/*

 Copyright (C) 2016 Apple Inc. All Rights Reserved.

 See LICENSE.txt for this sample’s licensing information

 Abstract:

 The CanvasScrollView exists just as a starting example of how to manually do drag and drop.

*/

import Cocoa

class CanvasScrollView: NSScrollView {

    override init(frame frameRect: NSRect) {

        super.init(frame: frameRect)

        commonSetup()

    }

    required init?(coder: NSCoder) {

        super.init(coder: coder)

        commonSetup()

    }

    private func commonSetup() {

        register(forDraggedTypes: [NSURLPboardType, NSFilesPromisePboardType])

    }

    // MARK: - Dragging destination support

    override func draggingEntered(_ sender: NSDraggingInfo) -> NSDragOperation {

        sender.draggingFormation = .stack // This is one possible representation for Drag Flocking

        return .copy

    }

    override func draggingExited(_ sender: NSDraggingInfo?) {

        sender?.draggingFormation = .default

    }

    override func prepareForDragOperation(_ sender: NSDraggingInfo) -> Bool {

        sender.animatesToDestination = true

        return true

    }

    override func performDragOperation(_ sender: NSDraggingInfo) -> Bool {

        // We perform no actual action here, but this is where you'd act upon a drag operation

        return true

    }

}