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.LayoutLog;
20 import com.android.ide.common.rendering.api.LayoutlibCallback;
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.BridgeConstants;
26 import com.android.layoutlib.bridge.MockView;
27 import com.android.layoutlib.bridge.android.BridgeContext;
28 import com.android.layoutlib.bridge.android.BridgeXmlBlockParser;
29 import com.android.layoutlib.bridge.android.support.DrawerLayoutUtil;
30 import com.android.layoutlib.bridge.android.support.RecyclerViewUtil;
31 import com.android.layoutlib.bridge.impl.ParserFactory;
32 import com.android.layoutlib.bridge.util.ReflectionUtils;
33 import com.android.resources.ResourceType;
34 import com.android.tools.layoutlib.annotations.NotNull;
35 import com.android.tools.layoutlib.annotations.Nullable;
36 import com.android.util.Pair;
37 
38 import org.xmlpull.v1.XmlPullParser;
39 
40 import android.annotation.NonNull;
41 import android.content.Context;
42 import android.content.res.TypedArray;
43 import android.graphics.drawable.Animatable;
44 import android.graphics.drawable.Drawable;
45 import android.util.AttributeSet;
46 import android.widget.ImageView;
47 import android.widget.NumberPicker;
48 
49 import java.io.File;
50 import java.lang.reflect.Constructor;
51 import java.lang.reflect.InvocationTargetException;
52 import java.lang.reflect.Method;
53 import java.util.HashMap;
54 import java.util.Map;
55 import java.util.function.BiFunction;
56 
57 import static com.android.layoutlib.bridge.android.BridgeContext.getBaseContext;
58 
59 /**
60  * Custom implementation of {@link LayoutInflater} to handle custom views.
61  */
62 public final class BridgeInflater extends LayoutInflater {
63 
64     private final LayoutlibCallback mLayoutlibCallback;
65 
66     private boolean mIsInMerge = false;
67     private ResourceReference mResourceReference;
68     private Map<View, String> mOpenDrawerLayouts;
69 
70     // Keep in sync with the same value in LayoutInflater.
71     private static final int[] ATTRS_THEME = new int[] {com.android.internal.R.attr.theme };
72 
73     /**
74      * List of class prefixes which are tried first by default.
75      * <p/>
76      * This should match the list in com.android.internal.policy.impl.PhoneLayoutInflater.
77      */
78     private static final String[] sClassPrefixList = {
79         "android.widget.",
80         "android.webkit.",
81         "android.app."
82     };
83     private BiFunction<String, AttributeSet, View> mCustomInflater;
84 
getClassPrefixList()85     public static String[] getClassPrefixList() {
86         return sClassPrefixList;
87     }
88 
BridgeInflater(LayoutInflater original, Context newContext)89     private BridgeInflater(LayoutInflater original, Context newContext) {
90         super(original, newContext);
91         newContext = getBaseContext(newContext);
92         mLayoutlibCallback = (newContext instanceof BridgeContext) ?
93                 ((BridgeContext) newContext).getLayoutlibCallback() :
94                 null;
95     }
96 
97     /**
98      * Instantiate a new BridgeInflater with an {@link LayoutlibCallback} object.
99      *
100      * @param context The Android application context.
101      * @param layoutlibCallback the {@link LayoutlibCallback} object.
102      */
BridgeInflater(BridgeContext context, LayoutlibCallback layoutlibCallback)103     public BridgeInflater(BridgeContext context, LayoutlibCallback layoutlibCallback) {
104         super(context);
105         mLayoutlibCallback = layoutlibCallback;
106         mConstructorArgs[0] = context;
107     }
108 
109     @Override
onCreateView(String name, AttributeSet attrs)110     public View onCreateView(String name, AttributeSet attrs) throws ClassNotFoundException {
111         View view = createViewFromCustomInflater(name, attrs);
112 
113         if (view == null) {
114             try {
115                 // First try to find a class using the default Android prefixes
116                 for (String prefix : sClassPrefixList) {
117                     try {
118                         view = createView(name, prefix, attrs);
119                         if (view != null) {
120                             break;
121                         }
122                     } catch (ClassNotFoundException e) {
123                         // Ignore. We'll try again using the base class below.
124                     }
125                 }
126 
127                 // Next try using the parent loader. This will most likely only work for
128                 // fully-qualified class names.
