vaadin-framework/client/src/main/java/com/vaadin/client/ui/VCssLayout.java

/*
 * Copyright 2000-2018 Vaadin Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

package com.vaadin.client.ui;

import com.google.gwt.user.client.ui.FlowPanel;
import com.google.gwt.user.client.ui.Widget;
import com.vaadin.client.Profiler;
import com.vaadin.client.StyleConstants;

/**
 * VCssLayout is a layout which supports configuring it's children with CSS
 * selectors.
 */
public class VCssLayout extends FlowPanel {

    public static final String CLASSNAME = "v-csslayout";

    /**
     * Default constructor.
     */
    public VCssLayout() {
        super();
        setStyleName(CLASSNAME);
        addStyleName(StyleConstants.UI_LAYOUT);
    }

    /**
     * For internal use only. May be removed or replaced in the future.
     */
    public void addOrMove(Widget child, int index) {
        Profiler.enter("VCssLayout.addOrMove");
        if (child.getParent() == this) {
            Profiler.enter("VCssLayout.addOrMove getWidgetIndex");
            int currentIndex = getWidgetIndex(child);
            Profiler.leave("VCssLayout.addOrMove getWidgetIndex");
            if (index == currentIndex) {
                Profiler.leave("VCssLayout.addOrMove");
                return;
            }
        } else if (index == getWidgetCount()) {
            // optimized path for appending components - faster especially for
            // initial rendering
            Profiler.enter("VCssLayout.addOrMove add");
            add(child);
            Profiler.leave("VCssLayout.addOrMove add");
            Profiler.leave("VCssLayout.addOrMove");
            return;
        }
        Profiler.enter("VCssLayout.addOrMove insert");
        insert(child, index);
        Profiler.leave("VCssLayout.addOrMove insert");
        Profiler.leave("VCssLayout.addOrMove");
    }
}