AutocompleteSelectorContentProposalProvider.java

/*******************************************************************************
 * Copyright (c) 2011 Softberries Krzysztof Grajek.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 *     Softberries Krzysztof Grajek - initial API and implementation
 ******************************************************************************/
package net.sf.swtaddons.autocomplete;

import java.util.List;

import org.eclipse.jface.fieldassist.IContentProposal;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.widgets.Combo;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Text;

public class AutocompleteSelectorContentProposalProvider extends AutocompleteContentProposalProvider  {

	private Control control = null;

	/**
	 * Construct a ContentProposalProvider on a Combo whose content proposals are
	 * the specified array of Objects.  This ContentProposalProvider will
	 * SELECT a completion for the input meaning that the text input
	 * MUST match one of the proposed completions
	 * 
	 * @param proposals
	 *            the array of Strings to be returned whenever proposals are
	 *            requested.
	 */
	public AutocompleteSelectorContentProposalProvider(String[] proposals, Combo combo) {
		super(proposals);
		this.control = combo;
	}
	
	/**
	 * Construct a ContentProposalProvider on a Text whose content proposals are
	 * the specified array of Objects.  This ContentProposalProvider will
	 * SELECT a completion for the input meaning that the text input
	 * MUST match one of the proposed completions
	 * 
	 * @param proposals
	 *            the array of Strings to be returned whenever proposals are
	 *            requested.
	 */
	public AutocompleteSelectorContentProposalProvider(String[] proposals, Text text) {
		super(proposals);
		this.control = text;
	}
	
	/**
	 * Return an array of Objects representing the valid content proposals for a
	 * field. Ignore the current contents of the field.
	 * 
	 * @param contents
	 *            the current contents of the field (ignored)
	 * @param position
	 *            the current cursor position within the field (ignored)
	 * @return the array of Objects that represent valid proposals for the field
	 *         given its current content.
	 */
	@Override
	public IContentProposal [] getProposals(String contents, int position) {
		List contentProposals = getMatchingProposals(this.proposals, contents);
		if (contentProposals.size() == 0) {
			if (this.control instanceof Text) {
				contentProposals = getContentProposals((Text) this.control);
			} else if (this.control instanceof Combo) {
				contentProposals = getContentProposals((Combo) this.control);
			}
		}
		return (IContentProposal[])contentProposals.toArray(new IContentProposal[contentProposals.size()]);
	}
	
	/**
	 * Return the matching proposals for the text currently in the Combo
	 * widget.  During the process check that the entered text matches at least
	 * one of the proposals, if not remove the last character entered
	 * 
	 * @param combo
	 * 			the widget containing the text
	 * @return
	 * 			list of possible Objects that complete the text contents
	 */
	private List getContentProposals(Combo combo) {
		combo.setText(combo.getText().substring(0, combo.getText().length()-1));
		combo.setSelection(new Point(combo.getText().length(), combo.getText().length()));
		return getMatchingProposals(this.proposals, combo.getText());		
	}

	/**
	 * Return the matching proposals for the text currently in the Text
	 * widget.  During the process check that the entered text matches at least
	 * one of the proposals, if not remove the last character entered
	 * 
	 * @param combo
	 * 			the widget containing the text
	 * @return
	 * 			list of possible Objects that complete the text contents
	 */
	private List getContentProposals(Text text) {
		text.setText(text.getText().substring(0, text.getText().length()-1));
		text.setSelection(new Point(text.getText().length(), text.getText().length()));
		return getMatchingProposals(this.proposals, text.getText());		
	}

}