/*
* 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 java.io.IOException;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.util.HashMap;
import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
import com.android.internal.view.menu.ExpandedMenuView;
import com.android.internal.view.menu.IconMenuItemView;
import com.android.internal.view.menu.IconMenuView;
import com.android.internal.app.AlertController.RecycleListView;
import android.content.Context;
import android.content.res.TypedArray;
import android.content.res.XmlResourceParser;
import android.util.AttributeSet;
import android.util.Log;
import android.util.Xml;
/**
* This class is used to instantiate layout XML file into its corresponding View
* objects. It is never be used directly -- 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. For example:
*
* <pre>
* LayoutInflater inflater = (LayoutInflater)context.getSystemService
* Context.LAYOUT_INFLATER_SERVICE);
* </pre>
*
* <p>
* 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.
*
* <p>
* 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.
* <em>something</em> file.)
*
* @see Context#getSystemService
*/
public class LayoutInflater {
private final HashMap<String, Class<?>> mLoadedClasses = new HashMap<String, Class<?>>();
private static final String[] sClassPrefixList = { "android.widget.",
"android.webkit.", "android.view." };
protected final Context mContext;
private static final String TAG = "LayoutInflater";
private static final String TAG_INCLUDE = "include";
private static final String TAG_MERGE = "merge";
// these are optional, set by the caller
private boolean mFactorySet;
private Factory mFactory;
private Filter mFilter;
private final Object[] mConstructorArgs = new Object[2];
private static final Class[] mConstructorSignature = new Class[] {
Context.class, AttributeSet.class };
private static final HashMap<String, Constructor> sConstructorMap = new HashMap<String, Constructor>();
private HashMap<String, Boolean> mFilterMap;
private static final String TAG_REQUEST_FOCUS = "requestFocus";
/**
* 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
*/
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.
*
* <p>
* 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.
*/
public View onCreateView(String name, Context context,
AttributeSet attrs);
}
private static class FactoryMerger implements Factory {
private final Factory mF1, mF2;
FactoryMerger(Factory f1, Factory f2) {
mF1 = f1;
mF2 = f2;
}
public View onCreateView(String name, Context context,
AttributeSet attrs) {
View v = mF1.onCreateView(name, context, attrs);
if (v != null)
return v;
return 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.
*/
public LayoutInflater(Context context) {
mContext = context;
}
/**
* 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) {
mContext = newContext;
mFactory = original.mFactory;
mFilter = original.mFilter;
}
/**
* Obtains the LayoutInflater from the given context.
*/
public static LayoutInflater from(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 LayoutInflater cloneInContext(Context newContext) {
return new LayoutInflater(this, newContext);
}
/**
* Return the context we are running in, for access to resources, class
* loader, etc.
*/
public Context getContext() {
return mContext;
}
/**
* Return the current 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;
}
/**
* 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.
*
* <p>
* 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, mFactory);
}
}
/**
* @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<String, Boolean>();
}
}
/**
* 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.,
* <code>R.layout.main_page</code>)
* @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(int resource, 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. *
* <p>
* <em><strong>Important</strong></em> 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, 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.,
* <code>R.layout.main_page</code>)
* @param root
* Optional view to be the parent of the generated hierarchy (if
* <em>attachToRoot</em> is true), or else simply an object that
* provides a set of LayoutParams values for root of the returned
* hierarchy (if <em>attachToRoot</em> 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(int resource, ViewGroup root, boolean attachToRoot) {
XmlResourceParser parser = getContext().getResources().getLayout(
resource);
try {
return inflate(parser, root, attachToRoot);
} finally {
parser.close();
}
}
/**
* Inflate a new view hierarchy from the specified XML node. Throws
* {@link InflateException} if there is an error.
* <p>
* <em><strong>Important</strong></em> 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
* <em>attachToRoot</em> is true), or else simply an object that
* provides a set of LayoutParams values for root of the returned
* hierarchy (if <em>attachToRoot</em> 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, ViewGroup root,
boolean attachToRoot) {
final AttributeSet attrs = (AttributeSet) parser;
Context lastContext = (Context) mConstructorArgs[0];
mConstructorArgs[0] = mContext;
View result = root;
// Look for the root node.
