avoid the NSImageView change the image after drag & drop

Question

I have coded drag & drop for the NSImageView, and I set the NSImageView as the PDF/image files drop zone. But I found once the files dropped, the NSImageView shows the dropped file content and image. How can I avoid that? I want NSImageView shows the default image I set when the application launch. I also tried to add this code but doesn't work:

[imgView setImage:[NSImage imageNamed:@"default.jpg"]];

Set the background image of your NSImmgeView object through Interface Builder. Or create your drop box with your NSView, which may be a little bit more difficult, though. — El Tomato, Dec 09 '15 at 10:37
I cannot see any place allows to set the background on Interface Builder for NSImageView — SuperBerry, Dec 09 '15 at 10:57
You are subclassing NSViewImage to create a drop box, right? — El Tomato, Dec 09 '15 at 11:21

score 2 · Answer 1 · answered Sep 16 '17 at 07:09

after you process data, you can clear NSDraggingInfo like this:

override func performDragOperation(_ sender: NSDraggingInfo) -> Bool {
    // process your data form NSDraggingInfo

    // and clearContents   
    sender.draggingPasteboard().clearContents()

    return true 
}

score 0 · Accepted Answer · answered Dec 09 '15 at 22:22

0

Create a subclass of ImageView. Remove the drawRect:(NSRect)rect method if there is in its implementation file. You won't need it.

Click on the identity inspector tab of the sidebar to the right. Then enter the name of your imageView subclass after selecting an imageView control, which you have already done, probably.
Click on the attributes inspector tab of the sidebar. Select your imageView control and then enter the name of the background image in the top combobox.

answered Dec 09 '15 at 22:22

El Tomato

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I use XCode V5.1.1 and cannot find that. However I find the solution finally. I write the (void)draggingEnded in the new class: [imgView setImage:[NSImage imageNamed:@"default.jpg"]]; Solved! :) – SuperBerry Dec 10 '15 at 01:04

score 0 · Answer 3 · answered Sep 09 '20 at 07:25

0

Subclass NSImageView and implement following method.
Setting new image with draggingInfo is done from concludeDragOperation by default.

override func concludeDragOperation(_ sender: NSDraggingInfo?) {
    return
}

answered Sep 09 '20 at 07:25

Ewan

31
1

avoid the NSImageView change the image after drag & drop

3 Answers3