1 files changed, 194 insertions, 0 deletions
diff --git a/toolkit/mozapps/downloads/DownloadLastDir.jsm b/toolkit/mozapps/downloads/DownloadLastDir.jsm
new file mode 100644
index 0000000000..d7a59b2219
--- /dev/null
+++ b/toolkit/mozapps/downloads/DownloadLastDir.jsm
@@ -0,0 +1,194 @@
+/* -*- 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 = Ci.nsIFile;
+
+var EXPORTED_SYMBOLS = ["DownloadLastDir"];
+
+const { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
+const { PrivateBrowsingUtils } = ChromeUtils.import(
+  "resource://gre/modules/PrivateBrowsingUtils.jsm"
+);
+
+let nonPrivateLoadContext = Cu.createLoadContext();
+let privateLoadContext = Cu.createPrivateLoadContext();
+
+var observer = {
+  QueryInterface: ChromeUtils.generateQI([
+    "nsIObserver",
+    "nsISupportsWeakReference",
+  ]),
+
+  observe(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 = Cc["@mozilla.org/content-pref/service;1"].getService(
+          Ci.nsIContentPrefService2
+        );
+
+        cps2.removeByName(LAST_DIR_PREF, nonPrivateLoadContext);
+        cps2.removeByName(LAST_DIR_PREF, privateLoadContext);
+        break;
+    }
+  },
+};
+
+Services.obs.addObserver(observer, "last-pb-context-exited", true);
+Services.obs.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();
+
+// aForcePrivate is only used when aWindow is null.
+function DownloadLastDir(aWindow, aForcePrivate) {
+  let isPrivate = false;
+  if (aWindow === null) {
+    isPrivate = aForcePrivate || PrivateBrowsingUtils.permanentPrivateBrowsing;
+  } else {
+    let loadContext = aWindow.docShell.QueryInterface(Ci.nsILoadContext);
+    isPrivate = loadContext.usePrivateBrowsing;
+  }
+
+  // We always use a fake load context because we may not have one (i.e.,
+  // in the aWindow == null case) and because the load context associated
+  // with aWindow may disappear by the time we need it. This approach is
+  // safe because 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 = isPrivate ? privateLoadContext : nonPrivateLoadContext;
+}
+
+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() {
+    gDownloadLastDirFile = null;
+  },
+
+  _getLastFile() {
+    if (gDownloadLastDirFile && !gDownloadLastDirFile.exists()) {
+      gDownloadLastDirFile = null;
+    }
+
+    if (this.isPrivate()) {
+      if (!gDownloadLastDirFile) {
+        gDownloadLastDirFile = readLastDirPref();
+      }
+      return gDownloadLastDirFile;
+    }
+    return readLastDirPref();
+  },
+
+  getFileAsync(aURI, aCallback) {
+    let plainPrefFile = this._getLastFile();
+    if (!aURI || !isContentPrefEnabled()) {
+      Services.tm.dispatchToMainThread(() => aCallback(plainPrefFile));
+      return;
+    }
+
+    let uri = aURI instanceof Ci.nsIURI ? aURI.spec : aURI;
+    let cps2 = Cc["@mozilla.org/content-pref/service;1"].getService(
+      Ci.nsIContentPrefService2
+    );
+    let result = null;
+    cps2.getByDomainAndName(uri, LAST_DIR_PREF, this.fakeContext, {
+      handleResult: aResult => (result = aResult),
+      handleCompletion(aReason) {
+        let file = plainPrefFile;
+        if (
+          aReason == Ci.nsIContentPrefCallback2.COMPLETE_OK &&
+          result instanceof Ci.nsIContentPref
+        ) {
+          try {
+            file = Cc["@mozilla.org/file/local;1"].createInstance(Ci.nsIFile);
+            file.initWithPath(result.value);
+          } catch (e) {
+            file = plainPrefFile;
+          }
+        }
+        aCallback(file);
+      },
+    });
+  },
+
+  setFile(aURI, aFile) {
+    if (aURI && isContentPrefEnabled()) {
+      let uri = aURI instanceof Ci.nsIURI ? aURI.spec : aURI;
+      let cps2 = Cc["@mozilla.org/content-pref/service;1"].getService(
+        Ci.nsIContentPrefService2
+      );
+      if (aFile instanceof Ci.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 Ci.nsIFile) {
+        gDownloadLastDirFile = aFile.clone();
+      } else {
+        gDownloadLastDirFile = null;
+      }
+    } else if (aFile instanceof Ci.nsIFile) {
+      Services.prefs.setComplexValue(LAST_DIR_PREF, nsIFile, aFile);
+    } else if (Services.prefs.prefHasUserValue(LAST_DIR_PREF)) {
+      Services.prefs.clearUserPref(LAST_DIR_PREF);
+    }
+  },
+};