From 1e5b1a842a07335b8c49ae4a20f439078b2670cc Mon Sep 17 00:00:00 2001
From: Tarandeep Singh <tarandeep@google.com>
Date: Fri, 24 Jan 2020 16:03:05 -0800
Subject: [PATCH] Move IME to a host display when target's display is
 reparented

By default IME shows in same display as IME target app window. This CL
moves IME to a more eligible display that can host and control IME. Host
display is chosen based on support to host IME/system decor. If nothing
else is eligible, we fallback to default display.

Bug: 111084606
Test: Use bubbles test app to verify IME appears in main display.

Change-Id: I5e1c0844beaae91eb63e5ac39587fa11834d31d2
---
 .../com/android/server/wm/DisplayContent.java | 52 +++++++++++++++++++
 .../server/wm/InsetsControlTarget.java        |  7 +++
 .../server/wm/InsetsSourceProvider.java       |  6 +++
 .../server/wm/WindowManagerService.java       | 44 +++++++---------
 .../com/android/server/wm/WindowState.java    | 23 ++++++++
 .../android/server/wm/WindowTestsBase.java    | 25 ++++++---
 6 files changed, 126 insertions(+), 31 deletions(-)

diff --git a/services/core/java/com/android/server/wm/DisplayContent.java b/services/core/java/com/android/server/wm/DisplayContent.java
index c50048eeab642..04fc1d2f202bd 100644
--- a/services/core/java/com/android/server/wm/DisplayContent.java
+++ b/services/core/java/com/android/server/wm/DisplayContent.java
@@ -122,6 +122,7 @@ import static com.android.server.wm.ProtoLogGroup.WM_DEBUG_FOCUS;
 import static com.android.server.wm.ProtoLogGroup.WM_DEBUG_FOCUS_LIGHT;
 import static com.android.server.wm.ProtoLogGroup.WM_DEBUG_ORIENTATION;
 import static com.android.server.wm.ProtoLogGroup.WM_DEBUG_SCREEN_ON;
+import static com.android.server.wm.ProtoLogGroup.WM_ERROR;
 import static com.android.server.wm.ProtoLogGroup.WM_SHOW_TRANSACTIONS;
 import static com.android.server.wm.RootWindowContainer.TAG_STATES;
 import static com.android.server.wm.WindowContainer.AnimationFlags.PARENTS;
@@ -3407,6 +3408,57 @@ class DisplayContent extends WindowContainer<DisplayContent.DisplayChildWindowCo
                 && mInputMethodTarget.mActivityRecord.matchParentBounds());
     }
 
+    /**
+     * Get IME target that should host IME when this display that is reparented to another
+     * WindowState.
+     * IME is never displayed in a child display.
+     * Use {@link WindowState#getImeControlTarget()} when IME target window
+     * which originally called
+     * {@link android.view.inputmethod.InputMethodManager#showSoftInput(View, int)} is known.
+     *
+     * @return {@link WindowState} of host that controls IME.
+     *         {@code null} when {@param dc} is not a virtual display.
+     * @see DisplayContent#reparent
+     */
+    @Nullable
+    WindowState getImeControlTarget() {
+        WindowState imeTarget = mInputMethodTarget;
+        if (imeTarget != null) {
+            return imeTarget.getImeControlTarget();
+        }
+
+        return getInsetsStateController().getImeSourceProvider().getControlTarget().getWindow();
+    }
+
+    /**
+     * Finds the window which can host IME if IME target cannot host it.
+     * e.g. IME target cannot host IME when it's display has a parent display OR when display
+     * doesn't support IME/system decorations.
+     *
+     * @param target current IME target.
+     * @return {@link WindowState} that can host IME.
+     * @see DisplayContent#getImeControlTarget()
+     */
+    WindowState getImeHostOrFallback(WindowState target) {
+        if (target != null && target.getDisplayContent().canShowIme()) {
+            return target;
+        }
+
+        // host is in non-default display that doesn't support system decor, default to
+        // default display's StatusBar to control IME.
+        // TODO: (b/148234093)find a better host OR control IME animation/visibility directly
+        //  because it won't work when statusbar isn't available.
+        return mWmService.getDefaultDisplayContentLocked().getDisplayPolicy().getStatusBar();
+    }
+
+    boolean canShowIme() {
+        if (isUntrustedVirtualDisplay()) {
+            return false;
+        }
+        return mWmService.mDisplayWindowSettings.shouldShowImeLocked(this)
+                || mWmService.mForceDesktopModeOnExternalDisplays;
+    }
+
     private void setInputMethodTarget(WindowState target, boolean targetWaitingAnim) {
         if (target == mInputMethodTarget && mInputMethodTargetWaitingAnim == targetWaitingAnim) {
             return;
diff --git a/services/core/java/com/android/server/wm/InsetsControlTarget.java b/services/core/java/com/android/server/wm/InsetsControlTarget.java
index 154cde1408104..20e8f2ba485ab 100644
--- a/services/core/java/com/android/server/wm/InsetsControlTarget.java
+++ b/services/core/java/com/android/server/wm/InsetsControlTarget.java
@@ -25,6 +25,13 @@ import android.view.WindowInsets.Type.InsetsType;
 interface InsetsControlTarget {
     void notifyInsetsControlChanged();
 
