/*
* Copyright (C) 2013 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.transition;
import android.annotation.TransitionRes;
import com.android.internal.R;
import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
import android.content.Context;
import android.content.res.Resources;
import android.content.res.TypedArray;
import android.content.res.XmlResourceParser;
import android.util.ArrayMap;
import android.util.AttributeSet;
import android.util.Xml;
import android.view.InflateException;
import android.view.ViewGroup;
import java.io.IOException;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
/**
* This class inflates scenes and transitions from resource files.
*
* Information on XML resource descriptions for transitions can be found for
* {@link android.R.styleable#Transition}, {@link android.R.styleable#TransitionSet},
* {@link android.R.styleable#TransitionTarget}, {@link android.R.styleable#Fade},
* and {@link android.R.styleable#TransitionManager}.
*/
public class TransitionInflater {
private static final Class<?>[] sConstructorSignature = new Class[] {
Context.class, AttributeSet.class};
private final static ArrayMap<String, Constructor> sConstructors =
new ArrayMap<String, Constructor>();
private Context mContext;
private TransitionInflater(Context context) {
mContext = context;
}
/**
* Obtains the TransitionInflater from the given context.
*/
public static TransitionInflater from(Context context) {
return new TransitionInflater(context);
}
/**
* Loads a {@link Transition} object from a resource
*
* @param resource The resource id of the transition to load
* @return The loaded Transition object
* @throws android.content.res.Resources.NotFoundException when the
* transition cannot be loaded
*/
public Transition inflateTransition(@TransitionRes int resource) {
//noinspection ResourceType
XmlResourceParser parser = mContext.getResources().getXml(resource);
try {
return createTransitionFromXml(parser, Xml.asAttributeSet(parser), null);
} catch (XmlPullParserException e) {
InflateException ex = new InflateException(e.getMessage());
ex.initCause(e);
throw ex;
} catch (IOException e) {
InflateException ex = new InflateException(
parser.getPositionDescription()
+ ": " + e.getMessage());
ex.initCause(e);
throw ex;
} finally {
parser.close();
}
}
/**
* Loads a {@link TransitionManager} object from a resource
*
* @param resource The resource id of the transition manager to load
* @return The loaded TransitionManager object
* @throws android.content.res.Resources.NotFoundException when the
* transition manager cannot be loaded
*/
public TransitionManager inflateTransitionManager(@TransitionRes int resource,
ViewGroup sceneRoot) {
//noinspection ResourceType
XmlResourceParser parser = mContext.getResources().getXml(resource);
try {
return createTransitionManagerFromXml(parser, Xml.asAttributeSet(parser), sceneRoot);
} catch (XmlPullParserException e) {
InflateException ex = new InflateException(e.getMessage());
ex.initCause(e);
throw ex;
} catch (IOException e) {
InflateException ex = new InflateException(
parser.getPositionDescription()
+ ": " + e.getMessage());
ex.initCause(e);
throw ex;
} finally {
parser.close();
}
}
//
// Transition loading
//
private Transition createTransitionFromXml(XmlPullParser parser,
AttributeSet attrs, Transition parent)
throws XmlPullParserException, IOException {
Transition transition = null;
// Make sure we are on a start tag.
int type;
int depth = parser.getDepth();
TransitionSet transitionSet = (parent instanceof TransitionSet)
? (TransitionSet) parent : null;
while (((type=parser.next()) != XmlPullParser.END_TAG || parser.getDepth() > depth)
&& type != XmlPullParser.END_DOCUMENT) {
if (type != XmlPullParser.START_TAG) {
continue;
}
String name = parser.getName();
if ("fade".equals(name)) {
transition = new Fade(mContext, attrs);
} else if ("changeBounds".equals(name)) {
transition = new ChangeBounds(mContext, attrs);
} else if ("slide".equals(name)) {
transition = new Slide(mContext, attrs);
} else if ("explode".equals(name)) {
transition = new Explode(mContext, attrs);
} else if ("changeImageTransform".equals(name)) {
transition = new ChangeImageTransform(mContext, attrs);
} else if ("changeTransform".equals(name)) {
transition = new ChangeTransform(mContext, attrs);
} else if ("changeClipBounds".equals(name)) {
transition = new ChangeClipBounds(mContext, attrs);
} else if ("autoTransition".equals(name)) {
transition = new AutoTransition(mContext, attrs);
} else if ("recolor".equals(name)) {
transition = new Recolor(mContext, attrs);
} else if ("changeScroll".equals(name)) {
transition = new ChangeScroll(mContext, attrs);
} else if ("transitionSet".equals(name)) {
transition = new TransitionSet(mContext, attrs);
} else if ("transition".equals(name)) {
transition = (Transition) createCustom(attrs, Transition.class, "transition");
} else if ("targets".equals(name)) {
getTargetIds(parser, attrs, parent);
} else if ("arcMotion".equals(name)) {
parent.setPathMotion(new ArcMotion(mContext, attrs));
} else if ("pathMotion".equals(name)) {
parent.setPathMotion((PathMotion)createCustom(attrs, PathMotion.class, "pathMotion"));
} else if ("patternPathMotion".equals(name)) {
parent.setPathMotion(new PatternPathMotion(mContext, attrs));
