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/*
* Copyright (C) 2007 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.view;
import android.annotation.LayoutRes;
import android.annotation.NonNull;
import android.annotation.Nullable;
import android.annotation.SystemService;
import android.annotation.TestApi;
import android.annotation.UiContext;
import android.compat.annotation.UnsupportedAppUsage;
import android.content.Context;
import android.content.pm.ApplicationInfo;
import android.content.res.Resources;
import android.content.res.TypedArray;
import android.content.res.XmlResourceParser;
import android.graphics.Canvas;
import android.os.Build;
import android.os.Handler;
import android.os.Message;
import android.os.StrictMode;
import android.os.Trace;
import android.util.AttributeSet;
import android.util.Log;
import android.util.TypedValue;
import android.util.Xml;
import android.widget.FrameLayout;
import com.android.internal.R;
import dalvik.system.PathClassLoader;
import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
import java.io.File;
import java.io.IOException;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Objects;
/**
* Instantiates a layout XML file into its corresponding {@link android.view.View}
* objects. It is never used directly. Instead, use
* {@link android.app.Activity#getLayoutInflater()} or
* {@link Context#getSystemService} to retrieve a standard LayoutInflater instance
* that is already hooked up to the current context and correctly configured
* for the device you are running on.
*
* To create a new LayoutInflater with an additional {@link Factory} for your
* own views, you can use {@link #cloneInContext} to clone an existing
* ViewFactory, and then call {@link #setFactory} on it to include your
* Factory.
*
* For performance reasons, view inflation relies heavily on pre-processing of
* XML files that is done at build time. Therefore, it is not currently possible
* to use LayoutInflater with an XmlPullParser over a plain XML file at runtime;
* it only works with an XmlPullParser returned from a compiled resource
* (R.something file.)
*
* Note: This class is not thread-safe and a given
* instance should only be accessed by a single thread.
*/
@SystemService(Context.LAYOUT_INFLATER_SERVICE)
public abstract class LayoutInflater {
private static final String TAG = LayoutInflater.class.getSimpleName();
private static final boolean DEBUG = false;
private static final String COMPILED_VIEW_DEX_FILE_NAME = "/compiled_view.dex";
/**
* Whether or not we use the precompiled layout.
*/
private static final String USE_PRECOMPILED_LAYOUT = "view.precompiled_layout_enabled";
/** Empty stack trace used to avoid log spam in re-throw exceptions. */
private static final StackTraceElement[] EMPTY_STACK_TRACE = new StackTraceElement[0];
/**
* This field should be made private, so it is hidden from the SDK.
* {@hide}
*/
// TODO(b/182007470): Use @ConfigurationContext instead
@UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P)
@UiContext
protected final Context mContext;
// these are optional, set by the caller
/**
* If any developer has desire to change this value, they should instead use
* {@link #cloneInContext(Context)} and set the new factory in thew newly-created
* LayoutInflater.
*/
@UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P)
private boolean mFactorySet;
@UnsupportedAppUsage
private Factory mFactory;
@UnsupportedAppUsage
private Factory2 mFactory2;
@UnsupportedAppUsage
private Factory2 mPrivateFactory;
private Filter mFilter;
// Indicates whether we should try to inflate layouts using a precompiled layout instead of
// inflating from the XML resource.
private boolean mUseCompiledView;
// This variable holds the classloader that will be used to look for precompiled layouts. The
// The classloader includes the generated compiled_view.dex file.
private ClassLoader mPrecompiledClassLoader;
/**
* This is not a public API. Two APIs are now available to alleviate the need to access
* this directly: {@link #createView(Context, String, String, AttributeSet)} and
* {@link #onCreateView(Context, View, String, AttributeSet)}.
*/
@UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P)
final Object[] mConstructorArgs = new Object[2];
@UnsupportedAppUsage
static final Class[] mConstructorSignature = new Class[] {
Context.class, AttributeSet.class};
@UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.P, trackingBug = 123769490)
private static final HashMap> sConstructorMap =
new HashMap>();
private HashMap mFilterMap;
private TypedValue mTempValue;
private static final String TAG_MERGE = "merge";
private static final String TAG_INCLUDE = "include";
private static final String TAG_1995 = "blink";
private static final String TAG_REQUEST_FOCUS = "requestFocus";
private static final String TAG_TAG = "tag";
private static final String ATTR_LAYOUT = "layout";
@UnsupportedAppUsage
private static final int[] ATTRS_THEME = new int[] {
com.android.internal.R.attr.theme };
/**
* Hook to allow clients of the LayoutInflater to restrict the set of Views that are allowed
* to be inflated.
