at.ac.fhcampuswien.atom.client.gui.dnd.MouseListBox.java Source code

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Here is the source code for at.ac.fhcampuswien.atom.client.gui.dnd.MouseListBox.java

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/*
 * 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 at.ac.fhcampuswien.atom.client.gui.dnd;

import java.util.ArrayList;

import at.ac.fhcampuswien.atom.client.App;

import com.google.gwt.user.client.ui.Composite;
import com.google.gwt.user.client.ui.Grid;
import com.google.gwt.user.client.ui.HTML;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.Widget;

/**
 * Either left or right hand side of a {@link DualListBox}.
 */
public class MouseListBox extends Composite {

    private static final class SpacerHTML extends HTML {

        public SpacerHTML() {
            super(" ");
        }
    }

    private static final String CSS_DEMO_DUAL_LIST_EXAMPLE_ITEM = "demo-DualListExample-item";

    private static final String CSS_DEMO_DUAL_LIST_EXAMPLE_ITEM_HAS_CONTENT = "demo-DualListExample-item-has-content";

    private static final String CSS_DEMO_MOUSELISTBOX = "demo-MouseListBox";

    private Grid grid;

    private int widgetCount = 0;

    /**
     * Used by {@link ListBoxDragController} to create a draggable listbox
     * containing the selected items.
     */
    MouseListBox(int size) {
        grid = new Grid(size, 1);
        initWidget(grid);
        grid.setCellPadding(0);
        grid.setCellSpacing(0);
        addStyleName(CSS_DEMO_MOUSELISTBOX);
        for (int i = 0; i < size; i++) {
            grid.getCellFormatter().addStyleName(i, 0, CSS_DEMO_DUAL_LIST_EXAMPLE_ITEM);
            setWidget(i, null);
        }
    }

    /**
     * Used by {@link DualListBox} to create the left and right list boxes.
     */
    MouseListBox() {
        this(200);
    }

    void add(String text) {
        add(new Label(text));
    }

    void add(Widget widget) {
        setWidget(widgetCount++, widget);
    }

    int getWidgetCount() {
        return widgetCount;
    }

    boolean remove(Widget widget) {
        int index = getWidgetIndex(widget);
        if (index == -1) {
            return false;
        }
        for (int i = index; i < widgetCount - 1; i++) {
            // explicitly remove and add widget back for correct draggability
            setWidget(i, removeWidget(i + 1));
        }
        setWidget(widgetCount - 1, null);
        widgetCount--;
        return true;
    }

    ArrayList<Widget> widgetList() {
        ArrayList<Widget> widgetList = new ArrayList<Widget>();
        for (int i = 0; i < getWidgetCount(); i++) {
            widgetList.add(getWidget(i));
        }
        return widgetList;
    }

    private Widget getWidget(int index) {
        return grid.getWidget(index, 0);
    }

    private int getWidgetIndex(Widget widget) {
        for (int i = 0; i < getWidgetCount(); i++) {
            if (getWidget(i) == widget) {
                return i;
            }
        }
        return -1;
    }

    private Widget removeWidget(int index) {
        Widget widget = getWidget(index);
        if (widget != null && !(widget instanceof SpacerHTML)) {
            App.unRegisterDndWidget(widget);
        }
        grid.getCellFormatter().removeStyleName(index, 0, CSS_DEMO_DUAL_LIST_EXAMPLE_ITEM_HAS_CONTENT);
        grid.setWidget(index, 0, new SpacerHTML());
        return widget;
    }

    private void setWidget(int index, Widget widget) {
        removeWidget(index);
        if (widget == null) {
            widget = new SpacerHTML();
        } else {
            grid.getCellFormatter().addStyleName(index, 0, CSS_DEMO_DUAL_LIST_EXAMPLE_ITEM_HAS_CONTENT);
            App.registerDndWidget(widget);
        }
        grid.setWidget(index, 0, widget);
    }
}