I am having troubles aligning NSViews next to each other using Autolayout programmatically. To illustrate, I have made a very simple example project. DiscView is a subclass of NSView which draws a disc with a specified color.
In the example below, I only add Autolayout constraints on one of two subviews, and the result is as I expected (see screenshot below).
- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
DiscView *discViewA = [[DiscView alloc] init];
DiscView *discViewB = [[DiscView alloc] init];
discViewA.color = [NSColor blackColor];
discViewB.color = [NSColor redColor];
discViewA.translatesAutoresizingMaskIntoConstraints = NO;
discViewB.translatesAutoresizingMaskIntoConstraints = NO;
[self.customView addSubview:discViewA];
[self.customView addSubview:discViewB];
NSDictionary *discViewDictionary = #{#"discViewA" : discViewA,
#"discViewB" : discViewB};
[self.customView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"H:|[discViewA]|" options:0
metrics:nil
views:discViewDictionary]];
[self.customView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"V:|[discViewA]|" options:0
metrics:nil
views:discViewDictionary]];
}
However, if I try to show the two subviews side by side using some additional constraints, I only see a red disc. That is, it is as if the red disc is drawn directly on top of the black disc.
[self.customView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"H:|[discViewA]-[discViewB]|" options:0
metrics:nil
views:discViewDictionary]];
[self.customView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"V:|[discViewA]|" options:0
metrics:nil
views:discViewDictionary]];
[self.customView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"V:|[discViewB]|" options:0
metrics:nil
views:discViewDictionary]];
What could possibly be wrong here?
[self.customView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"H:|[discViewA][discViewB]|"
options:NSLayoutFormatAlignAllTop | NSLayoutFormatAlignAllBottom
views:discViewDictionary]];
[self.customView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"H:|[discViewA]|" options:0
metrics:nil
views:discViewDictionary]];
Try this. It might help. If not do what someone else suggest and put a constraint like so.
[self.customView addConstraint:[NSLayoutConstraint constraintWithItem:discViewA
attribute:NSLayoutAttributeWidth
relatedBy:NSLayoutRelationEqual
toItem:self.customView
attribute:NSLayoutAttributeWidth
multiplier:0.5f
constant:0.f]];
My guess is that when you set both view to be side by side, AutoLayout does not know how to divide the width of the superview between your two views.
Try to add a width constraint to one of those subviews, it should be sufficient to resolve the ambiguity.
Related
I am trying to create a dynamic size NSView using visual auto layout. I am trying to achieve something like the following diagram.
I added following constraints to achieve this.
[self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"|-15-[_iconImageView(39)]-12-[_textView(239)]-15-|"
options:NSLayoutFormatAlignAllTop metrics:nil views:views]];
[self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"V:|-15-[_textView]-4-[_mainButton]-5-|"
options: NSLayoutFormatAlignAllLeft metrics:nil views:views]];
[self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"[_mainButton]-15-[_secondaryButton]"
options:NSLayoutFormatAlignAllTop metrics:nil views:views]];
But this creates the following layout.
As per my understanding, the following VFL will layout _textView 15px from top and then layout _mainButton after 4px from _textView bottom. But in actual _mainbottom is layout after 4px from top of _textView. Am i missing something here?
#"V:|-15-[_textView]-4-[_mainButton]-5-|"
Update
I replaced NSTextView with NSTextField. But now the problem is, NSTextField does not grow more than a single line height, but NSTextField is multi-line. Complete code for layouting and setting up views is as follow.