*
*/
public interface Filter {
/**
* Hook to allow clients of the LayoutInflater to restrict the set of Views
* that are allowed to be inflated.
*
* @param clazz The class object for the View that is about to be inflated
*
* @return True if this class is allowed to be inflated, or false otherwise
*/
@SuppressWarnings("unchecked")
boolean onLoadClass(Class clazz);
}
public interface Factory {
/**
* Hook you can supply that is called when inflating from a LayoutInflater.
* You can use this to customize the tag names available in your XML
* layout files.
*
*
* Note that it is good practice to prefix these custom names with your
* package (i.e., com.coolcompany.apps) to avoid conflicts with system
* names.
*
* @param name Tag name to be inflated.
* @param context The context the view is being created in.
* @param attrs Inflation attributes as specified in XML file.
*
* @return View Newly created view. Return null for the default
* behavior.
*/
@Nullable
View onCreateView(@NonNull String name, @NonNull Context context,
@NonNull AttributeSet attrs);
}
public interface Factory2 extends Factory {
/**
* Version of {@link #onCreateView(String, Context, AttributeSet)}
* that also supplies the parent that the view created view will be
* placed in.
*
* @param parent The parent that the created view will be placed
* in; note that this may be null.
* @param name Tag name to be inflated.
* @param context The context the view is being created in.
* @param attrs Inflation attributes as specified in XML file.
*
* @return View Newly created view. Return null for the default
* behavior.
*/
@Nullable
View onCreateView(@Nullable View parent, @NonNull String name,
@NonNull Context context, @NonNull AttributeSet attrs);
}
private static class FactoryMerger implements Factory2 {
private final Factory mF1, mF2;
private final Factory2 mF12, mF22;
FactoryMerger(Factory f1, Factory2 f12, Factory f2, Factory2 f22) {
mF1 = f1;
mF2 = f2;
mF12 = f12;
mF22 = f22;
}
@Nullable
public View onCreateView(@NonNull String name, @NonNull Context context,
@NonNull AttributeSet attrs) {
View v = mF1.onCreateView(name, context, attrs);
if (v != null) return v;
return mF2.onCreateView(name, context, attrs);
}
@Nullable
public View onCreateView(@Nullable View parent, @NonNull String name,
@NonNull Context context, @NonNull AttributeSet attrs) {
View v = mF12 != null ? mF12.onCreateView(parent, name, context, attrs)
: mF1.onCreateView(name, context, attrs);
if (v != null) return v;
return mF22 != null ? mF22.onCreateView(parent, name, context, attrs)
: mF2.onCreateView(name, context, attrs);
}
}
/**
* Create a new LayoutInflater instance associated with a particular Context.
* Applications will almost always want to use
* {@link Context#getSystemService Context.getSystemService()} to retrieve
* the standard {@link Context#LAYOUT_INFLATER_SERVICE Context.INFLATER_SERVICE}.
*
* @param context The Context in which this LayoutInflater will create its
* Views; most importantly, this supplies the theme from which the default
* values for their attributes are retrieved.
*/
protected LayoutInflater(Context context) {
StrictMode.assertConfigurationContext(context, "LayoutInflater");
mContext = context;
initPrecompiledViews();
}
/**
* Create a new LayoutInflater instance that is a copy of an existing
* LayoutInflater, optionally with its Context changed. For use in
* implementing {@link #cloneInContext}.
*
* @param original The original LayoutInflater to copy.
* @param newContext The new Context to use.
*/
protected LayoutInflater(LayoutInflater original, Context newContext) {
StrictMode.assertConfigurationContext(newContext, "LayoutInflater");
mContext = newContext;
mFactory = original.mFactory;
mFactory2 = original.mFactory2;
mPrivateFactory = original.mPrivateFactory;
setFilter(original.mFilter);
initPrecompiledViews();
}
/**
* Obtains the LayoutInflater from the given context.
*/
public static LayoutInflater from(@UiContext Context context) {
LayoutInflater LayoutInflater =
(LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
if (LayoutInflater == null) {
throw new AssertionError("LayoutInflater not found.");
}
return LayoutInflater;
}
/**
* Create a copy of the existing LayoutInflater object, with the copy
* pointing to a different Context than the original. This is used by
* {@link ContextThemeWrapper} to create a new LayoutInflater to go along
* with the new Context theme.
*
* @param newContext The new Context to associate with the new LayoutInflater.
* May be the same as the original Context if desired.
*
* @return Returns a brand spanking new LayoutInflater object associated with
* the given Context.
*/
public abstract LayoutInflater cloneInContext(Context newContext);
/**
* Return the context we are running in, for access to resources, class
* loader, etc.
