gecko/mobile/android/base/GeckoAccessibility.java

246 lines
13 KiB
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 org.mozilla.gecko.GeckoApp;
import org.mozilla.gecko.gfx.LayerView;
import android.view.accessibility.*;
import android.view.View;
import android.util.Log;
import android.os.Build;
import android.os.Bundle;
import android.content.Context;
import android.graphics.Rect;
import org.json.*;
public class GeckoAccessibility {
private static final String LOGTAG = "GeckoAccessibility";
private static final int VIRTUAL_CURSOR_PREVIOUS = 1;
private static final int VIRTUAL_CURSOR_POSITION = 2;
private static final int VIRTUAL_CURSOR_NEXT = 3;
private static JSONObject mEventMessage = null;
private static AccessibilityNodeInfo mVirtualCursorNode = null;
public static void updateAccessibilitySettings () {
GeckoAppShell.getHandler().post(new Runnable() {
public void run() {
JSONObject ret = new JSONObject();
AccessibilityManager accessibilityManager =
(AccessibilityManager) GeckoApp.mAppContext.getSystemService(Context.ACCESSIBILITY_SERVICE);
try {
ret.put("enabled", accessibilityManager.isEnabled());
if (Build.VERSION.SDK_INT >= 14) { // Build.VERSION_CODES.ICE_CREAM_SANDWICH
ret.put("exploreByTouch", accessibilityManager.isTouchExplorationEnabled());
} else {
ret.put("exploreByTouch", false);
}
} catch (Exception ex) {
Log.e(LOGTAG, "Error building JSON arguments for Accessibility:Settings:", ex);
}
GeckoAppShell.sendEventToGecko(GeckoEvent.createBroadcastEvent("Accessibility:Settings",
ret.toString()));
}
});
}
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 (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
event.setToIndex(message.optInt("toIndex", -1));
event.setScrollable(message.optBoolean("scrollable"));
event.setScrollX(message.optInt("scrollX", -1));
event.setScrollY(message.optInt("scrollY", -1));
}
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH_MR1) {
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(GeckoApp.mAppContext.getPackageName());
populateEventFromJSON(accEvent, message);
AccessibilityManager accessibilityManager =
(AccessibilityManager) GeckoApp.mAppContext.getSystemService(Context.ACCESSIBILITY_SERVICE);
try {
accessibilityManager.sendAccessibilityEvent(accEvent);
} catch (IllegalStateException e) {
// Accessibility is off.
}
}
public static void sendAccessibilityEvent (final JSONObject message) {
final int eventType = message.optInt("eventType", -1);
if (eventType < 0) {
Log.e(LOGTAG, "No accessibility event type provided");
return;
}
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN) {
// Before Jelly Bean we send events directly from here while spoofing the source by setting
// the package and class name manually.
GeckoAppShell.getHandler().post(new Runnable() {
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 = GeckoApp.mAppContext.getLayerView();
if (mVirtualCursorNode == null)
mVirtualCursorNode = AccessibilityNodeInfo.obtain(view, VIRTUAL_CURSOR_POSITION);
mVirtualCursorNode.setEnabled(message.optBoolean("enabled", true));
mVirtualCursorNode.setChecked(message.optBoolean("checked"));
mVirtualCursorNode.setPassword(message.optBoolean("password"));
JSONObject bounds = message.optJSONObject("bounds");
if (bounds != null) {
Rect relativeBounds = new Rect(bounds.optInt("left"), bounds.optInt("top"),
bounds.optInt("right"), bounds.optInt("bottom"));
mVirtualCursorNode.setBoundsInParent(relativeBounds);
int[] locationOnScreen = new int[2];
view.getLocationOnScreen(locationOnScreen);
Rect screenBounds = new Rect(relativeBounds);
screenBounds.offset(locationOnScreen[0], locationOnScreen[1]);
mVirtualCursorNode.setBoundsInScreen(screenBounds);
}
// Store the JSON message and use it to populate the event later in the code path.
mEventMessage = message;
GeckoApp.mAppContext.mMainHandler.post(new Runnable() {
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:
view.performAccessibilityAction(AccessibilityNodeInfo.ACTION_ACCESSIBILITY_FOCUS, null);
break;
case AccessibilityEvent.TYPE_ANNOUNCEMENT:
sendDirectAccessibilityEvent(eventType, message);
break;
default:
view.sendAccessibilityEvent(eventType);
break;
}
}
});
}
}
public static void setDelegate(LayerView layerview) {
// Only use this delegate in Jelly Bean.
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
layerview.setAccessibilityDelegate(new GeckoAccessibilityDelegate());
layerview.setImportantForAccessibility(View.IMPORTANT_FOR_ACCESSIBILITY_YES);
}
}
public static class GeckoAccessibilityDelegate extends View.AccessibilityDelegate {
AccessibilityNodeProvider mAccessibilityNodeProvider;
@Override
public void onPopulateAccessibilityEvent (View host, AccessibilityEvent event) {
super.onPopulateAccessibilityEvent(host, event);
if (mEventMessage != null)
populateEventFromJSON(event, mEventMessage);
mEventMessage = null;
// No matter where the a11y focus is requested, we always force it back to the current vc position.
event.setSource(host, VIRTUAL_CURSOR_POSITION);
}
@Override
public AccessibilityNodeProvider getAccessibilityNodeProvider(final View host) {
if (mAccessibilityNodeProvider == null)
// The accessibility node structure for web content consists of 3 LayerView child nodes:
// 1. VIRTUAL_CURSOR_PREVIOUS: Represents the virtual cursor position that is previous to the
// current one.
// 2. VIRTUAL_CURSOR_POSITION: Represents the current position of the virtual cursor.
// 3. VIRTUAL_CURSOR_NEXT: Represents the next virtual cursor position.
mAccessibilityNodeProvider = new AccessibilityNodeProvider() {
@Override
public AccessibilityNodeInfo createAccessibilityNodeInfo(int virtualDescendantId) {
AccessibilityNodeInfo info = (virtualDescendantId == VIRTUAL_CURSOR_POSITION && mVirtualCursorNode != null) ?
AccessibilityNodeInfo.obtain(mVirtualCursorNode) :
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_CURSOR_PREVIOUS);
info.addChild(host, VIRTUAL_CURSOR_POSITION);
info.addChild(host, VIRTUAL_CURSOR_NEXT);
break;
default:
info.setParent(host);
info.setSource(host, virtualDescendantId);
info.setVisibleToUser(true);
info.setPackageName(GeckoApp.mAppContext.getPackageName());
info.setClassName(host.getClass().getName());
info.addAction(AccessibilityNodeInfo.ACTION_CLEAR_ACCESSIBILITY_FOCUS);
info.addAction(AccessibilityNodeInfo.ACTION_ACCESSIBILITY_FOCUS);
info.addAction(AccessibilityNodeInfo.ACTION_CLICK);
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.
switch (virtualViewId) {
case VIRTUAL_CURSOR_PREVIOUS:
GeckoAppShell.
sendEventToGecko(GeckoEvent.createBroadcastEvent("Accessibility:PreviousObject", null));
return true;
case VIRTUAL_CURSOR_POSITION:
GeckoAppShell.
sendEventToGecko(GeckoEvent.createBroadcastEvent("Accessibility:CurrentObject", null));
return true;
case VIRTUAL_CURSOR_NEXT:
GeckoAppShell.
sendEventToGecko(GeckoEvent.createBroadcastEvent("Accessibility:NextObject", null));
return true;
default:
break;
}
}
return host.performAccessibilityAction(action, arguments);
}
};
return mAccessibilityNodeProvider;
}
}
}