michael@0: /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* vim: set ts=2 et sw=2 tw=80 filetype=javascript: */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: /**
michael@0:  * Handles the download progress indicator in the taskbar.
michael@0:  */
michael@0: 
michael@0: "use strict";
michael@0: 
michael@0: this.EXPORTED_SYMBOLS = [
michael@0:   "DownloadsTaskbar",
michael@0: ];
michael@0: 
michael@0: ////////////////////////////////////////////////////////////////////////////////
michael@0: //// Globals
michael@0: 
michael@0: const Cc = Components.classes;
michael@0: const Ci = Components.interfaces;
michael@0: const Cu = Components.utils;
michael@0: const Cr = Components.results;
michael@0: 
michael@0: Cu.import("resource://gre/modules/XPCOMUtils.jsm");
michael@0: 
michael@0: XPCOMUtils.defineLazyModuleGetter(this, "Downloads",
michael@0:                                   "resource://gre/modules/Downloads.jsm");
michael@0: XPCOMUtils.defineLazyModuleGetter(this, "RecentWindow",
michael@0:                                   "resource:///modules/RecentWindow.jsm");
michael@0: XPCOMUtils.defineLazyModuleGetter(this, "Services",
michael@0:                                   "resource://gre/modules/Services.jsm");
michael@0: 
michael@0: XPCOMUtils.defineLazyGetter(this, "gWinTaskbar", function () {
michael@0:   if (!("@mozilla.org/windows-taskbar;1" in Cc)) {
michael@0:     return null;
michael@0:   }
michael@0:   let winTaskbar = Cc["@mozilla.org/windows-taskbar;1"]
michael@0:                      .getService(Ci.nsIWinTaskbar);
michael@0:   return winTaskbar.available && winTaskbar;
michael@0: });
michael@0: 
michael@0: XPCOMUtils.defineLazyGetter(this, "gMacTaskbarProgress", function () {
michael@0:   return ("@mozilla.org/widget/macdocksupport;1" in Cc) &&
michael@0:          Cc["@mozilla.org/widget/macdocksupport;1"]
michael@0:            .getService(Ci.nsITaskbarProgress);
michael@0: });
michael@0: 
michael@0: ////////////////////////////////////////////////////////////////////////////////
michael@0: //// DownloadsTaskbar
michael@0: 
michael@0: /**
michael@0:  * Handles the download progress indicator in the taskbar.
michael@0:  */
michael@0: this.DownloadsTaskbar = {
michael@0:   /**
michael@0:    * Underlying DownloadSummary providing the aggregate download information, or
michael@0:    * null if the indicator has never been initialized.
michael@0:    */
michael@0:   _summary: null,
michael@0: 
michael@0:   /**
michael@0:    * nsITaskbarProgress object to which download information is dispatched.
michael@0:    * This can be null if the indicator has never been initialized or if the
michael@0:    * indicator is currently hidden on Windows.
michael@0:    */
michael@0:   _taskbarProgress: null,
michael@0: 
michael@0:   /**
michael@0:    * This method is called after a new browser window is opened, and ensures
michael@0:    * that the download progress indicator is displayed in the taskbar.
michael@0:    *
michael@0:    * On Windows, the indicator is attached to the first browser window that
michael@0:    * calls this method.  When the window is closed, the indicator is moved to
michael@0:    * another browser window, if available, in no particular order.  When there
michael@0:    * are no browser windows visible, the indicator is hidden.
michael@0:    *
michael@0:    * On Mac OS X, the indicator is initialized globally when this method is
michael@0:    * called for the first time.  Subsequent calls have no effect.
michael@0:    *
michael@0:    * @param aBrowserWindow
michael@0:    *        nsIDOMWindow object of the newly opened browser window to which the
michael@0:    *        indicator may be attached.
michael@0:    */
michael@0:   registerIndicator: function (aBrowserWindow)
michael@0:   {
michael@0:     if (!this._taskbarProgress) {
michael@0:       if (gMacTaskbarProgress) {
michael@0:         // On Mac OS X, we have to register the global indicator only once.
michael@0:         this._taskbarProgress = gMacTaskbarProgress;
michael@0:         // Free the XPCOM reference on shutdown, to prevent detecting a leak.
