org.polymap.rhei.batik.toolkit.md.RadioboxActionProvider.java Source code

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Here is the source code for org.polymap.rhei.batik.toolkit.md.RadioboxActionProvider.java

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/* 
 * polymap.org
 * Copyright (C) 2016, Falko Brutigam. All rights reserved.
 *
 * 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 3.0 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.
 */
package org.polymap.rhei.batik.toolkit.md;

import static org.polymap.rhei.batik.app.SvgImageRegistryHelper.NORMAL24;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.eclipse.swt.graphics.Image;

import org.eclipse.jface.viewers.ViewerCell;

import org.polymap.core.runtime.config.Config2;
import org.polymap.core.runtime.config.ConfigurationFactory;
import org.polymap.core.runtime.config.Mandatory;

import org.polymap.rhei.batik.BatikPlugin;

/**
 * 
 *
 * @author <a href="http://www.polymap.de">Falko Brutigam</a>
 */
public abstract class RadioboxActionProvider extends ActionProvider {

    private static final Log log = LogFactory.getLog(RadioboxActionProvider.class);

    /** Defaults to: "radiobox-marked.svg", NORMAL24 */
    @Mandatory
    public Config2<RadioboxActionProvider, Image> selectedImage;

    /** Defaults to: "radiobox-blank.svg", NORMAL24 */
    @Mandatory
    public Config2<RadioboxActionProvider, Image> unselectedImage;

    /** The selected element, or null. */
    private Object selection;

    public RadioboxActionProvider() {
        ConfigurationFactory.inject(this);
        selectedImage.set(BatikPlugin.images().svgImage("radiobox-marked.svg", NORMAL24));
        unselectedImage.set(BatikPlugin.images().svgImage("radiobox-blank.svg", NORMAL24));
        selection = initSelection(null);
    }

    public boolean isSelected(Object elm) {
        assert elm != null;
        return elm == selection;
    }

    /**
     * Updates the selection state of the given element. Should be called after the
     * model has been changed outside the viewer. This does not call
     * {@link #onSelection(MdListViewer, Object, boolean)} callback.
     *
     * @param elm The updated elm
     * @param selected The new selection state.
     */
    public void updateSelection(MdListViewer viewer, Object elm, boolean selected) {
        assert elm != null;
        this.selection = selected ? elm : null;
        viewer.update(elm, null);
    }

    /**
     * The initial selected element. This method is called from the constructor.
     */
    protected abstract Object initSelection(MdListViewer viewer);

    protected abstract void onSelection(MdListViewer viewer, Object elm, boolean selected);

    @Override
    public void update(ViewerCell cell) {
        cell.setImage(isSelected(cell.getElement()) ? selectedImage.get() : unselectedImage.get());
    }

    /**
     * This default implementation updates the {@link #isSelected()} state and
     * the image according to this new state. Override
     */
    @Override
    public void perform(MdListViewer viewer, Object elm) {
        Object _selected = selection;
        // unselect
        if (selection != null) {
            onSelection(viewer, selection, false);
            selection = null;
            viewer.update(_selected, null);
        }
        // select
        if (elm != _selected) {
            onSelection(viewer, elm, true);
            selection = elm;
            viewer.update(elm, null);
        }
    }

}