gecko-dev/mobile/android/base/GeckoAccessibility.java

439 строки
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Java

/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
package org.mozilla.gecko;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import org.mozilla.gecko.AppConstants.Versions;
import org.mozilla.gecko.gfx.LayerView;
import org.mozilla.gecko.util.ThreadUtils;
import org.mozilla.gecko.util.UIAsyncTask;
import android.app.ActivityManager;
import android.app.ActivityManager.RunningServiceInfo;
import android.content.Context;
import android.graphics.Rect;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.accessibility.AccessibilityEvent;
import android.view.accessibility.AccessibilityManager;
import android.view.accessibility.AccessibilityNodeInfo;
import android.view.accessibility.AccessibilityNodeProvider;
import com.googlecode.eyesfree.braille.selfbraille.SelfBrailleClient;
import com.googlecode.eyesfree.braille.selfbraille.WriteData;
public class GeckoAccessibility {
private static final String LOGTAG = "GeckoAccessibility";
private static final int VIRTUAL_ENTRY_POINT_BEFORE = 1;
private static final int VIRTUAL_CURSOR_PREVIOUS = 2;
private static final int VIRTUAL_CURSOR_POSITION = 3;
private static final int VIRTUAL_CURSOR_NEXT = 4;
private static final int VIRTUAL_ENTRY_POINT_AFTER = 5;
private static boolean sEnabled;
// Used to store the JSON message and populate the event later in the code path.
private static JSONObject sEventMessage;
private static AccessibilityNodeInfo sVirtualCursorNode;
private static int sCurrentNode;
// This is the number Brailleback uses to start indexing routing keys.
private static final int BRAILLE_CLICK_BASE_INDEX = -275000000;
private static SelfBrailleClient sSelfBrailleClient;
private static final HashSet<String> sServiceWhitelist =
new HashSet<String>(Arrays.asList(new String[] {
"com.google.android.marvin.talkback.TalkBackService", // Google Talkback screen reader
"com.mot.readout.ScreenReader", // Motorola screen reader
"info.spielproject.spiel.SpielService", // Spiel screen reader
"es.codefactory.android.app.ma.MAAccessibilityService" // Codefactory Mobile Accessibility screen reader
}));
public static void updateAccessibilitySettings (final Context context) {
new UIAsyncTask.WithoutParams<Void>(ThreadUtils.getBackgroundHandler()) {
@Override
public Void doInBackground() {
JSONObject ret = new JSONObject();
sEnabled = false;
AccessibilityManager accessibilityManager =
(AccessibilityManager) context.getSystemService(Context.ACCESSIBILITY_SERVICE);
if (accessibilityManager.isEnabled()) {
ActivityManager activityManager =
(ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
List<RunningServiceInfo> runningServices = activityManager.getRunningServices(Integer.MAX_VALUE);
for (RunningServiceInfo runningServiceInfo : runningServices) {
sEnabled = sServiceWhitelist.contains(runningServiceInfo.service.getClassName());
if (sEnabled)
break;
}
if (Versions.feature16Plus && sEnabled && sSelfBrailleClient == null) {
sSelfBrailleClient = new SelfBrailleClient(GeckoAppShell.getContext(), false);
}
}
try {
ret.put("enabled", sEnabled);
} catch (Exception ex) {
Log.e(LOGTAG, "Error building JSON arguments for Accessibility:Settings:", ex);
}
GeckoAppShell.sendEventToGecko(GeckoEvent.createBroadcastEvent("Accessibility:Settings",
ret.toString()));
return null;
}
@Override
public void onPostExecute(Void args) {
boolean isGeckoApp = false;
try {
isGeckoApp = context instanceof GeckoApp;
} catch (NoClassDefFoundError ex) {}
if (isGeckoApp) {
// Disable the dynamic toolbar when enabling accessibility.
// These features tend not to interact well.
