Handle BACK shortcuts in PWM by injection

Current BACK shortcuts are handled in InputDispatcher and
Meta+`, Meta+Backspace, Meta+Left are converted to KEY_BACK
in InputDispatcher instead of being handled in PWM since BACK is
processed on app side instead of System fully handling it.

This blocks us from handling shortcuts like Meta+Ctrl+Left since
by the time keys reach PWM it is converted to Key_Back+Left and
doesn't get processed. Instead we wil handle everything in PWM now
and try to get similar behavior by injecting KEY_BACK whenever
Back shortcuts are pressed.

Bug: 290473497
Test: atest ShortcutLoggingTests
Test: atest BackShortcutTests
Change-Id: Idc60b303abb9ebfd0142e7686aabc4a39e529c19

2 files changed, 40 insertions, 3 deletions

diff --git a/services/core/java/com/android/server/policy/PhoneWindowManager.java b/services/core/java/com/android/server/policy/PhoneWindowManager.java
index b3aa09b8f17b..d5199ff97376 100644
--- a/services/core/java/com/android/server/policy/PhoneWindowManager.java
+++ b/services/core/java/com/android/server/policy/PhoneWindowManager.java
@@ -3342,6 +3342,13 @@ public class PhoneWindowManager implements WindowManagerPolicy {
                     return true;
                 }
                 break;
+            case KeyEvent.KEYCODE_DEL:
+            case KeyEvent.KEYCODE_GRAVE:
+                if (firstDown && event.isMetaPressed()) {
+                    logKeyboardSystemsEvent(event, KeyboardLogEvent.BACK);
+                    injectBackGesture(event.getDownTime());
+                    return true;
+                }
             case KeyEvent.KEYCODE_DPAD_UP:
                 if (firstDown && event.isMetaPressed() && event.isCtrlPressed()) {
                     StatusBarManagerInternal statusbar = getStatusBarManagerInternal();
@@ -3353,9 +3360,14 @@ public class PhoneWindowManager implements WindowManagerPolicy {
                 }
                 break;
             case KeyEvent.KEYCODE_DPAD_LEFT:
-                if (firstDown && event.isMetaPressed() && event.isCtrlPressed()) {
-                    enterStageSplitFromRunningApp(true /* leftOrTop */);
-                    logKeyboardSystemsEvent(event, KeyboardLogEvent.SPLIT_SCREEN_NAVIGATION);
+                if (firstDown && event.isMetaPressed()) {
+                    if (event.isCtrlPressed()) {
+                        enterStageSplitFromRunningApp(true /* leftOrTop */);
+                        logKeyboardSystemsEvent(event, KeyboardLogEvent.SPLIT_SCREEN_NAVIGATION);
+                    } else {
+                        logKeyboardSystemsEvent(event, KeyboardLogEvent.BACK);
+                        injectBackGesture(event.getDownTime());
+                    }
                     return true;
                 }
                 break;
@@ -3618,6 +3630,25 @@ public class PhoneWindowManager implements WindowManagerPolicy {
         return (metaState & KeyEvent.META_META_ON) != 0;
     }
 
+    @SuppressLint("MissingPermission")
+    private void injectBackGesture(long downtime) {
+        // Create and inject down event
+        KeyEvent downEvent = new KeyEvent(downtime, downtime, KeyEvent.ACTION_DOWN,
+                KeyEvent.KEYCODE_BACK, 0 /* repeat */, 0 /* metaState */,
+                KeyCharacterMap.VIRTUAL_KEYBOARD, 0 /* scancode */,
+                KeyEvent.FLAG_FROM_SYSTEM | KeyEvent.FLAG_VIRTUAL_HARD_KEY,
+                InputDevice.SOURCE_KEYBOARD);
+        mInputManager.injectInputEvent(downEvent, InputManager.INJECT_INPUT_EVENT_MODE_ASYNC);
+
+
+        // Create and inject up event
+        KeyEvent upEvent = KeyEvent.changeAction(downEvent, KeyEvent.ACTION_UP);
+        mInputManager.injectInputEvent(upEvent, InputManager.INJECT_INPUT_EVENT_MODE_ASYNC);
+
+        downEvent.recycle();
+        upEvent.recycle();
+    }
+
     private boolean handleHomeShortcuts(int displayId, IBinder focusedToken, KeyEvent event) {
         // First we always handle the home key here, so applications
         // can never break it, although if keyguard is on, we do let
diff --git a/services/tests/wmtests/src/com/android/server/policy/ShortcutLoggingTests.java b/services/tests/wmtests/src/com/android/server/policy/ShortcutLoggingTests.java
index 8fadecd0dc38..e13dc3eea729 100644
--- a/services/tests/wmtests/src/com/android/server/policy/ShortcutLoggingTests.java
+++ b/services/tests/wmtests/src/com/android/server/policy/ShortcutLoggingTests.java
@@ -65,6 +65,12 @@ public class ShortcutLoggingTests extends ShortcutKeyTestBase {
                         KeyboardLogEvent.RECENT_APPS, KeyEvent.KEYCODE_TAB, ALT_ON},
                 {"BACK key -> Go back", new int[]{KeyEvent.KEYCODE_BACK}, KeyboardLogEvent.BACK,
                         KeyEvent.KEYCODE_BACK, 0},
+                {"Meta + `(grave) -> Go back", new int[]{META_KEY, KeyEvent.KEYCODE_GRAVE},
+                        KeyboardLogEvent.BACK, KeyEvent.KEYCODE_GRAVE, META_ON},
+                {"Meta + Left arrow -> Go back", new int[]{META_KEY, KeyEvent.KEYCODE_DPAD_LEFT},
+                        KeyboardLogEvent.BACK, KeyEvent.KEYCODE_DPAD_LEFT, META_ON},
+                {"Meta + Del -> Go back", new int[]{META_KEY, KeyEvent.KEYCODE_DEL},
+                        KeyboardLogEvent.BACK, KeyEvent.KEYCODE_DEL, META_ON},
                 {"APP_SWITCH key -> Open App switcher", new int[]{KeyEvent.KEYCODE_APP_SWITCH},
                         KeyboardLogEvent.APP_SWITCH, KeyEvent.KEYCODE_APP_SWITCH, 0},
                 {"ASSIST key -> Launch assistant", new int[]{KeyEvent.KEYCODE_ASSIST},