ltk/org.eclipse.statet.ltk.ui/src/org/eclipse/statet/ltk/ui/sourceediting/assist/QuickRefactoringAssistProposal.java

/*=============================================================================#
 # Copyright (c) 2021 Stephan Wahlbrink and others.
 # 
 # This program and the accompanying materials are made available under the
 # terms of the Eclipse Public License 2.0 which is available at
 # https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
 # which is available at https://www.apache.org/licenses/LICENSE-2.0.
 # 
 # SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
 # 
 # Contributors:
 #     Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
 #=============================================================================*/

package org.eclipse.statet.ltk.ui.sourceediting.assist;

import static org.eclipse.statet.ltk.ui.LtkUI.BUNDLE_ID;

import java.lang.reflect.InvocationTargetException;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.core.runtime.SubMonitor;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.ITextViewer;
import org.eclipse.jface.text.Position;
import org.eclipse.ltk.core.refactoring.TextChange;
import org.eclipse.text.edits.TextEdit;
import org.eclipse.ui.progress.IProgressService;
import org.eclipse.ui.statushandlers.StatusManager;

import org.eclipse.statet.jcommons.lang.NonNull;
import org.eclipse.statet.jcommons.lang.NonNullByDefault;
import org.eclipse.statet.jcommons.lang.Nullable;

import org.eclipse.statet.ecommons.text.ui.DefaultBrowserInformationInput;

import org.eclipse.statet.internal.ltk.ui.refactoring.TextEditAnnotator;
import org.eclipse.statet.ltk.model.core.element.SourceUnit;
import org.eclipse.statet.ltk.refactoring.core.QuickRefactoring;
import org.eclipse.statet.ltk.ui.refactoring.RefactoringExecutionHelper;
import org.eclipse.statet.ltk.ui.sourceediting.SourceEditor;


@NonNullByDefault
public class QuickRefactoringAssistProposal<TContext extends AssistInvocationContext>
		extends CommandAssistProposal<TContext> {
	
	
	private final QuickRefactoring refactoring;
	
	
	public QuickRefactoringAssistProposal(final ProposalParameters<TContext> parameters,
			final QuickRefactoring refactoring) {
		super(parameters);
		this.refactoring= refactoring;
		
		check();
	}
	
	public QuickRefactoringAssistProposal(final TContext invocationContext, final String commandId,
			final String label,
			final QuickRefactoring refactoring) {
		super(invocationContext, commandId, label, null);
		this.refactoring= refactoring;
		
		check();
	}
	
	protected void check() {
		if (getInvocationContext().getSourceUnit() == null) {
			throw new IllegalArgumentException();
		}
	}
	
	
	protected QuickRefactoring getRefactoring() {
		return this.refactoring;
	}
	
	
	@Override
	public @Nullable Object getAdditionalProposalInfo(final IProgressMonitor monitor) {
		final SubMonitor m= SubMonitor.convert(monitor, 2 + 2);
		try {
			final StringBuilder sb= new StringBuilder();
			final TextChange change= this.refactoring.createTextChange(m.newChild(2));
			change.setKeepPreviewEdits(true);
			final IDocument previewDocument= change.getPreviewDocument(m.newChild(1));
			final TextEdit rootEdit= change.getPreviewEdit(change.getEdit());
			final TextEditAnnotator ea= new TextEditAnnotator(sb, previewDocument);
			rootEdit.accept(ea); m.worked(1);
			return new DefaultBrowserInformationInput(getDisplayString(),
					sb.toString(), DefaultBrowserInformationInput.FORMAT_HTMLSOURCE_INPUT,
					getInvocationContext().getTabSize() );
		}
		catch (final CoreException e) {
			StatusManager.getManager().handle(new Status(IStatus.ERROR, BUNDLE_ID, -1,
					String.format("An error occured when generating the preview for quick assist '%1$s'.",
							getDisplayString() ),
					e ));
			return null;
		}
		finally {
			m.done();
		}
	}
	
	
	@Override
	public void apply(final ITextViewer viewer,
			final char trigger, final int stateMask, final int offset) {
		final var context= getInvocationContext();
		@SuppressWarnings("null")
		final @NonNull SourceUnit sourceUnit= context.getSourceUnit();
		final SourceEditor editor= context.getEditor();
		final var textWidget= editor.getViewer().getTextWidget();
		if (textWidget == null) {
			return;
		}
		
		IProgressService execContext= null;
		final var serviceLocator= editor.getServiceLocator();
		if (serviceLocator != null) {
			execContext= serviceLocator.getService(IProgressService.class);
		}
		if (execContext == null) {
			return;
		}
		final var applyData= getApplyData();
		try {
			final var refactoring= this.refactoring;
			final var helper= new RefactoringExecutionHelper(refactoring,
					offset, textWidget.getShell(), execContext );
			helper.enableInsertPosition(sourceUnit);
			helper.perform(false, false);
			
			final Position position= helper.getInsertPosition();
			if (position != null) {
				applyData.setSelection(position.getOffset());
			}
		}
		catch (final InterruptedException e) {}
		catch (final InvocationTargetException e) {
			StatusManager.getManager().handle(new Status(IStatus.ERROR, BUNDLE_ID, -1,
					String.format("An error occured when executing quick assist '%1$s'.",
							getDisplayString() ),
					e ));
		}
	}
	
}