((GeckoApp) context).setAccessibilityEnabled(sEnabled);
}
}
}.execute();
}
private static void populateEventFromJSON (AccessibilityEvent event, JSONObject message) {
final JSONArray textArray = message.optJSONArray("text");
if (textArray != null) {
for (int i = 0; i < textArray.length(); i++)
event.getText().add(textArray.optString(i));
}
event.setContentDescription(message.optString("description"));
event.setEnabled(message.optBoolean("enabled", true));
event.setChecked(message.optBoolean("checked"));
event.setPassword(message.optBoolean("password"));
event.setAddedCount(message.optInt("addedCount", -1));
event.setRemovedCount(message.optInt("removedCount", -1));
event.setFromIndex(message.optInt("fromIndex", -1));
event.setItemCount(message.optInt("itemCount", -1));
event.setCurrentItemIndex(message.optInt("currentItemIndex", -1));
event.setBeforeText(message.optString("beforeText"));
if (Versions.feature14Plus) {
event.setToIndex(message.optInt("toIndex", -1));
event.setScrollable(message.optBoolean("scrollable"));
event.setScrollX(message.optInt("scrollX", -1));
event.setScrollY(message.optInt("scrollY", -1));
}
if (Versions.feature15Plus) {
event.setMaxScrollX(message.optInt("maxScrollX", -1));
event.setMaxScrollY(message.optInt("maxScrollY", -1));
}
}
private static void sendDirectAccessibilityEvent(int eventType, JSONObject message) {
final AccessibilityEvent accEvent = AccessibilityEvent.obtain(eventType);
accEvent.setClassName(GeckoAccessibility.class.getName());
accEvent.setPackageName(GeckoAppShell.getContext().getPackageName());
populateEventFromJSON(accEvent, message);
AccessibilityManager accessibilityManager =
(AccessibilityManager) GeckoAppShell.getContext().getSystemService(Context.ACCESSIBILITY_SERVICE);
try {
accessibilityManager.sendAccessibilityEvent(accEvent);
} catch (IllegalStateException e) {
// Accessibility is off.
}
}
public static boolean isEnabled() {
return sEnabled;
}
public static void sendAccessibilityEvent (final JSONObject message) {
if (!sEnabled)
return;
final String exitView = message.optString("exitView");
if (exitView.equals("moveNext")) {
sCurrentNode = VIRTUAL_ENTRY_POINT_AFTER;
} else if (exitView.equals("movePrevious")) {
sCurrentNode = VIRTUAL_ENTRY_POINT_BEFORE;
} else {
sCurrentNode = VIRTUAL_CURSOR_POSITION;
}
final int eventType = message.optInt("eventType", -1);
if (eventType < 0) {
Log.e(LOGTAG, "No accessibility event type provided");
return;
}
if (Versions.preJB) {
// Before Jelly Bean we send events directly from here while spoofing the source by setting
// the package and class name manually.
ThreadUtils.postToBackgroundThread(new Runnable() {
@Override
public void run() {
sendDirectAccessibilityEvent(eventType, message);
}
});
} else {
// In Jelly Bean we populate an AccessibilityNodeInfo with the minimal amount of data to have
// it work with TalkBack.
final LayerView view = GeckoAppShell.getLayerView();
if (view == null)
return;
if (sVirtualCursorNode == null)
sVirtualCursorNode = AccessibilityNodeInfo.obtain(view, VIRTUAL_CURSOR_POSITION);
sVirtualCursorNode.setEnabled(message.optBoolean("enabled", true));
sVirtualCursorNode.setClickable(message.optBoolean("clickable"));
sVirtualCursorNode.setCheckable(message.optBoolean("checkable"));
sVirtualCursorNode.setChecked(message.optBoolean("checked"));
sVirtualCursorNode.setPassword(message.optBoolean("password"));
final JSONArray textArray = message.optJSONArray("text");
StringBuilder sb = new StringBuilder();
if (textArray != null && textArray.length() > 0) {
sb.append(textArray.optString(0));
for (int i = 1; i < textArray.length(); i++) {
sb.append(" ").append(textArray.optString(i));
}
}
sVirtualCursorNode.setText(sb.toString());
sVirtualCursorNode.setContentDescription(message.optString("description"));
JSONObject bounds = message.optJSONObject("bounds");
if (bounds != null) {
Rect relativeBounds = new Rect(bounds.optInt("left"), bounds.optInt("top"),
bounds.optInt("right"), bounds.optInt("bottom"));
sVirtualCursorNode.setBoundsInParent(relativeBounds);
int[] locationOnScreen = new int[2];
view.getLocationOnScreen(locationOnScreen);
Rect screenBounds = new Rect(relativeBounds);
screenBounds.offset(locationOnScreen[0], locationOnScreen[1]);
sVirtualCursorNode.setBoundsInScreen(screenBounds);
}
final JSONObject braille = message.optJSONObject("brailleOutput");
if (braille != null) {
sendBrailleText(view, braille.optString("text"),
braille.optInt("selectionStart"), braille.optInt("selectionEnd"));
}
ThreadUtils.postToUiThread(new Runnable() {
@Override
public void run() {
// If this is an accessibility focus, a lot of internal voodoo happens so we perform an
// accessibility focus action on the view, and it in turn sends the right events.
