com.google.gdt.eclipse.designer.model.widgets.GwtHierarchyProvider.java Source code

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Here is the source code for com.google.gdt.eclipse.designer.model.widgets.GwtHierarchyProvider.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.model.widgets;

import com.google.gdt.eclipse.designer.model.widgets.cell.CellTableInfo;

import org.eclipse.wb.core.model.JavaInfo;
import org.eclipse.wb.internal.core.model.JavaInfoUtils.HierarchyProvider;
import org.eclipse.wb.internal.core.utils.ast.AstEditor;
import org.eclipse.wb.internal.core.utils.reflect.ReflectionUtils;
import org.eclipse.wb.internal.core.utils.state.EditorState;

import org.apache.commons.lang.ArrayUtils;

import java.util.List;

/**
 * Implementation of {@link HierarchyProvider} for GWT.
 * 
 * @author scheglov_ke
 * @coverage gwt.model
 */
public final class GwtHierarchyProvider extends HierarchyProvider {
    ////////////////////////////////////////////////////////////////////////////
    //
    // Instance
    //
    ////////////////////////////////////////////////////////////////////////////
    public static final HierarchyProvider INSTANCE = new GwtHierarchyProvider();

    private GwtHierarchyProvider() {
    }

    ////////////////////////////////////////////////////////////////////////////
    //
    // HierarchyProvider
    //
    ////////////////////////////////////////////////////////////////////////////
    @Override
    public Object[] getAliases(Object object) throws Exception {
        if (isUserClass(object, "com.smartgwt.client.widgets.BaseWidget")) {
            return new Object[] { object };
        }
        if (isUserClass(object, "com.google.gwt.user.client.ui.UIObject")) {
            return new Object[] { object, ReflectionUtils.invokeMethod(object, "getElement()") };
        }
        // unknown
        return null;
    }

    @Override
    public Object getParentObject(Object object) throws Exception {
        // com.google.gwt.user.client.ui.Widget
        if (isUserClass(object, "com.google.gwt.user.client.ui.Widget")) {
            return ReflectionUtils.invokeMethod(object, "getParent()");
        }
        // com.google.gwt.user.client.Element
        if (isUserClass(object, "com.google.gwt.user.client.Element")) {
            Class<?> domClass = getEditorLoader().loadClass("com.google.gwt.user.client.DOM");
            return ReflectionUtils.invokeMethod(domClass, "getParent(com.google.gwt.user.client.Element)", object);
        }
        // unknown
        return null;
    }

    @Override
    public Object[] getChildrenObjects(Object object) throws Exception {
        // com.google.gwt.user.cellview.client.CellTable
        if (isUserClass(object, "com.google.gwt.user.cellview.client.CellTable")) {
            List<?> columnList = CellTableInfo.getColumnObjects(object);
            return columnList.toArray(new Object[columnList.size()]);
        }
        // com.google.gwt.user.client.ui.IndexedPanel
        if (isUserClass(object, "com.google.gwt.user.client.ui.IndexedPanel")) {
            int widgetCount = (Integer) ReflectionUtils.invokeMethod(object, "getWidgetCount()");
            Object widgets[] = new Object[widgetCount];
            for (int i = 0; i < widgetCount; i++) {
                widgets[i] = ReflectionUtils.invokeMethod(object, "getWidget(int)", i);
            }
            return widgets;
        }
        // com.google.gwt.user.client.ui.IndexedPanel
        if (isUserClass(object, "com.google.gwt.user.client.ui.Composite")) {
            Object widget = ReflectionUtils.invokeMethod(object, "getWidget()");
            if (widget != null) {
                return new Object[] { widget };
            }
        }
        // com.google.gwt.user.client.Element
        if (isUserClass(object, "com.google.gwt.user.client.Element")) {
            Class<?> domClass = getEditorLoader().loadClass("com.google.gwt.user.client.DOM");
            int childCount = (Integer) ReflectionUtils.invokeMethod(domClass,
                    "getChildCount(com.google.gwt.user.client.Element)", object);
            Object children[] = new Object[childCount];
            for (int i = 0; i < childCount; i++) {
                children[i] = ReflectionUtils.invokeMethod(domClass,
                        "getChild(com.google.gwt.user.client.Element,int)", object, i);
            }
            return children;
        }
        // unknown
        return ArrayUtils.EMPTY_OBJECT_ARRAY;
    }

    ////////////////////////////////////////////////////////////////////////////
    //
    // Internal
    //
    ////////////////////////////////////////////////////////////////////////////
    /**
     * @return the {@link ClassLoader} of active {@link JavaInfo} hierarchy.
     */
    private static ClassLoader getEditorLoader() {
        AstEditor editor = EditorState.getActiveJavaInfo().getEditor();
        return EditorState.get(editor).getEditorLoader();
    }

    /**
     * @return <code>true</code> if given object is successor of given class.
     */
    private static boolean isUserClass(Object o, String className) {
        return o != null && ReflectionUtils.isSuccessorOf(o.getClass(), className);
    }
}