ro.zg.open_groups.gui.components.CustomTabSheet.java Source code

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Here is the source code for ro.zg.open_groups.gui.components.CustomTabSheet.java

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/*******************************************************************************
 * Copyright 2011 Adrian Cristian Ionescu
 * 
 * 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 ro.zg.open_groups.gui.components;

import java.io.Serializable;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;

import com.vaadin.ui.Button;
import com.vaadin.ui.Component;
import com.vaadin.ui.HorizontalLayout;
import com.vaadin.ui.VerticalLayout;
import com.vaadin.ui.Button.ClickEvent;
import com.vaadin.ui.Button.ClickListener;
import com.vaadin.ui.themes.BaseTheme;

public class CustomTabSheet extends VerticalLayout {

    /**
     * 
     */
    private static final long serialVersionUID = -5331446610981425434L;

    private Map<Component, Button> tabs = new HashMap<Component, Button>();
    private HorizontalLayout tabsArea = new HorizontalLayout();
    private VerticalLayout displayArea = new VerticalLayout();
    private Component currentSelectedTabContent;
    boolean initialized;

    private void initialize() {
        tabsArea.setSpacing(true);
        addComponent(tabsArea);
        addComponent(displayArea);
    }

    public void addTab(final Component tabContent, String caption) {
        Button tab = tabs.get(tabContent);
        if (tab == null) {
            tab = new Button(caption);
            tab.addStyleName(BaseTheme.BUTTON_LINK);
            tabs.put(tabContent, tab);
            /* if this is the first tab in this tabsheet select it */
            if (tabs.size() == 1) {
                if (!initialized) {
                    /* laizy initialization when the first tab is added */
                    initialize();
                    initialized = true;
                }
                tabsArea.addComponent(tab);
                selectTab(tabContent, tab);
            } else {
                tabsArea.addComponent(tab);
            }
            /* add click listener for this tab */
            tab.addListener(new ClickListener() {

                @Override
                public void buttonClick(ClickEvent event) {
                    selectTab(tabContent, event.getButton());
                }
            });

        } else {
            tab.setCaption(caption);
        }
    }

    private void selectTab(Component tabContent, Button tab) {
        if (currentSelectedTabContent == tabContent) {
            return;
        }
        displayArea.removeAllComponents();
        displayArea.addComponent(tabContent);
        currentSelectedTabContent = tabContent;
        /* mark the tab as selected */
        // TODO
        /* fire tab change */
        fireSelectedTabChange();
    }

    public void setSelectedTab(Component tabContent) {
        Button tab = tabs.get(tabContent);
        if (tab != null) {
            selectTab(tabContent, tab);
        }
    }

    public Component getSelectedTab() {
        return currentSelectedTabContent;
    }

    /* listeners and stuff */

    private static final Method SELECTED_TAB_CHANGE_METHOD;
    static {
        try {
            SELECTED_TAB_CHANGE_METHOD = CustomSelectedTabChangeListener.class
                    .getDeclaredMethod("selectedTabChange", new Class[] { CustomSelectedTabChangeEvent.class });
        } catch (final java.lang.NoSuchMethodException e) {
            // This should never happen
            throw new java.lang.RuntimeException("Internal error finding methods in TabSheet");
        }
    }

    public class CustomSelectedTabChangeEvent extends Component.Event {

        /**
         * New instance of selected tab change event
         * 
         * @param source
         *            the Source of the event.
         */
        public CustomSelectedTabChangeEvent(Component source) {
            super(source);
        }

        /**
         * TabSheet where the event occurred.
         * 
         * @return the Source of the event.
         */
        public CustomTabSheet getTabSheet() {
            return (CustomTabSheet) getSource();
        }
    }

    /**
     * Selected tab change event listener. The listener is called whenever
     * another tab is selected, including when adding the first tab to a
     * tabsheet.
     * 
     * @author IT Mill Ltd.
     * 
     * @version
     * 6.4.2
     * @since 3.0
     */
    public interface CustomSelectedTabChangeListener extends Serializable {

        /**
         * Selected (shown) tab in tab sheet has has been changed.
         * 
         * @param event
         *            the selected tab change event.
         */
        public void selectedTabChange(CustomSelectedTabChangeEvent event);
    }

    /**
     * Adds a tab selection listener
     * 
     * @param listener
     *            the Listener to be added.
     */
    public void addListener(CustomSelectedTabChangeListener listener) {
        addListener(CustomSelectedTabChangeEvent.class, listener, SELECTED_TAB_CHANGE_METHOD);
    }

    /**
     * Removes a tab selection listener
     * 
     * @param listener
     *            the Listener to be removed.
     */
    public void removeListener(CustomSelectedTabChangeListener listener) {
        removeListener(CustomSelectedTabChangeEvent.class, listener, SELECTED_TAB_CHANGE_METHOD);
    }

    /**
     * Sends an event that the currently selected tab has changed.
     */
    protected void fireSelectedTabChange() {
        fireEvent(new CustomSelectedTabChangeEvent(this));
    }

}