com.google.gdt.eclipse.designer.smart.model.ComponentConfiguratorBeforeAssociation.java Source code

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Here is the source code for com.google.gdt.eclipse.designer.smart.model.ComponentConfiguratorBeforeAssociation.java

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/*******************************************************************************
 * Copyright 2011 Google Inc. All Rights Reserved.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * 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.gdt.eclipse.designer.smart.model;

import com.google.gdt.eclipse.designer.model.widgets.WidgetAttachAfterConstructor;

import org.eclipse.wb.core.eval.EvaluationContext;
import org.eclipse.wb.core.model.JavaInfo;
import org.eclipse.wb.core.model.broadcast.EvaluationEventListener;
import org.eclipse.wb.internal.core.model.JavaInfoUtils;
import org.eclipse.wb.internal.core.utils.ast.DomGenerics;

import org.eclipse.jdt.core.dom.ASTNode;
import org.eclipse.jdt.core.dom.Expression;
import org.eclipse.jdt.core.dom.MethodInvocation;

import org.apache.commons.lang.StringUtils;

/**
 * Helper for configuring {@link CanvasInfo} object directly before association.
 * 
 * @author scheglov_ke
 * @author sablin_aa
 * @coverage SmartGWT.model
 */
public abstract class ComponentConfiguratorBeforeAssociation {
    private final JavaInfo m_javaInfo;

    ////////////////////////////////////////////////////////////////////////////
    //
    // Constructor
    //
    ////////////////////////////////////////////////////////////////////////////
    public ComponentConfiguratorBeforeAssociation(JavaInfo javaInfo) {
        m_javaInfo = javaInfo;
        ensureConfigured_attachAfterConstructor();
        ensureConfigured_directlyBeforeAssociation();
    }

    ////////////////////////////////////////////////////////////////////////////
    //
    // Required models
    //
    ////////////////////////////////////////////////////////////////////////////
    /**
     * For "this", attaching, so rendering is going to be executed.
     */
    private void ensureConfigured_attachAfterConstructor() {
        m_javaInfo.addBroadcastListener(new WidgetAttachAfterConstructor() {
            public void invoke() throws Exception {
                if (!isRendered()) {
                    configure();
                }
            }
        });
    }

    /**
     * Ensure that each time when we try to associate this component with some parent (during parsing
     * and refresh), we ensure that it is configured.
     */
    private void ensureConfigured_directlyBeforeAssociation() {
        m_javaInfo.addBroadcastListener(new EvaluationEventListener() {
            @Override
            public void evaluateBefore(EvaluationContext context, ASTNode node) throws Exception {
                if (isPossibleAssociation(node)) {
                    configure();
                }
            }

            /**
             * Rough approximation for association checking, may fail sometimes. But I think that GWT-Ext
             * deserve hardly better implementation.
             */
            private boolean isPossibleAssociation(ASTNode node) {
                if (node instanceof MethodInvocation) {
                    MethodInvocation invocation = (MethodInvocation) node;
                    for (Expression argument : DomGenerics.arguments(invocation)) {
                        if (m_javaInfo.isRepresentedBy(argument)) {
                            return true;
                        }
                    }
                }
                return false;
            }
        });
    }

    private boolean isRendered() throws Exception {
        String script = JavaInfoUtils.getParameter(m_javaInfo, "objectReadyValidator");
        if (StringUtils.isEmpty(script)) {
            script = "if (object.isCreated()) return object.isDrawn(); else return false;";
        }
        Boolean result = (Boolean) JavaInfoUtils.executeScript(m_javaInfo, script);
        return result != null && result.booleanValue();
    }

    protected abstract void configure() throws Exception;
}