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      1 /*
      2  *
      3  * Licensed under the Apache License, Version 2.0 (the "License");
      4  * you may not use this file except in compliance with the License.
      5  * You may obtain a copy of the License at
      6  *
      7  *      http://www.apache.org/licenses/LICENSE-2.0
      8  *
      9  * Unless required by applicable law or agreed to in writing, software
     10  * distributed under the License is distributed on an "AS IS" BASIS,
     11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     12  * See the License for the specific language governing permissions and
     13  * limitations under the License.
     14  */
     15 
     16 package com.android.internal.policy.impl;
     17 
     18 import android.content.ComponentName;
     19 import android.content.Context;
     20 import android.content.Intent;
     21 import android.content.res.Resources;
     22 import android.content.res.XmlResourceParser;
     23 import android.os.UserHandle;
     24 import android.util.Log;
     25 import android.util.SparseArray;
     26 import android.view.KeyEvent;
     27 
     28 import com.android.internal.util.XmlUtils;
     29 
     30 import org.xmlpull.v1.XmlPullParserException;
     31 
     32 import java.io.IOException;
     33 
     34 /**
     35  * Stores a mapping of global keys.
     36  * <p>
     37  * A global key will NOT go to the foreground application and instead only ever be sent via targeted
     38  * broadcast to the specified component. The action of the intent will be
     39  * {@link Intent#ACTION_GLOBAL_BUTTON} and the KeyEvent will be included in the intent with
     40  * {@link Intent#EXTRA_KEY_EVENT}.
     41  */
     42 final class GlobalKeyManager {
     43 
     44     private static final String TAG = "GlobalKeyManager";
     45 
     46     private static final String TAG_GLOBAL_KEYS = "global_keys";
     47     private static final String ATTR_VERSION = "version";
     48     private static final String TAG_KEY = "key";
     49     private static final String ATTR_KEY_CODE = "keyCode";
     50     private static final String ATTR_COMPONENT = "component";
     51 
     52     private static final int GLOBAL_KEY_FILE_VERSION = 1;
     53 
     54     private SparseArray<ComponentName> mKeyMapping;
     55 
     56     public GlobalKeyManager(Context context) {
     57         mKeyMapping = new SparseArray<ComponentName>();
     58         loadGlobalKeys(context);
     59     }
     60 
     61     /**
     62      * Broadcasts an intent if the keycode is part of the global key mapping.
     63      *
     64      * @param context context used to broadcast the event
     65      * @param keyCode keyCode which triggered this function
     66      * @param event keyEvent which trigged this function
     67      * @return {@code true} if this was handled
     68      */
     69     boolean handleGlobalKey(Context context, int keyCode, KeyEvent event) {
     70         if (mKeyMapping.size() > 0) {
     71             ComponentName component = mKeyMapping.get(keyCode);
     72             if (component != null) {
     73                 Intent intent = new Intent(Intent.ACTION_GLOBAL_BUTTON)
     74                         .setComponent(component)
     75                         .putExtra(Intent.EXTRA_KEY_EVENT, event);
     76                 context.sendBroadcastAsUser(intent, UserHandle.CURRENT, null);
     77                 return true;
     78             }
     79         }
     80         return false;
     81     }
     82 
     83     /**
     84      * Returns {@code true} if the key will be handled globally.
     85      */
     86     boolean shouldHandleGlobalKey(int keyCode, KeyEvent event) {
     87         return mKeyMapping.get(keyCode) != null;
     88     }
     89 
     90     private void loadGlobalKeys(Context context) {
     91         XmlResourceParser parser = null;
     92         try {
     93             parser = context.getResources().getXml(com.android.internal.R.xml.global_keys);
     94             XmlUtils.beginDocument(parser, TAG_GLOBAL_KEYS);
     95             int version = parser.getAttributeIntValue(null, ATTR_VERSION, 0);
     96             if (GLOBAL_KEY_FILE_VERSION == version) {
     97                 while (true) {
     98                     XmlUtils.nextElement(parser);
     99                     String element = parser.getName();
    100                     if (element == null) {
    101                         break;
    102                     }
    103                     if (TAG_KEY.equals(element)) {
    104                         String keyCodeName = parser.getAttributeValue(null, ATTR_KEY_CODE);
    105                         String componentName = parser.getAttributeValue(null, ATTR_COMPONENT);
    106                         int keyCode = KeyEvent.keyCodeFromString(keyCodeName);
    107                         if (keyCode != KeyEvent.KEYCODE_UNKNOWN) {
    108                             mKeyMapping.put(keyCode, ComponentName.unflattenFromString(
    109                                     componentName));
    110                         }
    111                     }
    112                 }
    113             }
    114         } catch (Resources.NotFoundException e) {
    115             Log.w(TAG, "global keys file not found", e);
    116         } catch (XmlPullParserException e) {
    117             Log.w(TAG, "XML parser exception reading global keys file", e);
    118         } catch (IOException e) {
    119             Log.w(TAG, "I/O exception reading global keys file", e);
    120         } finally {
    121             if (parser != null) {
    122                 parser.close();
    123             }
    124         }
    125     }
    126 }
    127