I'm having a bit of trouble with the right parts of the view hierarchy in my iPhone app getting the touch events they should be. The code is all Swift in iOS 11.
I have a UIControl subclass which overrides beginTracking() and endTracking(). Originally, I had programmatically created a UIView, and then added an instance of my UIControl subclass as a subview. The code basically boiled down to:
myView = UIView()
view.addSubview(myView)
// add autolayout constraints for the view
myControl = TheControl(frame: theFrame)
myView.addSubview(myControl)
// add autolayout constraints for the control
This worked fine, but I wanted to have myView in Interface Builder to make autolayout a bit easier. So I got rid of the 'myView=UIView()' and 'view.addSubview(myView)' lines, created the view in IB, and connected it to an outlet in the view controller. The rest of the code stayed the same. So I programmatically create myControl, and add it as a subview of myView. Now that I have done this, myControl no longer receives touch events.
I can't figure out what is happening differently by doing this in Interface Builder vs. in code. I have toggled on and off "User Interaction Enabled" on myView in IB, and as far as I can tell it doesn't make any difference.
What am I doing wrong here?
Related
I'm trying to make my first game using SpriteKit + Swift.
The problem I'm trying to solve right now is that if I add to my main SKView a SUBVIEW without any buttons just with a background color and size and touch it, my main view handles this touch like there is no subview at all.
So the subView of type UIView like doesn't exist for UITapGestureRecognizer of parent view. And the only way I found to solve it, is to put a subView-sized button on the subview without text and handler. But this way looks creepy...
It could be that your subView (or one of its parents views) has the userInteractionEnabled set to false. UIView has the userInteractionEnabled set to true by default, but for example UIImageView (which is a subclass of UIView) has the userInteractionEnabled set to false by default.
When set to NO, user events—such as touch and keyboard—intended for
the view are ignored and removed from the event queue. When set to
YES, events are delivered to the view normally. The default value of
this property is YES.
(...)
Note
Some UIKit subclasses override this property and return a different
default value. See the documentation for that class to determine if it
returns a different value.
See Apple docs for more info.
It could be not your subView by itself, but one of its parents views too, because this setting is propagated down.
If set to NO, this view (along with its subviews) is excluded from
receiving touches. Touches on this view or one of its subviews "fall
through" to a view behind it.
source: Programming iOS by Matt Neuburg
For more, check On iOS, if a superview's userInteractionEnabled is NO, then all subviews are disabled as well?
I'm new to swift and I'm trying to move a UITextField up when the soft keyboard opens.
When I call view.frame.origin.y = -150 from the UIViewController, the UIView is moved but the UITextField inside it is not. (The UITextField "jumps" and animates back to its original position.)
It was working some time ago and I'm not sure what happened.
Found the problem.
I had a constraint mytextfield.Top = Top Layout Guide.Bottom, when it should be mytextfield.Top = SuperView.Bottom
I think LucaD is correct - you're missing constraints between your UITextField and UIViewController.
If you are using Interface Builder, see Apple's Adding Layout Constraints by Control-Dragging
Otherwise, if you are creating the UITextField programmatically, see SWIFT | Adding constraints programmatically
I have 2 UITableView in my UIViewController. one of them is in the right side of the screen till center of screen. The other is from center till left bound.
User can hide the right UITableview by pressing one a button on the navigation bar.
I use this code to make left UITableview full screen:
self.rightTableView.hidden= YES;
self.leftTable.frame= CGRectMake(0,
self.dataTableView.frame.origin.y,
self.view.frame.size.width,
self.dataTableView.frame.size.height);
But it is not working.
I even put this code on the viewdidload and viewDidAppear methods but the frame not changing.
Try self.leftTable.translatesAutoresizingMaskIntoConstraints = YES, then call to frame resize at runtime is automatically translated into new constraints.
But, translatesAutoresizingMaskIntoConstraints will also cause new constraints to be added based on the view's autoresizingMask. So make sure other constraints are working properly.
When using autolayout, modifying the frame will have no effect.
Instead, you should modify the constraints.
You can do this by creating outlets for your constraints and connecting then in the interface builder.
Quick question. Using IB, I have a subview in a ViewController. In that subview I have a label, which I would like to wire to my custom subview class. However, IB will not let me. What am I missing?
I also tried to add the label programmatically; however, it appears that the frame was not ever set. I could hard code the size of the label, but I could not make it dependent on the frame size of my subview, because the frame and the bounds were always zero rects, even after the view showed up in my view controller at a non zero size. Any ideas here would also be much appreciated.
You are actually completely right. It wont let you connect from IB to the Header of a custom view in Xcode 4.6.2
Personally I would file a Radar but I would want to do a bit more research to prove it and as this is a pattern I wouldn't ever use then I won't.
Fortunately you can get around it
Make sure your custom view is configured correctly in IB
and assuming you are setup something like this
Then you can manually declare in your header
#interface MyCustomView : UIView
#property (weak) IBOutlet UILabel *label;
#end
And drag FROM the dot that appears beside the property TO the label.
Or drag FROM the right-click HUD of the custom view TO the label.
Neither case will work by dragging from the label to the view.
In your header file, you need to define the label as an IBOutlet, then you can drag from your file's owner to the label.
IBOutlet * lblSomeLabel;
Disable AutoLayOut and try again.
I'm pretty new to ios. I'm working on a project which is going to frequently use a certain UIView class throughout the application. This class is simply an image that does some transparency stuff with the background color. This works fine so far. This class sometimes exists as a lone UIView, and sometimes as a button subview.
When I add this UIView to a UIButton as a subview, the full contents of the UIView are displayed at full size, but the clickable area of the button remains the size defined in the xib unless Use Autolayout is turned off (even if I manually try to set the button's frame.)
I would like to put a UIButton on the xib as a placeholder, and then later define its size/clickable area based on the size of the overlay image which the UIView that was initialized with.
Should this be possible, or am I misinterpreting the usage of xib files/autolayout?
under ViewDidLoad I have...
- (void)viewDidLoad{
[theButton addSubview:_theView];
CGRect buttonFrame = theButton.frame;
buttonFrame.size = CGSizeMake(_theView.getSize.width,_theView.getSize.height);
[theButton setFrame:buttonFrame];
}
However, the frame stays the same size when I print the button info before and after I try calling setFrame.
(note that '_theView.getSize' was added by me)
Under Autolayout, views don't have frames at viewDidLoad. Try your code in viewWillAppear: or viewDidLayoutSubviews.
Under Autolayout, you don't set frames. You edit constraints instead. Setting a frame will work until the next layout pass, when your layout will revert to that described by your constraints.
To size a button to fit a subview, you can try something like this (in visual format language): |-[theView]-| but it would depend what constraints are in place from your xib.