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      1 /*
      2  * Copyright (C) 2010 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.android.camera;
     18 
     19 import android.content.Context;
     20 import android.util.AttributeSet;
     21 import android.util.Xml;
     22 import android.view.InflateException;
     23 
     24 import org.xmlpull.v1.XmlPullParser;
     25 import org.xmlpull.v1.XmlPullParserException;
     26 
     27 import java.io.IOException;
     28 import java.lang.reflect.Constructor;
     29 import java.util.ArrayList;
     30 import java.util.HashMap;
     31 
     32 /**
     33  * Inflate <code>CameraPreference</code> from XML resource.
     34  */
     35 public class PreferenceInflater {
     36     private static final String PACKAGE_NAME =
     37             PreferenceInflater.class.getPackage().getName();
     38 
     39     private static final Class<?>[] CTOR_SIGNATURE =
     40             new Class[] {Context.class, AttributeSet.class};
     41     private static final HashMap<String, Constructor<?>> sConstructorMap =
     42             new HashMap<String, Constructor<?>>();
     43 
     44     private Context mContext;
     45 
     46     public PreferenceInflater(Context context) {
     47         mContext = context;
     48     }
     49 
     50     public CameraPreference inflate(int resId) {
     51         return inflate(mContext.getResources().getXml(resId));
     52     }
     53 
     54     private CameraPreference newPreference(String tagName, Object[] args) {
     55         String name = PACKAGE_NAME + "." + tagName;
     56         Constructor<?> constructor = sConstructorMap.get(name);
     57         try {
     58             if (constructor == null) {
     59                 // Class not found in the cache, see if it's real, and try to
     60                 // add it
     61                 Class<?> clazz = mContext.getClassLoader().loadClass(name);
     62                 constructor = clazz.getConstructor(CTOR_SIGNATURE);
     63                 sConstructorMap.put(name, constructor);
     64             }
     65             return (CameraPreference) constructor.newInstance(args);
     66         } catch (NoSuchMethodException e) {
     67             throw new InflateException("Error inflating class " + name, e);
     68         } catch (ClassNotFoundException e) {
     69             throw new InflateException("No such class: " + name, e);
     70         } catch (Exception e) {
     71             throw new InflateException("While create instance of" + name, e);
     72         }
     73     }
     74 
     75     private CameraPreference inflate(XmlPullParser parser) {
     76 
     77         AttributeSet attrs = Xml.asAttributeSet(parser);
     78         ArrayList<CameraPreference> list = new ArrayList<CameraPreference>();
     79         Object args[] = new Object[]{mContext, attrs};
     80 
     81         try {
     82             for (int type = parser.next();
     83                     type != XmlPullParser.END_DOCUMENT; type = parser.next()) {
     84                 if (type != XmlPullParser.START_TAG) continue;
     85                 CameraPreference pref = newPreference(parser.getName(), args);
     86 
     87                 int depth = parser.getDepth();
     88                 if (depth > list.size()) {
     89                     list.add(pref);
     90                 } else {
     91                     list.set(depth - 1, pref);
     92                 }
     93                 if (depth > 1) {
     94                     ((PreferenceGroup) list.get(depth - 2)).addChild(pref);
     95                 }
     96             }
     97 
     98             if (list.size() == 0) {
     99                 throw new InflateException("No root element found");
    100             }
    101             return list.get(0);
    102         } catch (XmlPullParserException e) {
    103             throw new InflateException(e);
    104         } catch (IOException e) {
    105             throw new InflateException(parser.getPositionDescription(), e);
    106         }
    107     }
    108 }
    109