Make AccessibleKeyboardViewProxy not singleton

This CL also renames AccessibleKeyboardViewProxy and
AccessibilityEntityProvider to MainKeyboardAccessibilityDelegate and
MainKeyboardAccessibilityNodeProvider.

Change-Id: I2b0ec091a11aa8a495794d633efecb6d8b818f42

1 files changed, 392 insertions, 0 deletions

diff --git a/java/src/com/android/inputmethod/accessibility/MainKeyboardAccessibilityDelegate.java b/java/src/com/android/inputmethod/accessibility/MainKeyboardAccessibilityDelegate.java
new file mode 100644
index 000000000..10929424b
--- /dev/null
+++ b/java/src/com/android/inputmethod/accessibility/MainKeyboardAccessibilityDelegate.java
@@ -0,0 +1,392 @@
+/*
+ * Copyright (C) 2011 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 com.android.inputmethod.accessibility;
+
+import android.content.Context;
+import android.os.SystemClock;
+import android.support.v4.view.AccessibilityDelegateCompat;
+import android.support.v4.view.ViewCompat;
+import android.support.v4.view.accessibility.AccessibilityEventCompat;
+import android.support.v4.view.accessibility.AccessibilityNodeInfoCompat;
+import android.util.SparseIntArray;
+import android.view.MotionEvent;
+import android.view.View;
+import android.view.ViewParent;
+import android.view.accessibility.AccessibilityEvent;
+
+import com.android.inputmethod.keyboard.Key;
+import com.android.inputmethod.keyboard.KeyDetector;
+import com.android.inputmethod.keyboard.Keyboard;
+import com.android.inputmethod.keyboard.KeyboardId;
+import com.android.inputmethod.keyboard.MainKeyboardView;
+import com.android.inputmethod.latin.R;
+import com.android.inputmethod.latin.utils.SubtypeLocaleUtils;
+
+public final class MainKeyboardAccessibilityDelegate extends AccessibilityDelegateCompat {
+    /** Map of keyboard modes to resource IDs. */
+    private static final SparseIntArray KEYBOARD_MODE_RES_IDS = new SparseIntArray();
+
+    static {
+        KEYBOARD_MODE_RES_IDS.put(KeyboardId.MODE_DATE, R.string.keyboard_mode_date);
+        KEYBOARD_MODE_RES_IDS.put(KeyboardId.MODE_DATETIME, R.string.keyboard_mode_date_time);
+        KEYBOARD_MODE_RES_IDS.put(KeyboardId.MODE_EMAIL, R.string.keyboard_mode_email);
+        KEYBOARD_MODE_RES_IDS.put(KeyboardId.MODE_IM, R.string.keyboard_mode_im);
+        KEYBOARD_MODE_RES_IDS.put(KeyboardId.MODE_NUMBER, R.string.keyboard_mode_number);
+        KEYBOARD_MODE_RES_IDS.put(KeyboardId.MODE_PHONE, R.string.keyboard_mode_phone);
+        KEYBOARD_MODE_RES_IDS.put(KeyboardId.MODE_TEXT, R.string.keyboard_mode_text);
+        KEYBOARD_MODE_RES_IDS.put(KeyboardId.MODE_TIME, R.string.keyboard_mode_time);
+        KEYBOARD_MODE_RES_IDS.put(KeyboardId.MODE_URL, R.string.keyboard_mode_url);
+    }
+
+    private final MainKeyboardView mView;
+    private Keyboard mKeyboard;
+    private MainKeyboardAccessibilityNodeProvider mAccessibilityNodeProvider;
+
+    private Key mLastHoverKey = null;
+
+    /**
+     * Inset in pixels to look for keys when the user's finger exits the keyboard area.
+     */
+    private int mEdgeSlop;
+
+    /** The most recently set keyboard mode. */
+    private int mLastKeyboardMode = KEYBOARD_IS_HIDDEN;
+    private static final int KEYBOARD_IS_HIDDEN = -1;
+
+    public MainKeyboardAccessibilityDelegate(final MainKeyboardView view) {
+        final Context context = view.getContext();
+        mEdgeSlop = context.getResources().getDimensionPixelSize(
+                R.dimen.config_accessibility_edge_slop);
+        mView = view;
+
+        // Ensure that the view has an accessibility delegate.
