// Copyright (c) 2019 The Chromium Embedded Framework Authors. All rights

// reserved. Use of this source code is governed by a BSD-style license that

// can be found in the LICENSE file.

package org.cef.browser;

import org.cef.callback.CefDragData;

import org.cef.misc.EventFlags;

import java.awt.datatransfer.DataFlavor;

import java.awt.datatransfer.Transferable;

import java.awt.dnd.DnDConstants;

import java.awt.dnd.DropTarget;

import java.awt.dnd.DropTargetDragEvent;

import java.awt.dnd.DropTargetDropEvent;

import java.awt.dnd.DropTargetEvent;

import java.awt.dnd.DropTargetListener;

import java.io.File;

import java.util.List;

class CefDropTargetListener implements DropTargetListener {

private CefBrowser_N browser_;

private CefDragData dragData_ = null;

private int dragOperations_ = CefDragData.DragOperations.DRAG_OPERATION_COPY;

private int dragModifiers_ = EventFlags.EVENTFLAG_NONE;

private int acceptOperations_ = DnDConstants.ACTION_COPY;

CefDropTargetListener(CefBrowser_N browser) {

browser_ = browser;

}

@Override

public void dragEnter(DropTargetDragEvent event) {

CreateDragData(event);

browser_.dragTargetDragEnter(

dragData_, event.getLocation(), dragModifiers_, dragOperations_);

}

@Override

public void dragExit(DropTargetEvent event) {

AssertDragData();

browser_.dragTargetDragLeave();

ClearDragData();

}

@Override

public void dragOver(DropTargetDragEvent event) {

AssertDragData();

browser_.dragTargetDragOver(event.getLocation(), dragModifiers_, dragOperations_);

}

@Override

public void dropActionChanged(DropTargetDragEvent event) {

AssertDragData();

acceptOperations_ = event.getDropAction();

switch (acceptOperations_) {

case DnDConstants.ACTION_LINK:

dragOperations_ = CefDragData.DragOperations.DRAG_OPERATION_LINK;

dragModifiers_ =

EventFlags.EVENTFLAG_CONTROL_DOWN | EventFlags.EVENTFLAG_SHIFT_DOWN;

break;

case DnDConstants.ACTION_COPY:

dragOperations_ = CefDragData.DragOperations.DRAG_OPERATION_COPY;

dragModifiers_ = EventFlags.EVENTFLAG_CONTROL_DOWN;

break;

case DnDConstants.ACTION_MOVE:

dragOperations_ = CefDragData.DragOperations.DRAG_OPERATION_MOVE;

dragModifiers_ = EventFlags.EVENTFLAG_SHIFT_DOWN;

break;

case DnDConstants.ACTION_NONE:

// The user did not select an action, so use COPY as the default.

dragOperations_ = CefDragData.DragOperations.DRAG_OPERATION_COPY;

dragModifiers_ = EventFlags.EVENTFLAG_NONE;

acceptOperations_ = DnDConstants.ACTION_COPY;

break;

}

}

@Override

public void drop(DropTargetDropEvent event) {

AssertDragData();

browser_.dragTargetDrop(event.getLocation(), dragModifiers_);

event.acceptDrop(acceptOperations_);

event.dropComplete(true);

ClearDragData();

}

private void CreateDragData(DropTargetDragEvent event) {

assert dragData_ == null;

dragData_ = createDragData(event);

dropActionChanged(event);

}

private void AssertDragData() {

assert dragData_ != null;

}

private void ClearDragData() {

dragData_ = null;

}

private static CefDragData createDragData(DropTargetDragEvent event) {

CefDragData dragData = CefDragData.create();

Transferable transferable = event.getTransferable();

DataFlavor[] flavors = transferable.getTransferDataFlavors();

for (DataFlavor flavor : flavors) {

try {

if (flavor.isFlavorTextType()) {

Object ob = transferable.getTransferData(flavor);

if (!(ob instanceof String)) continue;

dragData.setFragmentText((String) ob);

} else if (flavor.isFlavorJavaFileListType()) {

List<File> files = (List<File>) transferable.getTransferData(flavor);

for (File file : files) {

dragData.addFile(file.getPath(), file.getName());

}

}

} catch (Exception e) {

// Data is no longer available or of unsupported flavor.

e.printStackTrace();

}

}

return dragData;

}

}