Close IME when attaching dock stack

So we don't end up with animation weirdness.

Bug: 28905720
Change-Id: I04124995dd99fa26d2e9be467c5976d7b20810a7
diff --git a/services/core/java/com/android/server/InputMethodManagerService.java b/services/core/java/com/android/server/InputMethodManagerService.java
index 727bf5c..5d8fe7c 100644
--- a/services/core/java/com/android/server/InputMethodManagerService.java
+++ b/services/core/java/com/android/server/InputMethodManagerService.java
@@ -159,6 +159,7 @@
     static final int MSG_BIND_INPUT = 1010;
     static final int MSG_SHOW_SOFT_INPUT = 1020;
     static final int MSG_HIDE_SOFT_INPUT = 1030;
+    static final int MSG_HIDE_CURRENT_INPUT_METHOD = 1035;
     static final int MSG_ATTACH_TOKEN = 1040;
     static final int MSG_CREATE_SESSION = 1050;
 
@@ -2846,6 +2847,11 @@
                 }
                 args.recycle();
                 return true;
+            case MSG_HIDE_CURRENT_INPUT_METHOD:
+                synchronized (mMethodMap) {
+                    hideCurrentInputLocked(0, null);
+                }
+                return true;
             case MSG_ATTACH_TOKEN:
                 args = (SomeArgs)msg.obj;
                 try {
@@ -3880,6 +3886,12 @@
             mHandler.sendMessage(mHandler.obtainMessage(MSG_SWITCH_IME,
                     forwardDirection ? 1 : 0, 0));
         }
+
+        @Override
+        public void hideCurrentInputMethod() {
+            mHandler.removeMessages(MSG_HIDE_CURRENT_INPUT_METHOD);
+            mHandler.sendEmptyMessage(MSG_HIDE_CURRENT_INPUT_METHOD);
+        }
     }
 
     private static String imeWindowStatusToString(final int imeWindowVis) {
diff --git a/services/core/java/com/android/server/wm/DockedStackDividerController.java b/services/core/java/com/android/server/wm/DockedStackDividerController.java
index 1b31d07c..77b3bdb 100644
--- a/services/core/java/com/android/server/wm/DockedStackDividerController.java
+++ b/services/core/java/com/android/server/wm/DockedStackDividerController.java
@@ -45,9 +45,11 @@
 import android.view.animation.AnimationUtils;
 import android.view.animation.Interpolator;
 import android.view.animation.PathInterpolator;
+import android.view.inputmethod.InputMethodManagerInternal;
 
 import com.android.internal.policy.DividerSnapAlgorithm;
 import com.android.internal.policy.DockedDividerUtils;
+import com.android.server.LocalServices;
 import com.android.server.wm.DimLayer.DimLayerUser;
 import com.android.server.wm.WindowManagerService.H;
 
@@ -131,6 +133,7 @@
     private float mLastAnimationProgress;
     private float mLastDividerProgress;
     private final DividerSnapAlgorithm[] mSnapAlgorithmForRotation = new DividerSnapAlgorithm[4];
+    private boolean mImeHideRequested;
 
     DockedStackDividerController(WindowManagerService service, DisplayContent displayContent) {
         mService = service;
@@ -375,11 +378,39 @@
             }
         }
         mDockedStackListeners.finishBroadcast();
-        if (!exists) {
+        if (exists) {
+            InputMethodManagerInternal inputMethodManagerInternal =
+                    LocalServices.getService(InputMethodManagerInternal.class);
+            if (inputMethodManagerInternal != null) {
+
+                // Hide the current IME to avoid problems with animations from IME adjustment when
+                // attaching the docked stack.
+                inputMethodManagerInternal.hideCurrentInputMethod();
+                mImeHideRequested = true;
+            }
+        } else {
             setMinimizedDockedStack(false);
         }
     }
 
+    /**
+     * Resets the state that IME hide has been requested. See {@link #isImeHideRequested}.
+     */
+    void resetImeHideRequested() {
+        mImeHideRequested = false;
+    }
+
+    /**
+     * The docked stack divider controller makes sure the IME gets hidden when attaching the docked
+     * stack, to avoid animation problems. This flag indicates whether the request to hide the IME
+     * has been sent in an asynchronous manner, and the IME should be treated as hidden already.
+     *
+     * @return whether IME hide request has been sent
+     */
+    boolean isImeHideRequested() {
+        return mImeHideRequested;
+    }
+
     void notifyDockedStackMinimizedChanged(boolean minimizedDock, long animDuration) {
         mService.mH.removeMessages(NOTIFY_DOCKED_STACK_MINIMIZED_CHANGED);
         mService.mH.obtainMessage(NOTIFY_DOCKED_STACK_MINIMIZED_CHANGED,
diff --git a/services/core/java/com/android/server/wm/WindowManagerService.java b/services/core/java/com/android/server/wm/WindowManagerService.java
index 695ed36..08256e6 100644
--- a/services/core/java/com/android/server/wm/WindowManagerService.java
+++ b/services/core/java/com/android/server/wm/WindowManagerService.java
@@ -7596,7 +7596,8 @@
 
     void adjustForImeIfNeeded(final DisplayContent displayContent) {
         final WindowState imeWin = mInputMethodWindow;
-        final boolean imeVisible = imeWin != null && imeWin.isVisibleLw() && imeWin.isDisplayedLw();
+        final boolean imeVisible = imeWin != null && imeWin.isVisibleLw() && imeWin.isDisplayedLw()
+                && !displayContent.mDividerControllerLocked.isImeHideRequested();
         final boolean dockVisible = isStackVisibleLocked(DOCKED_STACK_ID);
         final TaskStack imeTargetStack = getImeFocusStackLocked();
         final int imeDockSide = (dockVisible && imeTargetStack != null) ?
diff --git a/services/core/java/com/android/server/wm/WindowStateAnimator.java b/services/core/java/com/android/server/wm/WindowStateAnimator.java
index 9dae0f2..c6422b9 100644
--- a/services/core/java/com/android/server/wm/WindowStateAnimator.java
+++ b/services/core/java/com/android/server/wm/WindowStateAnimator.java
@@ -1773,6 +1773,10 @@
                 mWin.mAppToken.onFirstWindowDrawn(mWin, this);
             }
 
+            if (mWin.mAttrs.type == TYPE_INPUT_METHOD) {
+                mWin.mDisplayContent.mDividerControllerLocked.resetImeHideRequested();
+            }
+
             return true;
         }
         return false;