SimpleListCellRenderer.java

/*******************************************************************************
 * Copyright (c) 1998, 2015 Oracle and/or its affiliates. All rights reserved.
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
 * which accompanies this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *     Oracle - initial API and implementation from Oracle TopLink
******************************************************************************/
package org.eclipse.persistence.tools.workbench.uitools.cell;

import java.awt.Component;

import javax.swing.DefaultListCellRenderer;
import javax.swing.Icon;
import javax.swing.JList;

/**
 * This renderer should behave the same as the DefaultListCellRenderer;
 * but it slightly refactors the calculation of the icon and text of the list
 * cell so that subclasses can easily override the methods that build
 * the icon and text.
 *
 * In most cases, you need only override:
 *     #buildIcon(Object value)
 *     #buildText(Object value)
 */
public class SimpleListCellRenderer
    extends DefaultListCellRenderer
{

    /**
     * Construct a simple renderer.
     */
    public SimpleListCellRenderer() {
        super();
    }

    /**
     * @see javax.swing.ListCellRenderer#getListCellRendererComponent(javax.swing.JList, Object, int, boolean, boolean)
     */
    public Component getListCellRendererComponent(JList list, Object value, int index, boolean isSelected, boolean cellHasFocus) {
        // substitute null for the cell value so nothing is drawn initially...
        super.getListCellRendererComponent(list, null, index, isSelected, cellHasFocus);
        this.setOpaque(true);

        // ...then set the icon and text manually
        this.setIcon(this.buildIcon(list, value, index, isSelected, cellHasFocus));
        this.setText(this.buildText(list, value, index, isSelected, cellHasFocus));

        this.setToolTipText(this.buildToolTipText(list, value, index, isSelected, cellHasFocus));

        // the context will be initialized only if a reader is running
        if (this.accessibleContext != null) {
            this.accessibleContext.setAccessibleName(this.buildAccessibleName(list, value, index, isSelected, cellHasFocus));
        }

        return this;
    }

    /**
     * Return the icon representation of the specified cell
     * value and other settings. (Even more settings are
     * accessible via inherited getters: hasFocus, isEnabled, etc.)
     */
    protected Icon buildIcon(JList list, Object value, int index, boolean isSelected, boolean cellHasFocus) {
        return this.buildIcon(value);
    }

    /**
     * Return the icon representation of the specified cell
     * value. The default is to display no icon at all unless the
     * value itself is an icon.
     */
    protected Icon buildIcon(Object value) {
        // replicate the default behavior
        return (value instanceof Icon) ? (Icon) value : null;
    }

    /**
     * Return the textual representation of the specified cell
     * value and other settings. (Even more settings are
     * accessible via inherited getters: hasFocus, isEnabled, etc.)
     */
    protected String buildText(JList list, Object value, int index, boolean isSelected, boolean cellHasFocus) {
        return this.buildText(value);
    }

    /**
     * Return the textual representation of the specified cell
     * value. The default is to display the object's default string
     * representation (as returned by #toString()); unless the
     * value itself is an icon, in which case no text is displayed.
     */
    protected String buildText(Object value) {
        return (value instanceof Icon) ? "" : ((value == null) ? "" : value.toString());
    }

    /**
     * Return the text displayed when the cursor lingers over the specified cell.
     * (Even more settings are accessible via inherited getters: hasFocus, isEnabled, etc.)
     */
    protected String buildToolTipText(JList list, Object value, int index, boolean isSelected, boolean cellHasFocus) {
        return this.buildToolTipText(value);
    }

    /**
     * Return the text displayed when the cursor lingers over the specified cell.
     */
    protected String buildToolTipText(Object value) {
        return null;
    }

    /**
     * Return the accessible name to be given to the component used to render
     * the given value and other settings. (Even more settings are accessible via
     * inherited getters: hasFocus, isEnabled, etc.)
     */
    protected String buildAccessibleName(JList list, Object value, int index, boolean isSelected, boolean cellHasFocus) {
        return this.buildAccessibleName(value);
    }

    /**
     * Return the accessible name to be given to the component used to render
     * the given value.
     */
    protected String buildAccessibleName(Object value) {
        return null;
    }

}