Prevent windows below the keyguard from showing

Fixes a bug where windows below the lock screen
could become visible if a SHOW_WHEN_LOCKED activity
hides the status bar.

Bug: 21450145
Change-Id: Ie660394cb96d7e6839bd4fb7c2729133bac2dfc5

core/java/android/view/WindowManagerPolicy.java

diff --git a/core/java/android/view/WindowManagerPolicy.java b/core/java/android/view/WindowManagerPolicy.java
index f7b6405..ca5f5ad 100644
--- a/core/java/android/view/WindowManagerPolicy.java
+++ b/core/java/android/view/WindowManagerPolicy.java
@@ -1058,6 +1058,13 @@
     public boolean isKeyguardSecure();
 
     /**
+     * Return whether the keyguard is on.
+     *
+     * @return true if in keyguard is on.
+     */
+    public boolean isKeyguardShowingOrOccluded();
+
+    /**
      * inKeyguardRestrictedKeyInputMode
      *
      * if keyguard screen is showing or in restricted key input mode (i.e. in

services/core/java/com/android/server/policy/PhoneWindowManager.java

diff --git a/services/core/java/com/android/server/policy/PhoneWindowManager.java b/services/core/java/com/android/server/policy/PhoneWindowManager.java
index b8d0692..2839f08 100644
--- a/services/core/java/com/android/server/policy/PhoneWindowManager.java
+++ b/services/core/java/com/android/server/policy/PhoneWindowManager.java
@@ -2116,7 +2116,9 @@
             case TYPE_KEYGUARD_SCRIM:
                 return false;
             default:
-                return true;
+                // Hide only windows below the keyguard host window.
+                return windowTypeToLayerLw(win.getBaseType())
+                        < windowTypeToLayerLw(TYPE_STATUS_BAR);
         }
     }
 
@@ -5517,6 +5519,12 @@
 
     /** {@inheritDoc} */
     @Override
+    public boolean isKeyguardShowingOrOccluded() {
+        return mKeyguardDelegate == null ? false : mKeyguardDelegate.isShowing();
+    }
+
+    /** {@inheritDoc} */
+    @Override
     public boolean inKeyguardRestrictedKeyInputMode() {
         if (mKeyguardDelegate == null) return false;
         return mKeyguardDelegate.isInputRestricted();

services/core/java/com/android/server/wm/WindowAnimator.java

diff --git a/services/core/java/com/android/server/wm/WindowAnimator.java b/services/core/java/com/android/server/wm/WindowAnimator.java
index 9169351..3305e1e 100644
--- a/services/core/java/com/android/server/wm/WindowAnimator.java
+++ b/services/core/java/com/android/server/wm/WindowAnimator.java
@@ -191,7 +191,8 @@
     private boolean shouldForceHide(WindowState win) {
         final WindowState imeTarget = mService.mInputMethodTarget;
         final boolean showImeOverKeyguard = imeTarget != null && imeTarget.isVisibleNow() &&
-                (imeTarget.getAttrs().flags & FLAG_SHOW_WHEN_LOCKED) != 0;
+                ((imeTarget.getAttrs().flags & FLAG_SHOW_WHEN_LOCKED) != 0
+                        || !mPolicy.canBeForceHidden(imeTarget, imeTarget.mAttrs));
 
         final WindowState winShowWhenLocked = (WindowState) mPolicy.getWinShowWhenLockedLw();
         final AppWindowToken appShowWhenLocked = winShowWhenLocked == null ?
@@ -203,7 +204,11 @@
                         || (win.mAttrs.flags & FLAG_SHOW_WHEN_LOCKED) != 0 && win.isAnimatingLw()
                         // Show error dialogs over apps that dismiss keyguard.
                         || (win.mAttrs.privateFlags & PRIVATE_FLAG_SYSTEM_ERROR) != 0)));
-        return (mForceHiding == KEYGUARD_SHOWN) && hideWhenLocked;
+
+        // Only hide windows if the keyguard is active and not animating away.
+        boolean keyguardOn = mPolicy.isKeyguardShowingOrOccluded()
+                && mForceHiding != KEYGUARD_ANIMATING_OUT;
+        return keyguardOn && hideWhenLocked;
     }
 
     private void updateWindowsLocked(final int displayId) {
@@ -228,6 +233,7 @@
                         winAnimator.mAnimation.setDuration(KEYGUARD_ANIM_TIMEOUT_MS);
                         winAnimator.mAnimationIsEntrance = false;
                         winAnimator.mAnimationStartTime = -1;
+                        winAnimator.mKeyguardGoingAwayAnimation = true;
                     }
                 } else {
                     if (DEBUG_KEYGUARD) Slog.d(TAG,
@@ -310,7 +316,7 @@
                         mKeyguardGoingAway = false;
                     }
                     if (win.isReadyForDisplay()) {
-                        if (nowAnimating) {
+                        if (nowAnimating && win.mWinAnimator.mKeyguardGoingAwayAnimation) {
                             mForceHiding = KEYGUARD_ANIMATING_OUT;
                         } else {
                             mForceHiding = win.isDrawnLw() ? KEYGUARD_SHOWN : KEYGUARD_NOT_SHOWN;