1 /*
2 * Copyright (C) 2007 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 android.graphics.Canvas;
20 import android.os.Handler;
21 import android.os.Message;
22 import android.os.Trace;
23 import android.widget.FrameLayout;
24 import org.xmlpull.v1.XmlPullParser;
25 import org.xmlpull.v1.XmlPullParserException;
26
27 import android.content.Context;
28 import android.content.res.TypedArray;
29 import android.content.res.XmlResourceParser;
30 import android.util.AttributeSet;
31 import android.util.Xml;
32
33 import java.io.IOException;
34 import java.lang.reflect.Constructor;
35 import java.util.HashMap;
36
37 /**
38 * Instantiates a layout XML file into its corresponding {@link android.view.View}
39 * objects. It is never used directly. Instead, use
40 * {@link android.app.Activity#getLayoutInflater()} or
41 * {@link Context#getSystemService} to retrieve a standard LayoutInflater instance
42 * that is already hooked up to the current context and correctly configured
43 * for the device you are running on. For example:
44 *
45 * <pre>LayoutInflater inflater = (LayoutInflater)context.getSystemService
46 * (Context.LAYOUT_INFLATER_SERVICE);</pre>
47 *
48 * <p>
49 * To create a new LayoutInflater with an additional {@link Factory} for your
50 * own views, you can use {@link #cloneInContext} to clone an existing
51 * ViewFactory, and then call {@link #setFactory} on it to include your
52 * Factory.
53 *
54 * <p>
55 * For performance reasons, view inflation relies heavily on pre-processing of
56 * XML files that is done at build time. Therefore, it is not currently possible
57 * to use LayoutInflater with an XmlPullParser over a plain XML file at runtime;
58 * it only works with an XmlPullParser returned from a compiled resource
59 * (R.<em>something</em> file.)
60 *
61 * @see Context#getSystemService
62 */
63 public abstract class LayoutInflater {
64 private final boolean DEBUG = false;
65
66 /**
67 * This field should be made private, so it is hidden from the SDK.
68 * {@hide}
69 */
70 protected final Context mContext;
71
72 // these are optional, set by the caller
73 private boolean mFactorySet;
74 private Factory mFactory;
75 private Factory2 mFactory2;
76 private Factory2 mPrivateFactory;
77 private Filter mFilter;
78
79 final Object[] mConstructorArgs = new Object[2];
80
81 static final Class<?>[] mConstructorSignature = new Class[] {
82 Context.class, AttributeSet.class};
83
84 private static final HashMap<String, Constructor<? extends View>> sConstructorMap =
85 new HashMap<String, Constructor<? extends View>>();
86
87 private HashMap<String, Boolean> mFilterMap;
88
89 private static final String TAG_MERGE = "merge";
90 private static final String TAG_INCLUDE = "include";
91 private static final String TAG_1995 = "blink";
92 private static final String TAG_REQUEST_FOCUS = "requestFocus";
93
94 /**
95 * Hook to allow clients of the LayoutInflater to restrict the set of Views that are allowed
96 * to be inflated.
97 *
98 */
99 public interface Filter {
100 /**
101 * Hook to allow clients of the LayoutInflater to restrict the set of Views
102 * that are allowed to be inflated.
103 *
104 * @param clazz The class object for the View that is about to be inflated
105 *
106 * @return True if this class is allowed to be inflated, or false otherwise
107 */
108 @SuppressWarnings("unchecked")
109 boolean onLoadClass(Class clazz);
110 }
111
112 public interface Factory {
113 /**
114 * Hook you can supply that is called when inflating from a LayoutInflater.
115 * You can use this to customize the tag names available in your XML
116 * layout files.
117 *
118 * <p>
119 * Note that it is good practice to prefix these custom names with your
120 * package (i.e., com.coolcompany.apps) to avoid conflicts with system
121 * names.
122 *
123 * @param name Tag name to be inflated.
124 * @param context The context the view is being created in.
125 * @param attrs Inflation attributes as specified in XML file.
126 *
127 * @return View Newly created view. Return null for the default
128 * behavior.
