package org.eclipse.jdt.internal.debug.ui.launcher;

/*
 * (c) Copyright IBM Corp. 2000, 2001.
 * All Rights Reserved.
 */
 
import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IResource;
import org.eclipse.debug.core.ILaunchConfigurationWorkingCopy;
import org.eclipse.debug.ui.AbstractLaunchConfigurationTab;
import org.eclipse.jdt.core.IJavaElement;
import org.eclipse.jdt.core.IJavaProject;
import org.eclipse.jdt.core.JavaCore;
import org.eclipse.jdt.internal.debug.ui.JDIDebugUIPlugin;
import org.eclipse.jdt.launching.IJavaLaunchConfigurationConstants;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.ui.IEditorInput;
import org.eclipse.ui.IEditorPart;
import org.eclipse.ui.IWorkbenchPage;

/**
 * Common function for Java launch configuration tabs.
 */
public abstract class JavaLaunchConfigurationTab extends AbstractLaunchConfigurationTab implements IEntriesChangedListener {
		
	/**
	 * Returns the current Java element context from which to initialize
	 * default settings, or <code>null</code> if none.
	 * 
	 * @return Java element context.
	 */
	protected IJavaElement getContext() {
		IWorkbenchPage page = JDIDebugUIPlugin.getActivePage();
		if (page != null) {
			ISelection selection = page.getSelection();
			if (selection instanceof IStructuredSelection) {
				IStructuredSelection ss = (IStructuredSelection)selection;
				if (!ss.isEmpty()) {
					Object obj = ss.getFirstElement();
					if (obj instanceof IJavaElement) {
						return (IJavaElement)obj;
					}
					if (obj instanceof IResource) {
						IJavaElement je = JavaCore.create((IResource)obj);
						if (je == null) {
							IProject pro = ((IResource)obj).getProject();
							je = JavaCore.create(pro);
						}
						if (je != null) {
							return je;
						}
					}
				}
			}
			IEditorPart part = page.getActiveEditor();
			if (part != null) {
				IEditorInput input = part.getEditorInput();
				return (IJavaElement) input.getAdapter(IJavaElement.class);
			}
		}
		return null;
	}
	
	/**
	 * Set the java project attribute based on the IJavaElement.
	 */
	protected void initializeJavaProject(IJavaElement javaElement, ILaunchConfigurationWorkingCopy config) {
		IJavaProject javaProject = javaElement.getJavaProject();
		String name = null;
		if (javaProject != null && javaProject.exists()) {
			name = javaProject.getElementName();
		}
		config.setAttribute(IJavaLaunchConfigurationConstants.ATTR_PROJECT_NAME, name);
	}	
	
	/**
	 * @see IEntriesChangedListener#entriesChanged(RuntimeClasspathViewer)
	 */
	public void entriesChanged(RuntimeClasspathViewer viewer) {
		updateLaunchConfigurationDialog();
	}

}