TwistieSection.java

package org.gudy.azureus2.ui.swt;

import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Composite;

public class TwistieSection
	extends Composite
	implements ITwistieConstants
{
	private TwistieContentPanel content = null;

	private TwistieLabel label = null;

	/**
	 * Create a TwistieSection with the given style bit.
	 * <p>Style bit can be one or more of:</p>
	 * <ul>
	 * <li> TwistieLabel.NONE</li> -- The default; does not show description and separator, and is collapsed
	 * <li> TwistieLabel.SHOW_DESCRIPTION</li> -- Show the description below the separator (or title if separator s not shown)
	 * <li> TwistieLabel.SHOW_SEPARATOR</li> -- Show a separator below the title
	 * <li> TwistieLabel.SHOW_EXPANDED</li> -- Show a separator below the title
	 * </ul>
		*/
	public TwistieSection(Composite parent, int style) {
		super(parent, SWT.NONE);

		GridLayout gLayout = new GridLayout();
		gLayout.marginHeight = 0;
		gLayout.marginWidth = 0;
		gLayout.verticalSpacing = 0;
		setLayout(gLayout);

		label = new TwistieLabel(this, style);
		label.setLayoutData(new GridData(SWT.FILL, SWT.CENTER, true, false));

		content = new TwistieContentPanel(this, SWT.NONE);
		final GridData gDataExpanded = new GridData(SWT.FILL, SWT.FILL, true, true);
		final GridData gDataCollapsed = new GridData(SWT.FILL, SWT.FILL, true,
				false);
		gDataCollapsed.heightHint = 0;

		content._setLayoutData((true == label.isCollapsed()) ? gDataCollapsed
				: gDataExpanded);

		label.addTwistieListener(new ITwistieListener() {
			public void isCollapsed(boolean value) {
				content._setLayoutData((true == value) ? gDataCollapsed : gDataExpanded);
				layout(true, true);

			}

		});

	}

	/**
	 * Returns the main body of the section.  Callers can add custom controls onto the returned
	 * <code>Composite</code>
	 * @return
	 */
	public Composite getContent() {
		return content;
	}

	public void setBackground(Color color) {
		if (null != label && false == label.isDisposed()) {
			label.setBackground(color);
		}

		if (null != content && false == content.isDisposed()) {
			content.setBackground(color);
		}

		super.setBackground(color);
	}

	public void setForeground(Color color) {
		if (null != label && false == label.isDisposed()) {
			label.setForeground(color);
		}

		if (null != content && false == content.isDisposed()) {
			content.setForeground(color);
		}
		super.setForeground(color);
	}

	public void setEnabled(boolean enabled) {
		if (null != label && false == label.isDisposed()) {
			label.setEnabled(enabled);
		}
		super.setEnabled(enabled);
	}

	/**
	 * Delegating to the <code>TwistieLabel</code>
	 * @param listener
	 */
	public void addTwistieListener(ITwistieListener listener) {
		if (null != label && false == label.isDisposed()) {
			label.addTwistieListener(listener);
		}
	}

	/**
	 * Delegating to the <code>TwistieLabel</code>
	 * @param listener
	 */
	public void removeTwistieListener(ITwistieListener listener) {
		if (null != label && false == label.isDisposed()) {
			label.removeTwistieListener(listener);
		}
	}

	/**
	 * Delegating to the <code>TwistieLabel</code>
	 * @param string
	 */

	public void setDescription(String string) {
		if (null != label && false == label.isDisposed()) {
			label.setDescription(string);
		}
	}

	/**
	 * Delegating to the <code>TwistieLabel</code>
	 * @param string
	 */

	public void setTitle(String string) {
		if (null != label && false == label.isDisposed()) {
			label.setTitle(string);
		}
	}

	/**
	 * Delegating to the <code>TwistieLabel</code>
	 * @param string
	 */

	public void setToolTipText(String string) {
		if (null != label && false == label.isDisposed()) {
			label.setToolTipText(string);
		}
	}

	/**
	 * Delegating to the <code>TwistieLabel</code>
	 * @param color
	 */

	public void setTwistieForeground(Color color) {
		if (null != label && false == label.isDisposed()) {
			label.setTwistieForeground(color);
		}
	}

	/**
	 * A simple extension of <code>Composite</code> that disallow modifying its layout data
	 * @author knguyen
	 *
	 */
	private class TwistieContentPanel
		extends Composite
	{

		public TwistieContentPanel(Composite parent, int style) {
			super(parent, style);
		}

		private void _setLayoutData(GridData gData) {
			super.setLayoutData(gData);
		}

		public void setLayoutData(Object layoutData) {
			throw new IllegalArgumentException(
					"This is a managed class therefore overriding its LayoutData is an illegal operation");
		}

	}

}