129 */
130 public View onCreateView(String name, Context context, AttributeSet attrs);
131 }
132
133 public interface Factory2 extends Factory {
134 /**
135 * Version of {@link #onCreateView(String, Context, AttributeSet)}
136 * that also supplies the parent that the view created view will be
137 * placed in.
138 *
139 * @param parent The parent that the created view will be placed
140 * in; <em>note that this may be null</em>.
141 * @param name Tag name to be inflated.
142 * @param context The context the view is being created in.
143 * @param attrs Inflation attributes as specified in XML file.
144 *
145 * @return View Newly created view. Return null for the default
146 * behavior.
147 */
148 public View onCreateView(View parent, String name, Context context, AttributeSet attrs);
149 }
150
151 private static class FactoryMerger implements Factory2 {
152 private final Factory mF1, mF2;
153 private final Factory2 mF12, mF22;
154
155 FactoryMerger(Factory f1, Factory2 f12, Factory f2, Factory2 f22) {
156 mF1 = f1;
157 mF2 = f2;
158 mF12 = f12;
159 mF22 = f22;
160 }
161
162 public View onCreateView(String name, Context context, AttributeSet attrs) {
163 View v = mF1.onCreateView(name, context, attrs);
164 if (v != null) return v;
165 return mF2.onCreateView(name, context, attrs);
166 }
167
168 public View onCreateView(View parent, String name, Context context, AttributeSet attrs) {
169 View v = mF12 != null ? mF12.onCreateView(parent, name, context, attrs)
170 : mF1.onCreateView(name, context, attrs);
171 if (v != null) return v;
172 return mF22 != null ? mF22.onCreateView(parent, name, context, attrs)
173 : mF2.onCreateView(name, context, attrs);
174 }
175 }
176
177 /**
178 * Create a new LayoutInflater instance associated with a particular Context.
179 * Applications will almost always want to use
180 * {@link Context#getSystemService Context.getSystemService()} to retrieve
181 * the standard {@link Context#LAYOUT_INFLATER_SERVICE Context.INFLATER_SERVICE}.
182 *
183 * @param context The Context in which this LayoutInflater will create its
184 * Views; most importantly, this supplies the theme from which the default
185 * values for their attributes are retrieved.
186 */
187 protected LayoutInflater(Context context) {
188 mContext = context;
189 }
190
191 /**
192 * Create a new LayoutInflater instance that is a copy of an existing
193 * LayoutInflater, optionally with its Context changed. For use in
194 * implementing {@link #cloneInContext}.
195 *
196 * @param original The original LayoutInflater to copy.
197 * @param newContext The new Context to use.
198 */
199 protected LayoutInflater(LayoutInflater original, Context newContext) {
200 mContext = newContext;
201 mFactory = original.mFactory;
202 mFactory2 = original.mFactory2;
203 mPrivateFactory = original.mPrivateFactory;
204 mFilter = original.mFilter;
205 }
206
207 /**
208 * Obtains the LayoutInflater from the given context.
209 */
210 public static LayoutInflater from(Context context) {
211 LayoutInflater LayoutInflater =
212 (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
213 if (LayoutInflater == null) {
214 throw new AssertionError("LayoutInflater not found.");
215 }
216 return LayoutInflater;
217 }
218
219 /**
220 * Create a copy of the existing LayoutInflater object, with the copy
221 * pointing to a different Context than the original. This is used by
222 * {@link ContextThemeWrapper} to create a new LayoutInflater to go along
223 * with the new Context theme.
224 *
225 * @param newContext The new Context to associate with the new LayoutInflater.
226 * May be the same as the original Context if desired.
227 *
228 * @return Returns a brand spanking new LayoutInflater object associated with
229 * the given Context.
230 */
231 public abstract LayoutInflater cloneInContext(Context newContext);
232
233 /**
234 * Return the context we are running in, for access to resources, class
235 * loader, etc.
236 */
237 public Context getContext() {
238 return mContext;
239 }
240
241 /**
242 * Return the current {@link Factory} (or null). This is called on each element
243 * name. If the factory returns a View, add that to the hierarchy. If it
244 * returns null, proceed to call onCreateView(name).
