How to call registerForDraggedTypes in NSViewController? - macos

Question

I have a MainViewController with a splitview in it. Next I have two viewcontroller to control each of the views in the splitview. I want to be able to drag and drop a file in one of those views.
But I can't seem to get the dragging to work? There's no "plus-sign" on the file when dragged to the view and dropping it doesn't do anything either.
What am I doing wrong?
First here's MainViewController.m
fileViewController = [[FileViewController alloc] initWithNibName:#"FileViewController" bundle:nil];
terminalViewController = [[TerminalViewController alloc] initWithNibName:#"TerminalViewController" bundle:nil];
[splitView replaceSubview:[[splitView subviews] objectAtIndex:0] with:[fileViewController view]];
[splitView replaceSubview:[[splitView subviews] objectAtIndex:1] with:[terminalViewController view]];
Next, my code to handle the dragging in the FileViewController
#dynamic isHighlighted;
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
NSLog(#"registering");
[self.view registerForDraggedTypes:[NSArray arrayWithObjects: NSFilenamesPboardType, nil]];
}
return self;
}
- (NSDragOperation)draggingEntered:(id <NSDraggingInfo>)sender {
NSLog(#"[%# %#]", NSStringFromClass([self class]), NSStringFromSelector(_cmd));
NSPasteboard *pboard = [sender draggingPasteboard];
if ([[pboard types] containsObject:NSFilenamesPboardType]) {
NSArray *paths = [pboard propertyListForType:NSFilenamesPboardType];
for (NSString *path in paths) {
NSError *error = nil;
NSString *utiType = [[NSWorkspace sharedWorkspace]
typeOfFile:path error:&error];
if (![[NSWorkspace sharedWorkspace]
type:utiType conformsToType:(id)kUTTypeFolder]) {
[self setHighlighted:NO];
return NSDragOperationNone;
}
}
}
[self setHighlighted:YES];
return NSDragOperationEvery;
}
- (void)draggingExited:(id <NSDraggingInfo>)sender {
[self setHighlighted:NO];
}
- (BOOL)prepareForDragOperation:(id <NSDraggingInfo>)sender {
return YES;
}
- (BOOL)performDragOperation:(id <NSDraggingInfo>)sender {
[self setHighlighted:NO];
return YES;
}
- (void)concludeDragOperation:(id )sender {
[self.view setNeedsDisplay:YES];
} // end concludeDragOperation
- (BOOL)isHighlighted {
return isHighlighted;
}
- (void)setHighlighted:(BOOL)value {
isHighlighted = value;
[self.view setNeedsDisplay:YES];
}
- (void)drawRect:(NSRect)frame {
[self.view drawRect:frame];
if (isHighlighted) {
[NSBezierPath setDefaultLineWidth:6.0];
[[NSColor keyboardFocusIndicatorColor] set];
[NSBezierPath strokeRect:frame];
}
}

Answer 1

I didn't seem to fix it, and because no one gave me any answers, I fixed it by making an NSView subclass and adding it to my viewcontroller like this.
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
draggable = [[DragView alloc] initWithFrame:CGRectMake(0, 0, 500, 500)];
[[self view] addSubview:draggable];
}
return self;
}

Answer 2

I've never done OS X programming, but the problem is that since you're registering self.view to receive drag and drop, your self.view should handle the drag and drop operations and not your view controller. So you're correct in subclassing NSView to DragView, and you should pass the drag operations back to the view controller.
Also, I believe - (NSDragOperation)draggingUpdated:(id<NSDraggingInfo>)sender should be implemented.