-(void)setupView {
_textField = [[NSTextField alloc] initWithFrame:NSZeroRect];
[[_textField cell] setWraps:YES];
[_textField setLineBreakMode:NSLineBreakByWordWrapping];
[[_textField cell] setTitle:#"This is a _textView, This will contain dynamic resizing text."];
[_textField setSelectable:NO];
[_textField setEditable:NO];
[_textField setDelegate:self];
[_textField setBordered:NO];
[_textField sizeToFit];
[_textField setTranslatesAutoresizingMaskIntoConstraints:NO];
[self addSubview:_textField];
_iconImageView = [[NSImageView alloc] initWithFrame:NSZeroRect];
[_iconImageView setImage:[NSImage imageNamed:#"notify-warning-icon"]];
[_iconImageView setTranslatesAutoresizingMaskIntoConstraints:NO];
[self addSubview:_iconImageView];
_mainButton = [[NSButton alloc] init];
_mainButton.translatesAutoresizingMaskIntoConstraints = NO;
[_mainButton setTitle:#"_mainButton"];
[self addSubview:_mainButton];
_secondaryButton = [[NSButton alloc] init];
_secondaryButton.translatesAutoresizingMaskIntoConstraints = NO;
[_secondaryButton setTitle:#"_secondaryButton"];
[self addSubview:_secondaryButton];
NSDictionary *views = NSDictionaryOfVariableBindings(_textField,_iconImageView,_mainButton,_secondaryButton);
[self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"|-15-[_iconImageView(39)]-12-[_textField(239)]-15-|"
options:NSLayoutFormatAlignAllTop metrics:nil views:views]];
[self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"V:|-15-[_textField]-4-[_mainButton]-5-|"
options: NSLayoutFormatAlignAllLeft metrics:nil views:views]];
[self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"[_mainButton]-15-[_secondaryButton]"
options:NSLayoutFormatAlignAllTop metrics:nil views:views]];
[self addConstraint:[NSLayoutConstraint constraintWithItem:self attribute:NSLayoutAttributeWidth relatedBy:NSLayoutRelationEqual toItem:self attribute:NSLayoutAttributeHeight multiplier:0.f constant:320.f]];
}
But if it changed this
#"V:|-15-[_textField]-4-[_mainButton]-5-|"
with this
#"V:|-15-[_textField(>=40)]-4-[_mainButton]-5-|"
I get the following output
But the problem is textfield content is dynamic and could change at runtime, it could be 2 lines, 3 lines etc. So how could i add some height constraint to NSTextField that will change NSTextField height depending on its content.
You can use a text field rather than a text view and set its preferredMaxLayoutWidth property.
By default, if preferredMaxLayoutWidth is 0, a text field will compute its intrinsic size as though its content were laid out in one long line (or, at least, without any maximum width). Even if you apply a constraint that limits its actual width, that doesn't change its intrinsic height and therefore it typically won't be tall enough to contain the text as wrapped.
If you set preferredMaxLayoutWidth, then the text field will compute its intrinsic size based on the text as wrapped to that width. That includes making its intrinsic height tall enough to fit.
I want to programmatically generate an overview (UIButton) in the lower left-hand corner.
This is currently being done using Interface Builder. However I need to repeat this for multiple host UIViews. So I decided to write a utility class method to do this.
+ (UIButton *)attachGreenPlusButtonTo:(UIView *)hostView {
NSLog(#"--- {attachGreenPlusButtonTo} ---");
// Green Button --------------------------------------------------------------------
UIImage *greenPlusImage = [UIImage imageNamed:#"btn_plus"];
UIButton *greenButton = [UIButton buttonWithType:UIButtonTypeCustom];
[greenButton setImage:greenPlusImage forState:UIControlStateNormal];
greenButton.tag = 22;
[greenButton setTranslatesAutoresizingMaskIntoConstraints:NO];
[hostView addSubview:greenButton];
// Positioning the Green '+' Button:
// Button is 4 pts from superview right edge:
NSArray *horizontalConstraints =
[NSLayoutConstraint constraintsWithVisualFormat:#"H:[greenButton(==57)]-4-[hostView]"
options:0
metrics:nil
views:NSDictionaryOfVariableBindings(hostView,greenButton)];
[hostView addConstraints:horizontalConstraints];
NSArray *verticalConstraints =
[NSLayoutConstraint constraintsWithVisualFormat: #"V:[greenButton(==57)]-34-[hostView]"
options:0
metrics:nil
views:NSDictionaryOfVariableBindings(hostView,greenButton)];
[hostView addConstraints:verticalConstraints];
[hostView layoutIfNeeded];
return greenButton;
}
I'm getting close, but now the button is being positioned at (-61, -91).
