Bug 822572 - Add a Clear Downloads button to the Library view.

r=Mano

browser/components/places/content/downloadsViewOverlay.xul

@@ -4,6 +4,11 @@
 
 <?xul-overlay href="chrome://browser/content/downloads/allDownloadsViewOverlay.xul"?>
 
+<!DOCTYPE overlay [
+<!ENTITY % downloadsDTD SYSTEM "chrome://browser/locale/downloads/downloads.dtd">
+%downloadsDTD;
+]>
+
 <overlay id="downloadsViewOverlay"
          xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
 
@@ -15,7 +20,8 @@
 
     ContentArea.setContentViewForQueryString(DOWNLOADS_QUERY,
       function() new DownloadsPlacesView(document.getElementById("downloadsRichListBox")),
-      { showDetailsPane: false });
+      { showDetailsPane: false,
+        toolbarSet: "back-button, forward-button, organizeButton, clearDownloadsButton, libraryToolbarSpacer, searchFilter" });
   ]]></script>
 
   <window id="places">
@@ -26,4 +32,13 @@
   <deck id="placesViewsDeck">
     <richlistbox id="downloadsRichListBox"/>
   </deck>
+
+  <toolbar id="placesToolbar">
+    <toolbarbutton id="clearDownloadsButton"
+                   insertbefore="libraryToolbarSpacer"
+                   label="&clearDownloadsButton.label;"
+                   command="downloadsCmd_clearDownloads"
+                   tooltiptext="&clearDownloadsButton.tooltip;"/>
+  </toolbar>
+
 </overlay>

browser/components/places/content/places.js

@@ -1252,6 +1252,7 @@ let ContentArea = {
 
   init: function CA_init() {
     this._deck = document.getElementById("placesViewsDeck");
+    this._toolbar = document.getElementById("placesToolbar");
     ContentTree.init();
   },
 
@@ -1315,9 +1316,25 @@ let ContentArea = {
   set currentPlace(aQueryString) {
     this.currentView = this.getContentViewForQueryString(aQueryString);
     this.currentView.place = aQueryString;
+    this._updateToolbarSet();
     return aQueryString;
   },
 
+  _updateToolbarSet: function CA__updateToolbarSet() {
+    let toolbarSet = this.currentViewOptions.toolbarSet;
+    for (let elt of this._toolbar.childNodes) {
+      // On Windows and Linux the menu buttons are menus wrapped in a menubar.
+      if (elt.id == "placesMenu") {
+        for (let menuElt of elt.childNodes) {
+          menuElt.hidden = toolbarSet.indexOf(menuElt.id) == -1;
+        }
+      }
+      else {
+        elt.hidden = toolbarSet.indexOf(elt.id) == -1;
+      }
+    }
+  },
+
   /**
    * Options for the current view.
    *
@@ -1347,7 +1364,10 @@ let ContentTree = {
 
   get view() this._view,
 
-  get viewOptions() Object.seal({ showDetailsPane: true }),
+  get viewOptions() Object.seal({
+    showDetailsPane: true,
+    toolbarSet: "back-button, forward-button, organizeButton, viewMenu, maintenanceButton, libraryToolbarSpacer, searchFilter"
+  }),
 
   openSelectedNode: function CT_openSelectedNode(aEvent) {
     let view = this.view;

browser/components/places/content/places.xul

@@ -326,7 +326,7 @@
       </menubar>
 #endif
 
-      <spacer flex="1"/>
+      <spacer id="libraryToolbarSpacer" flex="1"/>
 
       <textbox id="searchFilter"
                clickSelectsAll="true"

browser/locales/en-US/chrome/browser/downloads/downloads.dtd

@@ -74,3 +74,6 @@
      -->
 <!ENTITY downloadsHistory.label           "Show All Downloads">
 <!ENTITY downloadsHistory.accesskey       "S">
+
+<!ENTITY clearDownloadsButton.label       "Clear Downloads">
+<!ENTITY clearDownloadsButton.tooltip     "Clears completed, canceled and failed downloads">