gwtquery.plugins.droppable.client.permissionmanagersample.MemberTreeViewModel.java Source code

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Here is the source code for gwtquery.plugins.droppable.client.permissionmanagersample.MemberTreeViewModel.java

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/*
 * Copyright 2010 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 gwtquery.plugins.droppable.client.permissionmanagersample;

import com.google.gwt.cell.client.AbstractCell;
import com.google.gwt.safehtml.shared.SafeHtmlBuilder;
import com.google.gwt.view.client.ListDataProvider;
import com.google.gwt.view.client.SingleSelectionModel;
import com.google.gwt.view.client.TreeViewModel;

import gwtquery.plugins.droppable.client.DroppableOptions;
import gwtquery.plugins.droppable.client.DroppableOptions.DroppableFunction;
import gwtquery.plugins.droppable.client.events.DragAndDropContext;
import gwtquery.plugins.droppable.client.gwt.DragAndDropNodeInfo;
import gwtquery.plugins.droppable.client.permissionmanagersample.MemberDatabase.MemberInfo;
import gwtquery.plugins.droppable.client.permissionmanagersample.MemberDatabase.Permission;

import java.util.List;

/**
 * The {@link TreeViewModel} used to organize members into a permission
 * hierarchy.
 */
public class MemberTreeViewModel implements TreeViewModel {

    /**
     * A Cell used to render the member inside the tree.
     */
    private static class MemberCell extends AbstractCell<MemberInfo> {

        @Override
        public void render(Context ctx, MemberInfo value, SafeHtmlBuilder sb) {
            if (value != null) {
                sb.appendEscaped(value.getFullName());
            }
        }
    }

    /**
     * The cell used to render permission.
     */
    private static class PermissionCell extends AbstractCell<Permission> {

        public PermissionCell() {
        }

        @Override
        public void render(Context ctx, Permission value, SafeHtmlBuilder sb) {
            if (value != null) {
                sb.appendHtmlConstant("<div style='padding:15px 3px 3px 3px;' >");
                sb.appendEscaped(value.getDisplayName());
                sb.appendHtmlConstant("</div>");
            }
        }
    }

    private MemberCell memberCell;
    private PermissionCell permissionCell;
    private final ListDataProvider<Permission> permissionDataProvider;

    public MemberTreeViewModel() {

        permissionDataProvider = new ListDataProvider<Permission>();
        List<Permission> permissionList = permissionDataProvider.getList();

        for (Permission permission : MemberDatabase.get().queryPermissions()) {
            if (permission != Permission.NON_MEMBER) {
                permissionList.add(permission);
            }
        }

        permissionCell = new PermissionCell();
        memberCell = new MemberCell();

    }

    public <T> NodeInfo<?> getNodeInfo(T value) {

        if (value == null) {
            // permission tree node
            DragAndDropNodeInfo<Permission> permissionNodeInfo = new DragAndDropNodeInfo<Permission>(
                    permissionDataProvider, permissionCell);

            // setup drop operation
            DroppableOptions options = permissionNodeInfo.getDroppableOptions();
            options.setDroppableHoverClass(Resource.INSTANCE.css().droppableHover());
            // use a DroppableFunction here. We can also add a DropHandler in the tree
            // itself
            options.setOnDrop(new DroppableFunction() {

                public void f(DragAndDropContext context) {
                    MemberInfo droppedMember = context.getDraggableData();
                    Permission dropPermission = context.getDroppableData();

                    MemberDatabase.get().permissionChange(droppedMember, dropPermission);

                }
            });
            // permission cell are not draggable
            permissionNodeInfo.setCellDroppableOnly();
            return permissionNodeInfo;

        } else if (value instanceof Permission) {
            // member tree node
            Permission p = (Permission) value;

            ListDataProvider<MemberInfo> dataProvider = MemberDatabase.get().getDataProvider(p);

            DragAndDropNodeInfo<MemberInfo> memberNodeInfo = new DragAndDropNodeInfo<MemberInfo>(dataProvider,
                    memberCell, new SingleSelectionModel<MemberInfo>(), null);

            // setup the drag operation
            PermissionManagerSample.configureDragOperation(memberNodeInfo.getDraggableOptions());
            // member cell are only draggable
            memberNodeInfo.setCellDraggableOnly();

            return memberNodeInfo;
        }

        String type = value.getClass().getName();
        throw new IllegalArgumentException("Unsupported object type: " + type);
    }

    public boolean isLeaf(Object value) {
        return value instanceof MemberInfo;
    }

}