int type = -1;
try {
if (parser == null) {
throw new RuntimeException("LayoutInflater.inflate -> parser is null");
}
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!");
}
final String name = parser.getName();
// System.out.println("**************************");
// System.out.println("Creating root view: "
// + name);
// System.out.println("**************************");
// XmlResourceParser.XMLNode rootNode = parser.getRoot();
// temp is the root view that was found in the xml
if (TAG_MERGE.equals(name)) {
if (root == null || !attachToRoot) {
throw new InflateException("<merge /> can be used only with a valid "
+ "ViewGroup root and attachToRoot=true");
}
rInflate(parser, root, attrs);
} else {
View temp = createViewFromTag(name, attrs);
Log.i(TAG, "inflate>>>createView success");
ViewGroup.LayoutParams params = null;
if (root != null) {
// Create layout params that match root, if supplied
params = root.generateLayoutParams(attrs);
if (attachToRoot == false) {
// Set the layout params for temp if we are not
// attaching. (If we are, we use addView, below)
// temp.setLayoutParams(params);
// int uiid = temp.getUIElementID();
// /**
// @j2sNative
// var thisView = document.getElementById(uiid);
// if (null == thisView) {
// thisView = document.createElement("span");
// thisView.style.position = "absolute";
// thisView.id = uiid;
// thisView.style.zIndex = 10000;
// thisView.style.display = "block";
// thisView.style.visibility = "hidden";
// }
// document.body.appendChild(thisView);
// */
// {
// }
// System.out.println("root ID: " +
// root.getUIElementID());
root.addView(temp, params, false);
} else {
// System.out.println("root ID: " +
// root.getUIElementID());
root.addView(temp, params);
}
}
// Inflate all children under temp
rInflate(parser, temp, attrs);
// Decide whether to return the root that was passed in or the
// top view found in xml.
if (root == null || attachToRoot == false) {
result = temp;
}
}
} catch (XmlPullParserException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
// Don't retain static reference on context.
mConstructorArgs[0] = lastContext;
mConstructorArgs[1] = null;
}
return result;
}
/**
* Low-level function for instantiating a view by name. This attempts to
* instantiate a view class of the given <var>name</var> found in this
* LayoutInflater's ClassLoader.
*
* <p>
* 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 instantied view, or null.
*/
public final View createView(String name, String prefix, AttributeSet attrs)
throws ClassNotFoundException, InflateException {
Log.i(TAG, "createView:"+name+":"+prefix);
Constructor constructor = sConstructorMap.get(name);
Class clazz = null;
try {
if (constructor == null) {
// Class not found in the cache, see if it's real, and try to
// add it
String classPath = prefix != null ? (prefix + name) : name;
if (null == clazz) {
clazz = Class.forName(classPath);
}
if (clazz == null) {
Log.w(TAG, "createView:" + clazz);
throw new ClassNotFoundException("LayoutInflater.createView:<" + classPath
+ "> class not found");
}
if (mFilter != null && clazz != null) {
Log.i(TAG, "mFilter is not null");
boolean allowed = mFilter.onLoadClass(clazz);
if (!allowed) {
failNotAllowed(name, prefix, attrs);
}
}
constructor = clazz.getConstructor(mConstructorSignature);
// Class[] clazzes = constructor.getParameterTypes();
// for (int i = 0; i < clazzes.length; ++i) {
// System.out.println("param #" + i + ": "
// + clazzes[i].getName());
// }
if (null == constructor) {
Log.i(TAG, "constructor is null");
}
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 = mContext.getClassLoader().loadClass(prefix != null ? (prefix + name) : name);
//
// boolean allowed = clazz != null
// && mFilter.onLoadClass(clazz);
// mFilterMap.put(name, allowed);
// if (!allowed) {
// failNotAllowed(name, prefix, attrs);
// }
} else if (allowedState.equals(Boolean.FALSE)) {
failNotAllowed(name, prefix, attrs);
}
}
}
Object[] args = mConstructorArgs;
args[1] = attrs;
return (View) constructor.newInstance(args);
} catch (NoSuchMethodException e) {
InflateException ie = new InflateException(
attrs.getPositionDescription() + ": Error inflating class "
+ (prefix != null ? (prefix + name) : name));
ie.initCause(e);
throw ie;
} catch (ClassNotFoundException e) {
// If loadClass fails, we should propagate the exception.
throw e;
} catch (Exception e) {
InflateException ie = new InflateException(
attrs.getPositionDescription() + ": Error inflating class "
+ (clazz == null ? "<unknown>" : clazz.getName()));
ie.initCause(e);
e.printStackTrace();
throw ie;
}
}
/**
* Throw an excpetion because the specified class is not allowed to be
* inflated.
*/
private void failNotAllowed(String name, String prefix, AttributeSet attrs) {
InflateException ie = new InflateException(
attrs.getPositionDescription()
+ ": Class not allowed to be inflated "
+ (prefix != null ? (prefix + name) : name));
throw ie;
}
/**
* 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.
*/
public View onCreateView(String name, AttributeSet attrs) throws ClassNotFoundException {
View view = null;
for (String prefix : sClassPrefixList) {
try {
String classPath = prefix + name;
Class clazz = Class.forName(classPath);
if(clazz != null) {
view = createView(name, prefix, attrs);
}
} catch (ClassNotFoundException e) {
}
if (view != null) {
break;
}
}
return view;
}
/**
* default visibility so the BridgeInflater can override it.
