LatinIME/java/src/com/android/inputmethod/accessibility/AccessibilityUtils.java

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/*
* 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.media.AudioManager;
import android.os.Build;
import android.os.SystemClock;
import android.provider.Settings;
import android.support.v4.view.accessibility.AccessibilityEventCompat;
import android.text.TextUtils;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewParent;
import android.view.accessibility.AccessibilityEvent;
import android.view.accessibility.AccessibilityManager;
import android.view.inputmethod.EditorInfo;
import com.android.inputmethod.compat.SettingsSecureCompatUtils;
import com.android.inputmethod.latin.R;
import com.android.inputmethod.latin.SuggestedWords;
import com.android.inputmethod.latin.utils.InputTypeUtils;
public final class AccessibilityUtils {
private static final String TAG = AccessibilityUtils.class.getSimpleName();
private static final String CLASS = AccessibilityUtils.class.getClass().getName();
private static final String PACKAGE =
AccessibilityUtils.class.getClass().getPackage().getName();
private static final AccessibilityUtils sInstance = new AccessibilityUtils();
private Context mContext;
private AccessibilityManager mAccessibilityManager;
private AudioManager mAudioManager;
/** The most recent auto-correction. */
private String mAutoCorrectionWord;
/** The most recent typed word for auto-correction. */
private String mTypedWord;
/*
* Setting this constant to {@code false} will disable all keyboard
* accessibility code, regardless of whether Accessibility is turned on in
* the system settings. It should ONLY be used in the event of an emergency.
*/
private static final boolean ENABLE_ACCESSIBILITY = true;
public static void init(final Context context) {
if (!ENABLE_ACCESSIBILITY) return;
// These only need to be initialized if the kill switch is off.
sInstance.initInternal(context);
KeyCodeDescriptionMapper.init();
}
public static AccessibilityUtils getInstance() {
return sInstance;
}
private AccessibilityUtils() {
// This class is not publicly instantiable.
}
private void initInternal(final Context context) {
mContext = context;
mAccessibilityManager =
(AccessibilityManager) context.getSystemService(Context.ACCESSIBILITY_SERVICE);
mAudioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
}
/**
* Returns {@code true} if accessibility is enabled. Currently, this means
* that the kill switch is off and system accessibility is turned on.
*
* @return {@code true} if accessibility is enabled.
*/
public boolean isAccessibilityEnabled() {
return ENABLE_ACCESSIBILITY && mAccessibilityManager.isEnabled();
}
/**
* Returns {@code true} if touch exploration is enabled. Currently, this
* means that the kill switch is off, the device supports touch exploration,
* and system accessibility is turned on.
*
* @return {@code true} if touch exploration is enabled.
*/
public boolean isTouchExplorationEnabled() {
return isAccessibilityEnabled() && mAccessibilityManager.isTouchExplorationEnabled();
}
/**
* Returns {@true} if the provided event is a touch exploration (e.g. hover)
* event. This is used to determine whether the event should be processed by
* the touch exploration code within the keyboard.
*
* @param event The event to check.
* @return {@true} is the event is a touch exploration event
*/
public static boolean isTouchExplorationEvent(final MotionEvent event) {
final int action = event.getAction();
return action == MotionEvent.ACTION_HOVER_ENTER
|| action == MotionEvent.ACTION_HOVER_EXIT
|| action == MotionEvent.ACTION_HOVER_MOVE;
}
/**
* Returns whether the device should obscure typed password characters.
* Typically this means speaking "dot" in place of non-control characters.
*
* @return {@code true} if the device should obscure password characters.
*/
@SuppressWarnings("deprecation")
public boolean shouldObscureInput(final EditorInfo editorInfo) {
if (editorInfo == null) return false;
// The user can optionally force speaking passwords.
if (SettingsSecureCompatUtils.ACCESSIBILITY_SPEAK_PASSWORD != null) {
final boolean speakPassword = Settings.Secure.getInt(mContext.getContentResolver(),
SettingsSecureCompatUtils.ACCESSIBILITY_SPEAK_PASSWORD, 0) != 0;
if (speakPassword) return false;
}
// Always speak if the user is listening through headphones.
if (mAudioManager.isWiredHeadsetOn() || mAudioManager.isBluetoothA2dpOn()) {
return false;
}
// Don't speak if the IME is connected to a password field.
return InputTypeUtils.isPasswordInputType(editorInfo.inputType);
}
/**
* Sets the current auto-correction word and typed word. These may be used
* to provide the user with a spoken description of what auto-correction
* will occur when a key is typed.
