1 files changed, 328 insertions, 0 deletions
diff --git a/core/java/android/inputmethodservice/NavigationBarController.java b/core/java/android/inputmethodservice/NavigationBarController.java
new file mode 100644
index 000000000000..7295b72c276b
--- /dev/null
+++ b/core/java/android/inputmethodservice/NavigationBarController.java
@@ -0,0 +1,328 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.inputmethodservice;
+
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.app.StatusBarManager;
+import android.content.res.Resources;
+import android.graphics.Insets;
+import android.graphics.Rect;
+import android.graphics.Region;
+import android.inputmethodservice.navigationbar.NavigationBarFrame;
+import android.inputmethodservice.navigationbar.NavigationBarView;
+import android.view.Gravity;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.view.ViewTreeObserver;
+import android.view.Window;
+import android.view.WindowInsets;
+import android.view.WindowManagerPolicyConstants;
+import android.widget.FrameLayout;
+
+import java.util.Objects;
+
+/**
+ * This class hides details behind {@link InputMethodService#canImeRenderGesturalNavButtons()} from
+ * {@link InputMethodService}.
+ *
+ * <p>All the package-private methods are no-op when
+ * {@link InputMethodService#canImeRenderGesturalNavButtons()} returns {@code false}.</p>
+ */
+final class NavigationBarController {
+
+    private interface Callback {
+        default void updateTouchableInsets(@NonNull InputMethodService.Insets originalInsets,
+                @NonNull ViewTreeObserver.InternalInsetsInfo dest) {
+        }
+
+        default void onViewInitialized() {
+        }
+
+        default void onWindowShown() {
+        }
+
+        default void onDestroy() {
+        }
+
+        default String toDebugString() {
+            return "No-op implementation";
+        }
+
+        Callback NOOP = new Callback() {
+        };
+    }
+
+    private final Callback mImpl;
+
+    NavigationBarController(@NonNull InputMethodService inputMethodService) {
+        mImpl = InputMethodService.canImeRenderGesturalNavButtons()
+                ? new Impl(inputMethodService) : Callback.NOOP;
+    }
+
+    void updateTouchableInsets(@NonNull InputMethodService.Insets originalInsets,
+            @NonNull ViewTreeObserver.InternalInsetsInfo dest) {
+        mImpl.updateTouchableInsets(originalInsets, dest);
+    }
+
+    void onViewInitialized() {
+        mImpl.onViewInitialized();
+    }
+
+    void onWindowShown() {
+        mImpl.onWindowShown();
+    }
+
+    void onDestroy() {
+        mImpl.onDestroy();
+    }
+
+    String toDebugString() {
+        return mImpl.toDebugString();
+    }
+
+    private static final class Impl implements Callback {
+        @NonNull
+        private final InputMethodService mService;
+
+        private boolean mDestroyed = false;
+
+        private boolean mRenderGesturalNavButtons;
+
+        @Nullable
+        private NavigationBarFrame mNavigationBarFrame;
+        @Nullable
+        Insets mLastInsets;
+
+        Impl(@NonNull InputMethodService inputMethodService) {
+            mService = inputMethodService;
+        }
+
+        @Nullable
+        private Insets getSystemInsets() {
+            if (mService.mWindow == null) {
+                return null;
+            }
+            final View decorView = mService.mWindow.getWindow().getDecorView();
+            if (decorView == null) {
+                return null;
+            }
+            final WindowInsets windowInsets = decorView.getRootWindowInsets();
+            if (windowInsets == null) {
+                return null;
+            }
+            final Insets stableBarInsets =
+                    windowInsets.getInsetsIgnoringVisibility(WindowInsets.Type.systemBars());
+            return Insets.min(windowInsets.getInsets(WindowInsets.Type.systemBars()
+                    | WindowInsets.Type.displayCutout()), stableBarInsets);
+        }
+
+        private void installNavigationBarFrameIfNecessary() {
+            if (!mRenderGesturalNavButtons) {
+                return;
+            }
+            final View rawDecorView = mService.mWindow.getWindow().getDecorView();
+            if (!(rawDecorView instanceof ViewGroup)) {
+                return;
+            }
+            final ViewGroup decorView = (ViewGroup) rawDecorView;
+            mNavigationBarFrame = decorView.findViewByPredicate(
+                    NavigationBarFrame.class::isInstance);
+            final Insets systemInsets = getSystemInsets();
+            if (mNavigationBarFrame == null) {
+                mNavigationBarFrame = new NavigationBarFrame(mService);
+                LayoutInflater.from(mService).inflate(
+                        com.android.internal.R.layout.input_method_navigation_bar,
+                        mNavigationBarFrame);
+                if (systemInsets != null) {
+                    decorView.addView(mNavigationBarFrame, new FrameLayout.LayoutParams(
+                            ViewGroup.LayoutParams.MATCH_PARENT,
+                            systemInsets.bottom, Gravity.BOTTOM));
+                    mLastInsets = systemInsets;
+                } else {
+                    decorView.addView(mNavigationBarFrame);
+                }
+                final NavigationBarView navigationBarView = mNavigationBarFrame.findViewByPredicate(
+                        NavigationBarView.class::isInstance);
+                if (navigationBarView != null) {
+                    // TODO(b/213337792): Support InputMethodService#setBackDisposition().