} else {
throw new RuntimeException("Unknown scene name: " + parser.getName());
}
if (transition != null) {
if (!parser.isEmptyElementTag()) {
createTransitionFromXml(parser, attrs, transition);
}
if (transitionSet != null) {
transitionSet.addTransition(transition);
transition = null;
} else if (parent != null) {
throw new InflateException("Could not add transition to another transition.");
}
}
}
return transition;
}
private Object createCustom(AttributeSet attrs, Class expectedType, String tag) {
String className = attrs.getAttributeValue(null, "class");
if (className == null) {
throw new InflateException(tag + " tag must have a 'class' attribute");
}
try {
synchronized (sConstructors) {
Constructor constructor = sConstructors.get(className);
if (constructor == null) {
Class c = mContext.getClassLoader().loadClass(className)
.asSubclass(expectedType);
if (c != null) {
constructor = c.getConstructor(sConstructorSignature);
constructor.setAccessible(true);
sConstructors.put(className, constructor);
}
}
return constructor.newInstance(mContext, attrs);
}
} catch (InstantiationException e) {
throw new InflateException("Could not instantiate " + expectedType + " class " +
className, e);
} catch (ClassNotFoundException e) {
throw new InflateException("Could not instantiate " + expectedType + " class " +
className, e);
} catch (InvocationTargetException e) {
throw new InflateException("Could not instantiate " + expectedType + " class " +
className, e);
} catch (NoSuchMethodException e) {
throw new InflateException("Could not instantiate " + expectedType + " class " +
className, e);
} catch (IllegalAccessException e) {
throw new InflateException("Could not instantiate " + expectedType + " class " +
className, e);
}
}
private void getTargetIds(XmlPullParser parser,
AttributeSet attrs, Transition transition) throws XmlPullParserException, IOException {
// Make sure we are on a start tag.
int type;
int depth = parser.getDepth();
while (((type=parser.next()) != XmlPullParser.END_TAG || parser.getDepth() > depth)
&& type != XmlPullParser.END_DOCUMENT) {
if (type != XmlPullParser.START_TAG) {
continue;
}
String name = parser.getName();
if (name.equals("target")) {
TypedArray a = mContext.obtainStyledAttributes(attrs, R.styleable.TransitionTarget);
int id = a.getResourceId(R.styleable.TransitionTarget_targetId, 0);
String transitionName;
if (id != 0) {
transition.addTarget(id);
} else if ((id = a.getResourceId(R.styleable.TransitionTarget_excludeId, 0)) != 0) {
transition.excludeTarget(id, true);
} else if ((transitionName = a.getString(R.styleable.TransitionTarget_targetName))
!= null) {
transition.addTarget(transitionName);
} else if ((transitionName = a.getString(R.styleable.TransitionTarget_excludeName))
!= null) {
transition.excludeTarget(transitionName, true);
} else {
String className = a.getString(R.styleable.TransitionTarget_excludeClass);
try {
if (className != null) {
Class clazz = Class.forName(className);
transition.excludeTarget(clazz, true);
} else if ((className =
a.getString(R.styleable.TransitionTarget_targetClass)) != null) {
Class clazz = Class.forName(className);
transition.addTarget(clazz);
}
} catch (ClassNotFoundException e) {
throw new RuntimeException("Could not create " + className, e);
}
}
} else {
throw new RuntimeException("Unknown scene name: " + parser.getName());
}
}
}
//
// TransitionManager loading
//
private TransitionManager createTransitionManagerFromXml(XmlPullParser parser,
AttributeSet attrs, ViewGroup sceneRoot) throws XmlPullParserException, IOException {
// Make sure we are on a start tag.
int type;
int depth = parser.getDepth();
TransitionManager transitionManager = null;
while (((type=parser.next()) != XmlPullParser.END_TAG || parser.getDepth() > depth)
&& type != XmlPullParser.END_DOCUMENT) {
if (type != XmlPullParser.START_TAG) {
continue;
}
String name = parser.getName();
if (name.equals("transitionManager")) {
transitionManager = new TransitionManager();
} else if (name.equals("transition") && (transitionManager != null)) {
loadTransition(attrs, sceneRoot, transitionManager);
} else {
throw new RuntimeException("Unknown scene name: " + parser.getName());
}
}
return transitionManager;
}
private void loadTransition(AttributeSet attrs, ViewGroup sceneRoot,
TransitionManager transitionManager) throws Resources.NotFoundException {
TypedArray a = mContext.obtainStyledAttributes(attrs, R.styleable.TransitionManager);
int transitionId = a.getResourceId(R.styleable.TransitionManager_transition, -1);
int fromId = a.getResourceId(R.styleable.TransitionManager_fromScene, -1);
Scene fromScene = (fromId < 0) ? null: Scene.getSceneForLayout(sceneRoot, fromId, mContext);
int toId = a.getResourceId(R.styleable.TransitionManager_toScene, -1);
Scene toScene = (toId < 0) ? null : Scene.getSceneForLayout(sceneRoot, toId, mContext);
if (transitionId >= 0) {
Transition transition = inflateTransition(transitionId);
if (transition != null) {
if (toScene == null) {
throw new RuntimeException("No toScene for transition ID " + transitionId);
}
if (fromScene == null) {
transitionManager.setTransition(toScene, transition);
} else {
transitionManager.setTransition(fromScene, toScene, transition);
}
}
}
a.recycle();
}
}