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      1 /*
      2  * Copyright (C) 2008 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.ide.common.rendering.api.IProjectCallback;
     20 import com.android.ide.common.rendering.api.LayoutLog;
     21 import com.android.ide.common.rendering.api.MergeCookie;
     22 import com.android.ide.common.rendering.api.ResourceReference;
     23 import com.android.ide.common.rendering.api.ResourceValue;
     24 import com.android.layoutlib.bridge.Bridge;
     25 import com.android.layoutlib.bridge.android.BridgeContext;
     26 import com.android.layoutlib.bridge.android.BridgeXmlBlockParser;
     27 import com.android.layoutlib.bridge.impl.ParserFactory;
     28 import com.android.resources.ResourceType;
     29 import com.android.util.Pair;
     30 
     31 import org.xmlpull.v1.XmlPullParser;
     32 
     33 import android.content.Context;
     34 import android.util.AttributeSet;
     35 import android.view.InflateException;
     36 import android.view.LayoutInflater;
     37 import android.view.View;
     38 import android.view.ViewGroup;
     39 
     40 import java.io.File;
     41 
     42 /**
     43  * Custom implementation of {@link LayoutInflater} to handle custom views.
     44  */
     45 public final class BridgeInflater extends LayoutInflater {
     46 
     47     private final IProjectCallback mProjectCallback;
     48     private boolean mIsInMerge = false;
     49     private ResourceReference mResourceReference;
     50 
     51     /**
     52      * List of class prefixes which are tried first by default.
     53      * <p/>
     54      * This should match the list in com.android.internal.policy.impl.PhoneLayoutInflater.
     55      */
     56     private static final String[] sClassPrefixList = {
     57         "android.widget.",
     58         "android.webkit."
     59     };
     60 
     61     protected BridgeInflater(LayoutInflater original, Context newContext) {
     62         super(original, newContext);
     63         mProjectCallback = null;
     64     }
     65 
     66     /**
     67      * Instantiate a new BridgeInflater with an {@link IProjectCallback} object.
     68      *
     69      * @param context The Android application context.
     70      * @param projectCallback the {@link IProjectCallback} object.
     71      */
     72     public BridgeInflater(Context context, IProjectCallback projectCallback) {
     73         super(context);
     74         mProjectCallback = projectCallback;
     75         mConstructorArgs[0] = context;
     76     }
     77 
     78     @Override
     79     public View onCreateView(String name, AttributeSet attrs) throws ClassNotFoundException {
     80         View view = null;
     81 
     82         try {
     83             // First try to find a class using the default Android prefixes
     84             for (String prefix : sClassPrefixList) {
     85                 try {
     86                     view = createView(name, prefix, attrs);
     87                     if (view != null) {
     88                         break;
     89                     }
     90                 } catch (ClassNotFoundException e) {
     91                     // Ignore. We'll try again using the base class below.
     92                 }
     93             }
     94 
     95             // Next try using the parent loader. This will most likely only work for
     96             // fully-qualified class names.
     97             try {
     98                 if (view == null) {
     99                     view = super.onCreateView(name, attrs);
    100                 }
    101             } catch (ClassNotFoundException e) {
    102                 // Ignore. We'll try again using the custom view loader below.
    103             }
    104 
    105             // Finally try again using the custom view loader
    106             try {
    107                 if (view == null) {
    108                     view = loadCustomView(name, attrs);
    109                 }
    110             } catch (ClassNotFoundException e) {
    111                 // If the class was not found, we throw the exception directly, because this
    112                 // method is already expected to throw it.
    113                 throw e;
    114             }
    115         } catch (Exception e) {
    116             // Wrap the real exception in a ClassNotFoundException, so that the calling method
    117             // can deal with it.
    118             ClassNotFoundException exception = new ClassNotFoundException("onCreateView", e);
    119             throw exception;
    120         }
    121 
    122         setupViewInContext(view, attrs);
    123 
    124         return view;
    125     }
    126 
    127     @Override
    128     public View createViewFromTag(View parent, String name, AttributeSet attrs) {
    129         View view = null;
    130         try {
    131             view = super.createViewFromTag(parent, name, attrs);
    132         } catch (InflateException e) {
    133             // try to load the class from using the custom view loader
    134             try {
    135                 view = loadCustomView(name, attrs);
    136             } catch (Exception e2) {
    137                 // Wrap the real exception in an InflateException so that the calling
    138                 // method can deal with it.
