1 files changed, 160 insertions, 0 deletions
diff --git a/samples/ApiDemos/src/com/example/android/apis/accessibility/TaskBackService.java b/samples/ApiDemos/src/com/example/android/apis/accessibility/TaskBackService.java
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+++ b/samples/ApiDemos/src/com/example/android/apis/accessibility/TaskBackService.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.example.android.apis.accessibility;
+
+import com.example.android.apis.R;
+
+import android.accessibilityservice.AccessibilityService;
+import android.util.Log;
+import android.view.accessibility.AccessibilityEvent;
+import android.view.accessibility.AccessibilityNodeInfo;
+import android.view.accessibility.AccessibilityRecord;
+import android.speech.tts.TextToSpeech;
+import android.speech.tts.TextToSpeech.OnInitListener;
+
+import java.util.Locale;
+
+/** The TaskBackService listens for AccessibilityEvents, and turns them into information it can
+ *  communicate to the user with speech.
+ */
+public class TaskBackService extends AccessibilityService implements OnInitListener {
+
+    private final String LOG_TAG = "TaskBackService/onAccessibilityEvent";
+    private boolean mTextToSpeechInitialized = false;
+    private TextToSpeech mTts = null;
+    private static final String SEPARATOR = ", ";
+
+
+
+    /** Initializes the Text-To-Speech engine as soon as the service is connected. */
+    @Override
+    public void onServiceConnected() {
+        mTts = new TextToSpeech(getApplicationContext(), this);
+    }
+
+    /** Processes an AccessibilityEvent, by traversing the View's tree and putting together a
+     *  message to speak to the user.
+     */
+    @Override
+    public void onAccessibilityEvent(AccessibilityEvent event) {
+        if (!mTextToSpeechInitialized) {
+            Log.e(LOG_TAG, "Text-To-Speech engine not ready.  Bailing out.");
+            return;
+        }
+
+        int eventType = event.getEventType();
+        if (eventType != AccessibilityEvent.TYPE_VIEW_CLICKED) {
+            return;
+        }
+
+        /* This AccessibilityNodeInfo represents the view that fired the
+         * AccessibilityEvent.  The following code will use it to traverse
+         * the view hierarchy, using this node as a starting point.
+         */
+        AccessibilityNodeInfo entryNode = event.getSource();
+
+        /* Every method that returns an AccessibilityNodeInfo may return null,
+         * because the explored window is in another process and the corresponding
+         * View might be gone by the time your request reaches the view hierarchy."
+         */
+        if (entryNode == null) {
+          return;
+        }
+        // Grab the parent of the view that fired the event.
+        AccessibilityNodeInfo rowNode = entryNode.getParent();
+
+        if (rowNode == null) {
+          return;
+        }
+
+        /* Using this parent, get references to both child nodes,
+         * the label and the checkbox.
+         */
+        AccessibilityNodeInfo labelNode = rowNode.getChild(0);
+        AccessibilityNodeInfo completeNode = rowNode.getChild(1);
+
+        if (labelNode == null || completeNode == null) {
+          return;
+        }
+
+        /* Using these to determine what the task is and whether or not
+         * it's complete, based on the text inside the label, and the state
+         * of the checkbox.
+         */
+
+        // Quick check to make sure we're not in the ApiDemos nav.
+        if (rowNode.getChildCount() < 2 || !rowNode.getChild(1).isCheckable()) {
+            return;
+        }
+
+        CharSequence taskLabel = labelNode.getText();
+        boolean isComplete = completeNode.isChecked();
+
+        String completeStr = null;;
+        if (isComplete) {
+            completeStr = getString(R.string.task_complete);
+        } else {
+            completeStr = getString(R.string.task_not_complete);
+        }
+
+        String taskStr = getString(R.string.task_complete_template, taskLabel, completeStr);
+        StringBuilder forSpeech = new StringBuilder(taskStr);
+
+        /* The custom listview added extra context to the event by adding
+         * an AccessibilityRecord to it.  Extract that from the event and read it.
+         */
+        int records = event.getRecordCount();
+
+        for (int i = 0; i < records; i++) {
+            AccessibilityRecord record = event.getRecord(i);
+            CharSequence contentDescription = record.getContentDescription();
+            if (contentDescription != null) {
+                forSpeech.append(SEPARATOR).append(contentDescription);
+            }
+        }
+
+        /* Speak the forSpeech string to the user.  QUEUE_ADD adds the string to the end of the
+         * queue, QUEUE_FLUSH would interrupt whatever was currently being said.
+         */
+        mTts.speak(forSpeech.toString() ,  TextToSpeech.QUEUE_ADD, null);
+        Log.d(LOG_TAG, forSpeech.toString());
+    }
+
+    @Override
+    public void onInterrupt() {
+      /* do nothing */
+    }
+
+    /** Sets a flag so that the TaskBackService knows that the Text-To-Speech engine has been
+     *  initialized, and can now handle speaking requests.
+     */
+    @Override
+    public void onInit (int status) {
+        if (status == TextToSpeech.SUCCESS) {
+            mTts.setLanguage(Locale.US);
+            mTextToSpeechInitialized = true;
+        }
+    }
+
+    @Override
+    public void onDestroy() {
+        super.onDestroy();
+        if (mTextToSpeechInitialized) {
+            mTts.shutdown();
+        }
+    }
+}