+        ViewCompat.setAccessibilityDelegate(view, this);
+    }
+
+    /**
+     * Called when the keyboard layout changes.
+     * <p>
+     * <b>Note:</b> This method will be called even if accessibility is not
+     * enabled.
+     * @param keyboard The keyboard that is being set to the wrapping view.
+     */
+    public void setKeyboard(final Keyboard keyboard) {
+        if (keyboard == null) {
+            return;
+        }
+        if (mAccessibilityNodeProvider != null) {
+            mAccessibilityNodeProvider.setKeyboard(keyboard);
+        }
+        final Keyboard lastKeyboard = mKeyboard;
+        final int lastKeyboardMode = mLastKeyboardMode;
+        mKeyboard = keyboard;
+        mLastKeyboardMode = keyboard.mId.mMode;
+
+        // Since this method is called even when accessibility is off, make sure
+        // to check the state before announcing anything.
+        if (!AccessibilityUtils.getInstance().isAccessibilityEnabled()) {
+            return;
+        }
+        // Announce the language name only when the language is changed.
+        if (lastKeyboard == null || !keyboard.mId.mSubtype.equals(lastKeyboard.mId.mSubtype)) {
+            announceKeyboardLanguage(keyboard);
+            return;
+        }
+        // Announce the mode only when the mode is changed.
+        if (keyboard.mId.mMode != lastKeyboardMode) {
+            announceKeyboardMode(keyboard);
+            return;
+        }
+        // Announce the keyboard type only when the type is changed.
+        if (keyboard.mId.mElementId != lastKeyboard.mId.mElementId) {
+            announceKeyboardType(keyboard, lastKeyboard);
+            return;
+        }
+    }
+
+    /**
+     * Called when the keyboard is hidden and accessibility is enabled.
+     */
+    public void onHideWindow() {
+        announceKeyboardHidden();
+        mLastKeyboardMode = KEYBOARD_IS_HIDDEN;
+    }
+
+    /**
+     * Announces which language of keyboard is being displayed.
+     *
+     * @param keyboard The new keyboard.
+     */
+    private void announceKeyboardLanguage(final Keyboard keyboard) {
+        final String languageText = SubtypeLocaleUtils.getSubtypeDisplayNameInSystemLocale(
+                keyboard.mId.mSubtype);
+        sendWindowStateChanged(languageText);
+    }
+
+    /**
+     * Announces which type of keyboard is being displayed.
+     * If the keyboard type is unknown, no announcement is made.
+     *
+     * @param keyboard The new keyboard.
+     */
+    private void announceKeyboardMode(final Keyboard keyboard) {
+        final Context context = mView.getContext();
+        final int modeTextResId = KEYBOARD_MODE_RES_IDS.get(keyboard.mId.mMode);
+        if (modeTextResId == 0) {
+            return;
+        }
+        final String modeText = context.getString(modeTextResId);
+        final String text = context.getString(R.string.announce_keyboard_mode, modeText);
+        sendWindowStateChanged(text);
+    }
+
+    /**
+     * Announces which type of keyboard is being displayed.
+     *
+     * @param keyboard The new keyboard.
+     * @param lastKeyboard The last keyboard.
+     */
+    private void announceKeyboardType(final Keyboard keyboard, final Keyboard lastKeyboard) {
+        final int lastElementId = lastKeyboard.mId.mElementId;
+        final int resId;
+        switch (keyboard.mId.mElementId) {
+        case KeyboardId.ELEMENT_ALPHABET_AUTOMATIC_SHIFTED:
+        case KeyboardId.ELEMENT_ALPHABET:
+            if (lastElementId == KeyboardId.ELEMENT_ALPHABET
+                    || lastElementId == KeyboardId.ELEMENT_ALPHABET_AUTOMATIC_SHIFTED) {
+                return;
+            }
+            resId = R.string.spoken_description_mode_alpha;
+            break;
+        case KeyboardId.ELEMENT_ALPHABET_MANUAL_SHIFTED:
+            resId = R.string.spoken_description_shiftmode_on;
+            break;
+        case KeyboardId.ELEMENT_ALPHABET_SHIFT_LOCK_SHIFTED:
+        case KeyboardId.ELEMENT_ALPHABET_SHIFT_LOCKED:
+            resId = R.string.spoken_description_shiftmode_locked;
+            break;
+        case KeyboardId.ELEMENT_SYMBOLS:
+            resId = R.string.spoken_description_mode_symbol;
+            break;
+        case KeyboardId.ELEMENT_SYMBOLS_SHIFTED:
+            resId = R.string.spoken_description_mode_symbol_shift;
+            break;
+        case KeyboardId.ELEMENT_PHONE:
+            resId = R.string.spoken_description_mode_phone;
+            break;
+        case KeyboardId.ELEMENT_PHONE_SYMBOLS:
+            resId = R.string.spoken_description_mode_phone_shift;
+            break;
+        default:
+            return;
+        }
+        final String text = mView.getContext().getString(resId);
+        sendWindowStateChanged(text);
+    }
+
+    /**
+     * Announces that the keyboard has been hidden.
