r/org.eclipse.statet.r.ui/src/org/eclipse/statet/r/ui/editors/templates/REditorContext.java

/*=============================================================================#
 # Copyright (c) 2005, 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.r.ui.editors.templates;

import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.Document;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.templates.TemplateContextType;
import org.eclipse.jface.text.templates.TemplateVariable;
import org.eclipse.text.edits.DeleteEdit;
import org.eclipse.text.edits.InsertEdit;
import org.eclipse.text.edits.MultiTextEdit;
import org.eclipse.text.edits.ReplaceEdit;
import org.eclipse.text.edits.TextEdit;

import org.eclipse.statet.jcommons.lang.NonNullByDefault;
import org.eclipse.statet.jcommons.lang.Nullable;
import org.eclipse.statet.jcommons.text.core.TextRegion;
import org.eclipse.statet.jcommons.text.core.input.StringParserInput;

import org.eclipse.statet.ecommons.text.IndentUtil;
import org.eclipse.statet.ecommons.text.IndentUtil.IndentEditAction;

import org.eclipse.statet.internal.r.ui.RUIPlugin;
import org.eclipse.statet.ltk.ui.sourceediting.ISourceEditor;
import org.eclipse.statet.ltk.ui.templates.SourceEditorTemplateContext;
import org.eclipse.statet.r.core.IRCoreAccess;
import org.eclipse.statet.r.core.RCodeStyleSettings;
import org.eclipse.statet.r.core.RCore;
import org.eclipse.statet.r.core.rlang.RTerminal;
import org.eclipse.statet.r.core.rlang.RTokens;
import org.eclipse.statet.r.core.rsource.RLexer;
import org.eclipse.statet.r.ui.editors.IRSourceEditor;


@NonNullByDefault
public class REditorContext extends SourceEditorTemplateContext {
	
	
	public REditorContext(final TemplateContextType type, final IDocument document,
			final TextRegion region,
			final ISourceEditor editor, final int flags) {
		super(type, document, region, editor, flags);
	}
	
	
	protected IRCoreAccess getRCoreAccess() {
		final ISourceEditor editor= getEditor();
		return (editor instanceof IRSourceEditor) ?
				((IRSourceEditor) editor).getRCoreAccess() :
				RCore.WORKBENCH_ACCESS;
	}
	
	@Override
	public void setVariable(final String name, @Nullable String value) {
		if (SELECTION_VAR_NAME.equals(name) && value != null && value.length() > 0) {
			try {
				final IDocument valueDoc = new Document(value);
				
				final IndentUtil util = new IndentUtil(valueDoc, getRCoreAccess().getRCodeStyle());
				final int column = util.getMultilineIndentColumn(0, valueDoc.getNumberOfLines()-1);
				if (column > 0) {
					final IndentEditAction action = new IndentEditAction(column) {
						@Override
						public void doEdit(final int line, final int offset, final int length, final StringBuilder text)
								throws BadLocationException {
							TextEdit edit;
							if (text != null) {
								final int position = util.getIndentedOffsetAt(text, column);
								edit = new ReplaceEdit(offset, length, text.substring(position, text.length()));
							}
							else {
								final int end = util.getIndentedOffsetAt(line, column);
								edit = new DeleteEdit(offset, end-offset);
							}
							edit.apply(valueDoc, 0);
						}
					};
					util.editInIndent(0, valueDoc.getNumberOfLines()-1, action);
					setVariable(INDENTATION_VAR_NAME, util.createIndentString(column));
					value = valueDoc.get();
				}
			}
			catch (final BadLocationException e) {
				RUIPlugin.logError(RUIPlugin.INTERNAL_ERROR, "An error occurred while computing indentation variable for R editor templates.", e); //$NON-NLS-1$
			}
		}
		super.setVariable(name, value);
	}
	
	@Override
	protected void format(final MultiTextEdit root, final IDocument templateDoc,
			final TemplateVariable[] variables, final IDocument baseDoc)
			throws BadLocationException {
		indent(root, templateDoc, variables, baseDoc);
		
		if ((getFlags() & FORMAT_START) != 0 && getVariable(INDENTATION_VAR_NAME) == null
				&& getStart() > 0 && !RTokens.isWhitespace(baseDoc.getChar(getStart() - 1))
				&& templateDoc.getLength() > 0 && !RTokens.isWhitespace(templateDoc.getChar(0)) ) {
			final String line= templateDoc.get(0, templateDoc.getLineLength(0));
			final RLexer lexer= new RLexer();
			lexer.reset(new StringParserInput(line).init());
			final RCodeStyleSettings rCodeStyle= getRCoreAccess().getRCodeStyle();
			
			final RTerminal token= lexer.next();
			if (getSpaceBefore(token, rCodeStyle)) {
				root.addChild(new InsertEdit(0, " ")); //$NON-NLS-1$
			}
			
			if (variables.length == 0 && line.length() == templateDoc.getLength()
					&& lexer.next() == RTerminal.EOF
					&& getSpaceAfter(token, rCodeStyle) ) {
				root.addChild(new InsertEdit(line.length(), " ")); //$NON-NLS-1$
			}
		}
	}
	
	protected boolean getSpaceBefore(final RTerminal terminal, final RCodeStyleSettings rCodeStyle) {
		switch (terminal) {
		case EQUAL:
			return rCodeStyle.getWhitespaceArgAssignBefore();
			
		case ARROW_LEFT_S:
		case ARROW_LEFT_D:
			return rCodeStyle.getWhitespaceAssignBefore();
			
		case ARROW_RIGHT_S:
		case ARROW_RIGHT_D:
			return rCodeStyle.getWhitespaceArgAssignAfter();
			
		case PLUS:
		case MINUS:
		case MULT:
		case DIV:
		case OR:
		case OR_D:
		case AND:
		case AND_D:
		case NOT:
		case POWER:
		case SEQ:
		case SPECIAL:
		case COLON_EQUAL:
		case TILDE:
		case REL_NE:
		case REL_EQ:
		case REL_LT:
		case REL_LE:
		case REL_GT:
		case REL_GE:
			return rCodeStyle.getWhitespaceOtherOpBefore();
			
		default:
			return true;
		}
	}
	
	protected boolean getSpaceAfter(final RTerminal terminal, final RCodeStyleSettings rCodeStyle) {
		switch (terminal) {
		case EQUAL:
			return rCodeStyle.getWhitespaceArgAssignAfter();
			
		case ARROW_LEFT_S:
		case ARROW_LEFT_D:
			return rCodeStyle.getWhitespaceAssignAfter();
			
		case ARROW_RIGHT_S:
		case ARROW_RIGHT_D:
			return rCodeStyle.getWhitespaceArgAssignBefore();
			
		case PLUS:
		case MINUS:
		case MULT:
		case DIV:
		case OR:
		case OR_D:
		case AND:
		case AND_D:
		case NOT:
		case POWER:
		case SEQ:
		case SPECIAL:
		case COLON_EQUAL:
		case TILDE:
		case REL_NE:
		case REL_EQ:
		case REL_LT:
		case REL_LE:
		case REL_GT:
		case REL_GE:
			return rCodeStyle.getWhitespaceOtherOpAfter();
			
		default:
			return true;
		}
	}
	
}