bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/dialogs/PropertyPageNode.java

package org.eclipse.ui.internal.dialogs;

/*
 * (c) Copyright IBM Corp. 2000, 2001.
 * All Rights Reserved.
 */
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IAdaptable;
import org.eclipse.jface.dialogs.ErrorDialog;
import org.eclipse.jface.preference.PreferenceNode;
import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.ui.IWorkbenchPropertyPage;
import org.eclipse.ui.internal.WorkbenchMessages;

/**
 * Property page node allows us to achive presence in the property page dialog
 * without loading the page itself, thus loading the contributing plugin.
 * Only when the user selects the page will it be loaded.
 */
public class PropertyPageNode extends PreferenceNode {
	private RegistryPageContributor contributor;
	private IWorkbenchPropertyPage page;
	private Image icon;
	private IAdaptable element;
/**
 * PropertyPageNode constructor.
 */
public PropertyPageNode(RegistryPageContributor contributor, IAdaptable element) {
	super(contributor.getPageId());
	this.contributor = contributor;
	this.element = element;
}
/**
 * Creates the preference page this node stands for. If the page is null,
 * it will be created by loading the class. If loading fails,
 * empty filler page will be created instead.
 */
public void createPage() {
	try {
		page = contributor.createPage(element);
	} catch (CoreException e) {
		// Just inform the user about the error. The details are
		// written to the log by now.
		ErrorDialog.openError(
			(Shell)null, 
			WorkbenchMessages.getString("PropertyPageNode.errorTitle"),  //$NON-NLS-1$
			WorkbenchMessages.getString("PropertyPageNode.errorMessage"),  //$NON-NLS-1$
			e.getStatus());  
		page = new EmptyPropertyPage();
	}
	setPage(page);
}
/** (non-Javadoc)
 * Method declared on IPreferenceNode.
 */
public void disposeResources() {
	
	if (page != null) {
		page.dispose();
		page = null;
	}
	if (icon != null) {
		icon.dispose();
		icon = null;
	}
}
/**
 * Returns page icon, if defined.
 */
public Image getLabelImage() {
	if (icon==null) {
		ImageDescriptor desc = contributor.getPageIcon();
		if (desc != null) {
			icon = desc.createImage();
		}
	}
	return icon;
}
/**
 * Returns page label as defined in the registry.
 */
public String getLabelText() {
	return contributor.getPageName();	
}
}