NSSplitter how to prevent proportional space distribution on resize - cocoa

I have a window with a source list sidebar at the right side and a content view on the left both inside an NSSplitView.
When i resize the window, the additional space is distributed to the source list and the content view. How can i make the source list to maintain its fixed width. All Apple applications are doing this so i hope i just missed a method.

On SnowLeopard, there is a delegate method called splitView:shouldAdjustSizeOfSubview:. All you have to do is return NO for your source list view, and you should be good. If you need to support Leopard or earlier, you have to implement splitView:resizeSubviewsWithOldSize: and manually resize the subviews, keeping your source list view a fixed width, and resizing your other view to fill the split view's bounds (taking into account the divider's width).
Both methods are documented here

Related

OS X App - Cannot Resize App Window

I have an OS X app originally built using Xcode 4, now using Xcode 7. When "springs-and-struts" was superseded by constraints, I reworked the UI to use constraints. Simple enough, and seemed to work well.
Fast forward two years after first release, and for the second release I needed to add controls and increase the height of the main app view. Unfortunately, my test team is using smaller screens and cannot see the whole view. They need to resize vertically.
Problem - even though the resize controls box is checked, the window cannot be resized. The controls do not show at run time. I tried
Setting lower minimum window content size height, but that did not change anything.
Changing content compression resistance did not change anything.
I am thinking this issue has something to do with constraints.... Any ideas on how to get resize to work?
Edit: After playing with a new test app some, I am more certain the problem is due to constraints. I have a control where I have constrained leading and trailing space to superview and width - there went horizontal resize.
I really need to have a view where the user can resize the window, but scroll the content. However, in this case, the content is other controls. I think on iOS, I would use a UIScrollView. On OS X, I have tried a scroll view control and have tried embedding in a scroll view, and neither have the desired effect.
I had the same issue and solved it by adding a view to be used as a "container" in the view controller.
Pin the top left corner of the "container view" to the view controller (leading space 0 and top space 0). Add equal width and height constraints on the "container view" to the view controller. Then move all your objects into the "container view" and add your object constraints on the "container view" not the view controller.
In my case, it happened in this way (Xcode 13.1).
I mistakenly added a view from IB outside of the window view hierarchy. The new view was added as a separated object (a top node in the interface builder file). I added the new view into the window by drag-n-drop.
I found the new view had different behaviours, for example, I couldn't set the top space constraint. With this view in the view hierarchy, I couldn't change the window size (content view size) at all.
I removed the view and added another in the view hierarchy, it worked as normal.
I think IB initialises the view differently if it is a separated object (top node of the interface builder file).

Auto layout NSWindow respects minimum size in IB simulator, but not when running for real

I have a window I'm setting up with auto layout. There is a view in the middle of the window that contains three controls, and I would like the window to refuse to resize horizontally smaller than the intrinsic size of those three controls.
The outer buttons both have horizontal space constraints to "stick" them to the outside of their superview, and the checkbox in the middle has a horizontal space constraint sticking it to the left side of the "Sync text" button. There is also a >= constraint between the "Sync outline" button and the checkbox, to make sure they don't overlap, but the checkbox prefers to hang to the right. All these constraints have a priority of 1000. The window itself has no minimum size specified.
When I use the "Simulate Document" command in Xcode, everything works as I'd expect, and the window won't let you size it smaller than in the screenshot above. However, when I run my application, the window does allow resizing smaller than that width, so that the buttons start to shrink and eventually the controls overlap each other. I'm not implementing any of the size related window delegate methods, so I don't see any place in the app's code where it might be influencing the resizing.
Any ideas on what could be causing this difference in behavior?
OK, I finally figured out what the heck was going on here. It turns out the problem was that I was implementing the -splitView:constraintMinCoordinate:ofSubviewAt: delegate method (as well as the maxCoordinate one) to restrict the size of the split subviews in the vertical direction. Yes, restricting the vertical resizing of the split view affected the horizontal layout of the buttons.
It appears that what happens is that, if you implement those delegate methods, NSSplitView reverts back to using autoresizing masks to layout the subviews rather than auto layout constraints. Since the view containing those buttons is no longer participating in auto layout, the buttons smush together when you resize the window small. In the simulator, the split view doesn't have a delegate set, so all the auto layout stuff works fine in that environment. Note that merely having the methods implemented is enough to trigger this, even if they just return the proposed coordinates unchanged.
The solution ended up being quite easy, which was to delete the delegate methods and replace it with a vertical constraint on the subview to restrict its size instead.

How do you use NSScrollView with auto layout?

