GenericSelect2GroupDropDownSingleChoice.java

package fr.openwide.core.wicket.more.markup.html.select2;

import java.util.List;

import org.apache.wicket.markup.html.form.IChoiceRenderer;
import org.apache.wicket.model.IModel;
import org.apache.wicket.util.string.AppendingStringBuffer;
import org.apache.wicket.util.string.Strings;

public abstract class GenericSelect2GroupDropDownSingleChoice<T> extends GenericSelect2DropDownSingleChoice<T> {

	private static final long serialVersionUID = 8581582499159251418L;

	private T last;

	private boolean grouped = true;

	protected GenericSelect2GroupDropDownSingleChoice(String id, IModel<T> model, IModel<? extends List<? extends T>> choicesModel, IChoiceRenderer<? super T> renderer) {
		super(id, model, choicesModel, renderer);
	}

	private boolean isLast(int index) {
		return index - 1 == getChoices().size();
	}

	private boolean isFirst(int index) {
		return index == 0;
	}

	protected abstract boolean isNewGroup(T current, T last);

	protected abstract String getGroupLabel(T current);

	@Override
	protected void appendOptionHtml(AppendingStringBuffer buffer, T choice, int index, String selected) {
		if (grouped) {
			if (last == null || isNewGroup(choice, last)) {
				if (!isFirst(index)) {
					buffer.append("</optgroup>");
				}
				buffer.append("<optgroup label='");
				buffer.append(Strings.escapeMarkup(getGroupLabel(choice)));
				buffer.append("'>");
			}
			super.appendOptionHtml(buffer, choice, index, selected);
			if (isLast(index)) {
				buffer.append("</optgroup>");
			}
			last = choice;
		} else {
			super.appendOptionHtml(buffer, choice, index, selected);
		}
	}

	@Override
	protected void onAfterRender() {
		super.onAfterRender();
		last = null;
	}

	public boolean isGrouped() {
		return grouped;
	}

	public void setGrouped(boolean grouped) {
		this.grouped = grouped;
	}

}