Bug 1699570 - Make mouse_focuses_formcontrol on chrome documents match the old behavior. r=mstange

For that, we make accessibility.mouse_focuses_formcontrol a static pref,
and make it work in all platforms because it's simpler and allows to
test mac-specific things on other platforms more easily.

Differential Revision: https://phabricator.services.mozilla.com/D109006

dom/base/nsFocusManager.cpp

@@ -165,14 +165,12 @@ NS_IMPL_CYCLE_COLLECTION_WEAK(nsFocusManager, mActiveWindow,
                               mWindowBeingLowered, mDelayedBlurFocusEvents)
 
 StaticRefPtr<nsFocusManager> nsFocusManager::sInstance;
-bool nsFocusManager::sMouseFocusesFormControl = false;
 bool nsFocusManager::sTestMode = false;
 uint64_t nsFocusManager::sFocusActionCounter = 0;
 
-static const char* kObservedPrefs[] = {
-    "accessibility.browsewithcaret", "accessibility.tabfocus_applies_to_xul",
-    "accessibility.mouse_focuses_formcontrol", "focusmanager.testmode",
-    nullptr};
+static const char* kObservedPrefs[] = {"accessibility.browsewithcaret",
+                                       "accessibility.tabfocus_applies_to_xul",
+                                       "focusmanager.testmode", nullptr};
 
 nsFocusManager::nsFocusManager()
     : mActionIdForActiveBrowsingContextInContent(0),
@@ -198,9 +196,6 @@ nsresult nsFocusManager::Init() {
       Preferences::GetBool("accessibility.tabfocus_applies_to_xul",
                            nsIContent::sTabFocusModelAppliesToXUL);
 
-  sMouseFocusesFormControl =
-      Preferences::GetBool("accessibility.mouse_focuses_formcontrol", false);
-
   sTestMode = Preferences::GetBool("focusmanager.testmode", false);
 
   Preferences::RegisterCallbacks(nsFocusManager::PrefChanged, kObservedPrefs,
@@ -230,9 +225,6 @@ void nsFocusManager::PrefChanged(const char* aPref) {
     nsIContent::sTabFocusModelAppliesToXUL =
         Preferences::GetBool("accessibility.tabfocus_applies_to_xul",
                              nsIContent::sTabFocusModelAppliesToXUL);
-  } else if (pref.EqualsLiteral("accessibility.mouse_focuses_formcontrol")) {
-    sMouseFocusesFormControl =
-        Preferences::GetBool("accessibility.mouse_focuses_formcontrol", false);
   } else if (pref.EqualsLiteral("focusmanager.testmode")) {
     sTestMode = Preferences::GetBool("focusmanager.testmode", false);
   }

dom/base/nsFocusManager.h

@@ -295,8 +295,6 @@ class nsFocusManager final : public nsIFocusManager,
    */
   void NotifyOfReFocus(nsIContent& aContent);
 
-  static bool sMouseFocusesFormControl;
-
   static void MarkUncollectableForCCGeneration(uint32_t aGeneration);
 
   struct BlurredElementInfo {

dom/events/test/bug656379-1.html

@@ -128,7 +128,7 @@ function* tests() {
   // Release.
   sendMouseEvent("mouseup", label);
   yield undefined;
-  var focusOnMouse = navigator.platform.indexOf("Mac") != 0 || SpecialPowers.getBoolPref("accessibility.mouse_focuses_formcontrol");
+  var focusOnMouse = SpecialPowers.getIntPref("accessibility.mouse_focuses_formcontrol") > 0;
   compareSnapshots_(focusOnMouse ? normalFocusedButtonCanvas : normalButtonCanvas,
                     currentSnapshot, true, "Releasing the mouse over the label should have unpressed" +
                                             (focusOnMouse ? " (and focused)" : "") + " the button.");

dom/html/HTMLButtonElement.cpp

@@ -118,11 +118,7 @@ bool HTMLButtonElement::IsHTMLFocusable(bool aWithMouse, bool* aIsFocusable,
     return true;
   }
 
-  *aIsFocusable =
-#ifdef XP_MACOSX
-      (!aWithMouse || nsFocusManager::sMouseFocusesFormControl) &&
-#endif
-      !IsDisabled();
+  *aIsFocusable = IsFormControlDefaultFocusable(aWithMouse) && !IsDisabled();
 
   return false;
 }

dom/html/HTMLImageElement.cpp

@@ -528,11 +528,8 @@ bool HTMLImageElement::IsHTMLFocusable(bool aWithMouse, bool* aIsFocusable,
     *aTabIndex = (sTabFocusModel & eTabFocus_formElementsMask) ? tabIndex : -1;
   }
 
