r/org.eclipse.statet.r.ui/src/org/eclipse/statet/internal/r/ui/editors/RArgumentListContextInformation.java

/*=============================================================================#
 # Copyright (c) 2009, 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.r.ui.editors;

import org.eclipse.jface.text.contentassist.IContextInformationExtension;
import org.eclipse.swt.graphics.Image;

import org.eclipse.statet.jcommons.collections.IntArrayList;
import org.eclipse.statet.jcommons.collections.IntList;
import org.eclipse.statet.jcommons.lang.NonNullByDefault;
import org.eclipse.statet.jcommons.lang.Nullable;

import org.eclipse.statet.ltk.ui.sourceediting.assist.AssistInformationProposal;
import org.eclipse.statet.r.core.model.ArgsDefinition;
import org.eclipse.statet.r.core.model.IRMethod;
import org.eclipse.statet.r.ui.RLabelProvider;


@NonNullByDefault
public class RArgumentListContextInformation implements AssistInformationProposal,
		IContextInformationExtension {
	
	
	private final int offset; // can be negative for FragmentDocument
	
	private final @Nullable ArgsDefinition args;
	
	private final String information;
	private final int[] informationArgumentIdxs;
	
	
	public RArgumentListContextInformation(final int offset, final IRMethod method) {
		this.offset= offset;
		this.args= method.getArgsDefinition();
		final StringBuilder sb= new StringBuilder();
		final IntList idxs= new IntArrayList();
		new RLabelProvider().appendArgumentInformation(sb, idxs, this.args);
		this.information= sb.toString();
		this.informationArgumentIdxs= idxs.toArray();
	}
	
	
	public int getCallArgsOffset() {
		return this.offset;
	}
	
	public @Nullable ArgsDefinition getArgsDefinition() {
		return this.args;
	}
	
	
	@Override
	public String getContextDisplayString() {
		return getInformationDisplayString();
	}
	
	@Override
	public @Nullable Image getImage() {
		return null;
	}
	
	@Override
	public int getContextInformationPosition() {
		return Math.max(this.offset, 0);
	}
	
	@Override
	public String getInformationDisplayString() {
		return this.information;
	}
	
	public int[] getInformationDisplayStringArgumentIdxs() {
		return this.informationArgumentIdxs;
	}
	
	
	@Override
	public boolean equals(final @Nullable Object obj) {
		// prevent stacking of context information at the same position
		return true;
	}
	
}