Bug 632345 - [regression] Scrollbar position should not updated before showing the scrollbars [r=mfinkle]

mobile/chrome/content/browser.js

@@ -1288,6 +1288,7 @@ Browser.MainDragger.prototype = {
   },
 
   _showScrollbars: function _showScrollbars() {
+    this._updateScrollbars();
     let scaleX = this._scrollScales.x, scaleY = this._scrollScales.y;
     if (scaleX) {
       this._horizontalScrollbar.width = ViewableAreaObserver.width * scaleX;

mobile/chrome/tests/Makefile.in

@@ -72,6 +72,7 @@ _BROWSER_FILES = \
   browser_preferences_text.js \
   browser_rect.js \
   browser_rememberPassword.js \
+  browser_scrollbar.js \
   browser_select.html \
   browser_select.js \
   browser_sessionstore.js \
@@ -82,6 +83,7 @@ _BROWSER_FILES = \
   browser_vkb.js \
   browser_viewport.js \
   browser_viewport.sjs \
+  browser_scrollbar.sjs \
   browser_title.sjs \
   browser_install.xml \
   browser_upgrade.rdf\

mobile/chrome/tests/browser_scrollbar.js

@@ -0,0 +1,98 @@
+let baseURI = "http://mochi.test:8888/browser/mobile/chrome/";
+let testURL_01 = baseURI + "browser_scrollbar.sjs?";
+
+let gCurrentTest = null;
+let gTests = [];
+
+//------------------------------------------------------------------------------
+// Iterating tests by shifting test out one by one as runNextTest is called.
+function runNextTest() {
+  // Run the next test until all tests completed
+  if (gTests.length > 0) {
+    gCurrentTest = gTests.shift();
+    info(gCurrentTest.desc);
+    gCurrentTest.run();
+  }
+  else {
+    // Close the awesome panel just in case
+    BrowserUI.activePanel = null;
+    finish();
+  }
+}
+
+function waitForPageShow(aPageURL, aCallback) {
+  messageManager.addMessageListener("pageshow", function(aMessage) {
+    if (aMessage.target.currentURI.spec == aPageURL) {
+      messageManager.removeMessageListener("pageshow", arguments.callee);
+      setTimeout(function() { aCallback(); }, 0);
+    }
+  });
+};
+
+//------------------------------------------------------------------------------
+// Entry point (must be named "test")
+function test() {
+  // This test is async
+  waitForExplicitFinish();
+  runNextTest();
+}
+
+let horizontalScrollbar = document.getElementById("horizontal-scroller");
+let verticalScrollbar = document.getElementById("vertical-scroller");
+
+function checkScrollbars(aHorizontalVisible, aVerticalVisible, aHorizontalPosition, aVerticalPosition) {
+  let browser = getBrowser();
+  let width = browser.getBoundingClientRect().width;
+  let height = browser.getBoundingClientRect().height;
+  EventUtils.synthesizeMouse(browser, width / 2, height / 4, { type: "mousedown" });
+  EventUtils.synthesizeMouse(browser, width / 2, height * 3 / 4, { type: "mousemove" });
+
+  let horizontalVisible = horizontalScrollbar.hasAttribute("panning"),
+      verticalVisible = verticalScrollbar.hasAttribute("panning");
+  is(horizontalVisible, aHorizontalVisible, "The horizontal scrollbar should be " + (aHorizontalVisible ? "visible" : "hidden"));
+  is(verticalVisible, aVerticalVisible, "The vertical scrollbar should be " + (aVerticalVisible ? "visible" : "hidden"));
+
+  EventUtils.synthesizeMouse(browser, width / 2, height * 3 / 4, { type: "mouseup" });
+}
+
+gTests.push({
+  desc: "Testing visibility of scrollbars",
+
+  run: function() {
+    waitForPageShow(testURL_01 + "blank", gCurrentTest.checkNotScrollable);
+    Browser.addTab(testURL_01 + "blank", true);
+  },
+
+  checkNotScrollable: function() {
+    checkScrollbars(false, false);
+
+    waitForPageShow(testURL_01 + "horizontal", gCurrentTest.checkHorizontalScrollable);
+    Browser.addTab(testURL_01 + "horizontal", true);
+  },
+
+  checkHorizontalScrollable: function() {
+    checkScrollbars(true, false);
+
+    waitForPageShow(testURL_01 + "vertical", gCurrentTest.checkVerticalScrollable);
+    Browser.addTab(testURL_01 + "vertical", true);
+  },
+
+  checkVerticalScrollable: function() {
+    checkScrollbars(false, true);
+
+    waitForPageShow(testURL_01 + "both", gCurrentTest.checkBothScrollable);
+    Browser.addTab(testURL_01 + "both", true);
+  },
+
+  checkBothScrollable: function() {
+    checkScrollbars(true, true);
+    Elements.browsers.addEventListener("PanFinished", function(aEvent) {
+      setTimeout(function() {
+        while (Browser.tabs.length > 1)
+          BrowserUI.closeTab();
+      }, 0);
+    }, false);
+    runNextTest();
+  }
+});
+

mobile/chrome/tests/browser_scrollbar.sjs

@@ -0,0 +1,66 @@
+/* ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is Mozilla Mobile Browser.
+ *
+ * The Initial Developer of the Original Code is
+ * Mozilla Corporation.
+ * Portions created by the Initial Developer are Copyright (C) 2010
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+function handleRequest(request, response) {
+  response.setStatusLine(request.httpVersion, 200, "OK");
+  response.setHeader("Content-Type", "text/html", false);
+
+  let action = "";
+  let query = decodeURIComponent(request.queryString || "");
+  response.write("<html xmlns=\"http://www.w3.org/1999/xhtml\"><head>");
+  response.write("<meta name='viewport' content='width=device-width, initial-scale=1, maximum-scale=1'>");
+
+  switch (query) {
+    case "blank":
+      response.write("<title>This is a not a scrollable page</title>");
+      break;
+    case "horizontal":
+      response.write("<title>This is a horizontally scrollable page</title>");
+      response.write("<div style='height: 200px; width: 2000px; border: 1px solid red; background-color: grey; color: black'>Browser scrollbar test</div>");
+      break;
+    case "vertical":
+      response.write("<title>This is a vertically scrollable page</title>");
+      response.write("<div style='height: 2000px; width: 200px; border: 1px solid red; background-color: grey; color: black'>Browser scrollbar test</div>");
+      break;
+    case "both":
+      response.write("<title>This is a scrollable page in both directions</title>");
+      response.write("<div style='height: 2000px; width: 2000px; border: 1px solid red; background-color: grey; color: black'>Browser scrollbar test</div>");
+      break;
+    default:
+      break;
+  }
+  response.write("</head><body>" + query + "</body></html>");
+}