How do you position a larger NSImage inside of a smaller NSImageView programmatically?

Question

Let's say I have an NSImage that's 100x100. I also have an NSImageView that's 50x50. Is there a way I can place the NSImage at coordinates inside the NSImageView, so I can control which part of it shows? It didn't seem like NSImage had an initWithFrame method...

score 3 · Accepted Answer · answered Nov 08 '09 at 01:21

I did this in my NSImageView subclass, as Andrew suggested.

- (void)drawRect:(NSRect)rect
{
    [super drawRect:rect];
    NSRect cropRect = NSMakeRect(x, y, w, h);
    [image drawAtPoint:NSZeroPoint
              fromRect:cropRect
             operation:NSCompositeCopy
              fraction:1];
}

score 2 · Answer 2 · answered Nov 07 '09 at 22:40

2

I don't believe so, but it's trivial to roll your own NSImageView equivalent that supports center/stretch options by drawing the image yourself.

answered Nov 07 '09 at 22:40

Andrew Grant

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Could I create an NSView, add a sub NSImageView at a position within? – zekel Nov 07 '09 at 23:28
Yeap, or better yet just create an NSView that draws an NSImage at your desired position. – Andrew Grant Nov 08 '09 at 00:13
I suppose better yet, crop the NSImage, since I'm slicing an image up into squares. – zekel Nov 08 '09 at 00:37

score 1 · Answer 3 · answered Nov 08 '09 at 04:54

1

Make your imageview as big as the image, and put it inside a scrollview. Hide the scrollers if you want. No need for subclassing in this case.

answered Nov 08 '09 at 04:54

NSResponder

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score 1 · Answer 4 · answered Nov 08 '09 at 08:18

1

NSImageView has a method -setImageAlignment: which lets you control how the image is aligned within the image view. Unfortunately, if you want to display part of the image that doesn't correspond to any of the NSImageAlignment values, you're going to have to draw the image programmatically.

answered Nov 08 '09 at 08:18

Lily Ballard

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Right. I want to slice up a big image into little boxes, so basic image alignment won't do it in my case. – zekel Nov 09 '09 at 15:01

silverdr · Answer 5 · 2019-06-06T17:55:59.447

Depends on what your eventual goal is but the easiest thing to me seems to put your NSImageView inside an NSView (or a subclass – doesn't have to be NSScrollView as "@NSResponder" user suggests but this should work well too), set its imageScaling to NSImageScaleProportionallyUpOrDown and its frameSize to image's size. Then you can move your NSImageView freely around the upper view using setFrame:myDesiredFrame. No subclassing, no manual redrawing, etc.

How do you position a larger NSImage inside of a smaller NSImageView programmatically?

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