129                 try {
130                     if (view == null) {
131                         view = super.onCreateView(name, attrs);
132                     }
133                 } catch (ClassNotFoundException e) {
134                     // Ignore. We'll try again using the custom view loader below.
135                 }
136 
137                 // Finally try again using the custom view loader
138                 if (view == null) {
139                     view = loadCustomView(name, attrs);
140                 }
141             } catch (InflateException e) {
142                 // Don't catch the InflateException below as that results in hiding the real cause.
143                 throw e;
144             } catch (Exception e) {
145                 // Wrap the real exception in a ClassNotFoundException, so that the calling method
146                 // can deal with it.
147                 throw new ClassNotFoundException("onCreateView", e);
148             }
149         }
150 
151         setupViewInContext(view, attrs);
152 
153         return view;
154     }
155 
156     /**
157      * Finds the createView method in the given customInflaterClass. Since createView is
158      * currently package protected, it will show in the declared class so we iterate up the
159      * hierarchy and return the first instance we find.
160      * The returned method will be accessible.
161      */
162     @NotNull
getCreateViewMethod(Class<?> customInflaterClass)163     private static Method getCreateViewMethod(Class<?> customInflaterClass) throws NoSuchMethodException {
164         Class<?> current = customInflaterClass;
165         do {
166             try {
167                 Method method = current.getDeclaredMethod("createView", View.class, String.class,
168                                 Context.class, AttributeSet.class, boolean.class, boolean.class,
169                                 boolean.class, boolean.class);
170                 method.setAccessible(true);
171                 return method;
172             } catch (NoSuchMethodException ignore) {
173             }
174             current = current.getSuperclass();
175         } while (current != null && current != Object.class);
176 
177         throw new NoSuchMethodException();
178     }
179 
180     /**
181      * Finds the custom inflater class. If it's defined in the theme, we'll use that one (if the
182      * class does not exist, null is returned).
183      * If {@code viewInflaterClass} is not defined in the theme, we'll try to instantiate
184      * {@code android.support.v7.app.AppCompatViewInflater}
185      */
186     @Nullable
findCustomInflater(@otNull BridgeContext bc, @NotNull LayoutlibCallback layoutlibCallback)187     private static Class<?> findCustomInflater(@NotNull BridgeContext bc,
188             @NotNull LayoutlibCallback layoutlibCallback) {
189         ResourceValue value = bc.getRenderResources().findItemInTheme("viewInflaterClass", false);
190         String inflaterName = value != null ? value.getValue() : null;
191 
192         if (inflaterName != null) {
193             try {
194                 return layoutlibCallback.findClass(inflaterName);
195             } catch (ClassNotFoundException ignore) {
196             }
197 
198             // viewInflaterClass was defined but we couldn't find the class
199         } else if (bc.isAppCompatTheme()) {
200             // Older versions of AppCompat do not define the viewInflaterClass so try to get it
201             // manually
202             try {
203                 return layoutlibCallback.findClass("android.support.v7.app.AppCompatViewInflater");
204             } catch (ClassNotFoundException ignore) {
205             }
206         }
207 
208         return null;
209     }
210 
211     /**
212      * Checks if there is a custom inflater and, when present, tries to instantiate the view
213      * using it.
214      */
215     @Nullable
createViewFromCustomInflater(@otNull String name, @NotNull AttributeSet attrs)216     private View createViewFromCustomInflater(@NotNull String name, @NotNull AttributeSet attrs) {
217         if (mCustomInflater == null) {
218             Context context = getContext();
219             context = getBaseContext(context);
220             if (context instanceof BridgeContext) {
221                 BridgeContext bc = (BridgeContext) context;
222                 Class<?> inflaterClass = findCustomInflater(bc, mLayoutlibCallback);
223 
224                 if (inflaterClass != null) {
225                     try {
226                         Constructor<?> constructor =  inflaterClass.getDeclaredConstructor();
227                         constructor.setAccessible(true);
228                         Object inflater = constructor.newInstance();
229                         Method method = getCreateViewMethod(inflaterClass);
230                         Context finalContext = context;
231                         mCustomInflater = (viewName, attributeSet) -> {
232                             try {
233                                 return (View) method.invoke(inflater, null, viewName, finalContext,
234                                         attributeSet,
235                                         false,
236                                         false /*readAndroidTheme*/, // No need after L
237                                         true /*readAppTheme*/,
238                                         true /*wrapContext*/);
239                             } catch (IllegalAccessException | InvocationTargetException e) {
240                                 assert false : "Call to createView failed";
241                             }
242                             return null;
243                         };
244                     } catch (InvocationTargetException | IllegalAccessException |
245                             NoSuchMethodException | InstantiationException ignore) {
246                     }
247                 }
248             }
249 
250             if (mCustomInflater == null) {
251                 // There is no custom inflater. We'll create a nop custom inflater to avoid the
252                 // penalty of trying to instantiate again
253                 mCustomInflater = (s, attributeSet) -> null;
254             }
255         }
256 
257         return mCustomInflater.apply(name, attrs);
258     }
259 
260     @Override
createViewFromTag(View parent, String name, Context context, AttributeSet attrs, boolean ignoreThemeAttr)261     public View createViewFromTag(View parent, String name, Context context, AttributeSet attrs,
262             boolean ignoreThemeAttr) {
263         View view = null;
264         if (name.equals("view")) {
265             // This is usually done by the superclass but this allows us catching the error and
266             // reporting something useful.
