SymbolPlugin.java

/*
 * See the NOTICE file distributed with this work for additional
 * information regarding copyright ownership.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */
package org.xwiki.gwt.wysiwyg.client.plugin.symbol;

import org.xwiki.gwt.user.client.Config;
import org.xwiki.gwt.user.client.ui.CompositeDialogBox;
import org.xwiki.gwt.user.client.ui.rta.RichTextArea;
import org.xwiki.gwt.user.client.ui.rta.cmd.Command;
import org.xwiki.gwt.wysiwyg.client.Images;
import org.xwiki.gwt.wysiwyg.client.Strings;
import org.xwiki.gwt.wysiwyg.client.plugin.internal.AbstractPlugin;
import org.xwiki.gwt.wysiwyg.client.plugin.internal.FocusWidgetUIExtension;

import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.event.logical.shared.CloseEvent;
import com.google.gwt.event.logical.shared.CloseHandler;
import com.google.gwt.user.client.ui.Image;
import com.google.gwt.user.client.ui.PushButton;

/**
 * Allows the user to insert a special symbol chosen with a symbol picker in place of the current selection.
 * 
 * @version $Id: b66fa25fb9b6cc4a74f425c4d5f4e070b8412b76 $
 */
public class SymbolPlugin extends AbstractPlugin implements ClickHandler, CloseHandler<CompositeDialogBox>
{
    /**
     * The insert button to be placed on the tool bar.
     */
    private PushButton insert;

    /**
     * The symbol picker used for choosing the symbol to insert.
     */
    private SymbolPicker picker;

    /**
     * Tool bar extension.
     */
    private final FocusWidgetUIExtension toolBarExtension = new FocusWidgetUIExtension("toolbar");

    @Override
    public void init(RichTextArea textArea, Config config)
    {
        super.init(textArea, config);

        if (getTextArea().getCommandManager().isSupported(Command.INSERT_HTML)) {
            insert = new PushButton(new Image(Images.INSTANCE.charmap()));
            saveRegistration(insert.addClickHandler(this));
            insert.setTitle(Strings.INSTANCE.charmap());

            toolBarExtension.addFeature("symbol", insert);
        }

        if (toolBarExtension.getFeatures().length > 0) {
            getUIExtensionList().add(toolBarExtension);
        }
    }

    @Override
    public void destroy()
    {
        if (insert != null) {
            insert.removeFromParent();
            insert = null;

            if (picker != null) {
                picker.hide();
                picker.removeFromParent();
                picker = null;
            }
        }

        toolBarExtension.clearFeatures();

        super.destroy();
    }

    @Override
    public void onClick(ClickEvent event)
    {
        if (event.getSource() == insert) {
            onSymbols(true);
        }
    }

    @Override
    public void onClose(CloseEvent<CompositeDialogBox> event)
    {
        if (event.getSource() == getSymbolPicker() && !event.isAutoClosed()) {
            onSymbols(false);
        }
    }

    /**
     * Either shows the symbol picker dialog or inserts the chosen symbol depending in the given flag.
     * 
     * @param show whether to show the symbol picker or insert the chosen symbol.
     */
    public void onSymbols(boolean show)
    {
        if (show) {
            if (insert.isEnabled()) {
                getSymbolPicker().center();
            }
        } else {
            getTextArea().setFocus(true);
            String character = getSymbolPicker().getSymbol();
            if (character != null && getTextArea().getCommandManager().execute(Command.INSERT_HTML, character)) {
                getTextArea().getDocument().getSelection().collapseToEnd();
            }
        }
    }

    /**
     * We use lazy loading in case of the symbol picker to optimize editor loading time because the symbol palette is an
     * HTML table with many cells and takes a bit of time to be created. In the future we should consider using
     * innerHTML for creating the palette and widget binding.
     * 
     * @return the symbol picker to be used for selecting the symbol.
     */
    private SymbolPicker getSymbolPicker()
    {
        if (picker == null) {
            picker = new SymbolPicker();
            saveRegistration(picker.addCloseHandler(this));
        }
        return picker;
    }
}