Bug 250091, support page up and page down in menulists, r=neil

layout/xul/nsMenuPopupFrame.cpp

@@ -1635,6 +1635,87 @@ void nsMenuPopupFrame::EnsureMenuItemIsVisible(nsMenuFrame* aMenuItem)
   }
 }
 
+void nsMenuPopupFrame::ChangeByPage(bool aIsUp)
+{
+  nsIFrame* parentMenu = GetParent();
+  if (parentMenu) {
+    // Only scroll by page within menulists.
+    nsCOMPtr<nsIDOMXULMenuListElement> menulist = do_QueryInterface(parentMenu->GetContent());
+    if (!menulist) {
+      return;
+    }
+  }
+
+  nsMenuFrame* newMenu = nullptr;
+  nsIFrame* currentMenu = mCurrentMenu;
+  if (!currentMenu) {
+    // If there is no current menu item, get the first item. When moving up,
+    // just use this as the newMenu and leave currentMenu null so that no
+    // check for a later element is performed. When moving down, set currentMenu
+    // so that we look for one page down from the first item.
+    newMenu = nsXULPopupManager::GetNextMenuItem(this, nullptr, true);
+    if (!aIsUp) {
+      currentMenu = newMenu;
+    }
+  }
+
+  if (currentMenu) {
+    nscoord scrollHeight = mRect.height;
+    nsIScrollableFrame *scrollframe = GetScrollFrame(this);
+    if (scrollframe) {
+      scrollHeight = scrollframe->GetScrollPortRect().height;
+    }
+
+    // Get the position of the current item and add or subtract one popup's
+    // height to or from it.
+    nscoord targetPosition = aIsUp ? currentMenu->GetRect().YMost() - scrollHeight :
+                                     currentMenu->GetRect().y + scrollHeight;
+
+    // Indicates that the last visible child was a valid menuitem.
+    bool lastWasValid = false;
+
+    // Look for the next child which is just past the target position. This child
+    // will need to be selected.
+    while (currentMenu) {
+      // Only consider menu frames.
+      nsMenuFrame* menuFrame = do_QueryFrame(currentMenu);
+      if (menuFrame &&
+          nsXULPopupManager::IsValidMenuItem(PresContext(), menuFrame->GetContent(), true)) {
+
+        // If the right position was found, break out. Otherwise, look for another item.
+        if ((!aIsUp && currentMenu->GetRect().YMost() > targetPosition) ||
+            (aIsUp && currentMenu->GetRect().y < targetPosition)) {
+
+          // If the last visible child was not a valid menuitem or was disabled,
+          // use this as the menu to select, skipping over any non-valid items at
+          // the edge of the page.
+          if (!lastWasValid) {
+            newMenu = menuFrame;
+          }
+
+          break;
+        }
+
+        // Assign this item to newMenu. This item will be selected in case we
+        // don't find any more. 
+        lastWasValid = true;
+        newMenu = menuFrame;
+      }
+      else {
+        lastWasValid = false;
+      }
+
+      currentMenu = aIsUp ? currentMenu->GetPrevSibling() :
+                            currentMenu->GetNextSibling();
+    }
+  }
+
+  // Select the new menuitem.
+  if (newMenu) {
+    ChangeMenuItem(newMenu, false);
+  }
+}
+
 NS_IMETHODIMP nsMenuPopupFrame::SetCurrentMenuItem(nsMenuFrame* aMenuItem)
 {
   if (mCurrentMenu == aMenuItem)

layout/xul/nsMenuPopupFrame.h

@@ -326,6 +326,8 @@ public:
 
   void EnsureMenuItemIsVisible(nsMenuFrame* aMenuFrame);
 
+  void ChangeByPage(bool aIsUp);
+
   // Move the popup to the screen coordinate (aLeft, aTop) in CSS pixels.
   // If aUpdateAttrs is true, and the popup already has left or top attributes,
   // then those attributes are updated to the new location.

layout/xul/nsXULPopupManager.cpp

@@ -2172,6 +2172,13 @@ nsXULPopupManager::HandleKeyboardEventWithKeyCode(
       HandleKeyboardNavigation(keyCode);
       break;
 
+    case nsIDOMKeyEvent::DOM_VK_PAGE_DOWN:
+    case nsIDOMKeyEvent::DOM_VK_PAGE_UP:
+      if (aTopVisibleMenuItem) {
+        aTopVisibleMenuItem->Frame()->ChangeByPage(keyCode == nsIDOMKeyEvent::DOM_VK_PAGE_UP);
+      }
+      break;
+
     case nsIDOMKeyEvent::DOM_VK_ESCAPE:
       // Pressing Escape hides one level of menus only. If no menu is open,
       // check if a menubar is active and inform it that a menu closed. Even

toolkit/content/tests/chrome/chrome.ini

@@ -116,6 +116,7 @@ skip-if = buildapp == 'mulet'
 skip-if = buildapp == 'mulet'
 [test_menulist_keynav.xul]
 [test_menulist_null_value.xul]
+[test_menulist_paging.xul]
 [test_mousecapture.xul]
 skip-if = buildapp == 'mulet'
 [test_mousescroll.xul]