*/
@SuppressWarnings("finally")
View createViewFromTag(String name, AttributeSet attrs) {
// System.out.println("******** Creating view: " + name);
View view = null;
if (name.equals("view")) {
name = attrs.getAttributeValue(null, "class");
}
try {
view = (mFactory == null) ? null : mFactory.onCreateView(name,
mContext, attrs);
// System.out.println("CreateView:"+(view==null?"null":view));
if (view == null) {
if (-1 == name.indexOf('.')) {
view = onCreateView(name, attrs);
} else {
view = createView(name, null, attrs);
}
}
Log.i(TAG, "******** Creating view: " + name
+ " Done! UIID: " + view.getUIElementID() + ", ID: "
+ view.getId());
if (view.getUIElementID() == 47)
System.out.println();
} catch (Exception e) {
InflateException ie = new InflateException(
attrs.getPositionDescription() + ": Error inflating class "
+ name);
ie.initCause(e);
throw ie;
} finally {
return view;
}
}
/**
* Recursive method used to descend down the xml hierarchy and instantiate
* views, instantiate their children, and then call onFinishInflate().
*/
private void rInflate(XmlPullParser parser, View parent, AttributeSet attrs) {
Log.i(TAG, "in rInflate, for View: " + parent.getUIElementID());
final int depth = parser.getDepth();
int type;
try {
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)) {
parseRequestFocus(parser, parent);
} else if (TAG_INCLUDE.equals(name)) {
if (parser.getDepth() == 0) {
throw new InflateException("<include /> cannot be the root element");
}
parseInclude(parser, parent, attrs);
} else {
final View view = createViewFromTag(name, attrs);
final ViewGroup viewGroup = (ViewGroup) parent;
final ViewGroup.LayoutParams params = viewGroup
.generateLayoutParams(attrs);
viewGroup.addView(view, params);
rInflate(parser, view, attrs);
}
}
} catch (XmlPullParserException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
parent.onFinishInflate();
// System.out.println("rInflate done, for View: "
// + parent.getUIElementID());
}
private void parseRequestFocus(XmlPullParser parser, View parent)
throws XmlPullParserException, IOException {
int type;
parent.requestFocus();
final int currentDepth = parser.getDepth();
while (((type = parser.next()) != XmlPullParser.END_TAG ||
parser.getDepth() > currentDepth) && type != XmlPullParser.END_DOCUMENT) {
// Empty
}
}
private void parseInclude(XmlPullParser parser, View parent, AttributeSet attrs)
throws XmlPullParserException, IOException {
int type;
if (parent instanceof ViewGroup) {
final int layout = attrs.getAttributeResourceValue(null, "layout", 0);
if (layout == 0) {
final String value = attrs.getAttributeValue(null, "layout");
if (value == null) {
throw new InflateException("You must specifiy a layout in the"
+ " include tag: <include layout=\"@layout/layoutID\" />");
} else {
throw new InflateException("You must specifiy a valid layout "
+ "reference. The layout ID " + value + " is not valid.");
}
} else {
final XmlResourceParser childParser =
getContext().getResources().getLayout(layout);
try {
final AttributeSet childAttrs = Xml.asAttributeSet(childParser);
while ((type = childParser.next()) != XmlPullParser.START_TAG &&
type != XmlPullParser.END_DOCUMENT) {
// Empty.
}
if (type != XmlPullParser.START_TAG) {
throw new InflateException(childParser.getPositionDescription() +
": No start tag found!");
}
final String childName = childParser.getName();
if (TAG_MERGE.equals(childName)) {
// Inflate all children.
rInflate(childParser, parent, childAttrs);
} else {
final View view = createViewFromTag(childName, childAttrs);
final ViewGroup group = (ViewGroup) parent;
// We try to load the layout params set in the <include /> tag. If
// they don't exist, we will rely on the layout params set in the
// included XML file.
// During a layoutparams generation, a runtime exception is thrown
// if either layout_width or layout_height is missing. We catch
// this exception and set localParams accordingly: true means we
// successfully loaded layout params from the <include /> tag,
// false means we need to rely on the included layout params.
ViewGroup.LayoutParams params = null;
try {
params = group.generateLayoutParams(attrs);
} catch (RuntimeException e) {
params = group.generateLayoutParams(childAttrs);
} finally {
if (params != null) {
view.setLayoutParams(params);
}
}
// Inflate all children.
rInflate(childParser, view, childAttrs);
// Attempt to override the included layout's android:id with the
// one set on the <include /> tag itself.
TypedArray a = mContext.obtainStyledAttributes(attrs,
com.android.internal.R.styleable.View, 0, 0);
int id = a.getResourceId(com.android.internal.R.styleable.View_id, View.NO_ID);
// While we're at it, let's try to override android:visibility.
int visibility = a.getInt(com.android.internal.R.styleable.View_visibility, -1);
a.recycle();
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();
}
}
} else {
throw new InflateException("<include /> can only be used inside of a ViewGroup");
}
final int currentDepth = parser.getDepth();
while (((type = parser.next()) != XmlPullParser.END_TAG ||
parser.getDepth() > currentDepth) && type != XmlPullParser.END_DOCUMENT) {
// Empty
}
}
}