*
* @param suggestedWords the list of suggested auto-correction words
* @param typedWord the currently typed word
*/
public void setAutoCorrection(final SuggestedWords suggestedWords, final String typedWord) {
if (suggestedWords.mWillAutoCorrect) {
mAutoCorrectionWord = suggestedWords.getWord(SuggestedWords.INDEX_OF_AUTO_CORRECTION);
mTypedWord = typedWord;
} else {
mAutoCorrectionWord = null;
mTypedWord = null;
}
}
/**
* Obtains a description for an auto-correction key, taking into account the
* currently typed word and auto-correction.
*
* @param keyCodeDescription spoken description of the key that will insert
* an auto-correction
* @param shouldObscure whether the key should be obscured
* @return a description including a description of the auto-correction, if
* needed
*/
public String getAutoCorrectionDescription(
final String keyCodeDescription, final boolean shouldObscure) {
if (!TextUtils.isEmpty(mAutoCorrectionWord)) {
if (!TextUtils.equals(mAutoCorrectionWord, mTypedWord)) {
if (shouldObscure) {
// This should never happen, but just in case...
return mContext.getString(R.string.spoken_auto_correct_obscured,
keyCodeDescription);
}
return mContext.getString(R.string.spoken_auto_correct, keyCodeDescription,
mTypedWord, mAutoCorrectionWord);
}
}
return keyCodeDescription;
}
/**
* Sends the specified text to the {@link AccessibilityManager} to be
* spoken.
*
* @param view The source view.
* @param text The text to speak.
*/
public void announceForAccessibility(final View view, final CharSequence text) {
if (!mAccessibilityManager.isEnabled()) {
Log.e(TAG, "Attempted to speak when accessibility was disabled!");
return;
}
// The following is a hack to avoid using the heavy-weight TextToSpeech
// class. Instead, we're just forcing a fake AccessibilityEvent into
// the screen reader to make it speak.
final AccessibilityEvent event = AccessibilityEvent.obtain();
event.setPackageName(PACKAGE);
event.setClassName(CLASS);
event.setEventTime(SystemClock.uptimeMillis());
event.setEnabled(true);
event.getText().add(text);
// Platforms starting at SDK version 16 (Build.VERSION_CODES.JELLY_BEAN) should use
// announce events.
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
event.setEventType(AccessibilityEventCompat.TYPE_ANNOUNCEMENT);
} else {
event.setEventType(AccessibilityEvent.TYPE_VIEW_FOCUSED);
}
final ViewParent viewParent = view.getParent();
if ((viewParent == null) || !(viewParent instanceof ViewGroup)) {
Log.e(TAG, "Failed to obtain ViewParent in announceForAccessibility");
return;
}
viewParent.requestSendAccessibilityEvent(view, event);
}
/**
* Handles speaking the "connect a headset to hear passwords" notification
* when connecting to a password field.
*
* @param view The source view.
* @param editorInfo The input connection's editor info attribute.
* @param restarting Whether the connection is being restarted.
*/
public void onStartInputViewInternal(final View view, final EditorInfo editorInfo,
final boolean restarting) {
if (shouldObscureInput(editorInfo)) {
final CharSequence text = mContext.getText(R.string.spoken_use_headphones);
announceForAccessibility(view, text);
}
}
/**
* Sends the specified {@link AccessibilityEvent} if accessibility is
* enabled. No operation if accessibility is disabled.
*
* @param event The event to send.
*/
public void requestSendAccessibilityEvent(final AccessibilityEvent event) {
if (mAccessibilityManager.isEnabled()) {
mAccessibilityManager.sendAccessibilityEvent(event);
}
}
}