267             name = attrs.getAttributeValue(null, "class");
268 
269             if (name == null) {
270                 Bridge.getLog().error(LayoutLog.TAG_BROKEN, "Unable to inflate view tag without " +
271                   "class attribute", null);
272                 // We weren't able to resolve the view so we just pass a mock View to be able to
273                 // continue rendering.
274                 view = new MockView(context, attrs);
275                 ((MockView) view).setText("view");
276             }
277         }
278 
279         try {
280             if (view == null) {
281                 view = super.createViewFromTag(parent, name, context, attrs, ignoreThemeAttr);
282             }
283         } catch (InflateException e) {
284             // Creation of ContextThemeWrapper code is same as in the super method.
285             // Apply a theme wrapper, if allowed and one is specified.
286             if (!ignoreThemeAttr) {
287                 final TypedArray ta = context.obtainStyledAttributes(attrs, ATTRS_THEME);
288                 final int themeResId = ta.getResourceId(0, 0);
289                 if (themeResId != 0) {
290                     context = new ContextThemeWrapper(context, themeResId);
291                 }
292                 ta.recycle();
293             }
294             if (!(e.getCause() instanceof ClassNotFoundException)) {
295                 // There is some unknown inflation exception in inflating a View that was found.
296                 view = new MockView(context, attrs);
297                 ((MockView) view).setText(name);
298                 Bridge.getLog().error(LayoutLog.TAG_BROKEN, e.getMessage(), e, null);
299             } else {
300                 final Object lastContext = mConstructorArgs[0];
301                 mConstructorArgs[0] = context;
302                 // try to load the class from using the custom view loader
303                 try {
304                     view = loadCustomView(name, attrs);
305                 } catch (Exception e2) {
306                     // Wrap the real exception in an InflateException so that the calling
307                     // method can deal with it.
308                     InflateException exception = new InflateException();
309                     if (!e2.getClass().equals(ClassNotFoundException.class)) {
310                         exception.initCause(e2);
311                     } else {
312                         exception.initCause(e);
313                     }
314                     throw exception;
315                 } finally {
316                     mConstructorArgs[0] = lastContext;
317                 }
318             }
319         }
320 
321         setupViewInContext(view, attrs);
322 
323         return view;
324     }
325 
326     @Override
inflate(int resource, ViewGroup root)327     public View inflate(int resource, ViewGroup root) {
328         Context context = getContext();
329         context = getBaseContext(context);
330         if (context instanceof BridgeContext) {
331             BridgeContext bridgeContext = (BridgeContext)context;
332 
333             ResourceValue value = null;
334 
335             @SuppressWarnings("deprecation")
336             Pair<ResourceType, String> layoutInfo = Bridge.resolveResourceId(resource);
337             if (layoutInfo != null) {
338                 value = bridgeContext.getRenderResources().getFrameworkResource(
339                         ResourceType.LAYOUT, layoutInfo.getSecond());
340             } else {
341                 layoutInfo = mLayoutlibCallback.resolveResourceId(resource);
342 
343                 if (layoutInfo != null) {
344                     value = bridgeContext.getRenderResources().getProjectResource(
345                             ResourceType.LAYOUT, layoutInfo.getSecond());
346                 }
347             }
348 
349             if (value != null) {
350                 File f = new File(value.getValue());
351                 if (f.isFile()) {
352                     try {
353                         XmlPullParser parser = ParserFactory.create(f, true);
354 
355                         BridgeXmlBlockParser bridgeParser = new BridgeXmlBlockParser(
356                                 parser, bridgeContext, value.isFramework());
357 
358                         return inflate(bridgeParser, root);
359                     } catch (Exception e) {
360                         Bridge.getLog().error(LayoutLog.TAG_RESOURCES_READ,
361                                 "Failed to parse file " + f.getAbsolutePath(), e, null);
362 
363                         return null;
364                     }
365                 }
366             }
367         }
368         return null;
369     }
370 
371     /**
372      * Instantiates the given view name and returns the instance. If the view doesn't exist, a
373      * MockView or null might be returned.