*/
public Context getContext() {
return mContext;
}
/**
* Return the current {@link Factory} (or null). This is called on each element
* name. If the factory returns a View, add that to the hierarchy. If it
* returns null, proceed to call onCreateView(name).
*/
public final Factory getFactory() {
return mFactory;
}
/**
* Return the current {@link Factory2}. Returns null if no factory is set
* or the set factory does not implement the {@link Factory2} interface.
* This is called on each element
* name. If the factory returns a View, add that to the hierarchy. If it
* returns null, proceed to call onCreateView(name).
*/
public final Factory2 getFactory2() {
return mFactory2;
}
/**
* Attach a custom Factory interface for creating views while using
* this LayoutInflater. This must not be null, and can only be set once;
* after setting, you can not change the factory. This is
* called on each element name as the xml is parsed. If the factory returns
* a View, that is added to the hierarchy. If it returns null, the next
* factory default {@link #onCreateView} method is called.
*
*
If you have an existing
* LayoutInflater and want to add your own factory to it, use
* {@link #cloneInContext} to clone the existing instance and then you
* can use this function (once) on the returned new instance. This will
* merge your own factory with whatever factory the original instance is
* using.
*/
public void setFactory(Factory factory) {
if (mFactorySet) {
throw new IllegalStateException("A factory has already been set on this LayoutInflater");
}
if (factory == null) {
throw new NullPointerException("Given factory can not be null");
}
mFactorySet = true;
if (mFactory == null) {
mFactory = factory;
} else {
mFactory = new FactoryMerger(factory, null, mFactory, mFactory2);
}
}
/**
* Like {@link #setFactory}, but allows you to set a {@link Factory2}
* interface.
*/
public void setFactory2(Factory2 factory) {
if (mFactorySet) {
throw new IllegalStateException("A factory has already been set on this LayoutInflater");
}
if (factory == null) {
throw new NullPointerException("Given factory can not be null");
}
mFactorySet = true;
if (mFactory == null) {
mFactory = mFactory2 = factory;
} else {
mFactory = mFactory2 = new FactoryMerger(factory, factory, mFactory, mFactory2);
}
}
/**
* @hide for use by framework
*/
@UnsupportedAppUsage
public void setPrivateFactory(Factory2 factory) {
if (mPrivateFactory == null) {
mPrivateFactory = factory;
} else {
mPrivateFactory = new FactoryMerger(factory, factory, mPrivateFactory, mPrivateFactory);
}
}
/**
* @return The {@link Filter} currently used by this LayoutInflater to restrict the set of Views
* that are allowed to be inflated.
*/
public Filter getFilter() {
return mFilter;
}
/**
* Sets the {@link Filter} to by this LayoutInflater. If a view is attempted to be inflated
* which is not allowed by the {@link Filter}, the {@link #inflate(int, ViewGroup)} call will
* throw an {@link InflateException}. This filter will replace any previous filter set on this
* LayoutInflater.
*
* @param filter The Filter which restricts the set of Views that are allowed to be inflated.
* This filter will replace any previous filter set on this LayoutInflater.
*/
public void setFilter(Filter filter) {
mFilter = filter;
if (filter != null) {
mFilterMap = new HashMap();
}
}
private void initPrecompiledViews() {
// Precompiled layouts are not supported in this release.
boolean enabled = false;
initPrecompiledViews(enabled);
}
private void initPrecompiledViews(boolean enablePrecompiledViews) {
mUseCompiledView = enablePrecompiledViews;
if (!mUseCompiledView) {
mPrecompiledClassLoader = null;
return;
}
// Make sure the application allows code generation
ApplicationInfo appInfo = mContext.getApplicationInfo();
if (appInfo.isEmbeddedDexUsed() || appInfo.isPrivilegedApp()) {
mUseCompiledView = false;
return;
}
// Try to load the precompiled layout file.
try {
mPrecompiledClassLoader = mContext.getClassLoader();
String dexFile = mContext.getCodeCacheDir() + COMPILED_VIEW_DEX_FILE_NAME;
if (new File(dexFile).exists()) {
mPrecompiledClassLoader = new PathClassLoader(dexFile, mPrecompiledClassLoader);
} else {
// If the precompiled layout file doesn't exist, then disable precompiled
// layouts.
mUseCompiledView = false;
}
} catch (Throwable e) {
if (DEBUG) {
Log.e(TAG, "Failed to initialized precompiled views layouts", e);
}
mUseCompiledView = false;
}
if (!mUseCompiledView) {
mPrecompiledClassLoader = null;
}
}
/**
* @hide for use by CTS tests
*/
@TestApi
public void setPrecompiledLayoutsEnabledForTesting(boolean enablePrecompiledLayouts) {
initPrecompiledViews(enablePrecompiledLayouts);
}
/**
* Inflate a new view hierarchy from the specified xml resource. Throws
* {@link InflateException} if there is an error.
