org.eclipse.jface.fieldassist.SimpleContentProposalProvider.java Source code

Introduction

Here is the source code for org.eclipse.jface.fieldassist.SimpleContentProposalProvider.java

Source

/*******************************************************************************
 * Copyright (c) 2005, 2017 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Amir Kouchekinia <amir@pyrus.us> - Bug 200762
 *     Lars Vogel <Lars.Vogel@vogella.com> - Bug 525783
 *******************************************************************************/
package org.eclipse.jface.fieldassist;

import java.util.ArrayList;

/**
 * SimpleContentProposalProvider is a class designed to map a static list of
 * Strings to content proposals.
 *
 * @see IContentProposalProvider
 * @since 3.2
 *
 */
public class SimpleContentProposalProvider implements IContentProposalProvider {

    /*
     * The proposals provided.
     */
    private String[] proposals;

    /*
     * The proposals mapped to IContentProposal. Cached for speed in the case
     * where filtering is not used.
     */
    private IContentProposal[] contentProposals;

    /*
     * Boolean that tracks whether filtering is used.
     */
    private boolean filterProposals = false;

    /**
     * Construct a SimpleContentProposalProvider whose content proposals are always
     * the specified array of Objects.
     *
     * @param proposals
     *            the Strings to be returned whenever proposals are requested.
     */
    public SimpleContentProposalProvider(String... proposals) {
        super();
        this.proposals = proposals;
    }

    /**
     * Return an array of Objects representing the valid content proposals for a
     * field.
     *
     * @param contents
     *            the current contents of the field (only consulted if filtering
     *            is set to <code>true</code>)
     * @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) {
        if (filterProposals) {
            ArrayList<ContentProposal> list = new ArrayList<>();
            for (String proposal : proposals) {
                if (proposal.length() >= contents.length()
                        && proposal.substring(0, contents.length()).equalsIgnoreCase(contents)) {
                    list.add(new ContentProposal(proposal));
                }
            }
            return list.toArray(new IContentProposal[list.size()]);
        }
        if (contentProposals == null) {
            contentProposals = new IContentProposal[proposals.length];
            for (int i = 0; i < proposals.length; i++) {
                contentProposals[i] = new ContentProposal(proposals[i]);
            }
        }
        return contentProposals;
    }

    /**
     * Set the Strings to be used as content proposals.
     *
     * @param items
     *            the Strings to be used as proposals.
     */
    public void setProposals(String... items) {
        this.proposals = items;
        contentProposals = null;
    }

    /**
     * Set the boolean that controls whether proposals are filtered according to
     * the current field content.
     *
     * @param filterProposals
     *            <code>true</code> if the proposals should be filtered to
     *            show only those that match the current contents of the field,
     *            and <code>false</code> if the proposals should remain the
     *            same, ignoring the field content.
     * @since 3.3
     */
    public void setFiltering(boolean filterProposals) {
        this.filterProposals = filterProposals;
        // Clear any cached proposals.
        contentProposals = null;
    }
}