docmlet/org.eclipse.statet.docmlet.tex.ui/src/org/eclipse/statet/internal/docmlet/tex/ui/editors/LtxSymbolsMenuContributions.java

/*=============================================================================#
 # Copyright (c) 2012, 2019 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.internal.docmlet.tex.ui.editors;

import static org.eclipse.statet.jcommons.lang.ObjectUtils.nonNullAssert;

import java.util.ArrayList;
import java.util.List;

import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.NullProgressMonitor;
import org.eclipse.core.runtime.Status;
import org.eclipse.jface.action.IContributionItem;
import org.eclipse.jface.action.Separator;
import org.eclipse.jface.text.source.SourceViewer;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.widgets.Menu;
import org.eclipse.swt.widgets.MenuItem;
import org.eclipse.ui.IEditorPart;
import org.eclipse.ui.actions.CompoundContributionItem;
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.core.util.TextUtils;
import org.eclipse.statet.ecommons.ui.actions.SubMenuContributionItem;
import org.eclipse.statet.ecommons.ui.util.UIAccess;

import org.eclipse.statet.docmlet.tex.core.TexCore;
import org.eclipse.statet.docmlet.tex.core.commands.LtxCommandCategories;
import org.eclipse.statet.docmlet.tex.core.commands.LtxCommandCategories.Category;
import org.eclipse.statet.docmlet.tex.core.commands.TexCommand;
import org.eclipse.statet.docmlet.tex.ui.TexUI;
import org.eclipse.statet.docmlet.tex.ui.TexUIResources;
import org.eclipse.statet.docmlet.tex.ui.editors.LtxEditor;
import org.eclipse.statet.internal.docmlet.tex.ui.editors.LtxCommandCompletionProposal.LtxCommandProposalParameters;
import org.eclipse.statet.internal.docmlet.tex.ui.sourceediting.LtxAssistInvocationContext;


@NonNullByDefault
public class LtxSymbolsMenuContributions extends CompoundContributionItem {
	
	
	private static class CategoryContributions extends SubMenuContributionItem implements SelectionListener {
		
		
		private final Category category;
		
		
		public CategoryContributions(final Category category) {
			this.category= category;
		}
		
		
		@Override
		protected String getLabel() {
			return this.category.getLabel();
		}
		
		@Override
		protected @Nullable Image getImage() {
			return null;
		}
		
		@Override
		protected void fillMenu(final Menu menu) {
			final TexUIResources texResources= TexUIResources.INSTANCE;
			final List<TexCommand> commands= this.category.getCommands();
			for (final TexCommand command : commands) {
				final MenuItem item= new MenuItem(menu, SWT.PUSH);
				
				final Image image= texResources.getCommandImage(command);
				if (image != null) {
					item.setImage(image);
				}
				item.setText(command.getControlWord());
				item.setData(command);
				
				item.addSelectionListener(this);
			}
		}
		
		@Override
		public void widgetDefaultSelected(final SelectionEvent event) {
		}
		
		@Override
		public void widgetSelected(final SelectionEvent event) {
			final TexCommand command= (TexCommand) nonNullAssert(event.widget.getData());
			
			final IEditorPart editor= UIAccess.getActiveWorkbenchPage(true).getActiveEditor();
			if (editor instanceof LtxEditor) {
				final LtxEditor texEditor= (LtxEditor) editor;
				if (!texEditor.isEditable(true)) {
					return;
				}
				final SourceViewer viewer= ((LtxEditor) editor).getViewer();
				Point selection= viewer.getSelectedRange();
				if (selection == null || selection.x < 0) {
					return;
				}
				try {
					final String contentType= TextUtils.getContentType(viewer.getDocument(),
									texEditor.getDocumentContentInfo(), selection.x,
									selection.y == 0 );
					
					final LtxAssistInvocationContext context= new LtxAssistInvocationContext(texEditor,
							selection.x, contentType,
							true, new NullProgressMonitor() );
					final LtxCommandCompletionProposal proposal= new LtxCommandCompletionProposal(
							new LtxCommandProposalParameters(context, command) );
					proposal.apply(viewer, (char) 0, 1, context.getInvocationOffset());
					selection= proposal.getSelection(viewer.getDocument());
					if (selection != null) {
						viewer.setSelectedRange(selection.x, selection.y);
						viewer.revealRange(selection.x, selection.y);
					}
					else {
						viewer.revealRange(context.getInvocationOffset(), 0);
					}
				}
				catch (final Exception e) {
					StatusManager.getManager().handle(new Status(IStatus.ERROR, TexUI.BUNDLE_ID,
							"An error occurred when inserting LaTeX symbol.",
							e ));
				}
			}
		}
		
	}
	
	
	private LtxCommandCategories categories;
	
	
	public LtxSymbolsMenuContributions() {
	}
	
	
	@Override
	protected IContributionItem[] getContributionItems() {
		this.categories= new LtxCommandCategories(TexCore.getWorkbenchAccess().getTexCommandSet().getAllLtxCommands()) {
			@Override
			protected boolean include(final TexCommand command) {
				return ((command.getType() & TexCommand.MASK_MAIN) == TexCommand.MATHSYMBOL
						&& (command.getType() & TexCommand.MASK_C3) != TexCommand.C3_MATHSYMBOL_OP_NAMED);
			}
		};
		final List<Category> categories= this.categories.getCategories();
		final List<IContributionItem> items= new ArrayList<>(categories.size()+10);
		int sep= 0;
		for (final Category category : categories) {
			final int current= (category.getCommands().get(0).getType() & TexCommand.MASK_C2);
			if (sep != current) {
				sep= current;
				if (items.size() > 0) {
					items.add(new Separator());
				}
			}
			items.add(new CategoryContributions(category));
		}
		return items.toArray(new @NonNull IContributionItem[items.size()]);
	}
	
}