Fix system hotkey handling.

Fixed a problem where the key up for the ALT or META key was not
delivered to the task switcher dialog because it was deemed
to be inconsistent with the window's observed state.  Consequently
the dialog would not be dismissed when the key was released.

Moved global hotkey handling for META+* shortcuts and ALT/META-TAB
into the window manager policy's interceptKeyBeforeDispatching
method.  This change prevents applications from hijacking these
keys.

The original idea was that these shortcuts would be handled only
if the application did not handle them itself.  That way certain
applications, such as remote desktop tools, could deliberately
override some of these less important system shortcuts.
Unfortunately, that does make the behavior inconsistent across
applications.  What's more, bugs in the onKeyDown handler of
applications can cause the shortcuts to not work at all, for
no good reason.

Perhaps we can add an opt-in feature later to enable specific
applications to repurpose these keys when it makes sense.

Bug: 5720358
Change-Id: I22bf17606d12dbea6549c60d20763e6608576cf7

1 files changed, 11 insertions, 0 deletions

diff --git a/services/input/InputDispatcher.cpp b/services/input/InputDispatcher.cpp
index 04b4855..40268b0 100644
--- a/services/input/InputDispatcher.cpp
+++ b/services/input/InputDispatcher.cpp
@@ -4320,12 +4320,23 @@ bool InputDispatcher::InputState::trackKey(const KeyEntry* entry,
             mKeyMementos.removeAt(index);
             return true;
         }
+        /* FIXME: We can't just drop the key up event because that prevents creating
+         * popup windows that are automatically shown when a key is held and then
+         * dismissed when the key is released.  The problem is that the popup will
+         * not have received the original key down, so the key up will be considered
+         * to be inconsistent with its observed state.  We could perhaps handle this
+         * by synthesizing a key down but that will cause other problems.
+         *
+         * So for now, allow inconsistent key up events to be dispatched.
+         *
 #if DEBUG_OUTBOUND_EVENT_DETAILS
         LOGD("Dropping inconsistent key up event: deviceId=%d, source=%08x, "
                 "keyCode=%d, scanCode=%d",
                 entry->deviceId, entry->source, entry->keyCode, entry->scanCode);
 #endif
         return false;
+        */
+        return true;
     }
 
     case AKEY_EVENT_ACTION_DOWN: {