-  *aIsFocusable =
-#ifdef XP_MACOSX
-      (!aWithMouse || nsFocusManager::sMouseFocusesFormControl) &&
-#endif
-      (tabIndex >= 0 || GetTabIndexAttrValue().isSome());
+  *aIsFocusable = IsFormControlDefaultFocusable(aWithMouse) &&
+                  (tabIndex >= 0 || GetTabIndexAttrValue().isSome());
 
   return false;
 }

dom/html/HTMLInputElement.cpp

@@ -6131,13 +6131,7 @@ bool HTMLInputElement::IsHTMLFocusable(bool aWithMouse, bool* aIsFocusable,
     return false;
   }
 
-#ifdef XP_MACOSX
-  const bool defaultFocusable =
-      !aWithMouse || nsFocusManager::sMouseFocusesFormControl;
-#else
-  const bool defaultFocusable = true;
-#endif
-
+  const bool defaultFocusable = IsFormControlDefaultFocusable(aWithMouse);
   if (CreatesDateTimeWidget()) {
     if (aTabIndex) {
       // We only want our native anonymous child to be tabable to, not ourself.

dom/html/nsGenericHTMLElement.cpp

@@ -18,6 +18,7 @@
 #include "mozilla/TextEditor.h"
 #include "mozilla/StaticPrefs_html5.h"
 #include "mozilla/StaticPrefs_layout.h"
+#include "mozilla/StaticPrefs_accessibility.h"
 
 #include "nscore.h"
 #include "nsGenericHTMLElement.h"
@@ -1589,6 +1590,21 @@ bool nsGenericHTMLElement::LegacyTouchAPIEnabled(JSContext* aCx,
   return TouchEvent::LegacyAPIEnabled(aCx, aGlobal);
 }
 
+bool nsGenericHTMLElement::IsFormControlDefaultFocusable(
+    bool aWithMouse) const {
+  if (!aWithMouse) {
+    return true;
+  }
+  switch (StaticPrefs::accessibility_mouse_focuses_formcontrol()) {
+    case 0:
+      return false;
+    case 1:
+      return true;
+    default:
+      return !IsInChromeDocument();
+  }
+}
+
 //----------------------------------------------------------------------
 
 nsGenericHTMLFormElement::nsGenericHTMLFormElement(
@@ -1962,10 +1978,7 @@ bool nsGenericHTMLFormElement::IsHTMLFocusable(bool aWithMouse,
     return true;
   }
 
-#ifdef XP_MACOSX
-  *aIsFocusable = (!aWithMouse || nsFocusManager::sMouseFocusesFormControl) &&
-                  *aIsFocusable;
-#endif
+  *aIsFocusable = *aIsFocusable && IsFormControlDefaultFocusable(aWithMouse);
   return false;
 }
 

dom/html/nsGenericHTMLElement.h

@@ -152,6 +152,9 @@ class nsGenericHTMLElement : public nsGenericHTMLElementBase {
     }
   }
 
+  /** Returns whether a form control should be default-focusable. */
+  bool IsFormControlDefaultFocusable(bool aWithMouse) const;
+
   /**
    * Returns the count of descendants (inclusive of this node) in
    * the uncomposed document that are explicitly set as editable.

dom/tests/mochitest/chrome/test_focus.xhtml

@@ -16,7 +16,6 @@ if (navigator.platform.startsWith("Win")) {
 SimpleTest.waitForExplicitFinish();
 async function runTest()
 {
-  await SpecialPowers.pushPrefEnv({"set": [['accessibility.mouse_focuses_formcontrol', false]]});
   window.openDialog("window_focus.xhtml", "_blank", "chrome,width=600,height=550,noopener", window);
 }
 </script>

dom/tests/mochitest/chrome/window_focus.xhtml

@@ -281,7 +281,8 @@ function mouseWillTriggerFocus(element)
     return false;
   }
 
-  if (navigator.platform.indexOf("Mac") != 0) {
+  if (SpecialPowers.getIntPref("accessibility.mouse_focuses_formcontrol") == 1) {
+    // This is a chrome document, so we'll only trigger focus with the mouse if the value of the pref is 1.
     return true;
   }
 

dom/tests/mochitest/general/test_focusrings.xhtml

@@ -18,6 +18,8 @@
 
 SimpleTest.waitForExplicitFinish();
 
+const kIsMac = navigator.platform.includes("Mac");
+
 function snapShot(element) {
   var rect = element.getBoundingClientRect();
   adjustedRect = { left: rect.left - 6, top: rect.top - 6,
@@ -25,18 +27,25 @@ function snapShot(element) {
   return SpecialPowers.snapshotRect(window, adjustedRect, "transparent");
 }
 