+     */
+    private void announceKeyboardHidden() {
+        final Context context = mView.getContext();
+        final String text = context.getString(R.string.announce_keyboard_hidden);
+
+        sendWindowStateChanged(text);
+    }
+
+    /**
+     * Sends a window state change event with the specified text.
+     *
+     * @param text The text to send with the event.
+     */
+    private void sendWindowStateChanged(final String text) {
+        final AccessibilityEvent stateChange = AccessibilityEvent.obtain(
+                AccessibilityEvent.TYPE_WINDOW_STATE_CHANGED);
+        mView.onInitializeAccessibilityEvent(stateChange);
+        stateChange.getText().add(text);
+        stateChange.setContentDescription(null);
+
+        final ViewParent parent = mView.getParent();
+        if (parent != null) {
+            parent.requestSendAccessibilityEvent(mView, stateChange);
+        }
+    }
+
+    /**
+     * Delegate method for View.getAccessibilityNodeProvider(). This method is called in SDK
+     * version 15 (Build.VERSION_CODES.ICE_CREAM_SANDWICH_MR1) and higher to obtain the virtual
+     * node hierarchy provider.
+     *
+     * @param host The host view for the provider.
+     * @return The accessibility node provider for the current keyboard.
+     */
+    @Override
+    public MainKeyboardAccessibilityNodeProvider getAccessibilityNodeProvider(final View host) {
+        return getAccessibilityNodeProvider();
+    }
+
+    /**
+     * Receives hover events when touch exploration is turned on in SDK versions ICS and higher.
+     *
+     * @param event The hover event.
+     * @param keyDetector The {@link KeyDetector} to determine on which key the <code>event</code>
+     *     is hovering.
+     * @return {@code true} if the event is handled
+     */
+    public boolean dispatchHoverEvent(final MotionEvent event, final KeyDetector keyDetector) {
+        final int x = (int) event.getX();
+        final int y = (int) event.getY();
+        final Key previousKey = mLastHoverKey;
+        final Key key;
+
+        if (pointInView(x, y)) {
+            key = keyDetector.detectHitKey(x, y);
+        } else {
+            key = null;
+        }
+        mLastHoverKey = key;
+
+        switch (event.getAction()) {
+        case MotionEvent.ACTION_HOVER_EXIT:
+            // Make sure we're not getting an EXIT event because the user slid
+            // off the keyboard area, then force a key press.
+            if (key != null) {
+                final long downTime = simulateKeyPress(key);
+                simulateKeyRelease(key, downTime);
+            }
+            //$FALL-THROUGH$
+        case MotionEvent.ACTION_HOVER_ENTER:
+            return onHoverKey(key, event);
+        case MotionEvent.ACTION_HOVER_MOVE:
+            if (key != previousKey) {
+                return onTransitionKey(key, previousKey, event);
+            }
+            return onHoverKey(key, event);
+        }
+        return false;
+    }
+
+    /**
+     * @return A lazily-instantiated node provider for this view delegate.
+     */
+    private MainKeyboardAccessibilityNodeProvider getAccessibilityNodeProvider() {
+        // Instantiate the provide only when requested. Since the system
+        // will call this method multiple times it is a good practice to
+        // cache the provider instance.