+                    // TODO(b/213337792): Set NAVIGATION_HINT_IME_SHOWN only when necessary.
+                    final int hints = StatusBarManager.NAVIGATION_HINT_BACK_ALT
+                            | StatusBarManager.NAVIGATION_HINT_IME_SHOWN;
+                    navigationBarView.setNavigationIconHints(hints);
+                }
+            } else {
+                mNavigationBarFrame.setLayoutParams(new FrameLayout.LayoutParams(
+                        ViewGroup.LayoutParams.MATCH_PARENT, systemInsets.bottom, Gravity.BOTTOM));
+                mLastInsets = systemInsets;
+            }
+
+            mNavigationBarFrame.setBackground(null);
+        }
+
+        @Override
+        public void updateTouchableInsets(@NonNull InputMethodService.Insets originalInsets,
+                @NonNull ViewTreeObserver.InternalInsetsInfo dest) {
+            if (!mRenderGesturalNavButtons || mNavigationBarFrame == null
+                    || mService.isExtractViewShown()) {
+                return;
+            }
+
+            final Insets systemInsets = getSystemInsets();
+            if (systemInsets != null) {
+                final Window window = mService.mWindow.getWindow();
+                final View decor = window.getDecorView();
+                Region touchableRegion = null;
+                final View inputFrame = mService.mInputFrame;
+                switch (originalInsets.touchableInsets) {
+                    case ViewTreeObserver.InternalInsetsInfo.TOUCHABLE_INSETS_FRAME:
+                        if (inputFrame.getVisibility() == View.VISIBLE) {
+                            touchableRegion = new Region(inputFrame.getLeft(),
+                                    inputFrame.getTop(), inputFrame.getRight(),
+                                    inputFrame.getBottom());
+                        }
+                        break;
+                    case ViewTreeObserver.InternalInsetsInfo.TOUCHABLE_INSETS_CONTENT:
+                        if (inputFrame.getVisibility() == View.VISIBLE) {
+                            touchableRegion = new Region(inputFrame.getLeft(),
+                                    originalInsets.contentTopInsets, inputFrame.getRight(),
+                                    inputFrame.getBottom());
+                        }
+                        break;
+                    case ViewTreeObserver.InternalInsetsInfo.TOUCHABLE_INSETS_VISIBLE:
+                        if (inputFrame.getVisibility() == View.VISIBLE) {
+                            touchableRegion = new Region(inputFrame.getLeft(),
+                                    originalInsets.visibleTopInsets, inputFrame.getRight(),
+                                    inputFrame.getBottom());
+                        }
+                        break;
+                    case ViewTreeObserver.InternalInsetsInfo.TOUCHABLE_INSETS_REGION:
+                        touchableRegion = new Region();
+                        touchableRegion.set(originalInsets.touchableRegion);
+                        break;
+                }
+                final Rect navBarRect = new Rect(decor.getLeft(),
+                        decor.getBottom() - systemInsets.bottom,
+                        decor.getRight(), decor.getBottom());
+                if (touchableRegion == null) {
+                    touchableRegion = new Region(navBarRect);
+                } else {
+                    touchableRegion.union(navBarRect);
+                }
+
+                dest.touchableRegion.set(touchableRegion);
+                dest.setTouchableInsets(
+                        ViewTreeObserver.InternalInsetsInfo.TOUCHABLE_INSETS_REGION);
+
+                // TODO(b/205803355): See if we can use View#OnLayoutChangeListener().