245 */
246 public final Factory getFactory() {
247 return mFactory;
248 }
249
250 /**
251 * Return the current {@link Factory2}. Returns null if no factory is set
252 * or the set factory does not implement the {@link Factory2} interface.
253 * This is called on each element
254 * name. If the factory returns a View, add that to the hierarchy. If it
255 * returns null, proceed to call onCreateView(name).
256 */
257 public final Factory2 getFactory2() {
258 return mFactory2;
259 }
260
261 /**
262 * Attach a custom Factory interface for creating views while using
263 * this LayoutInflater. This must not be null, and can only be set once;
264 * after setting, you can not change the factory. This is
265 * called on each element name as the xml is parsed. If the factory returns
266 * a View, that is added to the hierarchy. If it returns null, the next
267 * factory default {@link #onCreateView} method is called.
268 *
269 * <p>If you have an existing
270 * LayoutInflater and want to add your own factory to it, use
271 * {@link #cloneInContext} to clone the existing instance and then you
272 * can use this function (once) on the returned new instance. This will
273 * merge your own factory with whatever factory the original instance is
274 * using.
275 */
276 public void setFactory(Factory factory) {
277 if (mFactorySet) {
278 throw new IllegalStateException("A factory has already been set on this LayoutInflater");
279 }
280 if (factory == null) {
281 throw new NullPointerException("Given factory can not be null");
282 }
283 mFactorySet = true;
284 if (mFactory == null) {
285 mFactory = factory;
286 } else {
287 mFactory = new FactoryMerger(factory, null, mFactory, mFactory2);
288 }
289 }
290
291 /**
292 * Like {@link #setFactory}, but allows you to set a {@link Factory2}
293 * interface.
294 */
295 public void setFactory2(Factory2 factory) {
296 if (mFactorySet) {
297 throw new IllegalStateException("A factory has already been set on this LayoutInflater");
298 }
299 if (factory == null) {
300 throw new NullPointerException("Given factory can not be null");
301 }
302 mFactorySet = true;
303 if (mFactory == null) {
304 mFactory = mFactory2 = factory;
305 } else {
306 mFactory = new FactoryMerger(factory, factory, mFactory, mFactory2);
307 }
308 }
309
310 /**
311 * @hide for use by framework
312 */
313 public void setPrivateFactory(Factory2 factory) {
314 mPrivateFactory = factory;
315 }
316
317 /**
318 * @return The {@link Filter} currently used by this LayoutInflater to restrict the set of Views
319 * that are allowed to be inflated.
320 */
321 public Filter getFilter() {
322 return mFilter;
323 }
324
325 /**
326 * Sets the {@link Filter} to by this LayoutInflater. If a view is attempted to be inflated
327 * which is not allowed by the {@link Filter}, the {@link #inflate(int, ViewGroup)} call will
328 * throw an {@link InflateException}. This filter will replace any previous filter set on this
329 * LayoutInflater.
330 *
331 * @param filter The Filter which restricts the set of Views that are allowed to be inflated.
332 * This filter will replace any previous filter set on this LayoutInflater.
333 */
334 public void setFilter(Filter filter) {
335 mFilter = filter;
336 if (filter != null) {
337 mFilterMap = new HashMap<String, Boolean>();
338 }
339 }
340
341 /**
342 * Inflate a new view hierarchy from the specified xml resource. Throws
343 * {@link InflateException} if there is an error.
344 *
345 * @param resource ID for an XML layout resource to load (e.g.,
346 * <code>R.layout.main_page</code>)
347 * @param root Optional view to be the parent of the generated hierarchy.
348 * @return The root View of the inflated hierarchy. If root was supplied,
349 * this is the root View; otherwise it is the root of the inflated
350 * XML file.
351 */
352 public View inflate(int resource, ViewGroup root) {
353 return inflate(resource, root, root != null);
354 }
355
356 /**
357 * Inflate a new view hierarchy from the specified xml node. Throws
358 * {@link InflateException} if there is an error. *
359 * <p>
360 * <em><strong>Important</strong></em> For performance
361 * reasons, view inflation relies heavily on pre-processing of XML files
362 * that is done at build time. Therefore, it is not currently possible to
363 * use LayoutInflater with an XmlPullParser over a plain XML file at runtime.
