UIView animation works faulty - ios

I'm using Objective-C. And I want to make the table view move down with animation when I add a search bar above it. This is my code(table here is my table view):
[UIView animateWithDuration:0.3 animations:^{
CGRect frame = self.table.frame;
frame.origin.y = frame.origin.y+30;
self.table.frame = frame;
}];
But it doesn't work. Someone can help me?

Add layoutIfNeeded at the end of animation block. Like that:
[UIView animateWithDuration:0.3 animations:^{
CGRect frame = self.table.frame;
frame.origin.y = frame.origin.y+30;
self.table.frame = frame;
[self.view layoutIfNeeded];
}];

Changing frames like this is not the best way to do it, and its old fashioned. The best way is to get access to one of the autolayout constraints on the view, and change it. For eg - say your tableview has a top constraint that defines the gap between the top of the tableview and the superview - eg 10px. Drag that constraint from IB, into your class. Best way to do this is to highlight the constraint on the left hand side of IB, in the list that contains all your views etc. Drag across to make it a property in your class, just like you do with a button or label. Then at runtime, you change the .constant property of that constraint. For eg. Heres my NSLayoutConstraint property when dragged across into the class :
#property (weak, nonatomic) IBOutlet NSLayoutConstraint *topBuffer;
Then at the point in code where you want the move to happen, you change the constant property, OUTSIDE of the animation call :
self.topBuffer.constant = 50; //<-- or whatever the new value is
Then all you do is call [self.view layoutIfNeeded] in the animation block. By the way - note here Ive used the anim block with springs etc for a bouncey effect too. Also note - layoutIfNeeded is called on the superview of the object you are changing - so self.view here is my main superview that contains the tableview.
[UIView animateWithDuration:0.7f delay:0 usingSpringWithDamping:1.0 initialSpringVelocity:0 options:UIViewAnimationOptionCurveEaseIn animations:^(void) {[self.view layoutIfNeeded];} completion:nil];

Related

Reduce view and subviews animated

I am currently trying to make a UIView containing some UILabel animate to a new size. But doing so I am having some trouble understanding what is really happening with my view. I read some other post about it but I am still unclear about what is really going on.
In my button I added something that just double the size of the right constraint :
[superView layoutIfNeeded];
rightConst.constant *= 2;
[UIView animateWithDuration:3
animations:^{
[superView layoutIfNeeded];
} completion:nil];
superView Being the view I wanna animate and rightConst the constraint to the right.
But doing so, the animation starts but it is actually coming from left. I don't understand this part. My goal would be to animate just the right side of the view to show the resize and maybe the bottom part of the view but the top left should be fixed.
Thanks.
As described in this document, if you call [aView layoutSubviews], layout of the subviews of aView is forced but layout of aView itself is NOT forced.
You need to call layoutSubviews of the superview of the view you want to animate. In this case, the superview of the superview of the two labels.
Solution is here
UIView *theView;
// theView is the superview of the superview of the two labels.
theView = superView.superview;
[theView layoutIfNeeded];
rightConst.constant *= 2;
[UIView animateWithDuration:3
animations:^{
[theView layoutIfNeeded];
} completion:nil];

How to animate imageview from off screen

I have an imageview I put onto the view controller of a circle.
I would like to start that circle from off screen and move it to the location I've put it.
What would be the best way to animate it?
Try this;
-(void)viewWillAppear {
[UIView animateWithDuration:5
delay:5
options:UIViewAnimationOptionCurveEaseOut
animations:^{
CGRect frame = view.frame;
frame.origin.y = self.view.frame.size.height-200;
frame.origin.x = 0;
view.frame = frame;
}completion:^(BOOL finished) {}];
}
You many animation option's [UIViewAnimationOptions]
UIViewAnimationOptionCurveEaseInOut,
UIViewAnimationOptionCurveLinear,
UIViewAnimationOptionTransitionFlipFromLeft,
UIViewAnimationOptionTransitionCurlUp,
UIViewAnimationOptionTransitionCrossDissolve,
UIViewAnimationOptionTransitionFlipFromTop..
You want to create your image view off-screen. Its easiest if you set it up in Interface Builder that way. you can create it on-screen, add a constraint to place it at the target location, note the value, and then change the constraint's constant so the view is moved off-screen.
Then control-drag the constraint into your view controller and create an outlet to it.
To animate the image view on-screen, change the constraint's constant value to the "on-screen" value you noted above, and then call layoutIfNeeded() on the view from inside an a UIView animateWithDuration block.
If you want to add the image view in code then you need to add it off-screen, add it as a subview, and then trigger a UIView animation to move it back on-screen. You should probably also do the positioning with constraints as outlined above, although it gets more complicated because you have to create those constraints in code.

about the animation on the subview of UIScrollView

When I add some animations on the subview of the scrollview that like extending or contract a textfield,it just not work. But it worked well when the subview add to a simple UIView.
How did it happen?
There should be no problem animating the frame of a UITextField within a UIScrollView.
The most common source of "my animation isn't animating" in iOS 6 and later is the attempt to animate a control by adjusting the frame when employing autolayout (because the adjustment of the frame can be thwarted by the constraints being reapplied by the most innocuous of actions). You can tell if you're using autolayout or not by selecting the File Inspector (the first tab) of the rightmost panel in Interface Builder, and seeing if "Use Autolayout" is checked:
For example, to animate the frame when not using autolayout, assuming your UITextField has an IBOutlet called textField, you might do something like:
[UIView animateWithDuration:0.5 animations:^{
CGRect frame = self.textField.frame;
frame.size.width = 280;
self.textField.frame = frame;
}];
But the equivalent when using autolayout is not achieved by adjusting the frame, but rather by changing the constraints' constant values. For example, assuming you created an IBOutlet for the width constraint called textFieldWidthConstraint on your UITextField, you would animate the changing of the width with something like:
self.textFieldWidthConstraint.constant = 280;
[UIView animateWithDuration:0.5 animations:^{
[self.view layoutIfNeeded];
}];
If you believe you are using the appropriate animation technique that corresponds to your choice of autolayout or non-autolayout, but it's still not working, you should show us some code and describe the situation in greater detail.

