SimpleDelta.java

/*******************************************************************************
 * Copyright (c) 2000, 2004 IBM Corporation and others.
 * 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:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.rubypeople.rdt.internal.core;

import org.rubypeople.rdt.core.IRubyElementDelta;


/**
 * A simple Ruby element delta that remembers the kind of changes only.
 */
public class SimpleDelta {

    /*
     * @see IRubyElementDelta#getKind()
     */
    protected int kind = 0;
    
    /*
     * @see IRubyElementDelta#getFlags()
     */
    protected int changeFlags = 0;
    
    /*
     * Marks this delta as added
     */
    public void added() {
        this.kind = IRubyElementDelta.ADDED;
    }
    
    /*
     * Marks this delta as changed with the given change flag
     */
    public void changed(int flags) {
        this.kind = IRubyElementDelta.CHANGED;
        this.changeFlags |= flags;
    }
    
    /*
     * @see IRubyElementDelta#getFlags()
     */
    public int getFlags() {
        return this.changeFlags;
    }
    
    /*
     * @see IRubyElementDelta#getKind()
     */
    public int getKind() {
        return this.kind;
    }

    /*
     * Mark this delta has a having a modifiers change
     */
    public void modifiers() {
        changed(IRubyElementDelta.F_MODIFIERS);
    }

    /*
     * Marks this delta as removed
     */
    public void removed() {
        this.kind = IRubyElementDelta.REMOVED;
        this.changeFlags = 0;
    }
    
    /*
     * Mark this delta has a having a super type change
     */
    public void superTypes() {
        changed(IRubyElementDelta.F_SUPER_TYPES);
    }

    protected void toDebugString(StringBuffer buffer) {
        buffer.append("["); //$NON-NLS-1$
        switch (getKind()) {
            case IRubyElementDelta.ADDED :
                buffer.append('+');
                break;
            case IRubyElementDelta.REMOVED :
                buffer.append('-');
                break;
            case IRubyElementDelta.CHANGED :
                buffer.append('*');
                break;
            default :
                buffer.append('?');
                break;
        }
        buffer.append("]: {"); //$NON-NLS-1$
        toDebugString(buffer, getFlags());
        buffer.append("}"); //$NON-NLS-1$
    }

    protected boolean toDebugString(StringBuffer buffer, int flags) {
        boolean prev = false;
        if ((flags & IRubyElementDelta.F_MODIFIERS) != 0) {
            if (prev)
                buffer.append(" | "); //$NON-NLS-1$
            buffer.append("MODIFIERS CHANGED"); //$NON-NLS-1$
            prev = true;
        }
        if ((flags & IRubyElementDelta.F_SUPER_TYPES) != 0) {
            if (prev)
                buffer.append(" | "); //$NON-NLS-1$
            buffer.append("SUPER TYPES CHANGED"); //$NON-NLS-1$
            prev = true;
        }
        return prev;
    }

    public String toString() {
        StringBuffer buffer = new StringBuffer();
        toDebugString(buffer);
        return buffer.toString();
    }
}