Bug 1239744 - no longer automatically show an on-screen keyboard for programmatic focus changes, tidy up osk logic in IMEHandler, r=masayuki

--HG--
extra : rebase_source : 013c2759f4faca65ed3de79ca1d7f0b97e6375cb

widget/IMEData.h

@@ -393,6 +393,18 @@ struct InputContextAction final
             (mCause == CAUSE_MOUSE || mCause == CAUSE_TOUCH));
   }
 
+  static bool IsUserAction(Cause aCause)
+  {
+    switch (aCause) {
+      case CAUSE_KEY:
+      case CAUSE_MOUSE:
+      case CAUSE_TOUCH:
+        return true;
+      default:
+        return false;
+    }
+  }
+
   InputContextAction()
     : mCause(CAUSE_UNKNOWN)
     , mFocusChange(FOCUS_NOT_CHANGED)

widget/windows/WinIMEHandler.cpp

@@ -606,7 +606,7 @@ IMEHandler::MaybeShowOnScreenKeyboard()
       !IsWin8OrLater() ||
       !Preferences::GetBool(kOskEnabled, true) ||
       GetOnScreenKeyboardWindow() ||
-      IMEHandler::IsKeyboardPresentOnSlate()) {
+      !IMEHandler::NeedOnScreenKeyboard()) {
     return;
   }
 
@@ -653,24 +653,31 @@ IMEHandler::WStringStartsWithCaseInsensitive(const std::wstring& aHaystack,
                 lowerCaseNeedle.c_str()) == lowerCaseHaystack.c_str();
 }
 
-// Returns true if a physical keyboard is detected on Windows 8 and up.
-// Uses the Setup APIs to enumerate the attached keyboards and returns true
-// if the keyboard count is 1 or more. While this will work in most cases
-// it won't work if there are devices which expose keyboard interfaces which
-// are attached to the machine.
-// Based on IsKeyboardPresentOnSlate() in Chromium's base/win/win_util.cc.
+// Returns false if a physical keyboard is detected on Windows 8 and up,
+// or there is some other reason why an onscreen keyboard is not necessary.
+// Returns true if no keyboard is found and this device looks like it needs
+// an on-screen keyboard for text input.
 // static
 bool
-IMEHandler::IsKeyboardPresentOnSlate()
+IMEHandler::NeedOnScreenKeyboard()
 {
   // This function is only supported for Windows 8 and up.
   if (!IsWin8OrLater()) {
     Preferences::SetString(kOskDebugReason, L"IKPOS: Requires Win8+.");
-    return true;
+    return false;
   }
 
   if (!Preferences::GetBool(kOskDetectPhysicalKeyboard, true)) {
     Preferences::SetString(kOskDebugReason, L"IKPOS: Detection disabled.");
+    return true;
+  }
+
+  // If the last focus cause was not user-initiated (ie a result of code
+  // setting focus to an element) then don't auto-show a keyboard. This
+  // avoids cases where the keyboard would pop up "just" because e.g. a
+  // web page chooses to focus a search field on the page, even when that
+  // really isn't what the user is trying to do at that moment.
+  if (!InputContextAction::IsUserAction(sLastContextActionCause)) {
     return false;
   }
 
@@ -679,13 +686,13 @@ IMEHandler::IsKeyboardPresentOnSlate()
         != NID_INTEGRATED_TOUCH) {
     Preferences::SetString(kOskDebugReason,
                            L"IKPOS: Touch screen not found.");
-    return true;
+    return false;
   }
 
   // If the device is docked, the user is treating the device as a PC.
   if (::GetSystemMetrics(SM_SYSTEMDOCKED) != 0) {
     Preferences::SetString(kOskDebugReason, L"IKPOS: System docked.");
-    return true;
+    return false;
   }
 
   // To determine whether a keyboard is present on the device, we do the
@@ -697,11 +704,15 @@ IMEHandler::IsKeyboardPresentOnSlate()
 
   // 2. If the device supports auto rotation, then we get its platform role
   //    and check the system metric SM_CONVERTIBLESLATEMODE to see if it is
-  //    being used in slate mode. If yes then we return false here to ensure
-  //    that the OSK is displayed.
+  //    being used in slate mode. If not then we return false here to ensure
+  //    that the OSK is not displayed.
 
