I'm trying to create a NSTableView inside a NSScrollView (the standard configuration, that is) in code, using auto layout. I can't figure out how to make this work.
Here's my loadView:
- (void)loadView
{
NSView *view = [[NSView alloc] init];
NSScrollView *tableScroll = [[NSScrollView alloc] init];
NSTableView *fileTable = [[NSTableView alloc] init];
[tableScroll setDocumentView:fileTable];
[tableScroll setHasVerticalScroller:YES];
[tableScroll setHasHorizontalScroller:NO];
fileTable.delegate = self;
fileTable.dataSource = self;
[fileTable setHeaderView:nil];
[fileTable setAllowsColumnReordering:NO];
NSTableColumn *column = [[NSTableColumn alloc] initWithIdentifier:#"column1"];
[fileTable addTableColumn:column];
[tableScroll setTranslatesAutoresizingMaskIntoConstraints:NO];
[fileTable setTranslatesAutoresizingMaskIntoConstraints:NO];
[view addSubview:tableScroll];
NSDictionary *topViews = NSDictionaryOfVariableBindings(tableScroll);
[view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"V:|[tableScroll]|" options:0 metrics:nil views:topViews]];
[view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"|[tableScroll]|" options:0 metrics:nil views:topViews]];
self.fileTable = fileTable;
self.view = view;
}
What happens is that my table view's frame will be always equal to the bounds of the NSClipView. The view is inside a window and gets resized with it, and when I do that it'll resize the scrollview, the clip view and the table, but I can never scroll anywhere.
Looking at constraints I get, the NSScrollView gets constraints that set the clip view to fill it, the clip view has no constraints at all and the table view has a bunch of constraints related to the NSTableRowViews inside it.
If I add a constraint like |[fileTable(>=500)] to the clip view I'll get 500 pixels of NSTableView, but obviously I don't want to do that.
Even though this was answered by the poster in the comments above, I thought I’d put the answer here (having run into the same issue). If you are adopting auto layout, you would typically uncheck “Translates Mask Into Constraints” in the xib. However, for classes like NSScrollView and NSTableView, you should generally let them manage their own internal views by setting their translatesAutoresizingMaskIntoConstraints property to YES. It is still ok to set constraints that are external to these views, i.e. to resize in relation to their superview.
If you set translatesAutoresizingMaskIntoConstraints to NO, then you will need to supply constraints for all of the internal views, which unless you specifically need custom behavior (almost never), you will not want to do. This was the specific problem above.
An obvious side effect of not setting this correctly is that a table (for example) will not properly scroll beyond what is visible in the view.
Related
If I resize the window to be smaller than the metal view I can see the scrollbars for a second but I cannot click on them nor they stay visible. Do you know how I can change this behavior? I would expect the scrollbars to be visible and clickable as long as the window is smaller than the metal view.
nsview = gdk_quartz_window_get_nsview(window);
NSScrollView *scroll_view = [[NSScrollView alloc]initWithFrame: [nsview frame]];
[scroll_view setBorderType: NSNoBorder];
[scroll_view setHasVerticalScroller: YES];
[scroll_view setHasHorizontalScroller: YES];
[scroll_view setAutoresizingMask: NSViewWidthSizable | NSViewHeightSizable];
[nsview addSubview: scroll_view];
self->clip_view = [[DvFlippedClipView alloc]initWithFrame: [nsview frame]];
[scroll_view setContentView: self->clip_view];
self->mtk_view = [[MTKView alloc]initWithFrame: [nsview frame]
device: self->device];
self->mtk_view.framebufferOnly = YES;
self->mtk_view.autoResizeDrawable = NO;
self->mtk_view.translatesAutoresizingMaskIntoConstraints = NO;
self->mtk_view_delegate = [[DvMetalViewDelegate alloc] init: self->mtk_view];
self->mtk_view.delegate = self->mtk_view_delegate;
[scroll_view setDocumentView: self->mtk_view];
From a different callback I do the following:
[self->mtk_view setBounds:NSMakeRect(0, 0, width, height)];
[self->mtk_view setFrame:NSMakeRect(0, 0, width, height)];
self->mtk_view.drawableSize = CGSizeMake(width, height);
I had a similar problem yesterday, and I suspect the strange scroller behavior and lack of scrolling altogether may be stemming from what I suspect your problem is. Hopefully it will at least enlighten your or someone else if you haven't already found an answer.
