1 files changed, 195 insertions, 0 deletions
diff --git a/components/downloads/src/DownloadLastDir.jsm b/components/downloads/src/DownloadLastDir.jsm
new file mode 100644
index 000000000..552fd3ef1
--- /dev/null
+++ b/components/downloads/src/DownloadLastDir.jsm
@@ -0,0 +1,195 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* 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/. */
+
+/*
+ * The behavior implemented by gDownloadLastDir is documented here.
+ *
+ * In normal browsing sessions, gDownloadLastDir uses the browser.download.lastDir
+ * preference to store the last used download directory. The first time the user
+ * switches into the private browsing mode, the last download directory is
+ * preserved to the pref value, but if the user switches to another directory
+ * during the private browsing mode, that directory is not stored in the pref,
+ * and will be merely kept in memory.  When leaving the private browsing mode,
+ * this in-memory value will be discarded, and the last download directory
+ * will be reverted to the pref value.
+ *
+ * Both the pref and the in-memory value will be cleared when clearing the
+ * browsing history.  This effectively changes the last download directory
+ * to the default download directory on each platform.
+ *
+ * If passed a URI, the last used directory is also stored with that URI in the
+ * content preferences database. This can be disabled by setting the pref
+ * browser.download.lastDir.savePerSite to false.
+ */
+
+const LAST_DIR_PREF = "browser.download.lastDir";
+const SAVE_PER_SITE_PREF = LAST_DIR_PREF + ".savePerSite";
+const nsIFile = Components.interfaces.nsIFile;
+
+this.EXPORTED_SYMBOLS = [ "DownloadLastDir" ];
+
+Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
+Components.utils.import("resource://gre/modules/Services.jsm");
+Components.utils.import("resource://gre/modules/PrivateBrowsingUtils.jsm");
+
+var observer = {
+  QueryInterface: function (aIID) {
+    if (aIID.equals(Components.interfaces.nsIObserver) ||
+        aIID.equals(Components.interfaces.nsISupports) ||
+        aIID.equals(Components.interfaces.nsISupportsWeakReference))
+      return this;
+    throw Components.results.NS_NOINTERFACE;
+  },
+  observe: function (aSubject, aTopic, aData) {
+    switch (aTopic) {
+      case "last-pb-context-exited":
+        gDownloadLastDirFile = null;
+        break;
+      case "browser:purge-session-history":
+        gDownloadLastDirFile = null;
+        if (Services.prefs.prefHasUserValue(LAST_DIR_PREF))
+          Services.prefs.clearUserPref(LAST_DIR_PREF);
+        // Ensure that purging session history causes both the session-only PB cache
+        // and persistent prefs to be cleared.
+        let cps2 = Components.classes["@mozilla.org/content-pref/service;1"].
+                     getService(Components.interfaces.nsIContentPrefService2);
+
+        cps2.removeByName(LAST_DIR_PREF, {usePrivateBrowsing: false});
+        cps2.removeByName(LAST_DIR_PREF, {usePrivateBrowsing: true});
+        break;
+    }
+  }
+};
+
+var os = Components.classes["@mozilla.org/observer-service;1"]
+                   .getService(Components.interfaces.nsIObserverService);
+os.addObserver(observer, "last-pb-context-exited", true);
+os.addObserver(observer, "browser:purge-session-history", true);
+
+function readLastDirPref() {
+  try {
+    return Services.prefs.getComplexValue(LAST_DIR_PREF, nsIFile);
+  }
+  catch (e) {
+    return null;
+  }
+}
+
+function isContentPrefEnabled() {
+  try {
+    return Services.prefs.getBoolPref(SAVE_PER_SITE_PREF);
+  }
+  catch (e) {
+    return true;
+  }
+}
+
+var gDownloadLastDirFile = readLastDirPref();
+
+this.DownloadLastDir = function DownloadLastDir(aWindow) {
+  let loadContext = aWindow.QueryInterface(Components.interfaces.nsIInterfaceRequestor)
+                           .getInterface(Components.interfaces.nsIWebNavigation)
+                           .QueryInterface(Components.interfaces.nsILoadContext);
+  // Need this in case the real thing has gone away by the time we need it.
+  // We only care about the private browsing state. All the rest of the
+  // load context isn't of interest to the content pref service.