*
* @param resource ID for an XML layout resource to load (e.g.,
* R.layout.main_page)
* @param root Optional view to be the parent of the generated hierarchy.
* @return The root View of the inflated hierarchy. If root was supplied,
* this is the root View; otherwise it is the root of the inflated
* XML file.
*/
public View inflate(@LayoutRes int resource, @Nullable ViewGroup root) {
return inflate(resource, root, root != null);
}
/**
* Inflate a new view hierarchy from the specified xml node. Throws
* {@link InflateException} if there is an error. *
*
* Important For performance
* reasons, view inflation relies heavily on pre-processing of XML files
* that is done at build time. Therefore, it is not currently possible to
* use LayoutInflater with an XmlPullParser over a plain XML file at runtime.
*
* @param parser XML dom node containing the description of the view
* hierarchy.
* @param root Optional view to be the parent of the generated hierarchy.
* @return The root View of the inflated hierarchy. If root was supplied,
* this is the root View; otherwise it is the root of the inflated
* XML file.
*/
public View inflate(XmlPullParser parser, @Nullable ViewGroup root) {
return inflate(parser, root, root != null);
}
/**
* Inflate a new view hierarchy from the specified xml resource. Throws
* {@link InflateException} if there is an error.
*
* @param resource ID for an XML layout resource to load (e.g.,
* R.layout.main_page)
* @param root Optional view to be the parent of the generated hierarchy (if
* attachToRoot is true), or else simply an object that
* provides a set of LayoutParams values for root of the returned
* hierarchy (if attachToRoot is false.)
* @param attachToRoot Whether the inflated hierarchy should be attached to
* the root parameter? If false, root is only used to create the
* correct subclass of LayoutParams for the root view in the XML.
* @return The root View of the inflated hierarchy. If root was supplied and
* attachToRoot is true, this is root; otherwise it is the root of
* the inflated XML file.
*/
public View inflate(@LayoutRes int resource, @Nullable ViewGroup root, boolean attachToRoot) {
final Resources res = getContext().getResources();
if (DEBUG) {
Log.d(TAG, "INFLATING from resource: \"" + res.getResourceName(resource) + "\" ("
+ Integer.toHexString(resource) + ")");
}
View view = tryInflatePrecompiled(resource, res, root, attachToRoot);
if (view != null) {
return view;
}
XmlResourceParser parser = res.getLayout(resource);
try {
return inflate(parser, root, attachToRoot);
} finally {
parser.close();
}
}
private @Nullable
View tryInflatePrecompiled(@LayoutRes int resource, Resources res, @Nullable ViewGroup root,
boolean attachToRoot) {
if (!mUseCompiledView) {
return null;
}
Trace.traceBegin(Trace.TRACE_TAG_VIEW, "inflate (precompiled)");
// Try to inflate using a precompiled layout.
String pkg = res.getResourcePackageName(resource);
String layout = res.getResourceEntryName(resource);
try {
Class clazz = Class.forName("" + pkg + ".CompiledView", false, mPrecompiledClassLoader);
Method inflater = clazz.getMethod(layout, Context.class, int.class);
View view = (View) inflater.invoke(null, mContext, resource);
if (view != null && root != null) {
// We were able to use the precompiled inflater, but now we need to do some work to
// attach the view to the root correctly.
XmlResourceParser parser = res.getLayout(resource);
try {
AttributeSet attrs = Xml.asAttributeSet(parser);
advanceToRootNode(parser);
ViewGroup.LayoutParams params = root.generateLayoutParams(attrs);
if (attachToRoot) {
root.addView(view, params);
} else {
view.setLayoutParams(params);
}
} finally {
parser.close();
}
}
return view;
} catch (Throwable e) {
if (DEBUG) {
Log.e(TAG, "Failed to use precompiled view", e);
}
} finally {
Trace.traceEnd(Trace.TRACE_TAG_VIEW);
}
return null;
}
/**
* Advances the given parser to the first START_TAG. Throws InflateException if no start tag is
* found.
*/
private void advanceToRootNode(XmlPullParser parser)
throws InflateException, IOException, XmlPullParserException {
// Look for the root node.
int type;
while ((type = parser.next()) != XmlPullParser.START_TAG &&
type != XmlPullParser.END_DOCUMENT) {
// Empty
}
if (type != XmlPullParser.START_TAG) {
throw new InflateException(parser.getPositionDescription()
+ ": No start tag found!");
}
}
/**
* Inflate a new view hierarchy from the specified XML node. Throws
* {@link InflateException} if there is an error.