My view hierarchy looks like this:
The problem was that I had set MTKView as the view property of CenterTopViewController, rather than the Bordered Scroll View. Doing that, for all practical intents and purposes, removed MTKView from the hierarchy and set it so that its superview property pointed to the split view in which all of this resides. The scroll view did not seem to be part of the responder chain, and was never handling any scroll events (or at least not in any meaningful way).
Setting the scroll view as the view property of the view controller fixed everything.
P.S.
If you're confused as to why there is an unnecessary view above the MTKView, it's just a result of almost desperate attempts to uncover the problem before I figured it out. I haven't gotten around to fixing it yet.
I have a UIView inside a UIScrollView. I can easily pin the height to the UIScrollView's frame height.
How do I add a constraint that pins to the UIScrollView's contentSize instead?
Thanks!
UIScrollView have dynamic constraints, left, top, width and height are generated at runtime. If you put a UIView inside a UIScrollview and Pin fixed constraints in Interface Builder it will generate an error because the parameters are relative to Superview/Container View.
You can try some workarounds:
1- Add UIView constraints Programmatically
http://www.thinkandbuild.it/learn-to-love-auto-layout-programmatically/
2- Manually resize your view bounds in initWithFrame function inside a UIView Subclass
Please give me any feedback about your progress.
The answer "Adding constraints programatically" is correct but it was a little light on detail for me to accept it as the full answer.
Here's how I did it!
Remove all storyboard constraints on the WebView
Add a Placeholder constraint in storyboard for the constraint that you will add with code. This step is very important (and easily missed) or you will get an error about conflicting constraints.
Add code to webviewDidFinishLoad delegate method
--Code--
- (void)webViewDidFinishLoad:(UIWebView *)webView {
_scrollView.contentSize = CGSizeMake(self.scrollView.frame.size.width, _headerImageView.frame.size.height + webView.scrollView.contentSize.height);
_webView.translatesAutoresizingMaskIntoConstraints = NO;
NSDictionary *viewsDictionary = #{#"myWebView":_webView};
NSString *constraintsString = [NSString stringWithFormat:#"V:[myWebView(%i)]", (int)_scrollView.contentSize.height];
NSArray *constraint_H = [NSLayoutConstraint constraintsWithVisualFormat:constraintsString options:0 metrics:nil views:viewsDictionary];
[_webView addConstraints:constraint_H];
}
I have the default NSWindow created in a new application which has a single NSView. I then create a new NSViewController which has it's own XIB and a view. In the app delegate I do the obvious
self.mainViewController = [[MainViewController alloc] initWithNibName:#"MainViewController" bundle:nil];
[self.window.contentView addSubview:self.mainViewController.view];
self.mainViewController.view.frame = ((NSView*)self.window.contentView).bounds;
OK, how do I set a constraint in the new way to have my subview keep its size identical to the Window, i.e. it's superview. It doesn't seem to work automatically. Autoresizessubviews is ON for both views.
Basically, you need to constrain four things:
The leading space of your subview to its superview to be zero
The top space of your subview to its superview to be zero
The width of your subview to be equal to its superview's width
The height of your subview to be equal to its superview's width
If the visual constraint isn't working out for you, you can build these four constraints individually in code. Use the method +constraintWithItem:attribute:relatedBy:toItem:attribute:multiplier:
constant: to specify exact relationships between different views' attributes. For example, constraint #1 above might be expressed by:
[NSLayoutConstraint constraintWithItem:mySubview
attribute:NSLayoutAttributeLeading
relatedBy:NSLayoutRelationEqual
toItem:mySuperview
attribute:NSLayoutAttributeLeading
multiplier:1.0f
constant:0.0f]
and #3 might be:
[NSLayoutConstraint constraintWithItem:mySubview
attribute:NSLayoutAttributeWidth
relatedBy:NSLayoutRelationEqual
toItem:mySuperview
attribute:NSLayoutAttributeWidth
multiplier:1.0f
constant:0.0f]
Once you've built up those four constraints, you can add them to your superview as needed.
Note that there are multiple ways to achieve the same effect as above:
You might constrain the trailing space and bottom space instead of the width and height
You might constrain the center X and center Y instead of the leading and top spaces
You can also probably come up with the same constraints in a visual representation, as in Peter Hosey's answer. For example, an equal-width constraint might look like #"[mySubview(==mySuperview)]" with the appropriate views dictionary.
Keep in mind that the Auto Layout Guide is a wealth of information about constraints, including how to debug them when things go wrong.
In the nib editor, drag the subview's size until it is the same size as its superview. Xcode will create an appropriate width constraint automatically.
In code, I would try |-0-[mySubview]-0-| (adapted from the example in the constraint syntax documentation).
