Support floating IMEs even when IMEs render the nav buttons

As discussed in Bug 201375975, the nevigation bar handling for
floating IMEs is a bit tricky.

This CL tweaks DecorView behabior only when

  InputMethodService#canImeRenderGesturalNavButtons(),

is true and the IME is floating in the gestural navigation mode.

Fix: 215550296
Test: Manually tested with ThemedNavBarKeyboard sample
  1. Build aosp_coral-userdebug and flash it
  2. adb root
  3. adb shell setprop \
      persist.sys.ime.can_render_gestural_nav_buttons true
  4. adb reboot
  5. make -j ThemedNavBarKeyboard
  6. adb install -r \
      $OUT/system/app/ThemedNavBarKeyboard/ThemedNavBarKeyboard.apk
  7. adb shell ime enable \
      com.example.android.themednavbarkeyboard/.ThemedNavBarKeyboard
  8. adb shell ime set \
      com.example.android.themednavbarkeyboard/.ThemedNavBarKeyboard
  9. Open the Dialer app
 10. Focus in the top edit field.
 11. Tap "FLOATING MODE" mode
 12. Make sure that the navigation buttons are visible.
Change-Id: Ia54499a3c2ac6e33e72f625eba3477fd81649d32

core/java/android/inputmethodservice/NavigationBarController.java

@@ -29,6 +29,7 @@ import android.content.Context;
 import android.content.Intent;
 import android.content.IntentFilter;
 import android.content.res.Resources;
+import android.graphics.Color;
 import android.graphics.Insets;
 import android.graphics.Rect;
 import android.graphics.Region;
@@ -158,6 +159,8 @@ final class NavigationBarController {
         @Nullable
         private ValueAnimator mTintAnimator;
 
+        private boolean mDrawLegacyNavigationBarBackground;
+
         Impl(@NonNull InputMethodService inputMethodService) {
             mService = inputMethodService;
         }
@@ -226,9 +229,14 @@ final class NavigationBarController {
                 mLastInsets = systemInsets;
             }
 
-            mNavigationBarFrame.setBackground(null);
+            if (mDrawLegacyNavigationBarBackground) {
+                mNavigationBarFrame.setBackgroundColor(Color.BLACK);
+            } else {
+                mNavigationBarFrame.setBackground(null);
+            }
 
-            setIconTintInternal(calculateTargetDarkIntensity(mAppearance));
+            setIconTintInternal(calculateTargetDarkIntensity(mAppearance,
+                    mDrawLegacyNavigationBarBackground));
         }
 
         private void uninstallNavigationBarFrameIfNecessary() {
@@ -478,7 +486,8 @@ final class NavigationBarController {
                 return;
             }
 
-            final float targetDarkIntensity = calculateTargetDarkIntensity(mAppearance);
+            final float targetDarkIntensity = calculateTargetDarkIntensity(mAppearance,
+                    mDrawLegacyNavigationBarBackground);
 
             if (mTintAnimator != null) {
                 mTintAnimator.cancel();
@@ -506,11 +515,33 @@ final class NavigationBarController {
         }
 
         @FloatRange(from = 0.0f, to = 1.0f)
-        private static float calculateTargetDarkIntensity(@Appearance int appearance) {
-            final boolean lightNavBar = (appearance & APPEARANCE_LIGHT_NAVIGATION_BARS) != 0;
+        private static float calculateTargetDarkIntensity(@Appearance int appearance,
+                boolean drawLegacyNavigationBarBackground) {
+            final boolean lightNavBar = !drawLegacyNavigationBarBackground
+                    && (appearance & APPEARANCE_LIGHT_NAVIGATION_BARS) != 0;
             return lightNavBar ? 1.0f : 0.0f;
         }
 
+        @Override
+        public boolean onDrawLegacyNavigationBarBackgroundChanged(
+                boolean drawLegacyNavigationBarBackground) {
+            if (mDestroyed) {
+                return false;
+            }
+
+            if (drawLegacyNavigationBarBackground != mDrawLegacyNavigationBarBackground) {
+                mDrawLegacyNavigationBarBackground = drawLegacyNavigationBarBackground;
+                if (mDrawLegacyNavigationBarBackground) {
+                    mNavigationBarFrame.setBackgroundColor(Color.BLACK);
+                } else {
+                    mNavigationBarFrame.setBackground(null);
+                }
+                scheduleRelayout();
+                onSystemBarAppearanceChanged(mAppearance);
+            }
+            return drawLegacyNavigationBarBackground;
+        }
+
         @Override
         public String toDebugString() {
             return "{mRenderGesturalNavButtons=" + mRenderGesturalNavButtons
@@ -518,6 +549,7 @@ final class NavigationBarController {
                     + " mShouldShowImeSwitcherWhenImeIsShown" + mShouldShowImeSwitcherWhenImeIsShown
                     + " mAppearance=0x" + Integer.toHexString(mAppearance)
                     + " mDarkIntensity=" + mDarkIntensity
+                    + " mDrawLegacyNavigationBarBackground=" + mDrawLegacyNavigationBarBackground
                     + "}";
         }
     }

