summaryrefslogtreecommitdiffstats
path: root/components/downloads/DownloadsTaskbar.jsm
blob: cf915abb58b4a52b8df137410f8eb6c822298171 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
/* vim: set ts=2 et sw=2 tw=80 filetype=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/. */

/**
 * Handles the download progress indicator in the taskbar.
 */

"use strict";

this.EXPORTED_SYMBOLS = [
  "DownloadsTaskbar",
];

////////////////////////////////////////////////////////////////////////////////
//// Globals

const Cc = Components.classes;
const Ci = Components.interfaces;
const Cu = Components.utils;
const Cr = Components.results;

Cu.import("resource://gre/modules/XPCOMUtils.jsm");

XPCOMUtils.defineLazyModuleGetter(this, "Downloads",
                                  "resource://gre/modules/Downloads.jsm");
XPCOMUtils.defineLazyModuleGetter(this, "RecentWindow",
                                  "resource:///modules/RecentWindow.jsm");
XPCOMUtils.defineLazyModuleGetter(this, "Services",
                                  "resource://gre/modules/Services.jsm");

XPCOMUtils.defineLazyGetter(this, "gWinTaskbar", function () {
  if (!("@mozilla.org/windows-taskbar;1" in Cc)) {
    return null;
  }
  let winTaskbar = Cc["@mozilla.org/windows-taskbar;1"]
                     .getService(Ci.nsIWinTaskbar);
  return winTaskbar.available && winTaskbar;
});

XPCOMUtils.defineLazyGetter(this, "gMacTaskbarProgress", function () {
  return ("@mozilla.org/widget/macdocksupport;1" in Cc) &&
         Cc["@mozilla.org/widget/macdocksupport;1"]
           .getService(Ci.nsITaskbarProgress);
});

////////////////////////////////////////////////////////////////////////////////
//// DownloadsTaskbar

/**
 * Handles the download progress indicator in the taskbar.
 */
this.DownloadsTaskbar = {
  /**
   * Underlying DownloadSummary providing the aggregate download information, or
   * null if the indicator has never been initialized.
   */
  _summary: null,

  /**
   * nsITaskbarProgress object to which download information is dispatched.
   * This can be null if the indicator has never been initialized or if the
   * indicator is currently hidden on Windows.
   */
  _taskbarProgress: null,

  /**
   * This method is called after a new browser window is opened, and ensures
   * that the download progress indicator is displayed in the taskbar.
   *
   * On Windows, the indicator is attached to the first browser window that
   * calls this method.  When the window is closed, the indicator is moved to
   * another browser window, if available, in no particular order.  When there
   * are no browser windows visible, the indicator is hidden.
   *
   * On Mac OS X, the indicator is initialized globally when this method is
   * called for the first time.  Subsequent calls have no effect.
   *
   * @param aBrowserWindow
   *        nsIDOMWindow object of the newly opened browser window to which the
   *        indicator may be attached.
   */
  registerIndicator(aBrowserWindow) {
    if (!this._taskbarProgress) {
      if (gMacTaskbarProgress) {
        // On Mac OS X, we have to register the global indicator only once.
        this._taskbarProgress = gMacTaskbarProgress;
        // Free the XPCOM reference on shutdown, to prevent detecting a leak.
        Services.obs.addObserver(() => {
          this._taskbarProgress = null;
          gMacTaskbarProgress = null;
        }, "quit-application-granted", false);
      } else if (gWinTaskbar) {
        // On Windows, the indicator is currently hidden because we have no
        // previous browser window, thus we should attach the indicator now.
        this._attachIndicator(aBrowserWindow);
      } else {
        // The taskbar indicator is not available on this platform.
        return;
      }
    }

    // Ensure that the DownloadSummary object will be created asynchronously.
    if (!this._summary) {
      Downloads.getSummary(Downloads.ALL).then(summary => {
        // In case the method is re-entered, we simply ignore redundant
        // invocations of the callback, instead of keeping separate state.
        if (this._summary) {
          return;
        }
        this._summary = summary;
        return this._summary.addView(this);
      }).then(null, Cu.reportError);
    }
  },

  /**
   * On Windows, attaches the taskbar indicator to the specified browser window.
   */
  _attachIndicator(aWindow) {
    // Activate the indicator on the specified window.
    let docShell = aWindow.QueryInterface(Ci.nsIInterfaceRequestor)
                          .getInterface(Ci.nsIWebNavigation)
                          .QueryInterface(Ci.nsIDocShellTreeItem).treeOwner
                          .QueryInterface(Ci.nsIInterfaceRequestor)
                          .getInterface(Ci.nsIXULWindow).docShell;
    this._taskbarProgress = gWinTaskbar.getTaskbarProgress(docShell);

    // If the DownloadSummary object has already been created, we should update
    // the state of the new indicator, otherwise it will be updated as soon as
    // the DownloadSummary view is registered.
    if (this._summary) {
      this.onSummaryChanged();
    }

    aWindow.addEventListener("unload", () => {
      // Locate another browser window, excluding the one being closed.
      let browserWindow = RecentWindow.getMostRecentBrowserWindow();
      if (browserWindow) {
        // Move the progress indicator to the other browser window.
        this._attachIndicator(browserWindow);
      } else {
        // The last browser window has been closed.  We remove the reference to
        // the taskbar progress object so that the indicator will be registered
        // again on the next browser window that is opened.
        this._taskbarProgress = null;
      }
    }, false);
  },

  //////////////////////////////////////////////////////////////////////////////
  //// DownloadSummary view

  onSummaryChanged() {
    // If the last browser window has been closed, we have no indicator any more.
    if (!this._taskbarProgress) {
      return;
    }

    if (this._summary.allHaveStopped || this._summary.progressTotalBytes == 0) {
      this._taskbarProgress.setProgressState(
                               Ci.nsITaskbarProgress.STATE_NO_PROGRESS, 0, 0);
    } else {
      // For a brief moment before completion, some download components may
      // report more transferred bytes than the total number of bytes.  Thus,
      // ensure that we never break the expectations of the progress indicator.
      let progressCurrentBytes = Math.min(this._summary.progressTotalBytes,
                                          this._summary.progressCurrentBytes);
      this._taskbarProgress.setProgressState(
                               Ci.nsITaskbarProgress.STATE_NORMAL,
                               progressCurrentBytes,
                               this._summary.progressTotalBytes);
    }
  },
};