Can I disable autolayout for a specific subview at runtime? - xcode

I have a view that needs to have its frame manipulated programmatically - it's a kind of document view that wraps to its content which is then scrolled and zoomed around a superview by manipulating the frame origin. Autolayout fights with this at runtime.
Disabling autolayout completely seems a bit harsh because it could reasonably be used to handle layout for the other views. It seems like what I might want is some kind of "null constraint".

I had the same problem. But I have resolved it.
Yes, you can disable auto layout at runtime for a specific UIView, instead of disabling it for the whole xib or storyboard which is set by default in Xcode 4.3 and later.
Set translatesAutoresizingMaskIntoConstraints to YES, before you set the frame of your subview:
self.exampleView.translatesAutoresizingMaskIntoConstraints = YES;
self.exampleView.frame = CGRectMake(20, 20, 50, 50);

I had a similar issue where Autolayout was overriding some of my frame-setting at run time (I had a dynamic view that in some cases pushed a new view controller...pushing and then pressing Back would reset the initial view).
I got around this by putting my manipulation code in viewDidLayoutSubviews of my View Controller. This seems to get called after whatever constraint mojo gets called, but before viewDidAppear, so the user is none the wiser.

Perhaps just setting translatesAutoresizingMaskIntoConstraints to YES (and not adding additional constraints affecting that view) will let you set the frame without fighting the auto layout system.

In iOS 8 you can set an NSLayoutConstraint to be active or not. So if I'm using interface builder, I add all my constraints to an OutletCollection and then activate or deactivate using:
NSLayoutConstraint.deactivateConstraints(self.landscapeConstraintsPad)
NSLayoutConstraint.activateConstraints(self.portraitConstraintsPad)
The particular application I'm using it for here is having different constraints in portrait and landscape mode and I activate/deactivate based on the rotation of the device. It means I can create some complex layout changes all in interface builder for both orientations, and still use auto layout without the verbose auto layout code.
Or you can activate / deactivate using removeConstraints and addConstraints.

I don't know if this will help anyone else, but I wrote a category to make this convenient because I find myself doing this a lot.
UIView+DisableAutolayoutTemporarily.h
#import <UIKit/UIKit.h>
#interface UIView (DisableAutolayoutTemporarily)
// the view as a parameter is a convenience so we don't have to always
// guard against strong-reference cycles
- (void)resizeWithBlock:(void (^)(UIView *view))block;
#end
UIView+DisableAutolayoutTemporarily.m
#import "UIView+DisableAutoResizeTemporarily.h"
#implementation UIView (DisableAutoResizeTemporarily)
- (void)resizeWithBlock:(void (^)(UIView * view))block
{
UIView *superview = self.superview;
[self removeFromSuperview];
[self setTranslatesAutoresizingMaskIntoConstraints:YES];
__weak UIView *weakSelf = self;
block(weakSelf);
[superview addSubview:self];
}
#end
I use it like this:
[cell.argumentLabel resizeWithBlock:^(UIView *view) {
[view setFrame:frame];
}];
Hope it helps.

You can set the translatesAutoresizingMaskIntoConstraints type Boolean, Value Yes in the User Defined Runtime Attributes of the UIView you want in the xib/storyboard.

In my view I had a Label and a Text. The label had pan gesture. The label moves around fine during drag. But when I use the text box keyboard, the label resets its position to the original location defined in auto layout. The issue got resolved when I added the following in swift for the label. I added this in viewWillAppear but it can be added pretty much anywhere you have access to the target field.
self.captionUILabel.translatesAutoresizingMaskIntoConstraints = true

Open project in 4.5
Select storyboard
Open the file inspector
Under Interface Builder Document uncheck 'Use Autolayout'
You can split across multiple storyboards if you want to use autolayout for some views.

For me it worked to create the subview programmatically, in my case the auto layout was messing with a view that I needed to rotate around its center but once I created this view programmatically it worked.

I've encountered a similar scenario, where I joined a project that was initiated with auto-layout, but I needed to make dynamic adjustments to several views. Here is what has worked for me:
Do NOT have views or components laid out in interface builder.
Add your views purely programmatically starting with alloc/init and setting their frames appropriately.
Done.

This happened to me in a project without storyboards or xib files. All 100% code. I had an ad banner at the bottom and wanted the view bounds to stop at the ad banner. The view would resize itself automatically after loading. I tried every resolution on this page but none of them worked.
I ended up just creating a sub view with the shortened height and placed that in into the main view of the controller. Then all my content went inside the sub view. That solved the problem very easily without doing anything that felt like it was going against the grain.
I am thinking if you want a view that is not the normal size that fills the window then you should use a sub view for that.

