com.swtxml.swt.types.LayoutType.java Source code

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Here is the source code for com.swtxml.swt.types.LayoutType.java

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/*******************************************************************************
 * Copyright (c) 2008 Ralf Ebert
 * 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:
 *     Ralf Ebert - initial API and implementation
 *******************************************************************************/
package com.swtxml.swt.types;

import java.util.List;
import java.util.Map;

import org.apache.commons.lang.StringUtils;
import org.eclipse.swt.layout.RowLayout;
import org.eclipse.swt.widgets.Layout;

import com.swtxml.swt.SwtInfo;
import com.swtxml.util.parser.KeyValueParser;
import com.swtxml.util.parser.ParseException;
import com.swtxml.util.parser.Strictness;
import com.swtxml.util.properties.ClassProperties;
import com.swtxml.util.properties.IInjector;
import com.swtxml.util.properties.PropertiesContentAssist;
import com.swtxml.util.proposals.Match;
import com.swtxml.util.reflector.ReflectorException;
import com.swtxml.util.types.IContentAssistable;
import com.swtxml.util.types.IType;

public class LayoutType implements IType<Layout>, IContentAssistable {

    private static final String LAYOUT_KEY = "layout";
    // TODO: use classes.txt file (same as for widgets)
    private final String[] LAYOUTS = new String[] { "fill", "row", "grid", "form" };
    private final static String SWT_LAYOUT_PACKAGE = RowLayout.class.getPackage().getName();

    public Layout convert(String value) {
        return convert(value, Strictness.STRICT);
    }

    public Layout convert(String value, Strictness strictness) {
        Map<String, String> layoutConstraints = KeyValueParser.parse(value, strictness);

        String layoutName = layoutConstraints.remove(LAYOUT_KEY);
        if (layoutName == null) {
            if (strictness == Strictness.STRICT) {
                throw new ParseException("no layout specified");
            } else {
                return null;
            }
        }

        Layout layout = createLayout(layoutName, Strictness.STRICT);

        IInjector injector = SwtInfo.LAYOUT_PROPERTIES.getProperties(layout.getClass()).getInjector(layout);
        injector.setPropertyValues(layoutConstraints);

        return layout;
    }

    private Layout createLayout(String layoutName, Strictness strictness) {
        try {
            return getLayoutClass(layoutName, strictness).newInstance();
        } catch (Exception e) {
            if (strictness == Strictness.STRICT) {
                throw new ReflectorException(e);
            }
            return null;
        }
    }

    @SuppressWarnings("unchecked")
    private Class<? extends Layout> getLayoutClass(String layoutName, Strictness strictness) {
        String className = SWT_LAYOUT_PACKAGE + "." + StringUtils.capitalize(layoutName) + "Layout";
        try {
            return (Class<? extends Layout>) Class.forName(className);
        } catch (Exception e) {
            if (strictness == Strictness.STRICT) {
                throw new ReflectorException(e);
            }
            return null;
        }
    }

    public List<Match> getProposals(Match match) {
        // TODO: this is a bit messy at the moment, because only the class
        // property definition is used for completion, so we have to smuggle the
        // "special" layout selector property in
        // maybe: separate namespace layout:[grid]=""
        PropertiesContentAssist assist = new PropertiesContentAssist() {

            @Override
            protected ClassProperties<?> getClassProperties(Map<String, String> values) {
                String layoutName = values.get("layout");
                if (layoutName == null) {
                    return null;
                }
                Class<? extends Layout> layoutClass = getLayoutClass(layoutName, Strictness.NICE);
                if (layoutClass == null) {
                    return null;
                }
                return SwtInfo.LAYOUT_PROPERTIES.getProperties(layoutClass);
            }

            @Override
            protected List<Match> keyProposals(Map<String, String> values, Match match) {
                if (getClassProperties(values) == null) {
                    return match.propose(LAYOUT_KEY + ":");
                }
                return super.keyProposals(values, match);
            }

            @Override
            protected List<Match> valueProposals(Map<String, String> values, String key, Match match) {
                if ("layout".equals(key.toLowerCase())) {
                    return match.propose(LAYOUTS);
                }
                return super.valueProposals(values, key, match);
            }

        };
        return assist.getProposals(match);
    }
}