/*
* Copyright 2008 Google Inc.
*
* 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 com.google.gwt.dev.shell;
import com.google.gwt.core.ext.BadPropertyValueException;
import com.google.gwt.core.ext.DefaultConfigurationProperty;
import com.google.gwt.core.ext.DefaultSelectionProperty;
import com.google.gwt.core.ext.PropertyOracle;
import com.google.gwt.core.ext.SelectionProperty;
import com.google.gwt.core.ext.TreeLogger;
import com.google.gwt.core.ext.UnableToCompleteException;
import com.google.gwt.dev.cfg.BindingProperty;
import com.google.gwt.dev.cfg.Condition;
import com.google.gwt.dev.cfg.ConfigurationProperty;
import com.google.gwt.dev.cfg.DeferredBindingQuery;
import com.google.gwt.dev.cfg.Properties;
import com.google.gwt.dev.cfg.Property;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.SortedSet;
import java.util.TreeSet;
/**
* Implements a {@link PropertyOracle} in terms of a module space, which makes
* it possible to execute property providers.
*/
public class ModuleSpacePropertyOracle implements PropertyOracle {
private final Set<String> activeLinkerNames;
private final Map<String, String> prevAnswers = new HashMap<String, String>();
private final Properties props;
private final ModuleSpace space;
/**
* Create a property oracle that computes its properties from a module.
*/
public ModuleSpacePropertyOracle(Properties props,
Set<String> activeLinkerNames, ModuleSpace space) {
this.space = space;
this.activeLinkerNames = activeLinkerNames;
this.props = props;
}
public com.google.gwt.core.ext.ConfigurationProperty getConfigurationProperty(
String propertyName) throws BadPropertyValueException {
Property prop = getProperty(propertyName);
if (prop instanceof ConfigurationProperty) {
final ConfigurationProperty cprop = (ConfigurationProperty) prop;
final String name = cprop.getName();
final List<String> values = cprop.getValues();
return new DefaultConfigurationProperty(name, values);
} else {
throw new BadPropertyValueException(propertyName);
}
}
/**
* Executes JavaScript to find the property value.
*/
@Deprecated
public String getPropertyValue(TreeLogger logger, String propertyName)
throws BadPropertyValueException {
Property prop = getProperty(propertyName);
// Check if this property has already been queried for; if so, return
// the same answer. This is necessary to match Production Mode behavior
// since property providers are only called once. We cache even values that
// cause exceptions to be thrown to make sure we are consistent even
// in throwing exceptions for the same property.
if (prevAnswers.containsKey(propertyName)) {
return prevAnswers.get(propertyName);
} else {
String value;
if (prop instanceof ConfigurationProperty) {
value = ((ConfigurationProperty) prop).getValue();
} else if (prop instanceof BindingProperty) {
value = computePropertyValue(logger, propertyName,
(BindingProperty) prop);
} else {
throw new BadPropertyValueException(propertyName);
}
prevAnswers.put(propertyName, value);
return value;
}
}
/**
* Returns the list of possible values for a property.
*/
@Deprecated
public String[] getPropertyValueSet(TreeLogger logger, String propertyName)
throws BadPropertyValueException {
Property prop = getProperty(propertyName);
if (prop instanceof BindingProperty) {
return ((BindingProperty) prop).getDefinedValues();
}
throw new BadPropertyValueException(propertyName);
}
public SelectionProperty getSelectionProperty(TreeLogger logger,
String propertyName) throws BadPropertyValueException {
Property prop = getProperty(propertyName);
if (prop instanceof BindingProperty) {
final BindingProperty cprop = (BindingProperty) prop;
final String name = cprop.getName();
final String value;
if (prevAnswers.containsKey(propertyName)) {
value = prevAnswers.get(propertyName);
} else {
value = computePropertyValue(logger, propertyName, cprop);
prevAnswers.put(propertyName, value);
}
final String fallback = cprop.getFallback();
final SortedSet<String> possibleValues = new TreeSet<String>();
for (String v : cprop.getDefinedValues()) {
possibleValues.add(v);
}
return new DefaultSelectionProperty(value, fallback, name, possibleValues,
cprop.getFallbackValuesMap());
} else {
throw new BadPropertyValueException(propertyName);
}
}
private Condition computeActiveCondition(TreeLogger logger,
BindingProperty prop) throws BadPropertyValueException {
// Last-one-wins
Condition winner = null;
for (Condition cond : prop.getConditionalValues().keySet()) {
try {
if (cond.isTrue(logger, new DeferredBindingQuery(this,
activeLinkerNames))) {
winner = cond;
}
} catch (UnableToCompleteException e) {
BadPropertyValueException t = new BadPropertyValueException(
prop.getName());
t.initCause(e);
throw t;
}
}
assert winner != null : "No active Condition for " + prop.getName();
return winner;
}
/**
* Returns the value of the specified property.
*
* @throws BadPropertyValueException if the property value could not be
* computed, or if the returned result is not a legal value for this
* property.
*/
private String computePropertyValue(TreeLogger logger, String propertyName,
BindingProperty prop) throws BadPropertyValueException {
String value = prop.getConstrainedValue();
if (value != null) {
// If there is only one legal value, use that.
return value;
}
Condition winner = computeActiveCondition(logger, prop);
String[] values = prop.getAllowedValues(winner);
if (values.length == 1) {
return values[0];
}
// Invokes the script function.
//
try {
// Invoke the property provider function in JavaScript.
//
value = (String) space.invokeNativeObject("__gwt_getProperty", null,
new Class[] {String.class}, new Object[] {prop.getName()});
} catch (Throwable e) {
// Treat as an unknown value.
//
String msg = "Error while executing the JavaScript provider for property '"
+ propertyName + "'";
logger.log(TreeLogger.ERROR, msg, e);
throw new BadPropertyValueException(propertyName, "<failed to compute>");
}
// value may be null if the provider returned an unknown property value.
if (Arrays.asList(values).contains(value)) {
return value;
} else {
// Bad value due to the provider returning an unknown value.
// The fact that the provider returned an invalid value will also
// have been reported to the JS bad property value handler function.
throw new BadPropertyValueException(propertyName, value);
}
}
/**
* Returns a Property given its name, handling error conditions.
*
* @throws BadPropertyValueException
*/
private Property getProperty(String propertyName)
throws BadPropertyValueException {
if (propertyName == null) {
throw new NullPointerException("propertyName");
}
Property prop = props.find(propertyName);
if (prop == null) {
// Don't know this property; that's not good.
//
throw new BadPropertyValueException(propertyName);
}
return prop;
}
}