Instead of disabling autolayout, I would just calculate the new constraint with the frame you are replacing. That appears to me to be the appropriate way. If you are adjusting components that rely on constraints, adjust them accordingly.
For example, if you have a vertical constraint of 0 between two views (myView and otherView), and you have a pan gesture or something that adjusts the height of myView then you can recalculate the constraint with the adjusted values.
self.verticalConstraint.constant = newMyViewYOriginValue - (self.otherView.frame.origin.y + self.otherView.frame.size.height);
[self.myView needsUpdateConstraints];

For those of you who are using auto layout, please check out my solution here. You should be making #IBOutlet's of the constraints you want to adjust and then change their constants.

if it's xib file:
select the .xib file
select the "File's Owner"
show the Utilities
click on: "File Inspector"
Under "Interface Builder Document" disable: "Use Autolayout"

Related

NSWindow launching with wrong size after setting contentViewController to NSTabViewController

I have an Xcode project with an NSWindowController whose contentViewController was set to a subclass of NSViewController. I recently removed the NSViewController subclass from the storyboard and replaced the contentViewController with an NSTabViewController subclass.
Now, when I run the application, the NSWindow opens with a size of 500x500 instead of the size of the first tab. What's more, there is no view I can see in the storyboard that has a size of 500x500, and that size isn't being programmatically, either. The window itself is set to a different size, as is the view in the NSTabViewController's first NSViewController.
I'm assuming that there is some sort of constraint I have to set somewhere, but if there is, I don't know where/how to find it. Using Xcode 9.2 and High Sierra.
Programmatically setting the window's size to the correct size in windowDidLoad() works, but if I ever change the size of the view, I'll have to change that, as well, which will get old, quick.
Sorry if this is vague; I genuinely have no clue what kind of screenshot or code snippet would be helpful.
I recently ran into this frustrating problem as well.
There are a couple options to workaround this problem:
As you mentioned, set preferredContentSize in each of your custom view controllers that hold the tab's content to your desired size. This is inflexible but it does work.
// Swift
class FooViewController: ViewController {
override func viewWillAppear() {
super.viewWillAppear()
preferredContentSize = NSSize(width: 400, height: 280)
}
}
I found a hint to a better solution in this SO answer. You can add a subview (stackview, nsview, etc...) to the main view of the view controller that handles the tab's content (phew!) and then add constraints that pin it to each edge and add constraints that set the size.
Here's a screenshot of what it looks like in Interface Builder. I added a Stack View and then added 6 constraints.
Hope this helps.
Joshua's answer with setting the preferredContentSize did the trick, all kudos to him! One remark worth making is that since this is done exclusively for the parent tab view controller it's a good idea to subclass it and move this handling into tabView(_ tabView: NSTabView, didSelect tabViewItem: NSTabViewItem?) delegate method, which gets invoked when the tab is selected:
override func tabView(_ tabView: NSTabView, didSelect tabViewItem: NSTabViewItem?) {
tabViewItem?.viewController?.preferredContentSize = tabViewItem?.view?.frame.size
// Alternatively: tabViewItem?.viewController?.preferredContentSize = tabViewItem?.view?.fittingSize
super.tabView(tabView, didSelect: tabViewItem)
}
This way the preferred content size is always up to date and you can worry not about manually refreshing it, assuming the view provides the correct frame size or fitting size, which is easily achieved with constraints.
This method also get's invoked after the window controller finishes loading and where the 500×500 gets initially set.
Setting the preferred content size in every tabbed view controller itself is not ideal: the same code is duplicated across multiple controllers and adds unnecessary noise if these controllers are reused else where.
I had a similar issue. I added a view controller with a container view as the window content and pointed the container view content to the tab view controller.

How is a subview of an NSView dynamically positioned?

I am attempting to change the coordinates of an NSButton that is contained within a parent NSView and something is clearly not working, because the button position does not change. Both elements are defined in a nib file and the parent view has animation applied to it using CoreAnimation.
I have tried the following.
button.frame.origin.x = 500
and...
var frame:CGRect = button.frame
frame.origin.x = 500
button.frame = frame
Even with the animations disabled, I can not seem to dynamically position the subview. Is there some feature that prevents children views from being positioned programmatically?
Please note that I am using Swift with XCode 6.3.1.
I'm guessing you're using AutoLayout constraints, given you're using the latest tools.
If so, setting a subview's frame directly won't work the way you're expecting (if it does anything at all, it'll cause strange drawing glitches / flashing when mixed with animation). You have to create outlets for your layout constraints and modify them.
If you're not using AutoLayout, I suggest having a look at your button outlet to make sure it's actually connected (ie, you're not talking to nil). Even if the outlet is connected, make sure it's not nil at runtime - you may be trying to talk to the button before the nib is loaded and the outlet / action connections are restored.