+    /**
+     * @return {@link WindowState} of this target, if any.
+     */
+    default WindowState getWindow() {
+        return null;
+    }
+
     /**
      * Instructs the control target to show inset sources.
      *
diff --git a/services/core/java/com/android/server/wm/InsetsSourceProvider.java b/services/core/java/com/android/server/wm/InsetsSourceProvider.java
index 2bb58ddc5b387..74f6b387f5eb6 100644
--- a/services/core/java/com/android/server/wm/InsetsSourceProvider.java
+++ b/services/core/java/com/android/server/wm/InsetsSourceProvider.java
@@ -209,6 +209,12 @@ class InsetsSourceProvider {
             // to control the window for now.
             return;
         }
+        if (target != null && target.getWindow() != null) {
+            // ime control target could be a different window.
+            // Refer WindowState#getImeControlTarget().
+            target = target.getWindow().getImeControlTarget();
+        }
+
         if (mWin == null) {
             mControlTarget = target;
             return;
diff --git a/services/core/java/com/android/server/wm/WindowManagerService.java b/services/core/java/com/android/server/wm/WindowManagerService.java
index 2c6c756dda3b3..f15e9eb80403f 100644
--- a/services/core/java/com/android/server/wm/WindowManagerService.java
+++ b/services/core/java/com/android/server/wm/WindowManagerService.java
@@ -6991,8 +6991,15 @@ public class WindowManagerService extends IWindowManager.Stub
             throw new SecurityException("Requires INTERNAL_SYSTEM_WINDOW permission");
         }
         boolean show;
+        final DisplayContent dc = mRoot.getDisplayContent(displayId);
+        if (dc == null) {
+            ProtoLog.w(WM_ERROR,
+                    "Attempted to get IME flag of a display that does not exist: %d",
+                    displayId);
+            return false;
+        }
         synchronized (mGlobalLock) {
-            show = shouldShowImeSystemWindowUncheckedLocked(displayId);
+            show = dc.canShowIme();
         }
 
         return show;
@@ -7405,15 +7412,13 @@ public class WindowManagerService extends IWindowManager.Stub
         @Override
         public void showImePostLayout(IBinder imeTargetWindowToken) {
             synchronized (mGlobalLock) {
-                final WindowState imeTarget = mWindowMap.get(imeTargetWindowToken);
+                WindowState imeTarget = mWindowMap.get(imeTargetWindowToken);
                 if (imeTarget == null) {
                     return;
                 }
-                final int displayId = imeTarget.getDisplayId();
-                if (!shouldShowImeSystemWindowUncheckedLocked(displayId)) {
-                    return;
-                }
+                imeTarget = imeTarget.getImeControlTarget();
 
+                final int displayId = imeTarget.getDisplayId();
                 mRoot.getDisplayContent(displayId).getInsetsStateController().getImeSourceProvider()
                         .scheduleShowImePostLayout(imeTarget);
             }
@@ -7423,12 +7428,16 @@ public class WindowManagerService extends IWindowManager.Stub
         public void hideIme(int displayId) {
             synchronized (mGlobalLock) {
                 final DisplayContent dc = mRoot.getDisplayContent(displayId);
-                if (dc != null && dc.mInputMethodTarget != null) {
+                if (dc != null) {
+                    WindowState imeTarget = dc.getImeControlTarget();
+                    if (imeTarget == null) {
+                        return;
+                    }
                     // If there was a pending IME show(), reset it as IME has been
                     // requested to be hidden.
-                    dc.getInsetsStateController().getImeSourceProvider().abortShowImePostLayout();
-                    dc.mInputMethodControlTarget.hideInsets(WindowInsets.Type.ime(),
-                            true /* fromIme */);
+                    imeTarget.getDisplayContent().getInsetsStateController().getImeSourceProvider()
+                            .abortShowImePostLayout();
+                    imeTarget.hideInsets(WindowInsets.Type.ime(), true /* fromIme */);
                 }
             }
         }
@@ -7936,21 +7945,6 @@ public class WindowManagerService extends IWindowManager.Stub
         return true;
     }
 
-    private boolean shouldShowImeSystemWindowUncheckedLocked(final int displayId) {
-        final DisplayContent displayContent = mRoot.getDisplayContent(displayId);
-        if (displayContent == null) {
-            ProtoLog.w(WM_ERROR,
-                    "Attempted to get IME flag of a display that does not exist: %d",
-                    displayId);
-            return false;
-        }
-        if (displayContent.isUntrustedVirtualDisplay()) {
-            return false;
-        }
-        return mDisplayWindowSettings.shouldShowImeLocked(displayContent)
-                || mForceDesktopModeOnExternalDisplays;
-    }
-
     @Override
     public void getWindowInsets(WindowManager.LayoutParams attrs,
             int displayId, Rect outContentInsets, Rect outStableInsets,
diff --git a/services/core/java/com/android/server/wm/WindowState.java b/services/core/java/com/android/server/wm/WindowState.java
index 874a25e50ae6b..47d808e6f0452 100644
--- a/services/core/java/com/android/server/wm/WindowState.java
+++ b/services/core/java/com/android/server/wm/WindowState.java
@@ -3517,6 +3517,11 @@ class WindowState extends WindowContainer<WindowState> implements WindowManagerP
         }
     }
 
