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      1 /*
      2  * Copyright (C) 2011 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 android.view;
     18 
     19 import com.android.tools.layoutlib.annotations.LayoutlibDelegate;
     20 
     21 import org.xmlpull.v1.XmlPullParser;
     22 import org.xmlpull.v1.XmlPullParserException;
     23 
     24 import android.content.res.TypedArray;
     25 import android.content.res.XmlResourceParser;
     26 import android.util.AttributeSet;
     27 import android.util.Xml;
     28 
     29 import java.io.IOException;
     30 
     31 /**
     32  * Delegate used to provide new implementation of a select few methods of {@link LayoutInflater}
     33  *
     34  * Through the layoutlib_create tool, the original  methods of LayoutInflater have been replaced
     35  * by calls to methods of the same name in this delegate class.
     36  *
     37  */
     38 public class LayoutInflater_Delegate {
     39 
     40     private static final String TAG_MERGE = "merge";
     41 
     42     public static boolean sIsInInclude = false;
     43 
     44     /**
     45      * Recursive method used to descend down the xml hierarchy and instantiate
     46      * views, instantiate their children, and then call onFinishInflate().
     47      *
     48      * This implementation just records the merge status before calling the default implementation.
     49      */
     50     @LayoutlibDelegate
     51     /*package*/ static void rInflate(LayoutInflater thisInflater,
     52             XmlPullParser parser, View parent, final AttributeSet attrs,
     53             boolean finishInflate) throws XmlPullParserException, IOException {
     54 
     55         if (finishInflate == false) {
     56             // this is a merge rInflate!
     57             if (thisInflater instanceof BridgeInflater) {
     58                 ((BridgeInflater) thisInflater).setIsInMerge(true);
     59             }
     60         }
     61 
     62         // ---- START DEFAULT IMPLEMENTATION.
     63 
     64         thisInflater.rInflate_Original(parser, parent, attrs, finishInflate);
     65 
     66         // ---- END DEFAULT IMPLEMENTATION.
     67 
     68         if (finishInflate == false) {
     69             // this is a merge rInflate!
     70             if (thisInflater instanceof BridgeInflater) {
     71                 ((BridgeInflater) thisInflater).setIsInMerge(false);
     72             }
     73         }
     74     }
     75 
     76     @LayoutlibDelegate
     77     public static void parseInclude(
     78             LayoutInflater thisInflater,
     79             XmlPullParser parser, View parent, AttributeSet attrs)
     80             throws XmlPullParserException, IOException {
     81 
     82         int type;
     83 
     84         if (parent instanceof ViewGroup) {
     85             final int layout = attrs.getAttributeResourceValue(null, "layout", 0);
     86             if (layout == 0) {
     87                 final String value = attrs.getAttributeValue(null, "layout");
     88                 if (value == null) {
     89                     throw new InflateException("You must specifiy a layout in the"
     90                             + " include tag: <include layout=\"@layout/layoutID\" />");
     91                 } else {
     92                     throw new InflateException("You must specifiy a valid layout "
     93                             + "reference. The layout ID " + value + " is not valid.");
     94                 }
     95             } else {
     96                 final XmlResourceParser childParser =
     97                     thisInflater.getContext().getResources().getLayout(layout);
     98 
     99                 try {
    100                     final AttributeSet childAttrs = Xml.asAttributeSet(childParser);
    101 
    102                     while ((type = childParser.next()) != XmlPullParser.START_TAG &&
    103                             type != XmlPullParser.END_DOCUMENT) {
    104                         // Empty.
    105                     }
    106 
    107                     if (type != XmlPullParser.START_TAG) {
    108                         throw new InflateException(childParser.getPositionDescription() +
    109                                 ": No start tag found!");
    110                     }
    111 
    112                     final String childName = childParser.getName();
    113 
    114                     if (TAG_MERGE.equals(childName)) {
    115                         // Inflate all children.
    116                         thisInflater.rInflate(childParser, parent, childAttrs, false);
    117                     } else {
    118                         final View view = thisInflater.createViewFromTag(parent, childName, childAttrs);
    119                         final ViewGroup group = (ViewGroup) parent;
    120 
    121                         // We try to load the layout params set in the <include /> tag. If
    122                         // they don't exist, we will rely on the layout params set in the
    123                         // included XML file.
    124                         // During a layoutparams generation, a runtime exception is thrown
    125                         // if either layout_width or layout_height is missing. We catch
    126                         // this exception and set localParams accordingly: true means we
    127                         // successfully loaded layout params from the <include /> tag,
    128                         // false means we need to rely on the included layout params.
    129                         ViewGroup.LayoutParams params = null;
    130                         try {
    131                             // ---- START CHANGES
    132                             sIsInInclude = true;
    133                             // ---- END CHANGES
    134 
    135                             params = group.generateLayoutParams(attrs);
    136 
    137                         } catch (RuntimeException e) {
    138                             // ---- START CHANGES
    139                             sIsInInclude = false;
    140                             // ---- END CHANGES
    141 
    142                             params = group.generateLayoutParams(childAttrs);
    143                         } finally {
    144                             // ---- START CHANGES
    145                             sIsInInclude = false;
    146                             // ---- END CHANGES
    147 
    148                             if (params != null) {
    149                                 view.setLayoutParams(params);
    150                             }
    151                         }
    152 
    153                         // Inflate all children.
    154                         thisInflater.rInflate(childParser, view, childAttrs, true);
    155 
    156                         // Attempt to override the included layout's android:id with the
    157                         // one set on the <include /> tag itself.
    158                         TypedArray a = thisInflater.mContext.obtainStyledAttributes(attrs,
    159                             com.android.internal.R.styleable.View, 0, 0);
    160                         int id = a.getResourceId(com.android.internal.R.styleable.View_id, View.NO_ID);
    161                         // While we're at it, let's try to override android:visibility.
    162                         int visibility = a.getInt(com.android.internal.R.styleable.View_visibility, -1);
    163                         a.recycle();
    164 
    165                         if (id != View.NO_ID) {
    166                             view.setId(id);
    167                         }
    168 
    169                         switch (visibility) {
    170                             case 0:
    171                                 view.setVisibility(View.VISIBLE);
    172                                 break;
    173                             case 1:
    174                                 view.setVisibility(View.INVISIBLE);
    175                                 break;
    176                             case 2:
    177                                 view.setVisibility(View.GONE);
    178                                 break;
    179                         }
    180 
    181                         group.addView(view);
    182                     }
    183                 } finally {
    184                     childParser.close();
    185                 }
    186             }
    187         } else {
    188             throw new InflateException("<include /> can only be used inside of a ViewGroup");
    189         }
    190 
    191         final int currentDepth = parser.getDepth();
    192         while (((type = parser.next()) != XmlPullParser.END_TAG ||
    193                 parser.getDepth() > currentDepth) && type != XmlPullParser.END_DOCUMENT) {
    194             // Empty
    195         }
    196     }
    197 
    198 
    199 }
    200