364 *
365 * @param parser XML dom node containing the description of the view
366 * hierarchy.
367 * @param root Optional view to be the parent of the generated hierarchy.
368 * @return The root View of the inflated hierarchy. If root was supplied,
369 * this is the root View; otherwise it is the root of the inflated
370 * XML file.
371 */
372 public View inflate(XmlPullParser parser, ViewGroup root) {
373 return inflate(parser, root, root != null);
374 }
375
376 /**
377 * Inflate a new view hierarchy from the specified xml resource. Throws
378 * {@link InflateException} if there is an error.
379 *
380 * @param resource ID for an XML layout resource to load (e.g.,
381 * <code>R.layout.main_page</code>)
382 * @param root Optional view to be the parent of the generated hierarchy (if
383 * <em>attachToRoot</em> is true), or else simply an object that
384 * provides a set of LayoutParams values for root of the returned
385 * hierarchy (if <em>attachToRoot</em> is false.)
386 * @param attachToRoot Whether the inflated hierarchy should be attached to
387 * the root parameter? If false, root is only used to create the
388 * correct subclass of LayoutParams for the root view in the XML.
389 * @return The root View of the inflated hierarchy. If root was supplied and
390 * attachToRoot is true, this is root; otherwise it is the root of
391 * the inflated XML file.
392 */
393 public View inflate(int resource, ViewGroup root, boolean attachToRoot) {
394 if (DEBUG) System.out.println("INFLATING from resource: " + resource);
395 XmlResourceParser parser = getContext().getResources().getLayout(resource);
396 try {
397 return inflate(parser, root, attachToRoot);
398 } finally {
399 parser.close();
400 }
401 }
402
403 /**
404 * Inflate a new view hierarchy from the specified XML node. Throws
405 * {@link InflateException} if there is an error.
406 * <p>
407 * <em><strong>Important</strong></em> For performance
408 * reasons, view inflation relies heavily on pre-processing of XML files
409 * that is done at build time. Therefore, it is not currently possible to
410 * use LayoutInflater with an XmlPullParser over a plain XML file at runtime.
411 *
412 * @param parser XML dom node containing the description of the view
413 * hierarchy.
414 * @param root Optional view to be the parent of the generated hierarchy (if
415 * <em>attachToRoot</em> is true), or else simply an object that
416 * provides a set of LayoutParams values for root of the returned
417 * hierarchy (if <em>attachToRoot</em> is false.)
418 * @param attachToRoot Whether the inflated hierarchy should be attached to
419 * the root parameter? If false, root is only used to create the
420 * correct subclass of LayoutParams for the root view in the XML.
421 * @return The root View of the inflated hierarchy. If root was supplied and
422 * attachToRoot is true, this is root; otherwise it is the root of
423 * the inflated XML file.
424 */
425 public View inflate(XmlPullParser parser, ViewGroup root, boolean attachToRoot) {
426 synchronized (mConstructorArgs) {
427 Trace.traceBegin(Trace.TRACE_TAG_VIEW, "inflate");
428
429 final AttributeSet attrs = Xml.asAttributeSet(parser);
430 Context lastContext = (Context)mConstructorArgs[0];
431 mConstructorArgs[0] = mContext;
432 View result = root;
433
434 try {
435 // Look for the root node.