Using Cocoa autolayout to hide and show a view

I'm trying to hide and show view #1 in the following picture based on whether the button is clicked using Autolayout. Anyone know how to do this?
I tried setting two NSLayoutConstraints for view #2, one where it is tied to the top of the superview of view #1 and view #2 and one where it is tied to the bottom of view #1, and then alter the priority of the NSLayoutConstraints to hide view #1, but that didn't seem to do anything.
Any advice would be appreciated. I'm mainly trying to do this in IB, but programatic solutions are welcome as well.
Pic for reference:
NSStackView is appropriate here. It automates creating constraints that tie its subviews to each other in stack.
Hiding a view does not change layout. It's still there, just isn't drawing.
If you were doing it without NSStackView, what you would do is change the constraints. Keep an instance variable, _stackConstraints. In one configuration, the stack constraints would be
V:|-[0]-[view1(v1Height)]-0-[view2]-0-[view3(v3Height)]-0-|
and in the other configuration
V:|-[0]-[view2]-0-[view3(v3Height)]-0-|
When you hit the button, do
[[self view] removeConstraints:_stackConstraints];
_stackConstraints = <make other set of constraints>
[[self view] addConstraints:_stackConstraints];
If you're willing to require 10.11+, you can just select "Detaches Hidden Views" on the NSStackView in Interface Builder (or set detachesHiddenViews = YES on it programmatically).
Then setting View #1 to hidden = YES will automatically re-layout the stack view, making View #2 take up more space (assuming the stack view height is fixed – if not, the stack view would just get less tall instead).
If you need to support 10.10 or earlier, then you can hide the view this way:
[stackView setVisibilityPriority:NSStackViewVisibilityPriorityNotVisible forView:view1];
And show it again via:
[stackView setVisibilityPriority:NSStackViewVisibilityPriorityMustHold forView:view1];
Answer here Hide autolayout UIView : How to get existing NSLayoutConstraint to update this one
With this category https://github.com/damienromito/UIView-UpdateAutoLayoutConstraints
//Hide View
[myView1 hideByHeight:YES];

Adding a custom view to toolbar

I'm struggling with Cocoa for 2 hours now without success. I want to add a custom view to the toolbar. So, I added a NSToolbar to the window (with IB), and added my view (which works perfectly). IB automatically created a NSToolbarItem.
I followed the instructions from Apple here: http://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/Toolbars/Tasks/AddRemoveToolbarItems.html#//apple_ref/doc/uid/20000755-BBCGJCDJ
The problem is that I don't know what to do now, the view doesn't show although it's label is displayed in the window.
Here's the code I use to draw (very simple, it's for testing purpose)
- (void)drawRect:(NSRect)dirtyRect {
[[NSColor blackColor] set];
[[NSBezierPath bezierPathWithRect:self.bounds] fill];
}
Can someone help me?
Thanks in advance.
I solved the problem.
I put my custom view in the root of the nib. I added a classic NSToolbarItem and created two outlets: one for the custom view and one for the NSToolbarItem. On -(void)awakeFromNib, I called setView: on the NSToolbarItem with the custom view.
According to some ressources on the internet, it is a bug with Interface Builder.
According to an Apple engineer in the discussion at http://www.mail-archive.com/cocoa-dev#lists.apple.com/msg35673.html, there is a bug in Interface Builder whereby "Custom Views" (NSViews created in IB) are not decoded properly when used as the view for an NSToolbarItem, and so do not appear in the toolbar. Other kinds of NSViews, such as NSButtons and NSBoxes, will work just fine as toolbar items: you can create these in Interface Builder and then drag them into the toolbar to make them into toolbar items.
(The discussion in the link above implies that the bug is down to how "Custom Views" are created from the XIB at runtime: using initWithFrame: instead of initWithCoder:. The discussion dates from 2009 but this still hasn't been fixed as of XCode 4.5/OS X 10.8.)
In my case I was using a regular NSView to wrap a set of controls (a volume slider and min/max buttons), rather than implementing a custom NSView subclass. I was able to avoid the problem by using an NSBox as the container instead of an NSView: I made the NSBox transparent, title-less and borderless, so it otherwise acted exactly like a plain NSView wrapper. This was a little more work in IB, but saved me the trouble of wiring up the view to the toolbar item programmatically.