+    @Override
+    public WindowState getWindow() {
+        return this;
+    }
+
     @Override
     public void showInsets(@InsetsType int types, boolean fromIme) {
         try {
@@ -5334,6 +5339,24 @@ class WindowState extends WindowContainer<WindowState> implements WindowManagerP
         return false;
     }
 
+    /**
+     * Get IME target that should host IME when this window's display has a parent.
+     * Note: IME is never hosted by a display that has a parent.
+     * When window calling
+     * {@link android.view.inputmethod.InputMethodManager#showSoftInput(View, int)} is unknown,
+     * use {@link DisplayContent#getImeControlTarget()} instead.
+     *
+     * @return {@link WindowState} of host that controls the IME.
+     *         When window is doesn't have a parent, it is returned as-is.
+     */
+    WindowState getImeControlTarget() {
+        final DisplayContent dc = getDisplayContent();
+        final WindowState parentWindow = dc.getParentWindow();
+
+        // If target's display has a parent, IME is displayed in the parent display.
+        return dc.getImeHostOrFallback(parentWindow != null ? parentWindow : this);
+    }
+
     @Override
     void assignLayer(Transaction t, int layer) {
         // See comment in assignRelativeLayerForImeTargetChild
diff --git a/services/tests/wmtests/src/com/android/server/wm/WindowTestsBase.java b/services/tests/wmtests/src/com/android/server/wm/WindowTestsBase.java
index 20eab5a45ff19..8e362ae4c59a0 100644
--- a/services/tests/wmtests/src/com/android/server/wm/WindowTestsBase.java
+++ b/services/tests/wmtests/src/com/android/server/wm/WindowTestsBase.java
@@ -110,7 +110,7 @@ class WindowTestsBase extends SystemServiceTestsBase {
             beforeCreateDisplay();
 
             context.getDisplay().getDisplayInfo(mDisplayInfo);
-            mDisplayContent = createNewDisplay();
+            mDisplayContent = createNewDisplay(true /* supportIme */);
 
             // Set-up some common windows.
             mCommonWindows = new HashSet<>();
@@ -349,16 +349,29 @@ class WindowTestsBase extends SystemServiceTestsBase {
         return WindowTestUtils.createTaskInStack(mWm, stack, userId);
     }
 
-    /** Creates a {@link DisplayContent} and adds it to the system. */
+    /** Creates a {@link DisplayContent} that supports IME and adds it to the system. */
     DisplayContent createNewDisplay() {
-        return createNewDisplay(mDisplayInfo);
+        return createNewDisplay(true /* supportIme */);
     }
 
     /** Creates a {@link DisplayContent} and adds it to the system. */
+    private DisplayContent createNewDisplay(boolean supportIme) {
+        return createNewDisplay(mDisplayInfo, supportIme);
+    }
+
+    /** Creates a {@link DisplayContent} that supports IME and adds it to the system. */
     DisplayContent createNewDisplay(DisplayInfo info) {
+        return createNewDisplay(info, true /* supportIme */);
+    }
+
+    /** Creates a {@link DisplayContent} and adds it to the system. */
+    private DisplayContent createNewDisplay(DisplayInfo info, boolean supportIme) {
         final DisplayContent display =
                 new TestDisplayContent.Builder(mWm.mAtmService, info).build();
-        return display.mDisplayContent;
+        final DisplayContent dc = display.mDisplayContent;
+        // this display can show IME.
+        dc.mWmService.mDisplayWindowSettings.setShouldShowImeLocked(dc, supportIme);
+        return dc;
     }
 
     /**
@@ -372,7 +385,7 @@ class WindowTestsBase extends SystemServiceTestsBase {
         DisplayInfo displayInfo = new DisplayInfo();
         displayInfo.copyFrom(mDisplayInfo);
         displayInfo.state = displayState;
-        return createNewDisplay(displayInfo);
+        return createNewDisplay(displayInfo, true /* supportIme */);
     }
 
     /** Creates a {@link com.android.server.wm.WindowTestUtils.TestWindowState} */
@@ -389,7 +402,7 @@ class WindowTestsBase extends SystemServiceTestsBase {
         displayInfo.copyFrom(mDisplayInfo);
         displayInfo.type = Display.TYPE_VIRTUAL;
         displayInfo.ownerUid = SYSTEM_UID;
-        return createNewDisplay(displayInfo);
+        return createNewDisplay(displayInfo, false /* supportIme */);
     }
 
     /** Sets the default minimum task size to 1 so that tests can use small task sizes */