fi.jasoft.draganddrop.client.configurations.OrderedLayoutDragAndDropConfiguration.java Source code

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Here is the source code for fi.jasoft.draganddrop.client.configurations.OrderedLayoutDragAndDropConfiguration.java

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/*
 * Copyright 2014 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.draganddrop.client.configurations;

import com.google.gwt.dom.client.Element;
import com.google.gwt.user.client.ui.Widget;
import com.vaadin.client.Util;
import com.vaadin.client.ui.orderedlayout.AbstractOrderedLayoutConnector;
import com.vaadin.client.ui.orderedlayout.Slot;

import fi.jasoft.draganddrop.client.DragAndDropEvent;
import fi.jasoft.draganddrop.client.DragAndDropEvent.DragEnterEvent;
import fi.jasoft.draganddrop.client.DragAndDropEvent.DragLeaveEvent;
import fi.jasoft.draganddrop.client.DragAndDropEvent.DragOverEvent;
import fi.jasoft.draganddrop.client.DragAndDropEvent.DropEvent;

public class OrderedLayoutDragAndDropConfiguration<T extends AbstractOrderedLayoutConnector>
        extends AbstractDragAndDropConfiguration<T> {

    protected Slot currentSlot;

    protected static final String ACTIVE_SLOT = "dd-active-slot";

    @Override
    public void dragEnter(DragEnterEvent event) {
        cleanupCurrentSlot();

        currentSlot = getSlot(event);

        if (currentSlot != null) {
            currentSlot.addStyleName(ACTIVE_SLOT);
        }
    }

    @Override
    public void dragOver(DragOverEvent event) {
        cleanupCurrentSlot();

        currentSlot = getSlot(event);

        if (currentSlot != null) {
            currentSlot.addStyleName(ACTIVE_SLOT);
        }
    }

    @Override
    public void dragLeave(DragLeaveEvent event) {
        cleanupCurrentSlot();
    }

    @Override
    public void drop(DropEvent event) {
        cleanupCurrentSlot();
    }

    protected void cleanupCurrentSlot() {
        if (currentSlot != null) {
            currentSlot.removeStyleName(ACTIVE_SLOT);
        }
    }

    protected Slot getSlot(DragAndDropEvent event) {
        Element e = Util.getElementUnderMouse(event.getEvent());

        /*
         * If we are hitting between slot search around the cursor for the
         * closest slot
         */
        int nextDirection = 0;
        int width = 1;
        int pageX = Util.getTouchOrMouseClientX(event.getEvent());
        int pageY = Util.getTouchOrMouseClientY(event.getEvent());
        while (event.getTargetConnector().getWidget().getElement() == e) {
            if (nextDirection == 0) {
                pageY -= width;
                nextDirection++;
            } else if (nextDirection == 1) {
                pageX += width;
                nextDirection++;
            } else if (nextDirection == 2) {
                pageY += width;
                nextDirection++;
            } else if (nextDirection == 3) {
                pageX -= width;
                width++;
                nextDirection = 0;
            }
            e = Util.getElementFromPoint(pageX, pageY);
        }

        assert e != null : "Event target was null";
        Widget w = Util.findWidget(e, null);
        assert w != null : "Widget was not found";

        if (w != null) {
            while (!(w instanceof Slot) && w != null) {
                w = w.getParent();
            }
        }

        assert w instanceof Slot;
        return (Slot) w;
    }

    protected int getSlotIndex(AbstractOrderedLayoutConnector connector, DragAndDropEvent event) {
        Slot slot = getSlot(event);
        assert slot != null;
        return connector.getWidget().getWidgetIndex(slot);
    }
}