+        if (mAccessibilityNodeProvider == null) {
+            mAccessibilityNodeProvider = new MainKeyboardAccessibilityNodeProvider(mView);
+        }
+        return mAccessibilityNodeProvider;
+    }
+
+    /**
+     * Utility method to determine whether the given point, in local coordinates, is inside the
+     * view, where the area of the view is contracted by the edge slop factor.
+     *
+     * @param localX The local x-coordinate.
+     * @param localY The local y-coordinate.
+     */
+    private boolean pointInView(final int localX, final int localY) {
+        return (localX >= mEdgeSlop) && (localY >= mEdgeSlop)
+                && (localX < (mView.getWidth() - mEdgeSlop))
+                && (localY < (mView.getHeight() - mEdgeSlop));
+    }
+
+    /**
+     * Simulates a key press by injecting touch an event into the keyboard view.
+     * This avoids the complexity of trackers and listeners within the keyboard.
+     *
+     * @param key The key to press.
+     */
+    private long simulateKeyPress(final Key key) {
+        final int x = key.getHitBox().centerX();
+        final int y = key.getHitBox().centerY();
+        final long downTime = SystemClock.uptimeMillis();
+        final MotionEvent downEvent = MotionEvent.obtain(
+                downTime, downTime, MotionEvent.ACTION_DOWN, x, y, 0);
+        mView.onTouchEvent(downEvent);
+        downEvent.recycle();
+        return downTime;
+    }
+
+    /**
+     * Simulates a key release by injecting touch an event into the keyboard view.
+     * This avoids the complexity of trackers and listeners within the keyboard.
+     *
+     * @param key The key to release.
+     */
+    private void simulateKeyRelease(final Key key, final long downTime) {
+        final int x = key.getHitBox().centerX();
+        final int y = key.getHitBox().centerY();
+        final MotionEvent upEvent = MotionEvent.obtain(
+                downTime, SystemClock.uptimeMillis(), MotionEvent.ACTION_UP, x, y, 0);
+        mView.onTouchEvent(upEvent);
+        upEvent.recycle();
+    }
+
+    /**
+     * Simulates a transition between two {@link Key}s by sending a HOVER_EXIT on the previous key,
+     * a HOVER_ENTER on the current key, and a HOVER_MOVE on the current key.
+     *
+     * @param currentKey The currently hovered key.
+     * @param previousKey The previously hovered key.
+     * @param event The event that triggered the transition.
+     * @return {@code true} if the event was handled.
+     */
+    private boolean onTransitionKey(final Key currentKey, final Key previousKey,
+            final MotionEvent event) {
+        final int savedAction = event.getAction();
+        event.setAction(MotionEvent.ACTION_HOVER_EXIT);
+        onHoverKey(previousKey, event);
+        event.setAction(MotionEvent.ACTION_HOVER_ENTER);
+        onHoverKey(currentKey, event);
+        event.setAction(MotionEvent.ACTION_HOVER_MOVE);
+        final boolean handled = onHoverKey(currentKey, event);
+        event.setAction(savedAction);
+        return handled;
+    }
+
+    /**
+     * Handles a hover event on a key. If {@link Key} extended View, this would be analogous to
+     * calling View.onHoverEvent(MotionEvent).
+     *
+     * @param key The currently hovered key.
+     * @param event The hover event.
+     * @return {@code true} if the event was handled.
+     */
+    private boolean onHoverKey(final Key key, final MotionEvent event) {
+        // Null keys can't receive events.
+        if (key == null) {
+            return false;
+        }
+        final MainKeyboardAccessibilityNodeProvider provider = getAccessibilityNodeProvider();
+
+        switch (event.getAction()) {
+        case MotionEvent.ACTION_HOVER_ENTER:
+            provider.sendAccessibilityEventForKey(
+                    key, AccessibilityEventCompat.TYPE_VIEW_HOVER_ENTER);
+            provider.performActionForKey(
+                    key, AccessibilityNodeInfoCompat.ACTION_ACCESSIBILITY_FOCUS, null);
+            break;
+        case MotionEvent.ACTION_HOVER_EXIT:
+            provider.sendAccessibilityEventForKey(
+                    key, AccessibilityEventCompat.TYPE_VIEW_HOVER_EXIT);
+            break;
+        }
+        return true;
+    }
+}