Drag and Drop with NSStatusItem

Question

I'm trying to write an application that allows the user to drag files from the Finder and drop them onto an NSStatusItem. So far, I've created a custom view that implements the drag and drop interface. When I add this view as a subview of an NSWindow it all works correctly -- the mouse cursor gives appropriate feedback, and when dropped my code gets executed.

However, when I use the same view as an NSStatusItem's view it doesn't behave correctly. The mouse cursor gives appropriate feedback indicating that the file can be dropped, but when I drop the file my drop code never gets executed.

Is there something special I need to do to enable drag and drop with an NSStatusItem?

Answer 1

Since Yosemite, the method for setting a view on NSStatusItem is deprecated but fortunately there is a much nicer way using the new NSStatusItemButton property on NSStatusItem:

- (void)applicationDidFinishLaunching: (NSNotification *)notification {
    NSImage *icon = [NSImage imageNamed:@"iconName"];
    //This is the only way to be compatible to all ~30 menu styles (e.g. dark mode) available in Yosemite
    [normalImage setTemplate:YES];
    statusItem.button.image = normalImage;

    // register with an array of types you'd like to accept
    [statusItem.button.window registerForDraggedTypes:@[NSFilenamesPboardType]];
    statusItem.button.window.delegate = self;

}

- (NSDragOperation)draggingEntered:(id<NSDraggingInfo>)sender {
    return NSDragOperationCopy;
}

- (BOOL)performDragOperation:(id<NSDraggingInfo>)sender {
  //drag handling logic
}

Please be aware that the button property is only available starting in 10.10 and you might have to keep your old solution if you support 10.9 Mavericks or below.

Answer 2

I finally got around to testing this and it works perfectly, so there's definitely something wrong with your code.

Here's a custom view that allows dragging:

@implementation DragStatusView

- (id)initWithFrame:(NSRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        //register for drags
        [self registerForDraggedTypes:[NSArray arrayWithObjects: NSFilenamesPboardType, nil]];
    }

    return self;
}

- (void)drawRect:(NSRect)dirtyRect
{
    //the status item will just be a yellow rectangle
    [[NSColor yellowColor] set];
    NSRectFill([self bounds]);
}

//we want to copy the files
- (NSDragOperation)draggingEntered:(id<NSDraggingInfo>)sender
{
    return NSDragOperationCopy;
}

//perform the drag and log the files that are dropped
- (BOOL)performDragOperation:(id <NSDraggingInfo>)sender 
{
    NSPasteboard *pboard;
    NSDragOperation sourceDragMask;

    sourceDragMask = [sender draggingSourceOperationMask];
    pboard = [sender draggingPasteboard];

    if ( [[pboard types] containsObject:NSFilenamesPboardType] ) {
        NSArray *files = [pboard propertyListForType:NSFilenamesPboardType];

        NSLog(@"Files: %@",files);
    }
    return YES;
}


@end

Here's how you'd create the status item:

NSStatusItem* item = [[[NSStatusBar systemStatusBar] statusItemWithLength:NSSquareStatusItemLength] retain];

DragStatusView* dragView = [[DragStatusView alloc] initWithFrame:NSMakeRect(0, 0, 24, 24)];
[item setView:dragView];
[dragView release];