NSTextField over NSOpenGLView

I have made a window with an NSOpenGLView that I am rendering openGL content into.
I want to add some buttons and text fields to the view: I can add NSTextFields and NSButtons using interface builder (or code) but they do not appear.
NSOpenGLView is documented as not being able to have sub views, so I then made my own CustomGLView by deriving directly from NSView and implementing the code to create and use a NSOpenGLContext in it. But the subviews are still not appearing :- the OpenGL context paints over them.
On Windows this problem does not exist:- Windows used to host OpenGL MUST have the WS_CLIPCHILDREN and WS_CHIPSIBLINGS styles set ensuring that any peer, or sub children (views) will not be obscured by the OpenGL surface.
How do I get subviews to display over a NSView thats drawing using OpenGL ?
You have 2 choices:
Create a window just for the text field. Add as a child window of the one hosting the OpenGL view. Major downside is you have to manage positioning it correctly if the Open GL view is moved.
Set up your view hierarchy like so:
Layer-backed view
Layer-hosting view whose layer contains an OpenGL layer
Text field
Simply call -setWantsLayer:YES on the subviews of the NSOpenGLView.
NSOpenGLView cannot have subviews according to the documentation. Even if you subclass the NSOpenGLView, that will change nothing.
What you can do is to create a NSView that will hold both the NSOpenGLView and the NSTextField. You then overlap them in the right order to make one draw atop the other.
I'm not heavily into OpenGL yet, but it's my understanding that you can accomplish the visual effect of subviews with Quartz Extreme using layer-backed views; however, those may be problematic. Since subviews are not supported directly, any solution is liable to be a hack.
Indeed, the solution in that link actually hacks a second window to appear over your OpenGL display, the second window displaying the Cocoa views you desire.
The following code (from the above link) is something I've not tested (again not being an OpenGL guy by nature -- yet), but appears like a fairly clever approach:
// This is the GL Window and view you already have
glWindow = [[GLWindow alloc] initWithContentRect:windowRect];
glView = [[[GLView alloc] initWithFrame:NSMakeRect(0, 0, windowRect.size.width, windowRect.size.height)] autorelease];
[glView translateOriginToPoint:NSMakePoint(glView.bounds.size.width/2, glView.bounds.size.height/2)];
[glWindow setContentView:glView];
// And here's your transparent UI window
uiWindow = [[TransparentWindow alloc] initWithContentRect:windowRect];
uiView = [[[NSView alloc] initWithFrame:NSMakeRect(0, 0, windowRect.size.width, windowRect.size.height)] autorelease];
[uiView translateOriginToPoint:NSMakePoint(uiView.bounds.size.width/2, uiView.bounds.size.height/2)];
uiView.wantsLayer = YES;
[uiWindow setContentView:uiView];
[glWindow addChildWindow:uiWindow ordered:NSWindowAbove];
Again, I've not tested this, but it looks like it will get you the visual effect you desire.
The text can be rendered into a texture -- I just used this for a project, did a lot of looking for sample code, and ultimately found Apple's GLString demo code, which was an absolute trove of how-to:
http://developer.apple.com/library/mac/#samplecode/CocoaGL/Listings/GLString_m.html
I haven't tried adding buttons, but you can, of course, draw your own and comparing the positions of click events with those of your buttons...
This was my solution:
1) Create a parent NSView (let's call it parentView).
2) Add an NSOpenGLView Child to parentView.
3) Add an additional NSView Child to parentView (make sure this is after the OpenGLView within the hierarchy). You can add additional TextFields, etc. to this view.
4) In the ViewController for the parent make sure you call [parentView setWantsLayer: TRUE]; I did this within -(void) viewWillAppear
1) The NSOpenGLView can have a subview. It can have plenty even.
2) The reason some views, controls and other elements are being bullied by NSOpenGLView is due to the loading process when the Application launches. I.e If you add a slider or textfield above and into the content view of the window where the NSOpenGLView also resides, upon Application-Launch that textfield will most likely wind up beneath the NSOpenGLView.
This is an Apple Bug. And they know about it.
You can solve it quite easily even without adding a subview to NSOpenGLView...
In Interface Builder drag i.e. a CustomView into the canvas (Not the view). And set it the way you want it with sliders, text and what not. Then create an outlet (Call it i.e topView) in your view controller. Then somewhere in your code... Perhaps (applicationDidFinishLaunching) add this line...
[_window.contentView addSubview:_topView];
(Do your positioning & layout)
This will do the exact same thing as if you had dragged it into the contentView yourself inside IB. Only it will draw the darn thing in the correct Z position.
You loose IB's constraints this way and have to it manually
One could also just subclass and CAOpenGLLayer and use that as a backing layer inside of a regular NSView. There too it is drawn correctly...
Here is Apple's way of wanting to do that. CALayers are a Godsend ;)
Enter following String ** NSOpenGLLayer** in search and hit enter to get to where it is...
NSOpenGLLayer
Hope this helps....

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