package org.apidesign.javabeans.with;

import java.util.ArrayList;

import java.util.List;

public abstract class AbstractHighlightsContainer implements HighlightsContainer {

    private List<HighlightsChangeListener> listeners = new ArrayList<HighlightsChangeListener>();

    protected AbstractHighlightsContainer() {

    }

    public abstract HighlightsSequence getHighlights(int startOffset, int endOffset);

    public final void addHighlightsChangeListener(HighlightsChangeListener listener) {

        synchronized (listeners) {

            listeners.add(listener);

        }

    }

    public final void removeHighlightsChangeListener(HighlightsChangeListener listener) {

        synchronized (listeners) {

            listeners.remove(listener);

        }

    }

    protected final void fireHighlightsChange(int changeStartOffset, int changeEndOffset) {

        List<HighlightsChangeListener> targets;

        synchronized (listeners) {

            targets = new ArrayList<HighlightsChangeListener>(listeners);

        }

        if (targets.size() > 0) {

            HighlightsChangeEvent evt = new HighlightsChangeEvent(this, changeStartOffset, changeEndOffset);

            for (HighlightsChangeListener l : targets) {

                l.highlightChanged(evt);

            }

        }

    }

}