    139                 InflateException exception = new InflateException();
    140                 if (e2.getClass().equals(ClassNotFoundException.class) == false) {
    141                     exception.initCause(e2);
    142                 } else {
    143                     exception.initCause(e);
    144                 }
    145                 throw exception;
    146             }
    147         }
    148 
    149         setupViewInContext(view, attrs);
    150 
    151         return view;
    152     }
    153 
    154     @Override
    155     public View inflate(int resource, ViewGroup root) {
    156         Context context = getContext();
    157         if (context instanceof BridgeContext) {
    158             BridgeContext bridgeContext = (BridgeContext)context;
    159 
    160             ResourceValue value = null;
    161 
    162             Pair<ResourceType, String> layoutInfo = Bridge.resolveResourceId(resource);
    163             if (layoutInfo != null) {
    164                 value = bridgeContext.getRenderResources().getFrameworkResource(
    165                         ResourceType.LAYOUT, layoutInfo.getSecond());
    166             } else {
    167                 layoutInfo = mProjectCallback.resolveResourceId(resource);
    168 
    169                 if (layoutInfo != null) {
    170                     value = bridgeContext.getRenderResources().getProjectResource(
    171                             ResourceType.LAYOUT, layoutInfo.getSecond());
    172                 }
    173             }
    174 
    175             if (value != null) {
    176                 File f = new File(value.getValue());
    177                 if (f.isFile()) {
    178                     try {
    179                         XmlPullParser parser = ParserFactory.create(f);
    180 
    181                         BridgeXmlBlockParser bridgeParser = new BridgeXmlBlockParser(
    182                                 parser, bridgeContext, false);
    183 
    184                         return inflate(bridgeParser, root);
    185                     } catch (Exception e) {
    186                         Bridge.getLog().error(LayoutLog.TAG_RESOURCES_READ,
    187                                 "Failed to parse file " + f.getAbsolutePath(), e, null /*data*/);
    188 
    189                         return null;
    190                     }
    191                 }
    192             }
    193         }
    194         return null;
    195     }
    196 
    197     private View loadCustomView(String name, AttributeSet attrs) throws ClassNotFoundException,
    198             Exception{
    199         if (mProjectCallback != null) {
    200             // first get the classname in case it's not the node name
    201             if (name.equals("view")) {
    202                 name = attrs.getAttributeValue(null, "class");
    203             }
    204 
    205             mConstructorArgs[1] = attrs;
    206 
    207             Object customView = mProjectCallback.loadView(name, mConstructorSignature,
    208                     mConstructorArgs);
    209 
    210             if (customView instanceof View) {
    211                 return (View)customView;
    212             }
    213         }
    214 
    215         return null;
    216     }
    217 
    218     private void setupViewInContext(View view, AttributeSet attrs) {
    219         if (getContext() instanceof BridgeContext) {
    220             BridgeContext bc = (BridgeContext) getContext();
    221             if (attrs instanceof BridgeXmlBlockParser) {
    222                 BridgeXmlBlockParser parser = (BridgeXmlBlockParser) attrs;
    223 
    224                 // get the view key
    225                 Object viewKey = parser.getViewCookie();
    226 
    227                 if (viewKey == null) {
    228                     int currentDepth = parser.getDepth();
    229 
    230                     // test whether we are in an included file or in a adapter binding view.
    231                     BridgeXmlBlockParser previousParser = bc.getPreviousParser();
    232                     if (previousParser != null) {
    233                         // looks like we inside an embedded layout.
    234                         // only apply the cookie of the calling node (<include>) if we are at the
    235                         // top level of the embedded layout. If there is a merge tag, then
    236                         // skip it and look for the 2nd level
    237                         int testDepth = mIsInMerge ? 2 : 1;
    238                         if (currentDepth == testDepth) {
    239                             viewKey = previousParser.getViewCookie();
    240                             // if we are in a merge, wrap the cookie in a MergeCookie.
    241                             if (viewKey != null && mIsInMerge) {
    242                                 viewKey = new MergeCookie(viewKey);
    243                             }
    244                         }
    245                     } else if (mResourceReference != null && currentDepth == 1) {
    246                         // else if there's a resource reference, this means we are in an adapter
    247                         // binding case. Set the resource ref as the view cookie only for the top
    248                         // level view.
    249                         viewKey = mResourceReference;
    250                     }
    251                 }
    252 
    253                 if (viewKey != null) {
    254                     bc.addViewKey(view, viewKey);
    255                 }
    256             }
    257         }
    258     }
    259 
    260     public void setIsInMerge(boolean isInMerge) {
    261         mIsInMerge = isInMerge;
    262     }
    263 
    264     public void setResourceReference(ResourceReference reference) {
    265         mResourceReference = reference;
    266     }
    267 
    268     @Override
    269     public LayoutInflater cloneInContext(Context newContext) {
    270         return new BridgeInflater(this, newContext);
    271     }
    272 }
    273