switch (eventType) {
case AccessibilityEvent.TYPE_VIEW_ACCESSIBILITY_FOCUSED:
sEventMessage = message;
view.performAccessibilityAction(AccessibilityNodeInfo.ACTION_ACCESSIBILITY_FOCUS, null);
break;
case AccessibilityEvent.TYPE_ANNOUNCEMENT:
case AccessibilityEvent.TYPE_VIEW_SCROLLED:
sEventMessage = null;
final AccessibilityEvent accEvent = AccessibilityEvent.obtain(eventType);
view.onInitializeAccessibilityEvent(accEvent);
populateEventFromJSON(accEvent, message);
view.getParent().requestSendAccessibilityEvent(view, accEvent);
break;
default:
sEventMessage = message;
view.sendAccessibilityEvent(eventType);
break;
}
}
});
}
}
private static void sendBrailleText(final View view, final String text, final int selectionStart, final int selectionEnd) {
AccessibilityNodeInfo info = AccessibilityNodeInfo.obtain(view, VIRTUAL_CURSOR_POSITION);
WriteData data = WriteData.forInfo(info);
data.setText(text);
// Set either the focus blink or the current caret position/selection
data.setSelectionStart(selectionStart);
data.setSelectionEnd(selectionEnd);
sSelfBrailleClient.write(data);
}
public static void setDelegate(LayerView layerview) {
// Only use this delegate in Jelly Bean.
if (Versions.feature16Plus) {
layerview.setAccessibilityDelegate(new GeckoAccessibilityDelegate());
layerview.setImportantForAccessibility(View.IMPORTANT_FOR_ACCESSIBILITY_YES);
}
}
public static void setAccessibilityStateChangeListener(final Context context) {
// The state change listener is only supported on API14+
if (Versions.feature14Plus) {
AccessibilityManager accessibilityManager =
(AccessibilityManager) context.getSystemService(Context.ACCESSIBILITY_SERVICE);
accessibilityManager.addAccessibilityStateChangeListener(new AccessibilityManager.AccessibilityStateChangeListener() {
@Override
public void onAccessibilityStateChanged(boolean enabled) {
updateAccessibilitySettings(context);
}
});
}
}
public static void onLayerViewFocusChanged(LayerView layerview, boolean gainFocus) {
if (sEnabled)
GeckoAppShell.sendEventToGecko(GeckoEvent.createBroadcastEvent("Accessibility:Focus",
gainFocus ? "true" : "false"));
}
public static class GeckoAccessibilityDelegate extends View.AccessibilityDelegate {
AccessibilityNodeProvider mAccessibilityNodeProvider;
@Override
public void onPopulateAccessibilityEvent (View host, AccessibilityEvent event) {
super.onPopulateAccessibilityEvent(host, event);
if (sEventMessage != null) {
populateEventFromJSON(event, sEventMessage);
event.setSource(host, sCurrentNode);
}
// We save the hover enter event so that we could reuse it for a subsequent accessibility focus event.
if (event.getEventType() != AccessibilityEvent.TYPE_VIEW_HOVER_ENTER)
sEventMessage = null;
}
@Override
public AccessibilityNodeProvider getAccessibilityNodeProvider(final View host) {
if (mAccessibilityNodeProvider == null)
// The accessibility node structure for web content consists of 5 LayerView child nodes:
// 1. VIRTUAL_ENTRY_POINT_BEFORE: Represents the entry point before the LayerView.
// 2. VIRTUAL_CURSOR_PREVIOUS: Represents the virtual cursor position that is previous to the
// current one.
// 3. VIRTUAL_CURSOR_POSITION: Represents the current position of the virtual cursor.
// 4. VIRTUAL_CURSOR_NEXT: Represents the next virtual cursor position.
// 5. VIRTUAL_ENTRY_POINT_AFTER: Represents the entry point after the LayerView.
mAccessibilityNodeProvider = new AccessibilityNodeProvider() {
@Override
public AccessibilityNodeInfo createAccessibilityNodeInfo(int virtualDescendantId) {
AccessibilityNodeInfo info = (virtualDescendantId == VIRTUAL_CURSOR_POSITION && sVirtualCursorNode != null) ?
AccessibilityNodeInfo.obtain(sVirtualCursorNode) :
AccessibilityNodeInfo.obtain(host, virtualDescendantId);
switch (virtualDescendantId) {
case View.NO_ID:
// This is the parent LayerView node, populate it with children.
