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
rInflate(LayoutInflater thisInflater, XmlPullParser parser, View parent, final AttributeSet attrs, boolean finishInflate, boolean inheritContext)51     /* package */ static void rInflate(LayoutInflater thisInflater, XmlPullParser parser,
52             View parent, final AttributeSet attrs, boolean finishInflate, boolean inheritContext)
53             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, inheritContext);
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
parseInclude(LayoutInflater thisInflater, XmlPullParser parser, View parent, AttributeSet attrs, boolean inheritContext)77     public static void parseInclude(LayoutInflater thisInflater, XmlPullParser parser, View parent,
78             AttributeSet attrs, boolean inheritContext) throws XmlPullParserException, IOException {
79 
80         int type;
81 
82         if (parent instanceof ViewGroup) {
83             final int layout = attrs.getAttributeResourceValue(null, "layout", 0);
84             if (layout == 0) {
85                 final String value = attrs.getAttributeValue(null, "layout");
86                 if (value == null) {
87                     throw new InflateException("You must specifiy a layout in the"
88                             + " include tag: <include layout=\"@layout/layoutID\" />");
89                 } else {
90                     throw new InflateException("You must specifiy a valid layout "
91                             + "reference. The layout ID " + value + " is not valid.");
92                 }
93             } else {
94                 final XmlResourceParser childParser =
95                     thisInflater.getContext().getResources().getLayout(layout);
96 
97                 try {
98                     final AttributeSet childAttrs = Xml.asAttributeSet(childParser);
99 
100                     while ((type = childParser.next()) != XmlPullParser.START_TAG &&
101                             type != XmlPullParser.END_DOCUMENT) {
102                         // Empty.
103                     }
104 
105                     if (type != XmlPullParser.START_TAG) {
106                         throw new InflateException(childParser.getPositionDescription() +
107                                 ": No start tag found!");
108                     }
109 
110                     final String childName = childParser.getName();
111 
112                     if (TAG_MERGE.equals(childName)) {
113                         // Inflate all children.
114                         thisInflater.rInflate(childParser, parent, childAttrs, false,
115                                 inheritContext);
116                     } else {
117                         final View view = thisInflater.createViewFromTag(parent, childName,
118                                 childAttrs, inheritContext);
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, 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