/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Eclipse Public License, Version 1.0 (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.eclipse.org/org/documents/epl-v10.php
*
* 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 com.android.ide.eclipse.adt.internal.editors.layout;
import com.android.ide.common.rendering.api.IProjectCallback;
import com.android.ide.common.rendering.api.LayoutLog;
import com.android.ide.common.rendering.legacy.LegacyCallback;
import com.android.ide.eclipse.adt.AdtPlugin;
import com.android.ide.eclipse.adt.AndroidConstants;
import com.android.ide.eclipse.adt.internal.project.AndroidManifestHelper;
import com.android.ide.eclipse.adt.internal.resources.manager.ProjectClassLoader;
import com.android.ide.eclipse.adt.internal.resources.manager.ProjectResources;
import com.android.resources.ResourceType;
import com.android.sdklib.SdkConstants;
import com.android.sdklib.xml.ManifestData;
import com.android.util.Pair;
import org.eclipse.core.resources.IProject;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Set;
import java.util.TreeSet;
/**
* Loader for Android Project class in order to use them in the layout editor.
* <p/>This implements {@link IProjectCallback} for the old and new API through
* {@link ILegacyCallback}
*/
public final class ProjectCallback extends LegacyCallback {
private final HashMap<String, Class<?>> mLoadedClasses = new HashMap<String, Class<?>>();
private final Set<String> mMissingClasses = new TreeSet<String>();
private final Set<String> mBrokenClasses = new TreeSet<String>();
private final IProject mProject;
private final ClassLoader mParentClassLoader;
private final ProjectResources mProjectRes;
private boolean mUsed = false;
private String mNamespace;
private ProjectClassLoader mLoader = null;
private LayoutLog mLogger;
/**
* Creates a new {@link ProjectCallback} to be used with the layout lib.
*
* @param classLoader The class loader that was used to load layoutlib.jar
* @param projectRes the {@link ProjectResources} for the project.
* @param project the project.
*/
public ProjectCallback(ClassLoader classLoader, ProjectResources projectRes, IProject project) {
mParentClassLoader = classLoader;
mProjectRes = projectRes;
mProject = project;
}
public Set<String> getMissingClasses() {
return mMissingClasses;
}
public Set<String> getUninstantiatableClasses() {
return mBrokenClasses;
}
/**
* Sets the {@link LayoutLog} logger to use for error messages during problems
*
* @param logger the new logger to use, or null to clear it out
*/
public void setLogger(LayoutLog logger) {
mLogger = logger;
}
/**
* Returns the {@link LayoutLog} logger used for error messages, or null
*
* @return the logger being used, or null if no logger is in use
*/
public LayoutLog getLogger() {
return mLogger;
}
/**
* {@inheritDoc}
*
* This implementation goes through the output directory of the Eclipse project and loads the
* <code>.class</code> file directly.
*/
@SuppressWarnings("unchecked")
public Object loadView(String className, Class[] constructorSignature,
Object[] constructorParameters)
throws ClassNotFoundException, Exception {
mUsed = true;
// look for a cached version
Class<?> clazz = mLoadedClasses.get(className);
if (clazz != null) {
return instantiateClass(clazz, constructorSignature, constructorParameters);
}
// load the class.
try {
if (mLoader == null) {
mLoader = new ProjectClassLoader(mParentClassLoader, mProject);
}
clazz = mLoader.loadClass(className);
} catch (Exception e) {
// Add the missing class to the list so that the renderer can print them later.
// no need to log this.
mMissingClasses.add(className);
}
try {
if (clazz != null) {
// first try to instantiate it because adding it the list of loaded class so that
// we don't add broken classes.
Object view = instantiateClass(clazz, constructorSignature, constructorParameters);
mLoadedClasses.put(className, clazz);
return view;
}
} catch (Throwable e) {
// Find root cause to log it.
while (e.getCause() != null) {
e = e.getCause();
}
AdtPlugin.log(e, "%1$s failed to instantiate.", className); //$NON-NLS-1$
// Add the missing class to the list so that the renderer can print them later.
mBrokenClasses.add(className);
}
// Create a mock view instead. We don't cache it in the mLoadedClasses map.
// If any exception is thrown, we'll return a CFN with the original class name instead.
try {
clazz = mLoader.loadClass(SdkConstants.CLASS_MOCK_VIEW);
Object view = instantiateClass(clazz, constructorSignature, constructorParameters);
// Set the text of the mock view to the simplified name of the custom class
Method m = view.getClass().getMethod("setText",
new Class<?>[] { CharSequence.class });
m.invoke(view, getShortClassName(className));
return view;
} catch (Exception e) {
// We failed to create and return a mock view.
