DefaultAccordionDropHandler.java

/*
 * Copyright 2011 John Ahlroos
 *
 * 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 fi.jasoft.dragdroplayouts.drophandlers;

import com.vaadin.event.dd.DragAndDropEvent;
import com.vaadin.event.dd.DropHandler;
import com.vaadin.event.dd.acceptcriteria.AcceptCriterion;
import com.vaadin.event.dd.acceptcriteria.Not;
import com.vaadin.terminal.Sizeable;
import com.vaadin.terminal.gwt.client.MouseEventDetails;
import com.vaadin.terminal.gwt.client.ui.dd.VerticalDropLocation;
import com.vaadin.ui.AbsoluteLayout.ComponentPosition;
import com.vaadin.ui.Component;
import com.vaadin.ui.ComponentContainer;
import com.vaadin.ui.TabSheet.Tab;

import fi.jasoft.dragdroplayouts.DDAbsoluteLayout;
import fi.jasoft.dragdroplayouts.DDAccordion;
import fi.jasoft.dragdroplayouts.DDAccordion.AccordionTargetDetails;
import fi.jasoft.dragdroplayouts.events.LayoutBoundTransferable;
import fi.jasoft.dragdroplayouts.events.VerticalLocationIs;

/**
 * A default drop handler for an accordion
 */
@SuppressWarnings("serial")
public class DefaultAccordionDropHandler extends AbstractDefaultLayoutDropHandler {

	/**
	 * Called when tabs are being rearranged
	 * 
	 * @param event
	 * 		A drag and drop event
	 */
	@Override
	protected void handleComponentReordering(DragAndDropEvent event){
		AccordionTargetDetails details = (AccordionTargetDetails) event
	                .getTargetDetails();
        DDAccordion acc = (DDAccordion) details.getTarget();
        VerticalDropLocation location = details.getDropLocation();
        LayoutBoundTransferable transferable = (LayoutBoundTransferable) event
                .getTransferable();
        Component c = transferable.getComponent();
        int idx = details.getOverIndex();
        
		Tab tab = acc.getTab(c);

        if (location == VerticalDropLocation.TOP) {
            // Left of previous tab
            int originalIndex = acc.getTabPosition(tab);
            if (originalIndex > idx) {
                acc.setTabPosition(tab, idx);
            } else if (idx - 1 >= 0) {
                acc.setTabPosition(tab, idx - 1);
            }

        } else if (location == VerticalDropLocation.BOTTOM) {
            // Right of previous tab
            int originalIndex = acc.getTabPosition(tab);
            if (originalIndex > idx) {
                acc.setTabPosition(tab, idx + 1);
            } else {
                acc.setTabPosition(tab, idx);
            }
        }
	}
	
	/**
	 * Adds a new tab from the drop
	 * 
	 * @param event
	 * 		The drag and drop event
	 */
	@Override
	protected void handleDropFromLayout(DragAndDropEvent event){
		LayoutBoundTransferable transferable = (LayoutBoundTransferable) event
	                .getTransferable();

        // Get the target details
        AccordionTargetDetails details = (AccordionTargetDetails) event
                .getTargetDetails();
        DDAccordion acc = (DDAccordion) details.getTarget();
        Component c = transferable.getComponent();
        int idx = details.getOverIndex();
        VerticalDropLocation location = details.getDropLocation();
        ComponentContainer source = (ComponentContainer) transferable
                .getSourceComponent();
        
		source.removeComponent(c);
        if (location == VerticalDropLocation.TOP) {
            acc.addTab(c, idx);
        } else if (location == VerticalDropLocation.BOTTOM) {
            acc.addTab(c, idx + 1);
        } else {
            acc.addTab(c);
        }
	}

    /*
     * (non-Javadoc)
     * @see com.vaadin.event.dd.DropHandler#getAcceptCriterion()
     */
	@Override
    public AcceptCriterion getAcceptCriterion() {
        return new Not(VerticalLocationIs.MIDDLE);
    }
}