+  this.fakeContext = {
+    QueryInterface: XPCOMUtils.generateQI([Components.interfaces.nsILoadContext]),
+    usePrivateBrowsing: loadContext.usePrivateBrowsing,
+    originAttributes: {},
+  };
+}
+
+DownloadLastDir.prototype = {
+  isPrivate: function DownloadLastDir_isPrivate() {
+    return this.fakeContext.usePrivateBrowsing;
+  },
+  // compat shims
+  get file() { return this._getLastFile(); },
+  set file(val) { this.setFile(null, val); },
+  cleanupPrivateFile: function () {
+    gDownloadLastDirFile = null;
+  },
+  // This function is now deprecated as it uses the sync nsIContentPrefService
+  // interface. New consumers should use the getFileAsync function.
+  getFile: function (aURI) {
+    let Deprecated = Components.utils.import("resource://gre/modules/Deprecated.jsm", {}).Deprecated;
+    Deprecated.warning("DownloadLastDir.getFile is deprecated. Please use getFileAsync instead.",
+                       "https://developer.mozilla.org/en-US/docs/Mozilla/JavaScript_code_modules/DownloadLastDir.jsm",
+                       Components.stack.caller);
+
+    if (aURI && isContentPrefEnabled()) {
+      let lastDir = Services.contentPrefs.getPref(aURI, LAST_DIR_PREF, this.fakeContext);
+      if (lastDir) {
+        var lastDirFile = Components.classes["@mozilla.org/file/local;1"]
+                                    .createInstance(Components.interfaces.nsIFile);
+        lastDirFile.initWithPath(lastDir);
+        return lastDirFile;
+      }
+    }
+    return this._getLastFile();
+  },
+
+  _getLastFile: function () {
+    if (gDownloadLastDirFile && !gDownloadLastDirFile.exists())
+      gDownloadLastDirFile = null;
+
+    if (this.isPrivate()) {
+      if (!gDownloadLastDirFile)
+        gDownloadLastDirFile = readLastDirPref();
+      return gDownloadLastDirFile;
+    }
+    return readLastDirPref();
+  },
+
+  getFileAsync: function(aURI, aCallback) {
+    let plainPrefFile = this._getLastFile();
+    if (!aURI || !isContentPrefEnabled()) {
+      Services.tm.mainThread.dispatch(() => aCallback(plainPrefFile),
+                                      Components.interfaces.nsIThread.DISPATCH_NORMAL);
+      return;
+    }
+
+    let uri = aURI instanceof Components.interfaces.nsIURI ? aURI.spec : aURI;
+    let cps2 = Components.classes["@mozilla.org/content-pref/service;1"]
+                         .getService(Components.interfaces.nsIContentPrefService2);
+    let result = null;
+    cps2.getByDomainAndName(uri, LAST_DIR_PREF, this.fakeContext, {
+      handleResult: aResult => result = aResult,
+      handleCompletion: function(aReason) {
+        let file = plainPrefFile;
+        if (aReason == Components.interfaces.nsIContentPrefCallback2.COMPLETE_OK &&
+           result instanceof Components.interfaces.nsIContentPref) {
+          file = Components.classes["@mozilla.org/file/local;1"]
+                           .createInstance(Components.interfaces.nsIFile);
+          file.initWithPath(result.value);
+        }
+        aCallback(file);
+      }
+    });
+  },
+
+  setFile: function (aURI, aFile) {
+    if (aURI && isContentPrefEnabled()) {
+      let uri = aURI instanceof Components.interfaces.nsIURI ? aURI.spec : aURI;
+      let cps2 = Components.classes["@mozilla.org/content-pref/service;1"]
+                           .getService(Components.interfaces.nsIContentPrefService2);
+      if (aFile instanceof Components.interfaces.nsIFile)
+        cps2.set(uri, LAST_DIR_PREF, aFile.path, this.fakeContext);
+      else
+        cps2.removeByDomainAndName(uri, LAST_DIR_PREF, this.fakeContext);
+    }
+    if (this.isPrivate()) {
+      if (aFile instanceof Components.interfaces.nsIFile)
+        gDownloadLastDirFile = aFile.clone();
+      else
+        gDownloadLastDirFile = null;
+    } else if (aFile instanceof Components.interfaces.nsIFile) {
+      Services.prefs.setComplexValue(LAST_DIR_PREF, nsIFile, aFile);
+    } else if (Services.prefs.prefHasUserValue(LAST_DIR_PREF)) {
+      Services.prefs.clearUserPref(LAST_DIR_PREF);
+    }
+  }
+};