What gives?
Call this after creating the greenButton:
[greenButton setTranslatesAutoresizingMaskIntoConstraints:NO];
otherwise the system will create (unwanted) constraints for you.
Your visual layout doesn't look right either. Use vertical bar | to refer to the superview:
"H:[greenButton(==57)]-4-|"
and
"V:[greenButton]-34-|"
I thought I had a problem using '|' for superview within the method due to a bug which eventually appeared to be due do something else. So...
Upon feedback, I return to the use of '|' as the superview vs the 'hostView':
// Positioning the Green '+' Button:
// Button is 4 pts from superview right edge:
NSArray *horizontalConstraints =
[NSLayoutConstraint constraintsWithVisualFormat:#"H:[greenButton(==57)]-4-|"
options:0
metrics:nil
views:NSDictionaryOfVariableBindings(hostView,greenButton)];
[hostView addConstraints:horizontalConstraints];
NSArray *verticalConstraints =
[NSLayoutConstraint constraintsWithVisualFormat: #"V:[greenButton(==57)]-34-|"
options:0
metrics:nil
views:NSDictionaryOfVariableBindings(hostView,greenButton)];
[hostView addConstraints:verticalConstraints];
[hostView layoutIfNeeded];
This worked.
All appears to be okay now.
It seems that it assumes you're using frames instead of Auto Layout, as you can only really init with a frame. Am I doing this wrong?
You can use autolayout programmatically.
You don't need to initialize the UITableView with a frame. Instead, you have to set translatesAutoresizingMaskIntoConstraints = NO, add the table view to the parent view and then define the constraints in code.
For example:
UITableView *tableView = [[UITableView alloc] initWithFrame:CGRectZero style:UITableViewStylePlain];
tableView.translatesAutoresizingMaskIntoConstraints = NO;
[self.view addSubview:tableView];
NSDictionary *views =
NSDictionaryOfVariableBindings(tableView);
[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:
#"H:|[tableView]|" options:0 metrics:nil views:views]];
[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:
#"V:|[tableView]|" options:0 metrics:nil views:views]];
Please refer to https://developer.apple.com/library/ios/documentation/UserExperience/Conceptual/AutolayoutPG/AdoptingAutoLayout/AdoptingAutoLayout.html to know more about the visual format. You can also choose not to use the visual format and describe the constraints programmatically.
I am trying to build a fairly simple view.. I've got a horizontal toolbar (toolbarView) and a bottom accent line (bottomAccent) running the full width of the view. I also have two sidebars and a vertical accent next to that on the left side of the screen.
If I have one sidebar (comment out sidebarView2), life is great, it all looks just right. As soon as I add sidebarview2, I get these fun errors.. I'm not entirely sure why or what I'm doing wrong. I would expect my constraints to basically split the space for the sidebar in half, and fill each half with one of the sidebar views.. What am I missing here?