+                // TODO(b/205803355): See if we can replace DecorView#mNavigationColorViewState.view
+                boolean zOrderChanged = false;
+                if (decor instanceof ViewGroup) {
+                    ViewGroup decorGroup = (ViewGroup) decor;
+                    final View navbarBackgroundView = window.getNavigationBarBackgroundView();
+                    zOrderChanged = navbarBackgroundView != null
+                            && decorGroup.indexOfChild(navbarBackgroundView)
+                            > decorGroup.indexOfChild(mNavigationBarFrame);
+                }
+                final boolean insetChanged = !Objects.equals(systemInsets, mLastInsets);
+                if (zOrderChanged || insetChanged) {
+                    final NavigationBarFrame that = mNavigationBarFrame;
+                    that.post(() -> {
+                        if (!that.isAttachedToWindow()) {
+                            return;
+                        }
+                        final Insets currentSystemInsets = getSystemInsets();
+                        if (!Objects.equals(currentSystemInsets, mLastInsets)) {
+                            that.setLayoutParams(
+                                    new FrameLayout.LayoutParams(
+                                            ViewGroup.LayoutParams.MATCH_PARENT,
+                                            currentSystemInsets.bottom, Gravity.BOTTOM));
+                            mLastInsets = currentSystemInsets;
+                        }
+                        if (decor instanceof ViewGroup) {
+                            ViewGroup decorGroup = (ViewGroup) decor;
+                            final View navbarBackgroundView =
+                                    window.getNavigationBarBackgroundView();
+                            if (navbarBackgroundView != null
+                                    && decorGroup.indexOfChild(navbarBackgroundView)
+                                    > decorGroup.indexOfChild(that)) {
+                                decorGroup.bringChildToFront(that);
+                            }
+                        }
+                    });
+                }
+            }
+        }
+
+        private boolean isGesturalNavigationEnabled() {
+            final Resources resources = mService.getResources();
+            if (resources == null) {
+                return false;
+            }
+            return resources.getInteger(com.android.internal.R.integer.config_navBarInteractionMode)
+                    == WindowManagerPolicyConstants.NAV_BAR_MODE_GESTURAL;
+        }
+
+        @Override
+        public void onViewInitialized() {
+            if (mDestroyed) {
+                return;
+            }
+            mRenderGesturalNavButtons = isGesturalNavigationEnabled();
+            installNavigationBarFrameIfNecessary();
+        }
+
+        @Override
+        public void onDestroy() {
+            mDestroyed = true;
+        }
+
+        @Override
+        public void onWindowShown() {
+            if (mDestroyed || !mRenderGesturalNavButtons || mNavigationBarFrame == null) {
+                return;
+            }
+            final Insets systemInsets = getSystemInsets();
+            if (systemInsets != null) {
+                if (!Objects.equals(systemInsets, mLastInsets)) {
+                    mNavigationBarFrame.setLayoutParams(new NavigationBarFrame.LayoutParams(
+                            ViewGroup.LayoutParams.MATCH_PARENT,
+                            systemInsets.bottom, Gravity.BOTTOM));
+                    mLastInsets = systemInsets;
+                }
+                final Window window = mService.mWindow.getWindow();
+                View rawDecorView = window.getDecorView();
+                if (rawDecorView instanceof ViewGroup) {
+                    final ViewGroup decor = (ViewGroup) rawDecorView;
+                    final View navbarBackgroundView = window.getNavigationBarBackgroundView();
+                    if (navbarBackgroundView != null
+                            && decor.indexOfChild(navbarBackgroundView)
+                            > decor.indexOfChild(mNavigationBarFrame)) {
+                        decor.bringChildToFront(mNavigationBarFrame);
+                    }
+                }
+                mNavigationBarFrame.setVisibility(View.VISIBLE);
+            }
+        }
+
+        @Override
+        public String toDebugString() {
+            return "{mRenderGesturalNavButtons=" + mRenderGesturalNavButtons + "}";
+        }
+    }
+}