Changing an NSImage in XCode - this line of code not working

Question

I am having a problem that is eating me alive. I really hope I am just missing something small here. It appears to be a rather "n00b" issue.

I have a blank NSImageView that I want to display a picture when a button is pressed — simple as that.

Here is my line of coding

NSBundle *mb = [NSBundle mainBundle];
NSString *fp = [mb pathForResource:@"tiles" ofType:@"PNG"];
NSImage *image = [[NSImage alloc] initWithContentsOfFile:fp];
if ( [image isValid] ) {
    [selection setImage:image];
    [selection setImageScaling:NSScaleProportionally];
}

Whereas,

tiles.PNG is a resource in my bundle

and if [image isValid] is satisfied, because I've inserted dummy code into the clause and had that work

selection is defined in my header file as follows

IBOutlet NSImageView *selection;

It is also linked up to the application delegate in IB.

I have a feeling I might not be linking it properly?

WHy wouldn't the image display? If anyone can see an error - or provide me with working code - I would be soooooo thankful

Brian

Answer 1

did you remember to send -setNeedsDisplay to the NSImageView after you set the image?

Answer 2

It's not a linking issue—your app wouldn't even launch (assuming it even links successfully) if you'd failed to link against Cocoa or AppKit.

More probably, either you haven't connected the outlet to your image view in your nib, or you haven't loaded the nib yet. The way to check this would be to NSLog the value of the imageView pointer, using the %p formatter.

Answer 3

I had a similar issue where my view wasn't displaying, and it turned out that the view was hidden. This was a setting in the view properties in Interface Builder. Just a punt, but give it a go.

Answer 4

You need to use the debugger and see what's going on as it runs. Is fp nil? Is image nil? Is selection nil? The debugger is your friend.