436 int type;
437 while ((type = parser.next()) != XmlPullParser.START_TAG &&
438 type != XmlPullParser.END_DOCUMENT) {
439 // Empty
440 }
441
442 if (type != XmlPullParser.START_TAG) {
443 throw new InflateException(parser.getPositionDescription()
444 + ": No start tag found!");
445 }
446
447 final String name = parser.getName();
448
449 if (DEBUG) {
450 System.out.println("**************************");
451 System.out.println("Creating root view: "
452 + name);
453 System.out.println("**************************");
454 }
455
456 if (TAG_MERGE.equals(name)) {
457 if (root == null || !attachToRoot) {
458 throw new InflateException("<merge /> can be used only with a valid "
459 + "ViewGroup root and attachToRoot=true");
460 }
461
462 rInflate(parser, root, attrs, false);
463 } else {
464 // Temp is the root view that was found in the xml
465 View temp;
466 if (TAG_1995.equals(name)) {
467 temp = new BlinkLayout(mContext, attrs);
468 } else {
469 temp = createViewFromTag(root, name, attrs);
470 }
471
472 ViewGroup.LayoutParams params = null;
473
474 if (root != null) {
475 if (DEBUG) {
476 System.out.println("Creating params from root: " +
477 root);
478 }
479 // Create layout params that match root, if supplied
480 params = root.generateLayoutParams(attrs);
481 if (!attachToRoot) {
482 // Set the layout params for temp if we are not
483 // attaching. (If we are, we use addView, below)
484 temp.setLayoutParams(params);
485 }
486 }
487
488 if (DEBUG) {
489 System.out.println("-----> start inflating children");
490 }
491 // Inflate all children under temp
492 rInflate(parser, temp, attrs, true);
493 if (DEBUG) {
494 System.out.println("-----> done inflating children");
495 }
496
497 // We are supposed to attach all the views we found (int temp)
498 // to root. Do that now.
499 if (root != null && attachToRoot) {
500 root.addView(temp, params);
501 }
502
503 // Decide whether to return the root that was passed in or the
504 // top view found in xml.
505 if (root == null || !attachToRoot) {
506 result = temp;
507 }
508 }
509
510 } catch (XmlPullParserException e) {
511 InflateException ex = new InflateException(e.getMessage());
512 ex.initCause(e);
513 throw ex;
514 } catch (IOException e) {
515 InflateException ex = new InflateException(
516 parser.getPositionDescription()
517 + ": " + e.getMessage());
518 ex.initCause(e);
519 throw ex;
520 } finally {
521 // Don't retain static reference on context.
522 mConstructorArgs[0] = lastContext;
523 mConstructorArgs[1] = null;
524 }
525
526 Trace.traceEnd(Trace.TRACE_TAG_VIEW);
527
528 return result;
529 }
530 }
531
532 /**
533 * Low-level function for instantiating a view by name. This attempts to
534 * instantiate a view class of the given <var>name</var> found in this
535 * LayoutInflater's ClassLoader.
536 *
537 * <p>
538 * There are two things that can happen in an error case: either the
539 * exception describing the error will be thrown, or a null will be
540 * returned. You must deal with both possibilities -- the former will happen
541 * the first time createView() is called for a class of a particular name,
542 * the latter every time there-after for that class name.
543 *
544 * @param name The full name of the class to be instantiated.
545 * @param attrs The XML attributes supplied for this instance.
546 *
547 * @return View The newly instantiated view, or null.
548 */
549 public final View createView(String name, String prefix, AttributeSet attrs)
550 throws ClassNotFoundException, InflateException {
551 Constructor<? extends View> constructor = sConstructorMap.get(name);
552 Class<? extends View> clazz = null;
553
554 try {
555 Trace.traceBegin(Trace.TRACE_TAG_VIEW, name);
556
557 if (constructor == null) {
558 // Class not found in the cache, see if it's real, and try to add it
559 clazz = mContext.getClassLoader().loadClass(
560 prefix != null ? (prefix + name) : name).asSubclass(View.class);
561
562 if (mFilter != null && clazz != null) {
563 boolean allowed = mFilter.onLoadClass(clazz);
564 if (!allowed) {
565 failNotAllowed(name, prefix, attrs);
566 }
567 }
568 constructor = clazz.getConstructor(mConstructorSignature);
569 sConstructorMap.put(name, constructor);
570 } else {
571 // If we have a filter, apply it to cached constructor
572 if (mFilter != null) {
573 // Have we seen this name before?