*
* Important For performance
* reasons, view inflation relies heavily on pre-processing of XML files
* that is done at build time. Therefore, it is not currently possible to
* use LayoutInflater with an XmlPullParser over a plain XML file at runtime.
*
* @param parser XML dom node containing the description of the view
* hierarchy.
* @param root Optional view to be the parent of the generated hierarchy (if
* attachToRoot is true), or else simply an object that
* provides a set of LayoutParams values for root of the returned
* hierarchy (if attachToRoot is false.)
* @param attachToRoot Whether the inflated hierarchy should be attached to
* the root parameter? If false, root is only used to create the
* correct subclass of LayoutParams for the root view in the XML.
* @return The root View of the inflated hierarchy. If root was supplied and
* attachToRoot is true, this is root; otherwise it is the root of
* the inflated XML file.
*/
public View inflate(XmlPullParser parser, @Nullable ViewGroup root, boolean attachToRoot) {
synchronized (mConstructorArgs) {
Trace.traceBegin(Trace.TRACE_TAG_VIEW, "inflate");
final Context inflaterContext = mContext;
final AttributeSet attrs = Xml.asAttributeSet(parser);
Context lastContext = (Context) mConstructorArgs[0];
mConstructorArgs[0] = inflaterContext;
View result = root;
try {
advanceToRootNode(parser);
final String name = parser.getName();
if (DEBUG) {
System.out.println("**************************");
System.out.println("Creating root view: "
+ name);
System.out.println("**************************");
}
if (TAG_MERGE.equals(name)) {
if (root == null || !attachToRoot) {
throw new InflateException("
* There are two things that can happen in an error case: either the
* exception describing the error will be thrown, or a null will be
* returned. You must deal with both possibilities -- the former will happen
* the first time createView() is called for a class of a particular name,
* the latter every time there-after for that class name.
*
* @param name The full name of the class to be instantiated.
* @param attrs The XML attributes supplied for this instance.
*
* @return View The newly instantiated view, or null.
*/
public final View createView(String name, String prefix, AttributeSet attrs)
throws ClassNotFoundException, InflateException {
Context context = (Context) mConstructorArgs[0];
if (context == null) {
context = mContext;
}
return createView(context, name, prefix, attrs);
}
/**
* Low-level function for instantiating a view by name. This attempts to
* instantiate a view class of the given name found in this
* LayoutInflater's ClassLoader.
*
*
* There are two things that can happen in an error case: either the
* exception describing the error will be thrown, or a null will be
* returned. You must deal with both possibilities -- the former will happen
* the first time createView() is called for a class of a particular name,
* the latter every time there-after for that class name.
*
* @param viewContext The context used as the context parameter of the View constructor
* @param name The full name of the class to be instantiated.
* @param attrs The XML attributes supplied for this instance.
*
* @return View The newly instantiated view, or null.
*/
@Nullable
public final View createView(@NonNull Context viewContext, @NonNull String name,
@Nullable String prefix, @Nullable AttributeSet attrs)
throws ClassNotFoundException, InflateException {
Objects.requireNonNull(viewContext);
Objects.requireNonNull(name);
Constructor constructor = sConstructorMap.get(name);
if (constructor != null && !verifyClassLoader(constructor)) {
constructor = null;
sConstructorMap.remove(name);
}
Class clazz = null;
try {
Trace.traceBegin(Trace.TRACE_TAG_VIEW, name);
if (constructor == null) {
// Class not found in the cache, see if it's real, and try to add it
clazz = Class.forName(prefix != null ? (prefix + name) : name, false,
mContext.getClassLoader()).asSubclass(View.class);
if (mFilter != null && clazz != null) {
boolean allowed = mFilter.onLoadClass(clazz);
if (!allowed) {
failNotAllowed(name, prefix, viewContext, attrs);
}
}
constructor = clazz.getConstructor(mConstructorSignature);
constructor.setAccessible(true);
sConstructorMap.put(name, constructor);
} else {
// If we have a filter, apply it to cached constructor
if (mFilter != null) {
// Have we seen this name before?