// Just throw back a CNF with the original class name.
throw new ClassNotFoundException(className, e);
}
}
private String getShortClassName(String fqcn) {
// The name is typically a fully-qualified class name. Let's make it a tad shorter.
if (fqcn.startsWith("android.")) { //$NON-NLS-1$
// For android classes, convert android.foo.Name to android...Name
int first = fqcn.indexOf('.');
int last = fqcn.lastIndexOf('.');
if (last > first) {
return fqcn.substring(0, first) + ".." + fqcn.substring(last); //$NON-NLS-1$
}
} else {
// For custom non-android classes, it's best to keep the 2 first segments of
// the namespace, e.g. we want to get something like com.example...MyClass
int first = fqcn.indexOf('.');
first = fqcn.indexOf('.', first + 1);
int last = fqcn.lastIndexOf('.');
if (last > first) {
return fqcn.substring(0, first) + ".." + fqcn.substring(last); //$NON-NLS-1$
}
}
return fqcn;
}
/**
* Returns the namespace for the project. The namespace contains a standard part + the
* application package.
*
* @return The package namespace of the project or null in case of error.
*/
public String getNamespace() {
if (mNamespace == null) {
ManifestData manifestData = AndroidManifestHelper.parseForData(mProject);
if (manifestData != null) {
String javaPackage = manifestData.getPackage();
mNamespace = String.format(AndroidConstants.NS_CUSTOM_RESOURCES, javaPackage);
}
}
return mNamespace;
}
public Pair<ResourceType, String> resolveResourceId(int id) {
if (mProjectRes != null) {
return mProjectRes.resolveResourceValue(id);
}
return null;
}
public String resolveResourceId(int[] id) {
if (mProjectRes != null) {
return mProjectRes.resolveResourceValue(id);
}
return null;
}
public Integer getResourceId(ResourceType type, String name) {
if (mProjectRes != null) {
return mProjectRes.getResourceValue(type, name);
}
return null;
}
/**
* Returns whether the loader has received requests to load custom views. Note that
* the custom view loading may not actually have succeeded; this flag only records
* whether it was <b>requested</b>.
* <p/>
* This allows to efficiently only recreate when needed upon code change in the
* project.
*
* @return true if the loader has been asked to load custom views
*/
public boolean isUsed() {
return mUsed;
}
/**
* Instantiate a class object, using a specific constructor and parameters.
* @param clazz the class to instantiate
* @param constructorSignature the signature of the constructor to use
* @param constructorParameters the parameters to use in the constructor.
* @return A new class object, created using a specific constructor and parameters.
* @throws Exception
*/
@SuppressWarnings("unchecked")
private Object instantiateClass(Class<?> clazz,
Class[] constructorSignature,
Object[] constructorParameters) throws Exception {
Constructor<?> constructor = null;
try {
constructor = clazz.getConstructor(constructorSignature);
} catch (NoSuchMethodException e) {
// Custom views can either implement a 3-parameter, 2-parameter or a
// 1-parameter. Let's synthetically build and try all the alternatives.
// That's kind of like switching to the other box.
//
// The 3-parameter constructor takes the following arguments:
// ...(Context context, AttributeSet attrs, int defStyle)
int n = constructorSignature.length;
if (n == 0) {
// There is no parameter-less constructor. Nobody should ask for one.
throw e;
}
for (int i = 3; i >= 1; i--) {
if (i == n) {
// Let's skip the one we know already fails
continue;
}
Class[] sig = new Class[i];
Object[] params = new Object[i];
int k = i;
if (n < k) {
k = n;
}
System.arraycopy(constructorSignature, 0, sig, 0, k);
System.arraycopy(constructorParameters, 0, params, 0, k);
for (k++; k <= i; k++) {
if (k == 2) {
// Parameter 2 is the AttributeSet
sig[k-1] = clazz.getClassLoader().loadClass("android.util.AttributeSet");
params[k-1] = null;
} else if (k == 3) {
// Parameter 3 is the int defstyle
sig[k-1] = int.class;
params[k-1] = 0;
}
}
constructorSignature = sig;
constructorParameters = params;
try {
// Try again...
constructor = clazz.getConstructor(constructorSignature);
if (constructor != null) {
// Found a suitable constructor, now let's use it.
// (But let's warn the user if the simple View constructor was found
// since Unexpected Things may happen if the attribute set constructors
// are not found)
if (constructorSignature.length < 2 && mLogger != null) {
mLogger.warning("wrongconstructor", //$NON-NLS-1$
String.format("Custom view %1$s is not using the 2- or 3-argument "
+ "View constructors; XML attributes will not work",
clazz.getSimpleName()), null /*data*/);
}
break;
}
} catch (NoSuchMethodException e1) {
// pass
}
}
// If all the alternatives failed, throw the initial exception.
if (constructor == null) {
throw e;
}
}
constructor.setAccessible(true);
return constructor.newInstance(constructorParameters);
}
}