toolkit/content/tests/chrome/test_menulist_paging.xul

@@ -0,0 +1,133 @@
+<?xml version="1.0"?>
+<?xml-stylesheet href="chrome://global/skin" type="text/css"?>
+<?xml-stylesheet href="chrome://mochikit/content/tests/SimpleTest/test.css" type="text/css"?>
+
+<window title="Menulist Tests"
+        onload="setTimeout(startTest, 0);"
+        onpopupshown="menulistShown()" onpopuphidden="runTest()"
+        xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul">
+
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>      
+  <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/EventUtils.js"></script>      
+
+<menulist id="menulist1">
+  <menupopup id="menulist-popup1">
+    <menuitem label="One"/>
+    <menuitem label="Two"/>
+    <menuitem label="Three"/>
+    <menuitem label="Four"/>
+    <menuitem label="Five"/>
+    <menuitem label="Six"/>
+    <menuitem label="Seven"/>
+    <menuitem label="Eight"/>
+    <menuitem label="Nine"/>
+    <menuitem label="Ten"/>
+  </menupopup>
+</menulist>
+
+<menulist id="menulist2">
+  <menupopup id="menulist-popup2">
+    <menuitem label="One" disabled="true"/>
+    <menuitem label="Two" selected="true"/>
+    <menuitem label="Three"/>
+    <menuitem label="Four"/>
+    <menuitem label="Five"/>
+    <menuitem label="Six"/>
+    <menuitem label="Seven"/>
+    <menuitem label="Eight"/>
+    <menuitem label="Nine"/>
+    <menuitem label="Ten" disabled="true"/>
+  </menupopup>
+</menulist>
+
+<menulist id="menulist3">
+  <menupopup id="menulist-popup3">
+    <label value="One"/>
+    <menuitem label="Two" selected="true"/>
+    <menuitem label="Three"/>
+    <menuitem label="Four"/>
+    <menuitem label="Five" disabled="true"/>
+    <menuitem label="Six" disabled="true"/>
+    <menuitem label="Seven"/>
+    <menuitem label="Eight"/>
+    <menuitem label="Nine"/>
+    <label value="Ten"/>
+  </menupopup>
+</menulist>
+
+<script class="testbody" type="application/javascript">
+<![CDATA[
+
+SimpleTest.waitForExplicitFinish();
+
+let test;
+
+// Windows allows disabled items to be selected.
+let isWindows = navigator.platform.indexOf("Win") >= 0;
+
+let tests = [
+  { list: "menulist1", initial: 0, downs: [3, 6, 9, 9],
+                                   ups: [6, 3, 0, 0] },
+  { list: "menulist2", initial: 1, downs: [4, 7, isWindows ? 9 : 8, isWindows ? 9 : 8],
+                                   ups: [isWindows ? 6 : 5, isWindows ? 3 : 2, isWindows ? 0 : 1] },
+  { list: "menulist3", initial: 1, downs: [isWindows ? 4 : 6, isWindows ? 7 : 8, 8],
+                                   ups: [isWindows ? 5 : 3, isWindows ? 2 : 1, 1] }
+];
+
+function startTest()
+{
+  let popup = document.getElementById("menulist-popup1");
+  let menupopupHeight = popup.getBoundingClientRect().height;
+  let menuitemHeight = popup.firstChild.getBoundingClientRect().height;
+
+  // First, set the height of each popup to the height of four menuitems plus
+  // any padding and border on the menupopup.
+  let height = menuitemHeight * 4 + (menupopupHeight - menuitemHeight * 10);
+  popup.height = height;
+  document.getElementById("menulist-popup2").height = height;
+  document.getElementById("menulist-popup3").height = height;
+
+  runTest();
+}
+
+function runTest()
+{
+  if (!tests.length) {
+    SimpleTest.finish();
+    return;
+  }
+
+  test = tests.shift();
+  document.getElementById(test.list).open = true;
+}
+
+function menulistShown()
+{
+  let menulist = document.getElementById(test.list);
+  is(menulist.menuBoxObject.activeChild.label, menulist.getItemAtIndex(test.initial).label, test.list + " initial selection");
+
+  for (let i = 0; i < test.downs.length; i++) {
+    sendKey("PAGE_DOWN");
+    is(menulist.menuBoxObject.activeChild.label, menulist.getItemAtIndex(test.downs[i]).label, test.list + " page down " + i);
+  }
+
+  for (let i = 0; i < test.ups.length; i++) {
+    sendKey("PAGE_UP");
+    is(menulist.menuBoxObject.activeChild.label, menulist.getItemAtIndex(test.ups[i]).label, test.list + " page up " + i);
+  }
+
+  menulist.open = false;
+}
+]]>
+</script>
+
+<body xmlns="http://www.w3.org/1999/xhtml">
+<p id="display">
+</p>
+<div id="content" style="display: none">
+</div>
+<pre id="test">
+</pre>
+</body>
+
+</window>