Boolean allowedState = mFilterMap.get(name);
if (allowedState == null) {
// New class -- remember whether it is allowed
clazz = Class.forName(prefix != null ? (prefix + name) : name, false,
mContext.getClassLoader()).asSubclass(View.class);
boolean allowed = clazz != null && mFilter.onLoadClass(clazz);
mFilterMap.put(name, allowed);
if (!allowed) {
failNotAllowed(name, prefix, viewContext, attrs);
}
} else if (allowedState.equals(Boolean.FALSE)) {
failNotAllowed(name, prefix, viewContext, attrs);
}
}
}
Object lastContext = mConstructorArgs[0];
mConstructorArgs[0] = viewContext;
Object[] args = mConstructorArgs;
args[1] = attrs;
try {
final View view = constructor.newInstance(args);
if (view instanceof ViewStub) {
// Use the same context when inflating ViewStub later.
final ViewStub viewStub = (ViewStub) view;
viewStub.setLayoutInflater(cloneInContext((Context) args[0]));
}
return view;
} finally {
mConstructorArgs[0] = lastContext;
}
} catch (NoSuchMethodException e) {
final InflateException ie = new InflateException(
getParserStateDescription(viewContext, attrs)
+ ": Error inflating class " + (prefix != null ? (prefix + name) : name), e);
ie.setStackTrace(EMPTY_STACK_TRACE);
throw ie;
} catch (ClassCastException e) {
// If loaded class is not a View subclass
final InflateException ie = new InflateException(
getParserStateDescription(viewContext, attrs)
+ ": Class is not a View " + (prefix != null ? (prefix + name) : name), e);
ie.setStackTrace(EMPTY_STACK_TRACE);
throw ie;
} catch (ClassNotFoundException e) {
// If loadClass fails, we should propagate the exception.
throw e;
} catch (Exception e) {
final InflateException ie = new InflateException(
getParserStateDescription(viewContext, attrs) + ": Error inflating class "
+ (clazz == null ? "" : clazz.getName()), e);
ie.setStackTrace(EMPTY_STACK_TRACE);
throw ie;
} finally {
Trace.traceEnd(Trace.TRACE_TAG_VIEW);
}
}
/**
* Throw an exception because the specified class is not allowed to be inflated.
*/
private void failNotAllowed(String name, String prefix, Context context, AttributeSet attrs) {
throw new InflateException(getParserStateDescription(context, attrs)
+ ": Class not allowed to be inflated "+ (prefix != null ? (prefix + name) : name));
}
/**
* This routine is responsible for creating the correct subclass of View
* given the xml element name. Override it to handle custom view objects. If
* you override this in your subclass be sure to call through to
* super.onCreateView(name) for names you do not recognize.
*
* @param name The fully qualified class name of the View to be create.
* @param attrs An AttributeSet of attributes to apply to the View.
*
* @return View The View created.
*/
protected View onCreateView(String name, AttributeSet attrs)
throws ClassNotFoundException {
return createView(name, "android.view.", attrs);
}
/**
* Version of {@link #onCreateView(String, AttributeSet)} that also
* takes the future parent of the view being constructed. The default
* implementation simply calls {@link #onCreateView(String, AttributeSet)}.
*
* @param parent The future parent of the returned view. Note that
* this may be null.
* @param name The fully qualified class name of the View to be create.
* @param attrs An AttributeSet of attributes to apply to the View.
*
* @return View The View created.
*/
protected View onCreateView(View parent, String name, AttributeSet attrs)
throws ClassNotFoundException {
return onCreateView(name, attrs);
}
/**
* Version of {@link #onCreateView(View, String, AttributeSet)} that also
* takes the inflation context. The default
* implementation simply calls {@link #onCreateView(View, String, AttributeSet)}.
*
* @param viewContext The Context to be used as a constructor parameter for the View
* @param parent The future parent of the returned view. Note that
* this may be null.
* @param name The fully qualified class name of the View to be create.
* @param attrs An AttributeSet of attributes to apply to the View.
*
* @return View The View created.
*/
@Nullable
public View onCreateView(@NonNull Context viewContext, @Nullable View parent,
@NonNull String name, @Nullable AttributeSet attrs)
throws ClassNotFoundException {
return onCreateView(parent, name, attrs);
}
/**
* Convenience method for calling through to the five-arg createViewFromTag
* method. This method passes {@code false} for the {@code ignoreThemeAttr}
* argument and should be used for everything except {@code >include>}
* tag parsing.
*/
@UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
private View createViewFromTag(View parent, String name, Context context, AttributeSet attrs) {
return createViewFromTag(parent, name, context, attrs, false);
}
/**
* Creates a view from a tag name using the supplied attribute set.
*
* Note: Default visibility so the BridgeInflater can
* override it.
