggers any// OnBeforeUnload events unless |skip_beforeunload| is true. If all// OnBeforeUnload events are confirmed or |skip_beforeunload| is true,// |on_close_success| is called, otherwise |on_close_aborted| is called. Both// callbacks may be null.// Note that if there is any browser window that has been used before, the// user should always have a chance to save their work before closing windows// without triggering beforeunload events.static void CloseAllBrowsersWithProfile(Profile* profile,const CloseCallback& on_close_success,const CloseCallback& on_close_aborted,bool skip_beforeunload);// Similarly to CloseAllBrowsersWithProfile, but DCHECK's that profile is// Off-the-Record and doesn't close browsers with the original profile.static void CloseAllBrowsersWithIncognitoProfile(Profile* profile,const CloseCallback& on_close_success,const CloseCallback& on_close_aborted,bool skip_beforeunload);// Returns true if at least one off-the-record browser is active across all// desktops.static bool IsOffTheRecordBrowserActive();// Returns the number of active off-the-record browsers for |profile| across// all desktops. Note that this function does not count devtools windows// opened for off-the-record windows.static int GetOffTheRecordBrowsersActiveForProfile(Profile* profile);// Returns the number of active incognito browsers except devtools windows// across all desktops.static size_t GetIncognitoBrowserCount();// Returns the number of active guest browsers except devtools windows// across all desktops.static size_t GetGuestBrowserCount();// Returns true if the off-the-record browser for |profile| is in use in any// window across all desktops. This function considers devtools windows as// well.static bool IsOffTheRecordBrowserInUse(Profile* profile);private:BrowserList();~BrowserList();// Helper method to remove a browser instance from a list of browsersstatic void RemoveBrowserFrom(Browser* browser, BrowserVector* browser_list);// Attempts to close |browsers_to_close| while respecting OnBeforeUnload// events. If there are no OnBeforeUnload events to be called,// |on_close_success| will be called, with a parameter of |profile_path|,// and the Browsers will then be closed. If at least one unfired// OnBeforeUnload event is found, handle it with a callback to// PostTryToCloseBrowserWindow, which upon success will recursively call this// method to handle any other OnBeforeUnload events. If aborted in the// OnBeforeUnload event, PostTryToCloseBrowserWindow will call// |on_close_aborted| instead and reset all OnBeforeUnload event handlers.static void TryToCloseBrowserList(const BrowserVector& browsers_to_close,const CloseCallback& on_close_success,const CloseCallback& on_close_aborted,const base::FilePath& profile_path,const bool skip_beforeunload);// Called after handling an OnBeforeUnload event. If |tab_close_confirmed| is// true, calls |TryToCloseBrowserList()|, passing the parameters// |browsers_to_close|, |on_close_success|, |on_close_aborted|, and// |profile_path|. Otherwise, resets all the OnBeforeUnload event handlers and// calls |on_close_aborted|.static void PostTryToCloseBrowserWindow(const BrowserVector& browsers_to_close,const CloseCallback& on_close_success,const CloseCallback& on_close_aborted,const base::FilePath& profile_path,const bool skip_beforeunload,bool tab_close_confirmed);// A vector of the browsers in this list, in the order they were added.BrowserVector browsers_;// A vector of the browsers in this list, in reverse order of activation. I.e.// the most recently used browser will be at the end. Inactive browser// windows, (e.g., created by session restore) are inserted at the front of// the list.BrowserVector browsers_ordered_by_activation_;// A vector of the browsers that are currently in the closing state.BrowserSet currently_closing_browsers_;// If an observer is added while iterating over them and notifying, it should// not be notified as it probably already saw the Browser* being added/removed// in the BrowserList.struct ObserverListTraits : base::internal::LeakyLazyInstanceTraits<base::ObserverList<BrowserListObserver>> {static base::ObserverList<BrowserListObserver>* New(void* instance) {return new (instance) base::ObserverList<BrowserListObserver>(base::ObserverListPolicy::EXISTING_ONLY);}};// A list of observers which will be notified of every browser addition and// removal across all BrowserLists.static base::LazyInstance<base::ObserverList<BrowserListObserver>,ObserverListTraits>observers_;static BrowserList* instance_;
};三、看下使用方法：
1、BrowserTest 类继承BrowserListObserver：
2、利用BrowserList::GetInstance()->AddObserver(this);和BrowserList::GetInstance()->RemoveObserver(this);添加和移除browser监听事件。
class BrowserTest : public BrowserListObserver {BrowserTest(Profile* profile);~BrowserTest();// BrowserListObserver overrides:void OnBrowserAdded(Browser* browser) override;void OnBrowserRemoved(Browser* browser) override;};BrowserTest::BrowserAppInstanceTracker(Profile* profile) {//注册监听BrowserList::GetInstance()->AddObserver(this);
}BrowserTest::~BrowserAppInstanceTracker() {//移除监听BrowserList::GetInstance()->RemoveObserver(this);
}void BrowserTest::OnBrowserAdded(Browser* browser) {//添加browser
}void BrowserTest::OnBrowserRemoved(Browser* browser) {//删除broser
}
至于监听其他事件可重载BrowserListObserver类里面的虚函数。