Unable to simultaneously satisfy constraints:
(
"<NSLayoutConstraint:0x7feefc3121e0 V:|-(8)-[NSTextField:0x7feefa4404e0] (Names: '|':BGView:0x7feefa440290 )>",
"<NSLayoutConstraint:0x7feefc312230 V:[NSTextField:0x7feefa4404e0]-(6)-[BGView:0x7feefa4408c0]>",
"<NSLayoutConstraint:0x7feefc3122b0 V:[BGView:0x7feefa4408c0(1)]>",
"<NSLayoutConstraint:0x7feefc312300 V:[BGView:0x7feefa4408c0]-(4)-[NSScrollView:0x7feefa440ba0]>",
"<NSLayoutConstraint:0x7feefc312350 V:[NSScrollView:0x7feefa440ba0]-(0)-| (Names: '|':BGView:0x7feefa440290 )>",
"<NSLayoutConstraint:0x7feefc313250 V:[BGView:0x7feefa440290]-(0)-[BGView:0x7feefa440290]>"
)
My code:
- (void)loadView {
NSView *rootView = [[NSView alloc] init];
NSView *toolbarView = _toolbarViewController.view;
[toolbarView setTranslatesAutoresizingMaskIntoConstraints:NO];
[rootView addSubview:toolbarView];
NSView *sidebarView = _titledScrollViewController.view;
[sidebarView setTranslatesAutoresizingMaskIntoConstraints:NO];
[rootView addSubview:sidebarView];
NSView *sidebarView2 = _titledScrollViewController.view;
[sidebarView2 setTranslatesAutoresizingMaskIntoConstraints:NO];
[rootView addSubview:sidebarView2];
BGView *horizontalSpacerSidebar = [[BGView alloc] initWithBackgroundColor:[NSColor colorWithDeviceRed:0.391 green:0.391 blue:0.43 alpha:1.0]];
[horizontalSpacerSidebar setTranslatesAutoresizingMaskIntoConstraints:NO];
[rootView addSubview:horizontalSpacerSidebar];
BGView *bottomAccent = [[BGView alloc] initWithBackgroundColor:[NSColor colorWithDeviceRed:0.223 green:0.77 blue:0.93 alpha:1.0]];
[bottomAccent setTranslatesAutoresizingMaskIntoConstraints:NO];
[rootView addSubview:bottomAccent];
NSDictionary *views = NSDictionaryOfVariableBindings(toolbarView, bottomAccent, sidebarView, sidebarView2, horizontalSpacerSidebar);
[rootView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"H:|[toolbarView]|" options:0 metrics:nil views:views]];
[rootView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"H:|[sidebarView(==200)][horizontalSpacerSidebar(==1)]" options:0 metrics:nil views:views]];
[rootView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"H:|[sidebarView2(==200)][horizontalSpacerSidebar(==1)]" options:0 metrics:nil views:views]];
[rootView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"H:|[bottomAccent]|" options:0 metrics:nil views:views]];
[rootView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"V:|[toolbarView(==53)][sidebarView][sidebarView2][bottomAccent(==3)]|" options:0 metrics:nil views:views]];
[rootView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"V:|[toolbarView(==53)][horizontalSpacerSidebar][bottomAccent(==3)]|" options:0 metrics:nil views:views]];
self.view = rootView;
}
Is there a way to combine below 3 syntax lines into a single one statement like (which doesn't work):
[_cardsContainer addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"V:|[cardContainer1]|[cardContainer2]|[cardContainer3]|" options:0 metrics:nil views:viewsDictionary]];
1. [_cardsContainer addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"V:|[cardContainer1]|" options:0 metrics:nil views:viewsDictionary]];
2. [_cardsContainer addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"V:|[cardContainer2]|" options:0 metrics:nil views:viewsDictionary]];
3. [_cardsContainer addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"V:|[cardContainer3]|" options:0 metrics:nil views:viewsDictionary]];
No, but you can do it in two lines:
[_cardsContainer addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"V:|[cardContainer1]|" options:0 metrics:nil views:viewsDictionary]];
This pins card container 1 to the top and bottom of the superview. Then:
[_cardsContainer addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"|[cardContainer1][cardContainer2][cardContainer3]|" options:NSLayoutFormatAlignAllTop | NSLayoutFormatAlignAllBottom metrics:nil views:viewsDictionary]];
Which aligns the top and bottom of the remaining card containers.
This assumes you want the views laid out next to each other, you didn't actually specify any horizontal layout details.
It helps when using the visual format to think about each line of visual format language representing a single row or column of layout in your view.
To the best of my knowledge, no.
It's not really a single line, but you can reduce the duplication of your three lines by doing them in a loop:
for (NSView *view in #[cardContainer1, cardContainer2, cardContainer3]) {
[_cardsContainer addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:#"V:|[view]|" options:0 metrics:nil views:NSDictionaryOfVariableBindings(view)]];
}