*
* @param parent the parent view, used to inflate layout params
* @param name the name of the XML tag used to define the view
* @param context the inflation context for the view, typically the
* {@code parent} or base layout inflater context
* @param attrs the attribute set for the XML tag used to define the view
* @param ignoreThemeAttr {@code true} to ignore the {@code android:theme}
* attribute (if set) for the view being inflated,
* {@code false} otherwise
*/
@UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
View createViewFromTag(View parent, String name, Context context, AttributeSet attrs,
boolean ignoreThemeAttr) {
if (name.equals("view")) {
name = attrs.getAttributeValue(null, "class");
}
// Apply a theme wrapper, if allowed and one is specified.
if (!ignoreThemeAttr) {
final TypedArray ta = context.obtainStyledAttributes(attrs, ATTRS_THEME);
final int themeResId = ta.getResourceId(0, 0);
if (themeResId != 0) {
context = new ContextThemeWrapper(context, themeResId);
}
ta.recycle();
}
try {
View view = tryCreateView(parent, name, context, attrs);
if (view == null) {
final Object lastContext = mConstructorArgs[0];
mConstructorArgs[0] = context;
try {
if (-1 == name.indexOf('.')) {
view = onCreateView(context, parent, name, attrs);
} else {
view = createView(context, name, null, attrs);
}
} finally {
mConstructorArgs[0] = lastContext;
}
}
return view;
} catch (InflateException e) {
throw e;
} catch (ClassNotFoundException e) {
final InflateException ie = new InflateException(
getParserStateDescription(context, attrs)
+ ": Error inflating class " + name, e);
ie.setStackTrace(EMPTY_STACK_TRACE);
throw ie;
} catch (Exception e) {
final InflateException ie = new InflateException(
getParserStateDescription(context, attrs)
+ ": Error inflating class " + name, e);
ie.setStackTrace(EMPTY_STACK_TRACE);
throw ie;
}
}
/**
* Tries to create a view from a tag name using the supplied attribute set.
*
* This method gives the factory provided by {@link LayoutInflater#setFactory} and
* {@link LayoutInflater#setFactory2} a chance to create a view. However, it does not apply all
* of the general view creation logic, and thus may return {@code null} for some tags. This
* method is used by {@link LayoutInflater#inflate} in creating {@code View} objects.
*
* @hide for use by precompiled layouts.
*
* @param parent the parent view, used to inflate layout params
* @param name the name of the XML tag used to define the view
* @param context the inflation context for the view, typically the
* {@code parent} or base layout inflater context
* @param attrs the attribute set for the XML tag used to define the view
*/
@UnsupportedAppUsage(trackingBug = 122360734)
@Nullable
public final View tryCreateView(@Nullable View parent, @NonNull String name,
@NonNull Context context,
@NonNull AttributeSet attrs) {
if (name.equals(TAG_1995)) {
// Let's party like it's 1995!
return new BlinkLayout(context, attrs);
}
View view;
if (mFactory2 != null) {
view = mFactory2.onCreateView(parent, name, context, attrs);
} else if (mFactory != null) {
view = mFactory.onCreateView(name, context, attrs);
} else {
view = null;
}
if (view == null && mPrivateFactory != null) {
view = mPrivateFactory.onCreateView(parent, name, context, attrs);
}
return view;
}
/**
* Recursive method used to inflate internal (non-root) children. This
* method calls through to {@link #rInflate} using the parent context as
* the inflation context.
* Note: Default visibility so the BridgeInflater can
* call it.
*/
final void rInflateChildren(XmlPullParser parser, View parent, AttributeSet attrs,
boolean finishInflate) throws XmlPullParserException, IOException {
rInflate(parser, parent, parent.getContext(), attrs, finishInflate);
}
/**
* Recursive method used to descend down the xml hierarchy and instantiate
* views, instantiate their children, and then call onFinishInflate().
*
* Note: Default visibility so the BridgeInflater can
* override it.
*/
void rInflate(XmlPullParser parser, View parent, Context context,
AttributeSet attrs, boolean finishInflate) throws XmlPullParserException, IOException {
final int depth = parser.getDepth();
int type;
boolean pendingRequestFocus = false;
while (((type = parser.next()) != XmlPullParser.END_TAG ||
parser.getDepth() > depth) && type != XmlPullParser.END_DOCUMENT) {
if (type != XmlPullParser.START_TAG) {
continue;
}
final String name = parser.getName();
if (TAG_REQUEST_FOCUS.equals(name)) {
pendingRequestFocus = true;
consumeChildElements(parser);
} else if (TAG_TAG.equals(name)) {
parseViewTag(parser, parent, attrs);
} else if (TAG_INCLUDE.equals(name)) {
if (parser.getDepth() == 0) {
throw new InflateException("<tag> element and sets a keyed tag on the
* containing View.
