bundles/org.eclipse.ui.workbench.compatibility/src/org/eclipse/ui/internal/CompatibleWorkbenchPage.java

/*******************************************************************************
 * Copyright (c) 2003 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.ui.internal;

import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IMarker;
import org.eclipse.core.runtime.IPluginDescriptor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Platform;
import org.eclipse.core.runtime.Status;

import org.eclipse.ui.IEditorInput;
import org.eclipse.ui.IEditorPart;
import org.eclipse.ui.IEditorRegistry;
import org.eclipse.ui.IWorkbenchPage;
import org.eclipse.ui.PartInitException;

/**
 * Internal class used in providing increased binary compatibility for
 * pre-3.0 plug-ins. This declaration masks the empty class of the same
 * name declared in the Workbench proper. This class implements
 * IWorkbenchPage that existed in 2.1 but were removed in 3.0 because they
 * referenced resource API.
 * 
 * @since 3.0
 */
public class CompatibleWorkbenchPage implements ICompatibleWorkbenchPage {
	/**
	 * openEditor(IFile) is declared on IWorkbenchPage in 2.1.
	 * This method was removed in 3.0 because it references resource API.
	 */
	public IEditorPart openEditor(IFile input) throws PartInitException {
		// invoke org.eclipse.ui.ide.IDE.openEditor(IWorkbenchPage, IFile, boolean);
		return openEditor(
				new Class[] {IWorkbenchPage.class, IFile.class, boolean.class},
				new Object[] {this, input, new Boolean(true)});
	}
	
	/**
	 * openEditor(IFile,String) is declared on IWorkbenchPage in 2.1.
	 * This method was removed in 3.0 because it references resource API.
	 */
	public IEditorPart openEditor(IFile input, String editorID) throws PartInitException {
		return openEditor(input, editorID, true);
	}


	/**
	 * openEditor(IFile,String,boolean) is declared on IWorkbenchPage in 2.1.
	 * This method was removed in 3.0 because it references resource API.
	 */
	public IEditorPart openEditor(IFile input, String editorID, boolean activate) throws PartInitException {
		return ((IWorkbenchPage) this).openEditor(getFileEditorInput(input), editorID);
	}


	/**
	 * openEditor(IMarker) is declared on IWorkbenchPage in 2.1.
	 * This method was removed in 3.0 because it references resource API.
	 */
	public IEditorPart openEditor(IMarker marker) throws PartInitException {
		return openEditor(marker, true);
	}


	/**
	 * openEditor(IMarker,boolean) is declared on IWorkbenchPage in 2.1.
	 * This method was removed in 3.0 because it references resource API.
	 */
	public IEditorPart openEditor(IMarker marker, boolean activate) throws PartInitException {
		// invoke org.eclipse.ui.ide.IDE.openEditor(IWorkbenchPage, IMarker, boolean);
		return openEditor(
				new Class[] {IWorkbenchPage.class, IMarker.class, boolean.class},
				new Object[] {this, marker, new Boolean(activate)});
	}


	/**
	 * openSystemEditor(IFile) is declared on IWorkbenchPage in 2.1.
	 * This method was removed in 3.0 because it references resource API.
	 */
	public void openSystemEditor(IFile file) throws PartInitException {
		((IWorkbenchPage) this).openEditor(getFileEditorInput(file), IEditorRegistry.SYSTEM_EXTERNAL_EDITOR_ID); 
		
	}

	/* Implementation support: Use reflection for the following code pattern: 
	 * new org.eclipse.ui.part.FileEditorInput(file)
	 * The class FileEditorInput is found in the org.eclipse.ui.ide plug-in.
	 */
	private IEditorInput getFileEditorInput(IFile file) throws PartInitException {
		IPluginDescriptor desc= Platform.getPluginRegistry().getPluginDescriptor("org.eclipse.ui.ide"); //$NON-NLS-1$		
		Exception problem;
		try {
			Class clazz =
				desc.getPluginClassLoader().loadClass("org.eclipse.ui.part.FileEditorInput"); //$NON-NLS-1$
			Constructor constructor = 
				clazz.getConstructor(new Class[] {IFile.class});
			return (IEditorInput) constructor.newInstance(new Object[] {file});
		} catch (NullPointerException e) {
			problem = e;
		} catch (ClassNotFoundException e) {
			problem = e;
		} catch (NoSuchMethodException e) {
			problem = e;
		} catch (IllegalArgumentException e) {
			problem = e;
		} catch (IllegalAccessException e) {
			problem = e;
		} catch (InvocationTargetException e) {
			problem = e;
		} catch (InstantiationException e) {
			problem = e;
		}
		IStatus status = new Status(IStatus.ERROR, WorkbenchPlugin.PI_WORKBENCH, 0, "openEditor() compatibility support failed - new FileEditorInput(file)", problem);  //$NON-NLS-1$
		WorkbenchPlugin.log(status.getMessage(), status);
		throw new PartInitException(status);
	}
	
	/* Implementation support: 
	 * Use reflection to invoke the appropriate static openEditor(...) method on IDE
	 * The IDE class is found in the org.eclipse.ui.ide plug-in.
	 */
	private IEditorPart openEditor(Class[] argTypes, Object[] args) throws PartInitException {
		IPluginDescriptor desc = Platform.getPluginRegistry().getPluginDescriptor("org.eclipse.ui.ide"); //$NON-NLS-1$
		Throwable problem;
		try {
			Class clazz =
				desc.getPluginClassLoader().loadClass("org.eclipse.ui.ide.IDE"); //$NON-NLS-1$
			Method method =
				clazz.getMethod("openEditor", argTypes); //$NON-NLS-1$
			return (IEditorPart) method.invoke(null, args);
		} catch (NullPointerException e) {
			problem = e;
		} catch (ClassNotFoundException e) {
			problem = e;
		} catch (NoSuchMethodException e) {
			problem = e;
		} catch (IllegalArgumentException e) {
			problem = e;
		} catch (IllegalAccessException e) {
			problem = e;
		} catch (InvocationTargetException e) {
			problem = e;
		}
		IStatus status = new Status(IStatus.ERROR, WorkbenchPlugin.PI_WORKBENCH, 0, "openEditor() compatibility support failed - IDE.openEditor()", problem);  //$NON-NLS-1$
		WorkbenchPlugin.log(status.getMessage(), status);
		throw new PartInitException(status);
	}
}