michael@0:         Services.obs.addObserver(() => {
michael@0:           this._taskbarProgress = null;
michael@0:           gMacTaskbarProgress = null;
michael@0:         }, "quit-application-granted", false);
michael@0:       } else if (gWinTaskbar) {
michael@0:         // On Windows, the indicator is currently hidden because we have no
michael@0:         // previous browser window, thus we should attach the indicator now.
michael@0:         this._attachIndicator(aBrowserWindow);
michael@0:       } else {
michael@0:         // The taskbar indicator is not available on this platform.
michael@0:         return;
michael@0:       }
michael@0:     }
michael@0: 
michael@0:     // Ensure that the DownloadSummary object will be created asynchronously.
michael@0:     if (!this._summary) {
michael@0:       Downloads.getSummary(Downloads.ALL).then(summary => {
michael@0:         // In case the method is re-entered, we simply ignore redundant
michael@0:         // invocations of the callback, instead of keeping separate state.
michael@0:         if (this._summary) {
michael@0:           return;
michael@0:         }
michael@0:         this._summary = summary;
michael@0:         return this._summary.addView(this);
michael@0:       }).then(null, Cu.reportError);
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * On Windows, attaches the taskbar indicator to the specified browser window.
michael@0:    */
michael@0:   _attachIndicator: function (aWindow)
michael@0:   {
michael@0:     // Activate the indicator on the specified window.
michael@0:     let docShell = aWindow.QueryInterface(Ci.nsIInterfaceRequestor)
michael@0:                           .getInterface(Ci.nsIWebNavigation)
michael@0:                           .QueryInterface(Ci.nsIDocShellTreeItem).treeOwner
michael@0:                           .QueryInterface(Ci.nsIInterfaceRequestor)
michael@0:                           .getInterface(Ci.nsIXULWindow).docShell;
michael@0:     this._taskbarProgress = gWinTaskbar.getTaskbarProgress(docShell);
michael@0: 
michael@0:     // If the DownloadSummary object has already been created, we should update
michael@0:     // the state of the new indicator, otherwise it will be updated as soon as
michael@0:     // the DownloadSummary view is registered.
michael@0:     if (this._summary) {
michael@0:       this.onSummaryChanged();
michael@0:     }
michael@0: 
michael@0:     aWindow.addEventListener("unload", () => {
michael@0:       // Locate another browser window, excluding the one being closed.
michael@0:       let browserWindow = RecentWindow.getMostRecentBrowserWindow();
michael@0:       if (browserWindow) {
michael@0:         // Move the progress indicator to the other browser window.
michael@0:         this._attachIndicator(browserWindow);
michael@0:       } else {
michael@0:         // The last browser window has been closed.  We remove the reference to
michael@0:         // the taskbar progress object so that the indicator will be registered
michael@0:         // again on the next browser window that is opened.
michael@0:         this._taskbarProgress = null;
michael@0:       }
michael@0:     }, false);
michael@0:   },
michael@0: 
michael@0:   //////////////////////////////////////////////////////////////////////////////
michael@0:   //// DownloadSummary view
michael@0: 
michael@0:   onSummaryChanged: function ()
michael@0:   {
michael@0:     // If the last browser window has been closed, we have no indicator anymore.
michael@0:     if (!this._taskbarProgress) {
michael@0:       return;
michael@0:     }
michael@0: 
michael@0:     if (this._summary.allHaveStopped || this._summary.progressTotalBytes == 0) {
michael@0:       this._taskbarProgress.setProgressState(
michael@0:                                Ci.nsITaskbarProgress.STATE_NO_PROGRESS, 0, 0);
michael@0:     } else {
michael@0:       // For a brief moment before completion, some download components may
michael@0:       // report more transferred bytes than the total number of bytes.  Thus,
michael@0:       // ensure that we never break the expectations of the progress indicator.
michael@0:       let progressCurrentBytes = Math.min(this._summary.progressTotalBytes,
michael@0:                                           this._summary.progressCurrentBytes);
michael@0:       this._taskbarProgress.setProgressState(
michael@0:                                Ci.nsITaskbarProgress.STATE_NORMAL,
michael@0:                                progressCurrentBytes,
michael@0:                                this._summary.progressTotalBytes);
michael@0:     }
michael@0:   },
michael@0: };