*/
private void parseViewTag(XmlPullParser parser, View view, AttributeSet attrs)
throws XmlPullParserException, IOException {
final Context context = view.getContext();
final TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.ViewTag);
final int key = ta.getResourceId(R.styleable.ViewTag_id, 0);
final CharSequence value = ta.getText(R.styleable.ViewTag_value);
view.setTag(key, value);
ta.recycle();
consumeChildElements(parser);
}
@UnsupportedAppUsage
private void parseInclude(XmlPullParser parser, Context context, View parent,
AttributeSet attrs) throws XmlPullParserException, IOException {
int type;
if (!(parent instanceof ViewGroup)) {
throw new InflateException(" overwrites
// values in the AttributeSet of the included View. So, if the
// included View has a theme attribute, we'll need to ignore it.
final TypedArray ta = context.obtainStyledAttributes(attrs, ATTRS_THEME);
final int themeResId = ta.getResourceId(0, 0);
final boolean hasThemeOverride = themeResId != 0;
if (hasThemeOverride) {
context = new ContextThemeWrapper(context, themeResId);
}
ta.recycle();
// If the layout is pointing to a theme attribute, we have to
// massage the value to get a resource identifier out of it.
int layout = attrs.getAttributeResourceValue(null, ATTR_LAYOUT, 0);
if (layout == 0) {
final String value = attrs.getAttributeValue(null, ATTR_LAYOUT);
if (value == null || value.length() <= 0) {
throw new InflateException("You must specify a layout in the"
+ " include tag: tag doesn't support android:theme, so
// nothing special to do here.
rInflate(childParser, parent, context, childAttrs, false);
} else {
final View view = createViewFromTag(parent, childName,
context, childAttrs, hasThemeOverride);
final ViewGroup group = (ViewGroup) parent;
final TypedArray a = context.obtainStyledAttributes(
attrs, R.styleable.Include);
final int id = a.getResourceId(R.styleable.Include_id, View.NO_ID);
final int visibility = a.getInt(R.styleable.Include_visibility, -1);
a.recycle();
// We try to load the layout params set in the
// tag, false means we need to rely on the included layout params.
ViewGroup.LayoutParams params = null;
try {
params = group.generateLayoutParams(attrs);
} catch (RuntimeException e) {
// Ignore, just fail over to child attrs.
}
if (params == null) {
params = group.generateLayoutParams(childAttrs);
}
view.setLayoutParams(params);
// Inflate all children.
rInflateChildren(childParser, view, childAttrs, true);
if (id != View.NO_ID) {
view.setId(id);
}
switch (visibility) {
case 0:
view.setVisibility(View.VISIBLE);
break;
case 1:
view.setVisibility(View.INVISIBLE);
break;
case 2:
view.setVisibility(View.GONE);
break;
}
group.addView(view);
}
} finally {
childParser.close();
}
}
LayoutInflater.consumeChildElements(parser);
}
/**
* Note: default visibility so that
* LayoutInflater_Delegate can call it.
*/
final static void consumeChildElements(XmlPullParser parser)
throws XmlPullParserException, IOException {
int type;
final int currentDepth = parser.getDepth();
while (((type = parser.next()) != XmlPullParser.END_TAG ||
parser.getDepth() > currentDepth) && type != XmlPullParser.END_DOCUMENT) {
// Empty
}
}
private static class BlinkLayout extends FrameLayout {
private static final int MESSAGE_BLINK = 0x42;
private static final int BLINK_DELAY = 500;
private boolean mBlink;
private boolean mBlinkState;
private final Handler mHandler;
public BlinkLayout(Context context, AttributeSet attrs) {
super(context, attrs);
mHandler = new Handler(new Handler.Callback() {
@Override
public boolean handleMessage(Message msg) {
if (msg.what == MESSAGE_BLINK) {
if (mBlink) {
mBlinkState = !mBlinkState;
makeBlink();
}
invalidate();
return true;
}
return false;
}
});
}
private void makeBlink() {
Message message = mHandler.obtainMessage(MESSAGE_BLINK);
mHandler.sendMessageDelayed(message, BLINK_DELAY);
}
@Override
protected void onAttachedToWindow() {
super.onAttachedToWindow();
mBlink = true;
mBlinkState = true;
makeBlink();
}
@Override
protected void onDetachedFromWindow() {
super.onDetachedFromWindow();
mBlink = false;
mBlinkState = true;
mHandler.removeMessages(MESSAGE_BLINK);
}
@Override
protected void dispatchDraw(Canvas canvas) {
if (mBlinkState) {
super.dispatchDraw(canvas);
}
}
}
}