core/java/android/view/Window.java

@@ -673,6 +673,24 @@ public abstract class Window {
          * @param appearance The newly applied appearance.
          */
         void onSystemBarAppearanceChanged(@WindowInsetsController.Appearance int appearance);
+
+        /**
+         * Called from
+         * {@link com.android.internal.policy.DecorView#updateColorViews(WindowInsets, boolean)}
+         * when {@link com.android.internal.policy.DecorView#mDrawLegacyNavigationBarBackground} is
+         * being updated.
+         *
+         * @param drawLegacyNavigationBarBackground the new value that is being set to
+         *        {@link com.android.internal.policy.DecorView#mDrawLegacyNavigationBarBackground}.
+         * @return The value to be set to
+         *   {@link com.android.internal.policy.DecorView#mDrawLegacyNavigationBarBackgroundHandled}
+         *         on behalf of the {@link com.android.internal.policy.DecorView}.
+         *         {@code true} to tell that the Window can render the legacy navigation bar
+         *         background on behalf of the {@link com.android.internal.policy.DecorView}.
+         *         {@code false} to let {@link com.android.internal.policy.DecorView} handle it.
+         */
+        boolean onDrawLegacyNavigationBarBackgroundChanged(
+                boolean drawLegacyNavigationBarBackground);
     }
 
     /**
@@ -1019,6 +1037,16 @@ public abstract class Window {
         }
     }
 
+    /** @hide */
+    public final boolean onDrawLegacyNavigationBarBackgroundChanged(
+            boolean drawLegacyNavigationBarBackground) {
+        if (mDecorCallback == null) {
+            return false;
+        }
+        return mDecorCallback.onDrawLegacyNavigationBarBackgroundChanged(
+                drawLegacyNavigationBarBackground);
+    }
+
     /**
      * Set a callback for changes of area where caption will draw its content.
      *

core/java/com/android/internal/policy/DecorView.java

@@ -285,6 +285,7 @@ public class DecorView extends FrameLayout implements RootViewSurfaceTaker, Wind
     private Insets mBackgroundInsets = Insets.NONE;
     private Insets mLastBackgroundInsets = Insets.NONE;
     private boolean mDrawLegacyNavigationBarBackground;
+    private boolean mDrawLegacyNavigationBarBackgroundHandled;
 
     private PendingInsetsController mPendingInsetsController = new PendingInsetsController();
 
@@ -1171,6 +1172,9 @@ public class DecorView extends FrameLayout implements RootViewSurfaceTaker, Wind
             mDrawLegacyNavigationBarBackground = mNavigationColorViewState.visible
                     && (mWindow.getAttributes().flags & FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS) == 0;
             if (oldDrawLegacy != mDrawLegacyNavigationBarBackground) {
+                mDrawLegacyNavigationBarBackgroundHandled =
+                        mWindow.onDrawLegacyNavigationBarBackgroundChanged(
+                                mDrawLegacyNavigationBarBackground);
                 if (viewRoot != null) {
                     viewRoot.requestInvalidateRootRenderNode();
                 }
@@ -1263,7 +1267,7 @@ public class DecorView extends FrameLayout implements RootViewSurfaceTaker, Wind
             }
         }
 
-        if (forceConsumingNavBar) {
+        if (forceConsumingNavBar && !mDrawLegacyNavigationBarBackgroundHandled) {
             mBackgroundInsets = Insets.of(mLastLeftInset, 0, mLastRightInset, mLastBottomInset);
         } else {
             mBackgroundInsets = Insets.NONE;
@@ -2488,7 +2492,7 @@ public class DecorView extends FrameLayout implements RootViewSurfaceTaker, Wind
     }
 
     private void drawLegacyNavigationBarBackground(RecordingCanvas canvas) {
-        if (!mDrawLegacyNavigationBarBackground) {
+        if (!mDrawLegacyNavigationBarBackground || mDrawLegacyNavigationBarBackgroundHandled) {
             return;
         }
         View v = mNavigationColorViewState.view;