onInitializeAccessibilityNodeInfo(host, info);
info.addChild(host, VIRTUAL_ENTRY_POINT_BEFORE);
info.addChild(host, VIRTUAL_CURSOR_PREVIOUS);
info.addChild(host, VIRTUAL_CURSOR_POSITION);
info.addChild(host, VIRTUAL_CURSOR_NEXT);
info.addChild(host, VIRTUAL_ENTRY_POINT_AFTER);
break;
default:
info.setParent(host);
info.setSource(host, virtualDescendantId);
info.setVisibleToUser(host.isShown());
info.setPackageName(GeckoAppShell.getContext().getPackageName());
info.setClassName(host.getClass().getName());
info.setEnabled(true);
info.addAction(AccessibilityNodeInfo.ACTION_CLEAR_ACCESSIBILITY_FOCUS);
info.addAction(AccessibilityNodeInfo.ACTION_ACCESSIBILITY_FOCUS);
info.addAction(AccessibilityNodeInfo.ACTION_CLICK);
info.addAction(AccessibilityNodeInfo.ACTION_LONG_CLICK);
info.addAction(AccessibilityNodeInfo.ACTION_PREVIOUS_AT_MOVEMENT_GRANULARITY);
info.addAction(AccessibilityNodeInfo.ACTION_NEXT_AT_MOVEMENT_GRANULARITY);
info.setMovementGranularities(AccessibilityNodeInfo.MOVEMENT_GRANULARITY_CHARACTER |
AccessibilityNodeInfo.MOVEMENT_GRANULARITY_WORD |
AccessibilityNodeInfo.MOVEMENT_GRANULARITY_PARAGRAPH);
break;
}
return info;
}
@Override
public boolean performAction (int virtualViewId, int action, Bundle arguments) {
if (action == AccessibilityNodeInfo.ACTION_ACCESSIBILITY_FOCUS) {
// The accessibility focus is permanently on the middle node, VIRTUAL_CURSOR_POSITION.
// When accessibility focus is requested on one of its siblings we move the virtual cursor
// either forward or backward depending on which sibling was selected.
// When we enter the view forward or backward we just ask Gecko to get focus, keeping the current position.
switch (virtualViewId) {
case VIRTUAL_CURSOR_PREVIOUS:
GeckoAppShell.
sendEventToGecko(GeckoEvent.createBroadcastEvent("Accessibility:PreviousObject", null));
return true;
case VIRTUAL_CURSOR_NEXT:
GeckoAppShell.
sendEventToGecko(GeckoEvent.createBroadcastEvent("Accessibility:NextObject", null));
return true;
case VIRTUAL_ENTRY_POINT_BEFORE:
case VIRTUAL_ENTRY_POINT_AFTER:
GeckoAppShell.
sendEventToGecko(GeckoEvent.createBroadcastEvent("Accessibility:Focus", "true"));
default:
break;
}
} else if (action == AccessibilityNodeInfo.ACTION_CLICK && virtualViewId == VIRTUAL_CURSOR_POSITION) {
GeckoAppShell.
sendEventToGecko(GeckoEvent.createBroadcastEvent("Accessibility:ActivateObject", null));
return true;
} else if (action == AccessibilityNodeInfo.ACTION_LONG_CLICK && virtualViewId == VIRTUAL_CURSOR_POSITION) {
GeckoAppShell.
sendEventToGecko(GeckoEvent.createBroadcastEvent("Accessibility:LongPress", null));
return true;
} else if (action == AccessibilityNodeInfo.ACTION_NEXT_AT_MOVEMENT_GRANULARITY &&
virtualViewId == VIRTUAL_CURSOR_POSITION) {
// XXX: Self brailling gives this action with a bogus argument instead of an actual click action;
// the argument value is the BRAILLE_CLICK_BASE_INDEX - the index of the routing key that was hit
int granularity = arguments.getInt(AccessibilityNodeInfo.ACTION_ARGUMENT_MOVEMENT_GRANULARITY_INT);
if (granularity < 0) {
int keyIndex = BRAILLE_CLICK_BASE_INDEX - granularity;
JSONObject activationData = new JSONObject();
try {
activationData.put("keyIndex", keyIndex);
} catch (JSONException e) {
return true;
}
GeckoAppShell.
sendEventToGecko(GeckoEvent.createBroadcastEvent("Accessibility:ActivateObject", activationData.toString()));
} else {
JSONObject movementData = new JSONObject();
try {
movementData.put("direction", "Next");
movementData.put("granularity", granularity);
} catch (JSONException e) {
return true;
}
GeckoAppShell.
sendEventToGecko(GeckoEvent.createBroadcastEvent("Accessibility:MoveByGranularity", movementData.toString()));
}
return true;
} else if (action == AccessibilityNodeInfo.ACTION_PREVIOUS_AT_MOVEMENT_GRANULARITY &&
virtualViewId == VIRTUAL_CURSOR_POSITION) {
JSONObject movementData = new JSONObject();
try {
movementData.put("direction", "Previous");
movementData.put("granularity", arguments.getInt(AccessibilityNodeInfo.ACTION_ARGUMENT_MOVEMENT_GRANULARITY_INT));
} catch (JSONException e) {
return true;
}
GeckoAppShell.
sendEventToGecko(GeckoEvent.createBroadcastEvent("Accessibility:MoveByGranularity", movementData.toString()));
return true;
}
return host.performAccessibilityAction(action, arguments);
}
};
return mAccessibilityNodeProvider;
}
}
}