I created a class in my project and this class is a subclass of another class; I want place this subview in the principal view, I reduced x and y to make it smaller, but it always appears at the top left, how can I set it in other position?
Would be easier to answer if you posted some code. Most likely, you need to modify the frame property of your view. frame is a rectangle (CGRect) that determines the position and size of your view in the coordinate system of its superview. The bounds property is similar but expresses origin and size in the coord system of itself (e.g. origin is 0,0).
For other layout tips, look at the autoresizingMask and contentMode properties of views. In fact, read up on views in general. The Apple docs are good and lots of stuff here about them.
Related
Is there a way to disable clipping of subviews of NSView? In UIView there is a “clip subviews checkbox” and the backing clipToBounds property, but I cant find anything similar in Cocoa.
Here is my scenario: I have this grey dot that you can drag on the screen:
When the user drags the dot I want to show up and down arrows that I have in the background. The up arrow is outside the bounds of the NSView holding the dot and arrow.
You could use the [NSView frameForAlignmentRect:] method. It defines the frame which is used for the constraints based layout. The actual frame can be much larger to allow displaying the arrows when the view is moved.
Cocoa is using this feature to compensate for shadows or other parts of views which do not "count" as actual frame of a control.
From the documentation:
The constraint-based layout system uses alignment rectangles to align views, rather than their frame. This allows custom views to be aligned based on the location of their content while still having a frame that encompasses any ornamentation they need to draw around their content, such as shadows or reflections.
Observe the following screenshot:
How do I anchor UIView a few pixel off the middle point using Autoresizing Mask so that it is always 20px to the left of the middle point?
I have tried setting the autoresizingMask property to UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleRightMargin and it's not really doing it.
I did manage to do it if I wrap the view in another bigger view that fills the entire screen and doesn't resize at all. But is there a way to do it without an additional view?
Autoresizing masks don't handle this case very well, as you've already discovered. They work great if you want to keep something a fixed distance from its superview or proportionally resizing/repositioning somewhere in the middle. You can do a surprising amount with just those options, but off-center anchoring is not something you can do easily
If you want do this with autoresizing masks, you'll need to put your box inside another empty UIView, one that is in a more convenient position for autoresizing masks. It will look like this.
Here's what you've got right now:
center
|
|---------------------------------------------------| <-- The main parent view
|-----| <-- your view
What you want is this:
center
|
|---------------------------------------------------| <-- The main parent view
|--------------------| <-- The new view, centered in the parent
|-----| <-- your view
The new view should be completely transparent, have a fixed width, and a flexible distance from both sides of the parent view. It should be wide enough to fully contain the off-center box, and no wider. If it is positioned exactly in the center of the main parent view, it will stay centered no matter what happens to the size of the parent view.
Then add your box as a subview of the new view, with a fixed width and fixed distance from the left edge of the parent. Now, using only autoresizing masks, your view will stay where you want it.
A simpler option might be to override -layoutSubviews on your view, or -viewDidLayoutSubviews on your controller (available iOS 5.0 and later) and just manually position the view. But you asked how to do it with autoresizing masks, so that's what you got. Without adding an extra view, there's no way to use autoresizing masks to get the positioning behavior you want.
I guess the best solution is to set center property to:
myview.center = CGPointMake(self.view.frame.size.width/2-20, myview.center.y);
And set up it in willRotate method.
Not exactly an answer, more of an avenue for exploration. You can try playing with the layer-level property anchorPoint. Setting it to (1.0, 0.5) means the layer's position will be defined by its right edge. In that case centered would mean the right edge is centered. Set flexible left margin and flexible right margin and it might stay left of the center.
To get it exactly 20p left of the center, just set the anchorPoint to 20p right of the center of the view. (But anchorPoint units are a fraction of the size of the layer, so do some math to find the right value.)
I'm not sure if it will work. I'm not sure what the effects are of mixing layer-level positioning with autoresizing.
Is it possible to make a UIView only appear inside a limited area of the screen, especially while animating? (When it reaches the boundary, it should simply cut off at the boundary point, as if it were being obscured by an object in front of it.) I need this because I have a roll-out menu comprised of UIButtons, and I don't want the menu to extend beyond the edge of the toolbar when closed. Thank you!
(Alternatively, hiding the entire UIView upon reaching the boundary would also be acceptable. I just don't know how to check for this condition without continuously querying the center property.)
You can define a clipping area for your UIVIew using the clipsToBounds property. If you are using CoreAnimation to animate your view, you may want to have a look a the maskToBounds property of CALayer objects as well (each UIVIew has a layer property of type CALayer).
From the UIView Class reference:
Normally, a subview’s visible area is
not clipped to the bounds of its
superview, but in iOS you can use the
clipsToBounds property to alter that
behavior.
I want to know what is the difference between 'frame' and 'bound' property of UIView. I get the same results using both properties. I can not figure out the difference between the two..
Thanx in advance.
The frame is the view's location in its superview, using the superview's coordinate system.
The bounds is the view's location and size in its own coordinate system.
If you are getting the same results for both properties, it means that the view fills its superview, and both views have (0, 0) as the origin. Try changing the frame, and you will see it move to different positions within its superview.
This is covered in the documentation. The frame and bounds are two different coordinate systems.
I know its too late but as this a common question so I am posting a link to apple documentation to have a detailed explanation on this
I created a UIView xib in Interface Builder and tried everything I could to indicate that the UIView should center itself, anchor itself at center, orient itself in central coordinates, etc. etc.
But whenever I add it as a subview in code, I also have to programmatically set its frame up with CGRectMake() or else it will always add to the top-left of its parent. The math to reframe it is pointless and ugly, so I presume I'm just not twiddling a bit in the IB inspector correctly.
Can anyone confirm this is possible, and if so, what I need to do in IB to accomplish this?
Why don't you just set .center of the subview just added, to be the point created by halving the width and height of the superview?
Either that or define the rectangle that view is going into with IB (I'm imagining a container view) and simply set the frame of the view you are adding to containerView.bounds (bounds is a position independent value and so x,y will be 0 while size will equal the container size.
Centering but maintaining size isn't possible in IB. Centering but maintaining margins to its superview is though.
You will have to override the layoutSubviews message or simply keep the calculation code you wrote.