Bug 583890 - Add visibleLabel attribute/property and tests. r=ttaubert,jaws

browser/base/content/tabbrowser.xml

@@ -1217,11 +1217,6 @@
             var uriIsBlankPage = !aURI || isBlankPageURL(aURI);
             var uriIsNotAboutBlank = aURI && aURI != "about:blank";
 
-            if (uriIsBlankPage)
-              t.setAttribute("label", this.mStringBundle.getString("tabs.emptyTabTitle"));
-            else
-              t.setAttribute("label", aURI);
-
             t.setAttribute("crop", "end");
             t.setAttribute("validate", "never");
             t.setAttribute("onerror", "this.removeAttribute('image');");
@@ -1327,6 +1322,14 @@
             // initialized by this point.
             this.mPanelContainer.appendChild(notificationbox);
 
+            // Happens after the browser is in the DOM: the TabTitleAbridger
+            // classifies tabs by domains, requiring access to the browser.
+            if (uriIsBlankPage) {
+              t.label = this.mStringBundle.getString("tabs.emptyTabTitle");
+            } else {
+              t.label = aURI;
+            }
+
             this.tabContainer.updateVisibility();
 
             if (uriIsNotAboutBlank) {
@@ -2819,8 +2822,7 @@
           this._closeWindowWithLastTab = Services.prefs.getBoolPref("browser.tabs.closeWindowWithLastTab");
 
           var tab = this.firstChild;
-          tab.setAttribute("label",
-                           this.tabbrowser.mStringBundle.getString("tabs.emptyTabTitle"));
+          tab.label = this.tabbrowser.mStringBundle.getString("tabs.emptyTabTitle");
           tab.setAttribute("crop", "end");
           tab.setAttribute("validate", "never");
           tab.setAttribute("onerror", "this.removeAttribute('image');");
@@ -3843,7 +3845,8 @@
                      class="tab-icon-image"
                      role="presentation"/>
           <xul:label flex="1"
-                     xbl:inherits="value=label,crop,accesskey,fadein,pinned,selected"
+                     anonid="tab-label"
+                     xbl:inherits="value=visibleLabel,crop,accesskey,fadein,pinned,selected"
                      class="tab-text tab-label"
                      role="presentation"/>
           <xul:toolbarbutton anonid="close-button"
@@ -3854,6 +3857,30 @@
     </content>
 
     <implementation>
+      <property name="label">
+        <getter>
+          return this.getAttribute("label");
+        </getter>
+        <setter>
+          this.setAttribute("label", val);
+          let event = new CustomEvent("TabLabelModified", {
+            bubbles: true,
+            cancelable: true
+          });
+          this.dispatchEvent(event);
+
+          if (!event.defaultPrevented)
+            this.visibleLabel = val;
+        </setter>
+      </property>
+      <property name="visibleLabel">
+        <getter>
+          return this.getAttribute("visibleLabel");
+        </getter>
+        <setter>
+          this.setAttribute("visibleLabel", val);
+        </setter>
+      </property>
       <property name="pinned" readonly="true">
         <getter>
           return this.getAttribute("pinned") == "true";

browser/base/content/test/Makefile.in

@@ -134,6 +134,7 @@ _BROWSER_FILES = \
                  browser_bug581242.js \
                  browser_bug581253.js \
                  browser_bug581947.js \
+                 browser_bug583890_label.js \
                  browser_bug585785.js \
                  browser_bug585830.js \
                  browser_bug590206.js \

browser/base/content/test/browser_bug583890_label.js

@@ -0,0 +1,88 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/* Tests:
+ *   verify that the visibleLabel attribute works
+ *   verify the TabLabelModified event works
+ */
+
+function test() {
+  waitForExplicitFinish();
+  let tab = gBrowser.addTab("about:newtab",
+                            {skipAnimation: true});
+  tab.linkedBrowser.addEventListener("load", function onLoad(event) {
+    event.currentTarget.removeEventListener("load", onLoad, true);
+    gBrowser.selectedTab = tab;
+    executeSoon(afterLoad);
+  }, true);
+  tab.addEventListener("TabLabelModified", handleInTest, true);
+}
+
+// Prevent interference
+function handleInTest(aEvent) {
+  aEvent.preventDefault();
+  aEvent.stopPropagation();
+  aEvent.target.visibleLabel = aEvent.target.label;
+}
+
+function afterLoad() {
+  let tab = gBrowser.selectedTab;
+  let xulLabel = document.getAnonymousElementByAttribute(tab, "anonid",
+                                                         "tab-label");
+  // Verify we're starting out on the right foot
+  is(tab.label, "New Tab", "Initial tab label is default");
+  is(xulLabel.value, "New Tab", "Label element is default");
+  is(tab.visibleLabel, "New Tab", "visibleLabel is default");
+
+  // Check that a normal label setting works correctly
+  tab.label = "Hello, world!";
+  is(tab.label, "Hello, world!", "tab label attribute set via tab.label");
+  is(xulLabel.value, "Hello, world!", "xul:label set via tab.label");
+  is(tab.visibleLabel, "Hello, world!", "visibleLabel set via tab.label");
+
+  // Check that setting visibleLabel only affects the label element
+  tab.visibleLabel = "Goodnight, Irene";
+  is(tab.label, "Hello, world!", "Tab.label unaffected by visibleLabel setter");
+  is(xulLabel.value, "Goodnight, Irene",
+     "xul:label set by visibleLabel setter");
+  is(tab.visibleLabel, "Goodnight, Irene",
+     "visibleLabel attribute set by visibleLabel setter");
+
+  // Check that setting the label property hits everything
+  tab.label = "One more label";
+  is(tab.label, "One more label",
+     "Tab label set via label property after diverging from visibleLabel");
+  is(xulLabel.value, "One more label",
+     "xul:label set via label property after diverging from visibleLabel");
+  is(tab.visibleLabel, "One more label",
+     "visibleLabel set from label property after diverging from visibleLabel");
+
+  tab.removeEventListener("TabLabelModified", handleInTest, true);
+  tab.addEventListener("TabLabelModified", handleTabLabel, true);
+  tab.label = "This won't be the visibleLabel";
+}
+
+function handleTabLabel(aEvent) {
+  aEvent.target.removeEventListener("TabLabelModified", handleTabLabel, true);
+  aEvent.preventDefault();
+  aEvent.stopPropagation();
+  aEvent.target.visibleLabel = "Handler set this as the visible label";
+  executeSoon(checkTabLabelModified);
+}
+
+function checkTabLabelModified() {
+  let tab = gBrowser.selectedTab;
+  let xulLabel = document.getAnonymousElementByAttribute(tab, "anonid",
+                                                         "tab-label");
+
+  is(tab.label, "This won't be the visibleLabel",
+     "Tab label set via label property that triggered event");
+  is(xulLabel.value, "Handler set this as the visible label",
+     "xul:label set by TabLabelModified handler");
+  is(tab.visibleLabel, "Handler set this as the visible label",
+     "visibleLabel set by TabLabelModified handler");
+
+  gBrowser.removeCurrentTab({animate: false});
+  finish();
+}
+