374      * @param name the custom view name
375      * @param attrs the {@link AttributeSet} to be passed to the view constructor
376      * @param silent if true, errors while loading the view won't be reported and, if the view
377      * doesn't exist, null will be returned.
378      */
loadCustomView(String name, AttributeSet attrs, boolean silent)379     private View loadCustomView(String name, AttributeSet attrs, boolean silent) throws Exception {
380         if (mLayoutlibCallback != null) {
381             // first get the classname in case it's not the node name
382             if (name.equals("view")) {
383                 name = attrs.getAttributeValue(null, "class");
384                 if (name == null) {
385                     return null;
386                 }
387             }
388 
389             mConstructorArgs[1] = attrs;
390 
391             Object customView = silent ?
392                     mLayoutlibCallback.loadClass(name, mConstructorSignature, mConstructorArgs)
393                     : mLayoutlibCallback.loadView(name, mConstructorSignature, mConstructorArgs);
394 
395             if (customView instanceof View) {
396                 return (View)customView;
397             }
398         }
399 
400         return null;
401     }
402 
loadCustomView(String name, AttributeSet attrs)403     private View loadCustomView(String name, AttributeSet attrs) throws Exception {
404         return loadCustomView(name, attrs, false);
405     }
406 
setupViewInContext(View view, AttributeSet attrs)407     private void setupViewInContext(View view, AttributeSet attrs) {
408         Context context = getContext();
409         context = getBaseContext(context);
410         if (context instanceof BridgeContext) {
411             BridgeContext bc = (BridgeContext) context;
412             // get the view key
413             Object viewKey = getViewKeyFromParser(attrs, bc, mResourceReference, mIsInMerge);
414             if (viewKey != null) {
415                 bc.addViewKey(view, viewKey);
416             }
417             String scrollPosX = attrs.getAttributeValue(BridgeConstants.NS_RESOURCES, "scrollX");
418             if (scrollPosX != null && scrollPosX.endsWith("px")) {
419                 int value = Integer.parseInt(scrollPosX.substring(0, scrollPosX.length() - 2));
420                 bc.setScrollXPos(view, value);
421             }
422             String scrollPosY = attrs.getAttributeValue(BridgeConstants.NS_RESOURCES, "scrollY");
423             if (scrollPosY != null && scrollPosY.endsWith("px")) {
424                 int value = Integer.parseInt(scrollPosY.substring(0, scrollPosY.length() - 2));
425                 bc.setScrollYPos(view, value);
426             }
427             if (ReflectionUtils.isInstanceOf(view, RecyclerViewUtil.CN_RECYCLER_VIEW)) {
428                 Integer resourceId = null;
429                 String attrListItemValue = attrs.getAttributeValue(BridgeConstants.NS_TOOLS_URI,
430                         BridgeConstants.ATTR_LIST_ITEM);
431                 int attrItemCountValue = attrs.getAttributeIntValue(BridgeConstants.NS_TOOLS_URI,
432                         BridgeConstants.ATTR_ITEM_COUNT, -1);
433                 if (attrListItemValue != null && !attrListItemValue.isEmpty()) {
434                     ResourceValue resValue = bc.getRenderResources().findResValue(attrListItemValue, false);
435                     if (resValue.isFramework()) {
436                         resourceId = Bridge.getResourceId(resValue.getResourceType(),
437                                 resValue.getName());
438                     } else {
439                         resourceId = mLayoutlibCallback.getResourceId(resValue.getResourceType(),
440                                 resValue.getName());
441                     }
442                 }
443                 if (resourceId == null) {
444                     resourceId = 0;
445                 }
446                 RecyclerViewUtil.setAdapter(view, bc, mLayoutlibCallback, resourceId, attrItemCountValue);
447             } else if (ReflectionUtils.isInstanceOf(view, DrawerLayoutUtil.CN_DRAWER_LAYOUT)) {
448                 String attrVal = attrs.getAttributeValue(BridgeConstants.NS_TOOLS_URI,
449                         BridgeConstants.ATTR_OPEN_DRAWER);
450                 if (attrVal != null) {
451                     getDrawerLayoutMap().put(view, attrVal);
452                 }
453             }
