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/*
 * Copyright (C) 2000-2024 Vaadin Ltd
 *
 * This program is available under Vaadin Commercial License and Service Terms.
 *
 * See  for the full
 * license.
 */
package com.vaadin.ui.dnd.event;

import java.util.Map;
import java.util.Optional;

import com.vaadin.shared.MouseEventDetails;
import com.vaadin.shared.ui.dnd.DragSourceState;
import com.vaadin.shared.ui.dnd.DropEffect;
import com.vaadin.ui.AbstractComponent;
import com.vaadin.ui.Component;
import com.vaadin.ui.dnd.DragSourceExtension;
import com.vaadin.ui.dnd.DropTargetExtension;

/**
 * Server side drop event. Fired when an HTML5 drop happens.
 *
 * @param 
 *            Type of the drop target component.
 * @author Vaadin Ltd
 * @see DropTargetExtension#addDropListener(DropListener)
 * @since 8.1
 */
public class DropEvent extends Component.Event {
    private final Map data;
    private final DragSourceExtension dragSourceExtension;
    private final AbstractComponent dragSource;
    private final DropEffect dropEffect;
    private final MouseEventDetails mouseEventDetails;

    /**
     * Creates a server side drop event.
     *
     * @param target
     *            Component that received the drop.
     * @param data
     *            Map containing all types and corresponding data from the
     *            {@code
     *         DataTransfer} object.
     * @param dropEffect
     *            the desired drop effect
     * @param dragSourceExtension
     *            Drag source extension of the component that initiated the drop
     *            event.
     * @param mouseEventDetails
     *            Mouse event details object containing information about the
     *            drop event
     */
    public DropEvent(T target, Map data, DropEffect dropEffect,
            DragSourceExtension dragSourceExtension,
            MouseEventDetails mouseEventDetails) {
        super(target);

        this.data = data;
        this.dropEffect = dropEffect;
        this.dragSourceExtension = dragSourceExtension;
        this.dragSource = Optional.ofNullable(dragSourceExtension)
                .map(DragSourceExtension::getParent).orElse(null);
        this.mouseEventDetails = mouseEventDetails;
    }

    /**
     * Get data from the {@code DataTransfer} object.
     *
     * @param type
     *            Data format, e.g. {@code text/plain} or {@code text/uri-list}.
     * @return Optional data for the given format if exists in the {@code
     * DataTransfer}, otherwise {@code Optional.empty()}.
     */
    public Optional getDataTransferData(String type) {
        return Optional.ofNullable(data.get(type));
    }

    /**
     * Get data of any of the types {@code "text"}, {@code "Text"} or {@code
     * "text/plain"}.
     * 
     * IE 11 transfers data dropped from the desktop as {@code "Text"} while
     * most other browsers transfer textual data as {@code "text/plain"}.
     *
     * @return First existing data of types in order {@code "text"}, {@code
     * "Text"} or {@code "text/plain"}, or {@code null} if none of them exist.
     */
    public String getDataTransferText() {
        // Read data type "text"
        String text = data.get(DragSourceState.DATA_TYPE_TEXT);

        // IE stores data dragged from the desktop as "Text"
        if (text == null) {
            text = data.get(DragSourceState.DATA_TYPE_TEXT_IE);
        }

        // Browsers may store the key as "text/plain"
        if (text == null) {
            text = data.get(DragSourceState.DATA_TYPE_TEXT_PLAIN);
        }

        return text;
    }

    /**
     * Get all of the transfer data from the {@code DataTransfer} object. The
     * data can be iterated to find the most relevant data as it preserves the
     * order in which the data was set to the drag source element.
     *
     * @return Map of type/data pairs, containing all the data from the {@code
     * DataTransfer} object.
     */
    public Map getDataTransferData() {
        return data;
    }

    /**
     * Get the desired dropEffect for the drop event.
     * 

     * NOTE: Currently you cannot trust this to work on all browsers!
     * https://github.com/vaadin/framework/issues/9247 For Chrome and IE11 it is
     * never set and always returns {@link DropEffect#NONE} even though the drop
     * succeeded!
     *
     * @return the drop effect
     */
    public DropEffect getDropEffect() {
        return dropEffect;
    }

    /**
     * Returns the drag source component if the drag originated from a component
     * in the same UI as the drop target component, or an empty optional.
     *
     * @return Drag source component or an empty optional.
     */
    public Optional getDragSourceComponent() {
        return Optional.ofNullable(dragSource);
    }

    /**
     * Returns the extension of the drag source component if the drag originated
     * from a component in the same UI as the drop target component, or an empty
     * optional.
     *
     * @return Drag source extension or an empty optional
     */
    public Optional> getDragSourceExtension() {
        return Optional.ofNullable(dragSourceExtension);
    }

    /**
     * Gets the server side drag data. This data can be set during the drag
     * start event on the server side and can be used to transfer data between
     * drag source and drop target when they are in the same UI.
     *
     * @return Optional server side drag data if set and the drag source and the
     *         drop target are in the same UI, otherwise empty {@code Optional}.
     * @see DragSourceExtension#setDragData(Object)
     */
    public Optional