574 Boolean allowedState = mFilterMap.get(name);
575 if (allowedState == null) {
576 // New class -- remember whether it is allowed
577 clazz = mContext.getClassLoader().loadClass(
578 prefix != null ? (prefix + name) : name).asSubclass(View.class);
579
580 boolean allowed = clazz != null && mFilter.onLoadClass(clazz);
581 mFilterMap.put(name, allowed);
582 if (!allowed) {
583 failNotAllowed(name, prefix, attrs);
584 }
585 } else if (allowedState.equals(Boolean.FALSE)) {
586 failNotAllowed(name, prefix, attrs);
587 }
588 }
589 }
590
591 Object[] args = mConstructorArgs;
592 args[1] = attrs;
593
594 final View view = constructor.newInstance(args);
595 if (view instanceof ViewStub) {
596 // always use ourselves when inflating ViewStub later
597 final ViewStub viewStub = (ViewStub) view;
598 viewStub.setLayoutInflater(this);
599 }
600 return view;
601
602 } catch (NoSuchMethodException e) {
603 InflateException ie = new InflateException(attrs.getPositionDescription()
604 + ": Error inflating class "
605 + (prefix != null ? (prefix + name) : name));
606 ie.initCause(e);
607 throw ie;
608
609 } catch (ClassCastException e) {
610 // If loaded class is not a View subclass
611 InflateException ie = new InflateException(attrs.getPositionDescription()
612 + ": Class is not a View "
613 + (prefix != null ? (prefix + name) : name));
614 ie.initCause(e);
615 throw ie;
616 } catch (ClassNotFoundException e) {
617 // If loadClass fails, we should propagate the exception.
618 throw e;
619 } catch (Exception e) {
620 InflateException ie = new InflateException(attrs.getPositionDescription()
621 + ": Error inflating class "
622 + (clazz == null ? "<unknown>" : clazz.getName()));
623 ie.initCause(e);
624 throw ie;
625 } finally {
626 Trace.traceEnd(Trace.TRACE_TAG_VIEW);
627 }
628 }
629
630 /**
631 * Throw an exception because the specified class is not allowed to be inflated.
632 */
633 private void failNotAllowed(String name, String prefix, AttributeSet attrs) {
634 throw new InflateException(attrs.getPositionDescription()
635 + ": Class not allowed to be inflated "
636 + (prefix != null ? (prefix + name) : name));
637 }
638
639 /**
640 * This routine is responsible for creating the correct subclass of View
641 * given the xml element name. Override it to handle custom view objects. If
642 * you override this in your subclass be sure to call through to
643 * super.onCreateView(name) for names you do not recognize.
644 *
645 * @param name The fully qualified class name of the View to be create.
646 * @param attrs An AttributeSet of attributes to apply to the View.
647 *
648 * @return View The View created.
649 */
650 protected View onCreateView(String name, AttributeSet attrs)
651 throws ClassNotFoundException {
652 return createView(name, "android.view.", attrs);
653 }
654
655 /**
656 * Version of {@link #onCreateView(String, AttributeSet)} that also
657 * takes the future parent of the view being constructed. The default
658 * implementation simply calls {@link #onCreateView(String, AttributeSet)}.
659 *
660 * @param parent The future parent of the returned view. <em>Note that
661 * this may be null.</em>
662 * @param name The fully qualified class name of the View to be create.
663 * @param attrs An AttributeSet of attributes to apply to the View.
664 *
665 * @return View The View created.
666 */
667 protected View onCreateView(View parent, String name, AttributeSet attrs)
668 throws ClassNotFoundException {
669 return onCreateView(name, attrs);
670 }
671
672 /*
673 * default visibility so the BridgeInflater can override it.
674 */
675 View createViewFromTag(View parent, String name, AttributeSet attrs) {
676 if (name.equals("view")) {
677 name = attrs.getAttributeValue(null, "class");
678 }
679
680 if (DEBUG) System.out.println("******** Creating view: " + name);
681
682 try {
683 View view;
684 if (mFactory2 != null) view = mFactory2.onCreateView(parent, name, mContext, attrs);
685 else if (mFactory != null) view = mFactory.onCreateView(name, mContext, attrs);
686 else view = null;
687
688 if (view == null && mPrivateFactory != null) {
689 view = mPrivateFactory.onCreateView(parent, name, mContext, attrs);
690 }
691
692 if (view == null) {
693 if (-1 == name.indexOf('.')) {
694 view = onCreateView(parent, name, attrs);
695 } else {
696 view = createView(name, null, attrs);
697 }
698 }
699
700 if (DEBUG) System.out.println("Created view is: " + view);
701 return view;
702
703 } catch (InflateException e) {
704 throw e;
705
706 } catch (ClassNotFoundException e) {
707 InflateException ie = new InflateException(attrs.getPositionDescription()
708 + ": Error inflating class " + name);
709 ie.initCause(e);
710 throw ie;
711
712 } catch (Exception e) {
713 InflateException ie = new InflateException(attrs.getPositionDescription()
714 + ": Error inflating class " + name);
715 ie.initCause(e);
716 throw ie;
717 }
718 }
719
720 /**
721 * Recursive method used to descend down the xml hierarchy and instantiate
722 * views, instantiate their children, and then call onFinishInflate().