454             else if (view instanceof NumberPicker) {
455                 NumberPicker numberPicker = (NumberPicker) view;
456                 String minValue = attrs.getAttributeValue(BridgeConstants.NS_TOOLS_URI, "minValue");
457                 if (minValue != null) {
458                     numberPicker.setMinValue(Integer.parseInt(minValue));
459                 }
460                 String maxValue = attrs.getAttributeValue(BridgeConstants.NS_TOOLS_URI, "maxValue");
461                 if (maxValue != null) {
462                     numberPicker.setMaxValue(Integer.parseInt(maxValue));
463                 }
464             }
465             else if (view instanceof ImageView) {
466                 ImageView img = (ImageView) view;
467                 Drawable drawable = img.getDrawable();
468                 if (drawable instanceof Animatable) {
469                     if (!((Animatable) drawable).isRunning()) {
470                         ((Animatable) drawable).start();
471                     }
472                 }
473             }
474 
475         }
476     }
477 
setIsInMerge(boolean isInMerge)478     public void setIsInMerge(boolean isInMerge) {
479         mIsInMerge = isInMerge;
480     }
481 
setResourceReference(ResourceReference reference)482     public void setResourceReference(ResourceReference reference) {
483         mResourceReference = reference;
484     }
485 
486     @Override
cloneInContext(Context newContext)487     public LayoutInflater cloneInContext(Context newContext) {
488         return new BridgeInflater(this, newContext);
489     }
490 
getViewKeyFromParser(AttributeSet attrs, BridgeContext bc, ResourceReference resourceReference, boolean isInMerge)491     /*package*/ static Object getViewKeyFromParser(AttributeSet attrs, BridgeContext bc,
492             ResourceReference resourceReference, boolean isInMerge) {
493 
494         if (!(attrs instanceof BridgeXmlBlockParser)) {
495             return null;
496         }
497         BridgeXmlBlockParser parser = ((BridgeXmlBlockParser) attrs);
498 
499         // get the view key
500         Object viewKey = parser.getViewCookie();
501 
502         if (viewKey == null) {
503             int currentDepth = parser.getDepth();
504 
505             // test whether we are in an included file or in a adapter binding view.
506             BridgeXmlBlockParser previousParser = bc.getPreviousParser();
507             if (previousParser != null) {
508                 // looks like we are inside an embedded layout.
509                 // only apply the cookie of the calling node (<include>) if we are at the
510                 // top level of the embedded layout. If there is a merge tag, then
511                 // skip it and look for the 2nd level
512                 int testDepth = isInMerge ? 2 : 1;
513                 if (currentDepth == testDepth) {
514                     viewKey = previousParser.getViewCookie();
515                     // if we are in a merge, wrap the cookie in a MergeCookie.
516                     if (viewKey != null && isInMerge) {
517                         viewKey = new MergeCookie(viewKey);
518                     }
519                 }
520             } else if (resourceReference != null && currentDepth == 1) {
521                 // else if there's a resource reference, this means we are in an adapter
522                 // binding case. Set the resource ref as the view cookie only for the top
523                 // level view.
524                 viewKey = resourceReference;
525             }
526         }
527 
528         return viewKey;
529     }
530 
postInflateProcess(View view)531     public void postInflateProcess(View view) {
532         if (mOpenDrawerLayouts != null) {
533             String gravity = mOpenDrawerLayouts.get(view);
534             if (gravity != null) {
535                 DrawerLayoutUtil.openDrawer(view, gravity);
536             }
537             mOpenDrawerLayouts.remove(view);
538         }
539     }
540 
541     @NonNull
getDrawerLayoutMap()542     private Map<View, String> getDrawerLayoutMap() {
543         if (mOpenDrawerLayouts == null) {
544             mOpenDrawerLayouts = new HashMap<View, String>(4);
545         }
546         return mOpenDrawerLayouts;
547     }
548 
onDoneInflation()549     public void onDoneInflation() {
550         if (mOpenDrawerLayouts != null) {
551             mOpenDrawerLayouts.clear();
552         }
553     }
554 }
555