Ok. I've been at this over and over. I've seen blogs and cocoa dev threads.
I've seen Kyle Sluder's proposed solution, but have yet to find a solution that really works.
How can you position subviews of an NSScrollView with auto layout?
Is it just silently broken ?
Nothing seems to work.
Ok, old question, but this particular issue is a personal bugbear of mine so I'll answer it anyway!
The first thing to note is that an NSScrollView contains an NSClipView, which itself has a view outlet called documentView. These are all added for you when you drag a new scroll view into your storyboard or nib file. By default, the document view is an NSView called simply "View". If you're using a custom view, you can just select this and set its type in the inspector on the right to whatever you want. Otherwise, you'll be adding subviews to it.
The big thing that is easy to miss here is that, by default, the document view has its layout set to 'Translates Mask Into Constraints'. This is fine if the content size will never, ever change, and if that's the case you can simply set the frame of the document view to whatever you want and leave it at that. If you want it to automatically resize itself to fit its content however, there's a few things you'll need to do.
First off, that document view needs to have a completely unambiguous size. If you're using a custom view, I'd recommend giving it an intrinsicContentSize. You should also set 'Intrinsic Size' in IB's inspector to 'Placeholder' and give it a suitable value, or you'll get a bunch of autolayout warnings. If your document view gets its size from its content, all of the subviews must be linked in an unbroken chain from top to bottom, and from left to right, such that the content knows exactly how big it ought to be. This is quite an art in itself, so I won't go into it. A simple example where you have only one subview would be to pin its top, bottom, leading and trailing constraints to its parent, but as noted above if you're doing this, you might as well just set the type of the document view.
Now the fun bit. Select your document view and set its layout to 'Automatic'. Next, add top, bottom, leading and trailing constraints to its superview with a suitable value. I'm using zero, but you might want a small border. Finally, select the TRAILING and BOTTOM constraints you just made and set them to '>=' (greater than or equal) and a priority of 500 or less. The priority is very important, as it has to be less than the priority that the clip view uses to determine its own minimum size. Too high and the clip view will be forced to remain larger than its content, making it impossible in turn for the scroll view to be smaller than its content, rendering it useless.
The technical details aren't important. Just remember to set the document view to layout: automatic, pin all edges, and make the trailing and bottom constraints >= and priority 500.
Note that this will cause your content to hug the top-left corner.
Have you tried setting the document view's setTranslatesAutoresizingMaskIntoConstraints to TRUE?
[_scrollView.documentView setTranslatesAutoresizingMaskIntoConstraints:YES];

Custom NSView in a NSScrollView that takes up the whole visible space

I have a custom NSView subclass, and I put it in a NSScrollView, and the basics are working fine. It always takes up the full width of its available space, so its constraints take up the whole width of the scroll view. How much vertical space it takes up depends on how much data it has to display, so it can scroll vertically, only. That's all great.
The catch is that if my custom view needs less space than the NSScrollView that it's in, it doesn't expand to fill the visible area. In cases where there's less data than fits in the visible area, I want it to expand downwards -- so that space is available as a drag-and-drop target, among other things.
I've tried changing its "hugging priority". I've tried adding a constraint to keep the bottom below the NSClipView's bottom. I can't come up with any constraint-based solution to fix this (though I haven't ruled out the possibility, either).
I've tried catching the notifications when the NSScrollView changes size, and adjusting the custom view's frame if it's too small, but (presumably because I can only change its current frame, while the layout system does all layout later) I can't seem to make this work, either.
Is there a trick for adding a view to an NSScrollView such that it expands to the bottom of the visible area, whenever it would otherwise be too short? It seems like it should be so simple, and I've done it before in cases where I just call -setFrame on everything manually, but once you move to the autolayout world, that approach stops working.
Without knowing what your constraints and content hugging and content compression actually look like...
Content hugging with at least one edge having >= constraint to superview might do it but you might need to adjust priorities.
You might also need to make sure you've implemented intrinsicContentSize in your custom view class this tells the content hugging and compression what they need to knowfirst.

make NSRect selectable

Is there a simple way to create a selectable NSRect in Cocoa? In need a rectangle that can be selected and stays selected after a mouse click.
Thanks.
NSRect is just a struct with a position and size. It's not an object that can actually do anything or have any properties other than a width and height. It sounds like what you want is to create an NSView that can be selected. (Here's Apple's Guide on the subject.)
Though not as immediate as you would like, you may be interested in the management of tracking rectangles and tracking areas performed by NSView class.
This mechanism allows you to define specific areas of your custom view. Then, an event is generated whenever the cursor enters or leaves the area, or a mouse button is pressed in this area (-mouseEntered:, -mouseExited:, -mouseDown:, -mouseUp:, -mouseDragged:, ... of NSResponder class). This up to you to define what you want your application do in response to these events (set the rectangle as selected and display it accordingly).
For an example implementation of this, take a look at the Sketch example included with the Apple developer tools (look in /Developer/Examples/AppKit). Sketch allows the user to create new graphics (including rectangles, but also ovals, lines, and text), select them, move them around in the document, etc. In particular, you'll probably want to look at the SKTGraphic class, which represents a single graphic object in the document, and the SKTGraphicView class, which is an NSView subclass that perform the actual layout and drawing, handling mouse events for dragging views around, etc.

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