723 */
724 void rInflate(XmlPullParser parser, View parent, final AttributeSet attrs,
725 boolean finishInflate) throws XmlPullParserException, IOException {
726
727 final int depth = parser.getDepth();
728 int type;
729
730 while (((type = parser.next()) != XmlPullParser.END_TAG ||
731 parser.getDepth() > depth) && type != XmlPullParser.END_DOCUMENT) {
732
733 if (type != XmlPullParser.START_TAG) {
734 continue;
735 }
736
737 final String name = parser.getName();
738
739 if (TAG_REQUEST_FOCUS.equals(name)) {
740 parseRequestFocus(parser, parent);
741 } else if (TAG_INCLUDE.equals(name)) {
742 if (parser.getDepth() == 0) {
743 throw new InflateException("<include /> cannot be the root element");
744 }
745 parseInclude(parser, parent, attrs);
746 } else if (TAG_MERGE.equals(name)) {
747 throw new InflateException("<merge /> must be the root element");
748 } else if (TAG_1995.equals(name)) {
749 final View view = new BlinkLayout(mContext, attrs);
750 final ViewGroup viewGroup = (ViewGroup) parent;
751 final ViewGroup.LayoutParams params = viewGroup.generateLayoutParams(attrs);
752 rInflate(parser, view, attrs, true);
753 viewGroup.addView(view, params);
754 } else {
755 final View view = createViewFromTag(parent, name, attrs);
756 final ViewGroup viewGroup = (ViewGroup) parent;
757 final ViewGroup.LayoutParams params = viewGroup.generateLayoutParams(attrs);
758 rInflate(parser, view, attrs, true);
759 viewGroup.addView(view, params);
760 }
761 }
762
763 if (finishInflate) parent.onFinishInflate();
764 }
765
766 private void parseRequestFocus(XmlPullParser parser, View parent)
767 throws XmlPullParserException, IOException {
768 int type;
769 parent.requestFocus();
770 final int currentDepth = parser.getDepth();
771 while (((type = parser.next()) != XmlPullParser.END_TAG ||
772 parser.getDepth() > currentDepth) && type != XmlPullParser.END_DOCUMENT) {
773 // Empty
774 }
775 }
776
777 private void parseInclude(XmlPullParser parser, View parent, AttributeSet attrs)
778 throws XmlPullParserException, IOException {
779
780 int type;
781
782 if (parent instanceof ViewGroup) {
783 final int layout = attrs.getAttributeResourceValue(null, "layout", 0);
784 if (layout == 0) {
785 final String value = attrs.getAttributeValue(null, "layout");
786 if (value == null) {
787 throw new InflateException("You must specifiy a layout in the"
788 + " include tag: <include layout=\"@layout/layoutID\" />");
789 } else {
790 throw new InflateException("You must specifiy a valid layout "
791 + "reference. The layout ID " + value + " is not valid.");
792 }
793 } else {
794 final XmlResourceParser childParser =
795 getContext().getResources().getLayout(layout);
796
797 try {
798 final AttributeSet childAttrs = Xml.asAttributeSet(childParser);
799
800 while ((type = childParser.next()) != XmlPullParser.START_TAG &&
801 type != XmlPullParser.END_DOCUMENT) {
802 // Empty.