-  // 3. If step 1 and 2 fail then we check attached keyboards and return true
-  //    if we find ACPI\*, HID\VID* or bluetooth keyboards.
+  // 3. If step 1 and 2 both confirm this *could* be a device with no usable
+  //    keyboard, we check whether the last input was touch-based. If so,
+  //    we return true immediately to get an on-screen keyboard.
+
+  // 4. If this was a mouse or (on-screen) keyboard event, we check if
+  //    this device has keyboards attached to it.
 
   typedef BOOL (WINAPI* GetAutoRotationState)(PAR_STATE state);
   GetAutoRotationState get_rotation_state =
@@ -717,11 +728,11 @@ IMEHandler::IsKeyboardPresentOnSlate()
     if (auto_rotation_state & AR_NOSENSOR) {
       Preferences::SetString(kOskDebugReason,
                              L"IKPOS: Rotation sensor not found.");
-      return true;
+      return false;
     } else if (auto_rotation_state & AR_NOT_SUPPORTED) {
       Preferences::SetString(kOskDebugReason,
                              L"IKPOS: Auto-rotation not supported.");
-      return true;
+      return false;
     }
   }
 
@@ -747,13 +758,13 @@ IMEHandler::IsKeyboardPresentOnSlate()
   if (sPowerPlatformRole != PlatformRoleMobile &&
       sPowerPlatformRole != PlatformRoleSlate) {
     Preferences::SetString(kOskDebugReason, L"IKPOS: PlatformRole is neither Mobile nor Slate.");
-    return true;
+    return false;
   }
 
   // Likewise, if the tablet/mobile isn't in "slate" mode, we should bail:
   if (::GetSystemMetrics(SM_CONVERTIBLESLATEMODE) != 0) {
     Preferences::SetString(kOskDebugReason, L"IKPOS: ConvertibleSlateMode is non-zero");
-    return true;
+    return false;
   }
 
   // Before we check for a keyboard, we should check if the last input was touch,
@@ -761,9 +772,20 @@ IMEHandler::IsKeyboardPresentOnSlate()
   if (sLastContextActionCause == InputContextAction::CAUSE_TOUCH) {
     Preferences::SetString(kOskDebugReason,
       L"IKPOS: Used touch to focus control, ignoring keyboard presence");
-    return false;
+    return true;
   }
+  return !IMEHandler::IsKeyboardPresentOnSlate();
+}
 
+// Uses the Setup APIs to enumerate the attached keyboards and returns true
+// if the keyboard count is 1 or more. While this will work in most cases
+// it won't work if there are devices which expose keyboard interfaces which
+// are attached to the machine.
+// Based on IsKeyboardPresentOnSlate() in Chromium's base/win/win_util.cc.
+// static
+bool
+IMEHandler::IsKeyboardPresentOnSlate()
+{
   const GUID KEYBOARD_CLASS_GUID =
     { 0x4D36E96B, 0xE325,  0x11CE,
       { 0xBF, 0xC1, 0x08, 0x00, 0x2B, 0xE1, 0x03, 0x18 } };

widget/windows/WinIMEHandler.h

@@ -145,6 +145,7 @@ private:
   static void MaybeDismissOnScreenKeyboard(nsWindow* aWindow);
   static bool WStringStartsWithCaseInsensitive(const std::wstring& aHaystack,
                                                const std::wstring& aNeedle);
+  static bool NeedOnScreenKeyboard();
   static bool IsKeyboardPresentOnSlate();
   static bool IsInTabletMode();
   static bool AutoInvokeOnScreenKeyboardInDesktopMode();