org.cruxframework.crux.widgets.client.paging.RandomPager.java Source code

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Here is the source code for org.cruxframework.crux.widgets.client.paging.RandomPager.java

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/*
 * Copyright 2014 cruxframework.org.
 * 
 * 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 org.cruxframework.crux.widgets.client.paging;

import org.cruxframework.crux.widgets.client.event.paging.PageEvent;

import com.google.gwt.event.dom.client.ChangeEvent;
import com.google.gwt.event.dom.client.ChangeHandler;
import com.google.gwt.user.client.ui.HasHorizontalAlignment;
import com.google.gwt.user.client.ui.HasVerticalAlignment;
import com.google.gwt.user.client.ui.HorizontalPanel;
import com.google.gwt.user.client.ui.ListBox;

/**
 * A pager which knows the total number of pages.  
 * @author Gesse S. F. Dafe
 */
public class RandomPager extends NavigationButtonsPager {
    private HorizontalPanel panel;
    private ListBox listBox;
    private int pageCount;

    /**
     * Constructor
     */
    public RandomPager() {
        this.listBox = createListBox();

        this.panel = new HorizontalPanel();
        this.panel.setHorizontalAlignment(HasHorizontalAlignment.ALIGN_CENTER);
        this.panel.setVerticalAlignment(HasVerticalAlignment.ALIGN_MIDDLE);
        this.panel.setSpacing(2);

        this.panel.add(createFirstPageButton());
        this.panel.add(createPreviousButton());
        this.panel.add(listBox);
        this.panel.add(createNextButton());
        this.panel.add(createLastPageButton());

        this.panel.setStyleName("crux-RandomPager");
        initWidget(this.panel);
    }

    @Override
    protected void onUpdate() {
        if (this.pageCount != getPageCount()) {
            this.pageCount = getPageCount();
            this.listBox.clear();

            for (int i = 1; i <= getPageCount(); i++) {
                String page = "" + i;
                listBox.addItem(page, page);
            }
        }

        if (this.listBox.getItemCount() > 0) {
            listBox.setEnabled(true);
            listBox.setSelectedIndex(getCurrentPage() - 1);
        } else {
            listBox.setEnabled(false);
        }
    }

    /**
     * @see org.cruxframework.crux.widgets.client.paging.AbstractPager#showLoading()
     */
    @Override
    protected void showLoading() {
        listBox.setEnabled(false);
    }

    /**
     * @see org.cruxframework.crux.widgets.client.paging.AbstractPager#hideLoading()
     */
    @Override
    protected void hideLoading() {
        listBox.setEnabled(true);
    }

    /**
     * Creates a list box with page numbers
     * @return
     */
    private ListBox createListBox() {
        final ListBox list = new ListBox();
        list.setEnabled(false);
        list.addChangeHandler(new ChangeHandler() {
            public void onChange(ChangeEvent event) {
                if (isEnabled()) {
                    PageEvent pageEvent = PageEvent.fire(RandomPager.this, getCurrentPage() + 1);
                    if (!pageEvent.isCanceled()) {
                        int selected = list.getSelectedIndex();
                        String page = list.getValue(selected);
                        goToPage(Integer.valueOf(page));
                    } else {
                        list.setSelectedIndex(getCurrentPage() - 1);
                    }
                }
            }
        });

        return list;
    }
}