gecko-dev/browser/modules/NetworkPrioritizer.jsm
2012-05-21 12:12:37 +01:00

186 lines
5.6 KiB
JavaScript

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/*
* This module adjusts network priority for tabs in a way that gives 'important'
* tabs a higher priority. There are 3 levels of priority. Each is listed below
* with the priority adjustment used.
*
* Highest (-10): Selected tab in the focused window.
* Medium (0): Background tabs in the focused window.
* Selected tab in background windows.
* Lowest (+10): Background tabs in background windows.
*/
let EXPORTED_SYMBOLS = ["trackBrowserWindow"];
const Ci = Components.interfaces;
Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
// Lazy getters
XPCOMUtils.defineLazyServiceGetter(this, "_focusManager",
"@mozilla.org/focus-manager;1",
"nsIFocusManager");
// Constants
const TAB_EVENTS = ["TabOpen", "TabSelect"];
const WINDOW_EVENTS = ["activate", "unload"];
// PRIORITY DELTA is -10 because lower priority value is actually a higher priority
const PRIORITY_DELTA = -10;
// Variables
let _lastFocusedWindow = null;
let _windows = [];
// Exported symbol
function trackBrowserWindow(aWindow) {
WindowHelper.addWindow(aWindow);
}
// Global methods
function _handleEvent(aEvent) {
switch (aEvent.type) {
case "TabOpen":
BrowserHelper.onOpen(aEvent.target.linkedBrowser);
break;
case "TabSelect":
BrowserHelper.onSelect(aEvent.target.linkedBrowser);
break;
case "activate":
WindowHelper.onActivate(aEvent.target);
break;
case "unload":
WindowHelper.removeWindow(aEvent.currentTarget);
break;
}
}
// Methods that impact a browser. Put into single object for organization.
let BrowserHelper = {
onOpen: function NP_BH_onOpen(aBrowser) {
// If the tab is in the focused window, leave priority as it is
if (aBrowser.ownerDocument.defaultView != _lastFocusedWindow)
this.decreasePriority(aBrowser);
},
onSelect: function NP_BH_onSelect(aBrowser) {
let windowEntry = WindowHelper.getEntry(aBrowser.ownerDocument.defaultView);
if (windowEntry.lastSelectedBrowser)
this.decreasePriority(windowEntry.lastSelectedBrowser);
this.increasePriority(aBrowser);
windowEntry.lastSelectedBrowser = aBrowser;
},
// Auxiliary methods
getLoadgroup: function NP_BH_getLoadgroup(aBrowser) {
return aBrowser.webNavigation.QueryInterface(Ci.nsIDocumentLoader)
.loadGroup.QueryInterface(Ci.nsISupportsPriority);
},
increasePriority: function NP_BH_increasePriority(aBrowser) {
this.getLoadgroup(aBrowser).adjustPriority(PRIORITY_DELTA);
},
decreasePriority: function NP_BH_decreasePriority(aBrowser) {
this.getLoadgroup(aBrowser).adjustPriority(PRIORITY_DELTA * -1);
}
};
// Methods that impact a window. Put into single object for organization.
let WindowHelper = {
addWindow: function NP_WH_addWindow(aWindow) {
// Build internal data object
_windows.push({ window: aWindow, lastSelectedBrowser: null });
// Add event listeners
TAB_EVENTS.forEach(function(event) {
aWindow.gBrowser.tabContainer.addEventListener(event, _handleEvent, false);
});
WINDOW_EVENTS.forEach(function(event) {
aWindow.addEventListener(event, _handleEvent, false);
});
// This gets called AFTER activate event, so if this is the focused window
// we want to activate it. Otherwise, deprioritize it.
if (aWindow == _focusManager.activeWindow)
this.handleFocusedWindow(aWindow);
else
this.decreasePriority(aWindow);
// Select the selected tab
BrowserHelper.onSelect(aWindow.gBrowser.selectedBrowser);
},
removeWindow: function NP_WH_removeWindow(aWindow) {
if (aWindow == _lastFocusedWindow)
_lastFocusedWindow = null;
// Delete this window from our tracking
_windows.splice(this.getEntryIndex(aWindow), 1);
// Remove the event listeners
TAB_EVENTS.forEach(function(event) {
aWindow.gBrowser.tabContainer.removeEventListener(event, _handleEvent, false);
});
WINDOW_EVENTS.forEach(function(event) {
aWindow.removeEventListener(event, _handleEvent, false);
});
},
onActivate: function NP_WH_onActivate(aWindow, aHasFocus) {
// If this window was the last focused window, we don't need to do anything
if (aWindow == _lastFocusedWindow)
return;
// handleFocusedWindow will deprioritize the current window
this.handleFocusedWindow(aWindow);
// Lastly we should increase priority for this window
this.increasePriority(aWindow);
},
handleFocusedWindow: function NP_WH_handleFocusedWindow(aWindow) {
// If we have a last focused window, we need to deprioritize it first
if (_lastFocusedWindow)
this.decreasePriority(_lastFocusedWindow);
// aWindow is now focused
_lastFocusedWindow = aWindow;
},
// Auxiliary methods
increasePriority: function NP_WH_increasePriority(aWindow) {
aWindow.gBrowser.browsers.forEach(function(aBrowser) {
BrowserHelper.increasePriority(aBrowser);
});
},
decreasePriority: function NP_WH_decreasePriority(aWindow) {
aWindow.gBrowser.browsers.forEach(function(aBrowser) {
BrowserHelper.decreasePriority(aBrowser);
});
},
getEntry: function NP_WH_getEntry(aWindow) {
return _windows[this.getEntryIndex(aWindow)];
},
getEntryIndex: function NP_WH_getEntryAtIndex(aWindow) {
// Assumes that every object has a unique window & it's in the array
for (let i = 0; i < _windows.length; i++)
if (_windows[i].window == aWindow)
return i;
}
};