Just like Peter wrote, you should use the visual format language.
When doing this, however, order is important: when you create a constraint, all views it references have to be part of the same view hierarchy.
So given your example, the code would have to become:
self.mainViewController = [[MainViewController alloc] initWithNibName:#"MainViewContoller" bundle:nil];
NSView *containerView = self.window.contentView;
NSView *contentView = self.mainViewController.view;
[contentView setTranslatesAutoresizingMaskIntoConstraints: NO];
[containerView addSubview:contentView];
NSDictionary *viewBindings = NSDictionaryOfVariableBindings(contentView);
[containerView addConstraints: [NSLayoutConstraint constraintsWithVisualFormat:#"H:|[contentView]|" options:0 metrics:nil views:viewBindings]];
[containerView addConstraints: [NSLayoutConstraint constraintsWithVisualFormat:#"V:|[contentView]|" options:0 metrics:nil views:viewBindings]];
You can override setContentView:, contentView:, and contentRectForFrameRect: so they will deal with window.frame - sized view.
If you're ok with using a 3rd party library, you can accomplish this with ReactiveCocoaLayout in one simple line:
RAC(view,rcl_frame) = parentView.rcl_frameSignal;
I had the same problem and I ended up with this solution which is working with SDK 10.10. Just set the autoresizingMask of the new view to be the same as the parent window. Only one row of code and it works like a charm...
self.masterViewController = [[MasterViewController alloc] initWithNibName:#"MasterViewController" bundle:nil];
[self.window.contentView addSubview:self.masterViewController.view];
self.masterViewController.view.frame = ((NSView *)self.window.contentView).bounds;
self.masterViewController.view.autoresizingMask = ((NSView *)self.window.contentView).autoresizingMask;
Say,
UILabel *label = [[UILabel alloc] init];
....
[view1 addSubview:label];
[view2 addSubview:label];
Doesn't addSubview retain a reference to the current label? That is, it has its own copy of the UILabel but why the label only shows up on view 2?
Thanks.
That does not work because view can have only 1 superview. So if you want to have multiple instances of same label in different views you have to create a copy of your label yourself and add it to another superview.
Quote from reference:
Views can have only one superview. If
view already has a superview and that
view is not the receiver, this method
removes the previous superview before
making the receiver its new superview.
I am doing manual layouting for my Cocoa application and at some point I need to figure out what the inner size of a NSView subclass is. (E.g. What is the height available for my child view inside of a NSBox?)
One of the reasons is that I am using a coordinate system with origin at the top-left and need to perform coordinate transformations.
I could not figure out a way to get this size so far and would be glad if somebody can give me a hint.
Another very interesting property I would like to know is the minimum size of a view.
-bounds is the one you're looking for in most views. NSBox is a bit of a special case, however, since you want to look at the bounds of the box's content view, not the bounds of the box view itself (the box view includes the title, edges, etc.). Also, the bounds rect is always the real size of the box, while the frame rect can be modified relative to the bounds to apply transformations to the view's contents (such as squashing a 200x200 image into a 200x100 frame).
So, for most views you just use [parentView bounds], and for NSBox you'll use [[theBox contentView] bounds], and you'll use [[theBox contentView] addSubview: myView] rather than [parentView addSubview: myView] to add your content.
Unfortunately, there is no standard way to do this for all NSView subclasses. In your specific example, the position and size of a child view within an NSBox can be computed as follows:
NSRect availableRect = [someNSBox bounds];
NSSize boxMargins = [someBox contentViewMargins];
availableRect = NSInsetRect(availableRect, boxMargins.width, boxMargins.height);
If you find yourself using this often, you could create a category on NSBox as follows:
// MyNSBoxCategories.h
#interface NSBox (MyCategories)
- (NSRect)contentFrame;
#end
// MyNSBoxCategories.m
#implementation NSBox (MyCategories)
- (NSRect)contentFrame
{
NSRect frameRect = [self bounds];
NSSize margins = [self contentViewMargins];
return NSInsetRect(frameRect, margins.width, margins.height);
}
#end
And you would use it like so:
#import "MyNSBoxCategories.h"
//...
NSRect frameRect = [someNSBox contentFrame];
[myContentView setFrame:frameRect];
[someNSBox addSubview:myContentView];
The bounds property of NSView returns an NSRect with the origin (usually (0,0)) and the size of an NSView. See this Apple Developer documentation page.
I'm not sure (I never had to go too deep in that stuff), but isn't it [NSView bounds]?
http://www.cocoadev.com/index.pl?DifferenceBetweenFrameAndBounds