Bug 647886 - Pulling down Back/Forward menu requires an unnecessary delay. r=sdwilsh

--HG--
extra : rebase_source : a2628b38bd336925155bb05b53b407a11b7a3df2

browser/base/content/browser.js

@@ -261,10 +261,10 @@ function UpdateBackForwardCommands(aWebNavigation) {
 function SetClickAndHoldHandlers() {
   var timer;
 
-  function timerCallback(aButton) {
+  function openMenu(aButton) {
+    cancelHold(aButton);
     aButton.firstChild.hidden = false;
     aButton.open = true;
-    timer = null;
   }
 
   function mousedownHandler(aEvent) {
@@ -276,7 +276,29 @@ function SetClickAndHoldHandlers() {
     // Prevent the menupopup from opening immediately
     aEvent.currentTarget.firstChild.hidden = true;
 
-    timer = setTimeout(timerCallback, 500, aEvent.currentTarget);
+    aEvent.currentTarget.addEventListener("mouseout", mouseoutHandler, false);
+    aEvent.currentTarget.addEventListener("mouseup", mouseupHandler, false);
+    timer = setTimeout(openMenu, 500, aEvent.currentTarget);
+  }
+
+  function mouseoutHandler(aEvent) {
+    let buttonRect = aEvent.currentTarget.getBoundingClientRect();
+    if (aEvent.clientX >= buttonRect.left &&
+        aEvent.clientX <= buttonRect.right &&
+        aEvent.clientY >= buttonRect.bottom)
+      openMenu(aEvent.currentTarget);
+    else
+      cancelHold(aEvent.currentTarget);
+  }
+
+  function mouseupHandler(aEvent) {
+    cancelHold(aEvent.currentTarget);
+  }
+
+  function cancelHold(aButton) {
+    clearTimeout(timer);
+    aButton.removeEventListener("mouseout", mouseoutHandler, false);
+    aButton.removeEventListener("mouseup", mouseupHandler, false);
   }
 
   function clickHandler(aEvent) {
@@ -292,17 +314,8 @@ function SetClickAndHoldHandlers() {
     }
   }
 
-  function stopTimer(aEvent) {
-    if (timer) {
-      clearTimeout(timer);
-      timer = null;
-    }
-  }
-
   function _addClickAndHoldListenersOnElement(aElm) {
     aElm.addEventListener("mousedown", mousedownHandler, true);
-    aElm.addEventListener("mouseup", stopTimer, false);
-    aElm.addEventListener("mouseout", stopTimer, false);
     aElm.addEventListener("click", clickHandler, true);
   }
 

browser/base/content/test/Makefile.in

@@ -170,6 +170,7 @@ _BROWSER_FILES = \
                  browser_bug616836.js \
                  browser_bug623893.js \
                  browser_bug624734.js \
+                 browser_bug647886.js \
                  browser_findbarClose.js \
                  browser_contextSearchTabPosition.js \
                  browser_ctrlTab.js \

browser/base/content/test/browser_bug647886.js

@@ -0,0 +1,34 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+function test() {
+  waitForExplicitFinish();
+
+  gBrowser.selectedBrowser.addEventListener("load", function () {
+    gBrowser.selectedBrowser.removeEventListener("load", arguments.callee, true);
+
+    content.history.pushState({}, "2", "2.html");
+
+    testBackButton();
+  }, true);
+
+  loadURI("http://example.com");
+}
+
+function testBackButton() {
+  var backButton = document.getElementById("back-button");
+  var rect = backButton.getBoundingClientRect();
+
+  info("waiting for the history menu to open");
+
+  backButton.addEventListener("popupshown", function (event) {
+    backButton.removeEventListener("popupshown", arguments.callee, false);
+
+    ok(true, "history menu opened");
+    event.target.hidePopup();
+    finish();
+  }, false);
+
+  EventUtils.synthesizeMouseAtCenter(backButton, {type: "mousedown"});
+  EventUtils.synthesizeMouse(backButton, rect.width / 2, rect.height, {type: "mouseup"});
+}