-function initTest()
-{
-  SpecialPowers.pushPrefEnv({
-    "set": [
-      ['accessibility.mouse_focuses_formcontrol', false],
-    ]
-  }, runTest);
+async function initTest() {
+  if (kIsMac) {
+    // FIXME: Historically this pref was only respected on mac,
+    // and the test uses that assumption.
+    //
+    // Ideally it should be refactored to test with the different
+    // values of the pref, independently of the platform.
+    await SpecialPowers.pushPrefEnv({
+      "set": [
+        ['accessibility.mouse_focuses_formcontrol', 0],
+      ]
+    });
+  }
+
+  runTest();
 }
 
 function runTest()
 {
-  var isMac = (navigator.platform.includes("Mac"));
   var isWinOrLinux = navigator.platform.includes("Win") || navigator.platform.includes("Linux");
 
   function checkFocus(element, visible, testid)
@@ -61,7 +70,7 @@ function runTest()
   // the test regardless of which user input last occurred.
   $("l1").focus();
   var expectedVisible = (!isWinOrLinux || getComputedStyle($("l1"), "").outlineWidth == "2px");
-  testHTMLElements(htmlElements, isMac, isWinOrLinux && !expectedVisible);
+  testHTMLElements(htmlElements, isWinOrLinux && !expectedVisible);
 
   $("l1").focus();
   checkFocus($("l1"), expectedVisible, "appearance on list after focus() with :moz-focusring");
@@ -80,15 +89,15 @@ function runTest()
   checkFocus($("b1"), false, "appearance on button after mouse focus with :moz-focusring");
 
   synthesizeMouse($("b2"), 4, 4, { });
-  checkFocus($("b2"), !isMac, "appearance on button after mouse focus with :focus");
+  checkFocus($("b2"), !kIsMac, "appearance on button after mouse focus with :focus");
 
   // after a key is pressed, the focus ring will always be visible
   $("l2").focus();
   synthesizeKey("KEY_Tab");
   checkFocus($("l3"), true, "appearance on list after tab focus");
 
-  if (isMac) {
-    SpecialPowers.pushPrefEnv({"set": [['accessibility.mouse_focuses_formcontrol', true]]}, testMacFocusesFormControl);
+  if (kIsMac) {
+    SpecialPowers.pushPrefEnv({"set": [['accessibility.mouse_focuses_formcontrol', 1]]}, testMacFocusesFormControl);
   }
   else {
     SimpleTest.finish();
@@ -97,7 +106,7 @@ function runTest()
 
 function testMacFocusesFormControl()
 {
-  testHTMLElements(htmlElementsMacPrefSet, true, false);
+  testHTMLElements(htmlElementsMacPrefSet, false);
   SimpleTest.finish();
 }
 
@@ -126,8 +135,7 @@ function createElement(str) {
   return doc.body.firstChild;
 }
 
-function testHTMLElements(list, isMac, expectedNoRingsOnWin)
-{
+function testHTMLElements(list, expectedNoRingsOnWin) {
   var childwin = frames[0];
   var childdoc = childwin.document;
   var container = childdoc.getElementById("container");
@@ -137,7 +145,7 @@ function testHTMLElements(list, isMac, expectedNoRingsOnWin)
     var elem = childdoc.adoptNode(createElement(list[e]));
     container.appendChild(elem);
 
-    var shouldFocus = !isMac || (elem.className == "canfocus");
+    var shouldFocus = !kIsMac || (elem.className == "canfocus");
     var ringSize = (shouldFocus ? (expectedNoRingsOnWin ? 2 : 1) : 0) + "px";
 
     var expectedMatchWithMouse = shouldFocus && !expectedNoRingsOnWin;
@@ -156,7 +164,7 @@ function testHTMLElements(list, isMac, expectedNoRingsOnWin)
 
     if (elem.localName == "a") {
       mouseRingSize = ringSize = "0px";
-      expectedMatchWithMouse = expectedMatchWithMouse && !isMac;
+      expectedMatchWithMouse = expectedMatchWithMouse && !kIsMac;
     }
 
     synthesizeMouse(elem, 8, 8, { }, childwin);

modules/libpref/init/StaticPrefList.yaml

@@ -200,6 +200,23 @@
   value: false
   mirror: always
 
+# Whether form controls and images should be focusable with mouse, in content
+# documents.
+#
+# This matches historical macOS / Safari behavior.
+#
+#  * 0: never
+#  * 1: always
+#  * 2: on content documents
+- name: accessibility.mouse_focuses_formcontrol
+  type: int32_t
+#ifdef XP_MACOSX
+  value: 2
+#else
+  value: 1
+#endif
+  mirror: always
+
 #---------------------------------------------------------------------------
 # Prefs starting with "alerts."
 #---------------------------------------------------------------------------

modules/libpref/init/all.js

@@ -720,7 +720,6 @@ pref("accessibility.force_disabled", 0);
 pref("focusmanager.testmode", false);
 
 pref("accessibility.usetexttospeech", "");
-pref("accessibility.mouse_focuses_formcontrol", true);
 
 // Type Ahead Find
 pref("accessibility.typeaheadfind", true);

testing/web-platform/meta/css/selectors/focus-visible-005.html.ini

@@ -1,2 +0,0 @@
-[focus-visible-005.html]
-  prefs: [accessibility.mouse_focuses_formcontrol:true]