803 }
804
805 if (type != XmlPullParser.START_TAG) {
806 throw new InflateException(childParser.getPositionDescription() +
807 ": No start tag found!");
808 }
809
810 final String childName = childParser.getName();
811
812 if (TAG_MERGE.equals(childName)) {
813 // Inflate all children.
814 rInflate(childParser, parent, childAttrs, false);
815 } else {
816 final View view = createViewFromTag(parent, childName, childAttrs);
817 final ViewGroup group = (ViewGroup) parent;
818
819 // We try to load the layout params set in the <include /> tag. If
820 // they don't exist, we will rely on the layout params set in the
821 // included XML file.
822 // During a layoutparams generation, a runtime exception is thrown
823 // if either layout_width or layout_height is missing. We catch
824 // this exception and set localParams accordingly: true means we
825 // successfully loaded layout params from the <include /> tag,
826 // false means we need to rely on the included layout params.
827 ViewGroup.LayoutParams params = null;
828 try {
829 params = group.generateLayoutParams(attrs);
830 } catch (RuntimeException e) {
831 params = group.generateLayoutParams(childAttrs);
832 } finally {
833 if (params != null) {
834 view.setLayoutParams(params);
835 }
836 }
837
838 // Inflate all children.
839 rInflate(childParser, view, childAttrs, true);
840
841 // Attempt to override the included layout's android:id with the
842 // one set on the <include /> tag itself.
843 TypedArray a = mContext.obtainStyledAttributes(attrs,
844 com.android.internal.R.styleable.View, 0, 0);
845 int id = a.getResourceId(com.android.internal.R.styleable.View_id, View.NO_ID);
846 // While we're at it, let's try to override android:visibility.
847 int visibility = a.getInt(com.android.internal.R.styleable.View_visibility, -1);
848 a.recycle();
849
850 if (id != View.NO_ID) {
851 view.setId(id);
852 }
853
854 switch (visibility) {
855 case 0:
856 view.setVisibility(View.VISIBLE);
857 break;
858 case 1:
859 view.setVisibility(View.INVISIBLE);
860 break;
861 case 2:
862 view.setVisibility(View.GONE);
863 break;
864 }
865
866 group.addView(view);
867 }
868 } finally {
869 childParser.close();
870 }
871 }
872 } else {
873 throw new InflateException("<include /> can only be used inside of a ViewGroup");
874 }
875
876 final int currentDepth = parser.getDepth();
877 while (((type = parser.next()) != XmlPullParser.END_TAG ||
878 parser.getDepth() > currentDepth) && type != XmlPullParser.END_DOCUMENT) {
879 // Empty
880 }
881 }
882
883 private static class BlinkLayout extends FrameLayout {
884 private static final int MESSAGE_BLINK = 0x42;
885 private static final int BLINK_DELAY = 500;
886
887 private boolean mBlink;
888 private boolean mBlinkState;
889 private final Handler mHandler;
890
891 public BlinkLayout(Context context, AttributeSet attrs) {
892 super(context, attrs);
893 mHandler = new Handler(new Handler.Callback() {
894 @Override
895 public boolean handleMessage(Message msg) {
896 if (msg.what == MESSAGE_BLINK) {
897 if (mBlink) {
898 mBlinkState = !mBlinkState;
899 makeBlink();
900 }
901 invalidate();
902 return true;
903 }
904 return false;
905 }
906 });
907 }
908
909 private void makeBlink() {
910 Message message = mHandler.obtainMessage(MESSAGE_BLINK);
911 mHandler.sendMessageDelayed(message, BLINK_DELAY);
912 }
913
914 @Override
915 protected void onAttachedToWindow() {
916 super.onAttachedToWindow();
917
918 mBlink = true;
919 mBlinkState = true;
920
921 makeBlink();
922 }
923
924 @Override
925 protected void onDetachedFromWindow() {
926 super.onDetachedFromWindow();
927
928 mBlink = false;
929 mBlinkState = true;
930
931 mHandler.removeMessages(MESSAGE_BLINK);
932 }
933
934 @Override
935 protected void dispatchDraw(Canvas canvas) {
936 if (mBlinkState) {
937 super.dispatchDraw(canvas);
938 }
939 }
940 }
941 }
