/* 
@VaadinApache2LicenseForJavaFiles@
 */

package com.vaadin.terminal.gwt.client.ui.csslayout;

import com.google.gwt.user.client.DOM;
import com.google.gwt.user.client.Element;
import com.google.gwt.user.client.ui.FlowPanel;
import com.google.gwt.user.client.ui.SimplePanel;
import com.google.gwt.user.client.ui.Widget;
import com.vaadin.terminal.gwt.client.StyleConstants;
import com.vaadin.terminal.gwt.client.ui.VMarginInfo;

public class VCssLayout extends SimplePanel {
    public static final String TAGNAME = "csslayout";
    public static final String CLASSNAME = "v-" + TAGNAME;

    FlowPane panel = new FlowPane();

    Element margin = DOM.createDiv();

    public VCssLayout() {
        super();
        getElement().appendChild(margin);
        setStyleName(CLASSNAME);
        margin.setClassName(CLASSNAME + "-margin");
        setWidget(panel);
    }

    @Override
    protected Element getContainerElement() {
        return margin;
    }

    public class FlowPane extends FlowPanel {

        public FlowPane() {
            super();
            setStyleName(CLASSNAME + "-container");
        }

        void addOrMove(Widget child, int index) {
            if (child.getParent() == this) {
                int currentIndex = getWidgetIndex(child);
                if (index == currentIndex) {
                    return;
                }
            }
            insert(child, index);
        }

    }

    /**
     * Sets CSS classes for margin based on the given parameters.
     * 
     * @param margins
     *            A {@link VMarginInfo} object that provides info on
     *            top/left/bottom/right margins
     */
    protected void setMarginStyles(VMarginInfo margins) {
        setStyleName(margin, VCssLayout.CLASSNAME + "-"
                + StyleConstants.MARGIN_TOP, margins.hasTop());
        setStyleName(margin, VCssLayout.CLASSNAME + "-"
                + StyleConstants.MARGIN_RIGHT, margins.hasRight());
        setStyleName(margin, VCssLayout.CLASSNAME + "-"
                + StyleConstants.MARGIN_BOTTOM, margins.hasBottom());
        setStyleName(margin, VCssLayout.CLASSNAME + "-"
                + StyleConstants.MARGIN_LEFT, margins.hasLeft());
    }
}