SaveStateVisitor.java

/*
 * Copyright (C) 2012 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 com.motorola.studio.android.generateviewbylayout;

import java.util.HashSet;
import java.util.Set;

import org.eclipse.jdt.core.IJavaElement;
import org.eclipse.jdt.core.IType;
import org.eclipse.jdt.core.JavaModelException;
import org.eclipse.jdt.core.dom.ASTVisitor;
import org.eclipse.jdt.core.dom.Expression;
import org.eclipse.jdt.core.dom.ITypeBinding;
import org.eclipse.jdt.core.dom.MethodInvocation;
import org.eclipse.jdt.core.dom.SimpleName;

import com.motorola.studio.android.codeutils.CodeUtilsActivator;
import com.motorola.studio.android.common.log.StudioLogger;
import com.motorola.studio.android.generatecode.JDTUtils;
import com.motorola.studio.android.generateviewbylayout.codegenerators.SaveStateCodeGenerator;
import com.motorola.studio.android.generateviewbylayout.model.LayoutNode.ViewProperties;

/**
 * Visitor responsible to identify already saved or restored views inside a View (generally Activity / Fragment) 
 */
public class SaveStateVisitor extends ASTVisitor
{
    private final Set<String> viewIds = new HashSet<String>();

    public Set<String> getViewIds()
    {
        return viewIds;
    }

    @Override
    public boolean visit(MethodInvocation node)
    {
        boolean handled = false;
        int i = 0;
        while (!handled && (i < SaveStateCodeGenerator.saveStateNodeTypes.length))
        {
            if ((node.getName().toString().equals(SaveStateCodeGenerator.saveStateNodeTypes[i]
                    .getProperty(ViewProperties.ViewStateGetMethod))))
            {
                identifySavedView(node);
                handled = true;
            }
            else if (node
                    .getName()
                    .toString()
                    .equals(SaveStateCodeGenerator.saveStateNodeTypes[i]
                            .getProperty(ViewProperties.ViewStateSetMethod)))
            {
                identifyRestoredView(node);
                handled = true;
            }
            i++;
        }

        return super.visit(node);
    }

    /**
     * Restored views are in form
     * <variable>.<viewSetMethod>(preferences.<preferenceGetMethod>("property", <defaultValue>));
     * @param node
     */
    private void identifyRestoredView(MethodInvocation node)
    {
        Expression expression = node.getExpression();

        if (expression instanceof SimpleName)
        {
            ITypeBinding binding = ((SimpleName) expression).resolveTypeBinding();
            IJavaElement javaElement = binding.getJavaElement();
            if (javaElement != null)
            {
                try
                {
                    IType type = (IType) javaElement.getAdapter(IType.class);
                    if (JDTUtils.isSubclass(type, "android.view.View"))
                    {
                        viewIds.add(((SimpleName) expression).getFullyQualifiedName());
                    }
                }
                catch (JavaModelException e)
                {
                    StudioLogger.warn(CodeUtilsActivator.PLUGIN_ID, "Unable to identify if "
                            + binding.getName() + " is a subclass of android.view.View", e);
                }
            }
        }
    }

    /**
     * Saved views are in form
     * editor.<propertySetMethod>("property", <variable>.<viewGetMethod>);
     * @param node
     */
    private void identifySavedView(MethodInvocation node)
    {
        Expression expression = node.getExpression();

        if (expression instanceof SimpleName)
        {
            ITypeBinding binding = ((SimpleName) expression).resolveTypeBinding();
            IJavaElement javaElement = binding.getJavaElement();
            if (javaElement != null)
            {
                try
                {
                    IType type = (IType) javaElement.getAdapter(IType.class);
                    if (JDTUtils.isSubclass(type, "android.view.View"))
                    {
                        viewIds.add(((SimpleName) expression).getFullyQualifiedName());
                    }
                }
                catch (JavaModelException e)
                {
                    StudioLogger.warn(CodeUtilsActivator.PLUGIN_ID, "Unable to identify if "
                            + binding.getName() + " is a subclass of android.view.View", e);
                }
            }
        }
    }
}