InsertPanelExample.java

/*
 * Copyright 2009 Fred Sauer
 * 
 * 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.allen_sauer.gwt.dnd.demo.client.example.insertpanel;

import com.google.gwt.user.client.Random;
import com.google.gwt.user.client.ui.AbsolutePanel;
import com.google.gwt.user.client.ui.HTML;
import com.google.gwt.user.client.ui.HorizontalPanel;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.VerticalPanel;

import com.allen_sauer.gwt.dnd.client.PickupDragController;
import com.allen_sauer.gwt.dnd.client.drop.HorizontalPanelDropController;
import com.allen_sauer.gwt.dnd.client.drop.VerticalPanelDropController;
import com.allen_sauer.gwt.dnd.demo.client.DemoDragHandler;
import com.allen_sauer.gwt.dnd.demo.client.example.Example;

/**
 * Example of columns that can be rearranged, with widget that can be moved within a column or
 * between columns.
 */
public final class InsertPanelExample extends Example {

  private static final int COLUMNS = 3;

  private static final String CSS_DEMO_INSERT_PANEL_EXAMPLE = "demo-InsertPanelExample";

  private static final String CSS_DEMO_INSERT_PANEL_EXAMPLE_COLUMN_COMPOSITE = "demo-InsertPanelExample-column-composite";

  private static final String CSS_DEMO_INSERT_PANEL_EXAMPLE_CONTAINER = "demo-InsertPanelExample-container";

  private static final String CSS_DEMO_INSERT_PANEL_EXAMPLE_HEADING = "demo-InsertPanelExample-heading";

  private static final String CSS_DEMO_INSERT_PANEL_EXAMPLE_WIDGET = "demo-InsertPanelExample-widget";

  private static final int ROWS = 4;

  private static final int SPACING = 0;

  public InsertPanelExample(DemoDragHandler demoDragHandler) {
    addStyleName(CSS_DEMO_INSERT_PANEL_EXAMPLE);
    int count = 0;

    // use the boundary panel as this composite's widget
    AbsolutePanel boundaryPanel = new AbsolutePanel();
    boundaryPanel.setSize("100%", "100%");
    setWidget(boundaryPanel);

    // initialize our column drag controller
    PickupDragController columnDragController = new PickupDragController(boundaryPanel, false);
    columnDragController.setBehaviorMultipleSelection(false);
    columnDragController.addDragHandler(demoDragHandler);

    // initialize our widget drag controller
    PickupDragController widgetDragController = new PickupDragController(boundaryPanel, false);
    widgetDragController.setBehaviorMultipleSelection(false);
    widgetDragController.addDragHandler(demoDragHandler);

    // initialize horizontal panel to hold our columns
    HorizontalPanel horizontalPanel = new HorizontalPanel();
    horizontalPanel.addStyleName(CSS_DEMO_INSERT_PANEL_EXAMPLE_CONTAINER);
    horizontalPanel.setSpacing(SPACING);
    boundaryPanel.add(horizontalPanel);

    // initialize our column drop controller
    HorizontalPanelDropController columnDropController = new HorizontalPanelDropController(
        horizontalPanel);
    columnDragController.registerDropController(columnDropController);

    for (int col = 1; col <= COLUMNS; col++) {
      // initialize a vertical panel to hold the heading and a second vertical
      // panel
      VerticalPanel columnCompositePanel = new VerticalPanel();
      columnCompositePanel.addStyleName(CSS_DEMO_INSERT_PANEL_EXAMPLE_COLUMN_COMPOSITE);

      // initialize inner vertical panel to hold individual widgets
      VerticalPanel verticalPanel = new VerticalPanelWithSpacer();
      verticalPanel.addStyleName(CSS_DEMO_INSERT_PANEL_EXAMPLE_CONTAINER);
      verticalPanel.setSpacing(SPACING);
      horizontalPanel.add(columnCompositePanel);

      // initialize a widget drop controller for the current column
      VerticalPanelDropController widgetDropController = new VerticalPanelDropController(
          verticalPanel);
      widgetDragController.registerDropController(widgetDropController);

      // Put together the column pieces
      Label heading = new Label("Column " + col);
      heading.addStyleName(CSS_DEMO_INSERT_PANEL_EXAMPLE_HEADING);
      columnCompositePanel.add(heading);
      columnCompositePanel.add(verticalPanel);

      // make the column draggable by its heading
      columnDragController.makeDraggable(columnCompositePanel, heading);

      for (int row = 1; row <= ROWS; row++) {
        // initialize a widget
        HTML widget = new HTML("Draggable #" + ++count);
        widget.addStyleName(CSS_DEMO_INSERT_PANEL_EXAMPLE_WIDGET);
        widget.setHeight(Random.nextInt(4) + 2 + "em");
        verticalPanel.add(widget);

        // make the widget draggable
        widgetDragController.makeDraggable(widget);
      }
    }
  }

  @Override
  public String getDescription() {
    return "Allows drop to occur anywhere among the children of a supported <code>InsertPanel</code>.";
  }

  @Override
  public Class<?>[] getInvolvedClasses() {
    return new Class[] {
        InsertPanelExample.class, VerticalPanelDropController.class, VerticalPanelWithSpacer.class,
        HorizontalPanelDropController.class,
        PickupDragController.class,};
  }
}