iOS: How does one animate to new autolayout constraint (height)

I've never worked with autolayout constraints before. I have a small new app I'm working on and noticed that the NIB's views are defaulting to autolayout. So, I figured I'd take the opportunity to work with it and try to figure out where Apple is going with this.
First challenge:
I need to resize an MKMapView and I'd like to animate it to the new position. If I do this the way I'm used to:
[UIView animateWithDuration:1.2f
animations:^{
CGRect theFrame = worldView.frame;
CGRect newFrame = CGRectMake(theFrame.origin.x, theFrame.origin.y, theFrame.size.width, theFrame.size.height - 170);
worldView.frame = newFrame;
}];
...then the MKMapView will 'snap' back to its original height whenever a sibling view gets updated (in my case a UISegmentedControl's title is being updated [myUISegmentedControl setTitle:newTitle forSegmentAtIndex:0]).
So, what I think I want to do is change the constraints of the MKMapView from being equal to the parent view's hight to being relative to the top of the UISegmentedControl that it was covering: V:[MKMapView]-(16)-[UISegmentedControl]
What I want is for the MKMapView height to shorten so that some controls beneath the map view are revealed. To do so I think I need to change the constraint from a fixed full size view to one where the bottom is constrained to the top of a UISegmentedControl...and I'd like it to animate as view shrinks to new size.
How does one go about this?
Edit - this animation is not animating though the bottom of the view does move up 170 instantly:
[UIView animateWithDuration:1.2f
animations:^{
self.nibMapViewConstraint.constant = -170;
}];
and the nibMapViewConstraint is wired up in IB to the bottom Vertical Space constraint.
After updating your constraint:
[UIView animateWithDuration:0.5 animations:^{[self.view layoutIfNeeded];}];
Replace self.view with a reference to the containing view.
This works for me (Both iOS7 and iOS8+). Click on the auto layout constraint you would like to adjust (in interface builder e.g top constraint). Next make this an IBOutlet;
#property (strong, nonatomic) IBOutlet NSLayoutConstraint *topConstraint;
Animate upwards;
self.topConstraint.constant = -100;
[self.viewToAnimate setNeedsUpdateConstraints];
[UIView animateWithDuration:1.5 animations:^{
[self.viewToAnimate layoutIfNeeded];
}];
Animate back to original place
self.topConstraint.constant = 0;
[self.viewToAnimate setNeedsUpdateConstraints];
[UIView animateWithDuration:1.5 animations:^{
[self.viewToAnimate layoutIfNeeded];
}];
There is a very good tutorial from apple itself that explain how to use animation with autolayout.
Follow this link and then find the video named "Auto layout by example"
It gives some interesting stuff about autolayout and the last part is about how to use animation.
I have made this small demo available. It shows how auto-layout constraints can be changed and animated in a very simple example. Simply take a look at the DemoViewController.m.
Most people use autolayout to layout items on their views and modify the layout constrains to create animations.
An easy way to do this without a lot of code is creating the UIView you want to animate in Storyboard and then creating a hidden UIView where you want the UIView to end. You can use the preview in xcode to make sure both UIViews are where you want them to be. After that, hide the ending UIView and swap the layout constraints.
There is a podfile for swapping layout constrains called SBP if you don't want to write it yourself.
Here's a tutorial.
No need to use more IBOutlet reference of the constraint instead of this you can directly access or update already applied constraint either applied by Programmatically or from Interface Builder on any view using the KVConstraintExtensionsMaster library. This library is also managing the Cumulative behavior of NSLayoutConstraint.
To add Height Constraint on containerView
CGFloat height = 200;
[self.containerView applyHeightConstrain:height];
To update Height Constraint of containerView with animation
[self.containerView accessAppliedConstraintByAttribute:NSLayoutAttributeHeight completion:^(NSLayoutConstraint *expectedConstraint){
if (expectedConstraint) {
expectedConstraint.constant = 100;
/* for the animation */
[self.containerView updateModifyConstraintsWithAnimation:NULL];
}
}];

UIImageView animation not working correctly

I want to make the width of an UIImageView larger through an animation. I have an UIView with and UIImageView made in the story board. What I want to achieve is so that it looks like the view is scaling from left to right, and keeping its original position. I have tried the following code, but what it does is animating the imageview from the top left corner of its parent view and moving and scaling it until it reaches the position and scale it had from the beginning.
[UIView animateWithDuration:4.0f delay:1.0f options:UIViewAnimationCurveEaseOut animations:^{
CGRect currentFrame = self.imageview1.frame;
currentFrame.size.width = 150;
self.imageview1.frame = currentFrame;
}completion:nil];
Any ideas why this behaviour?
A bit late answer, but I solved the problem. It seems that you cannot change the frame of views in code if autolayout is enabled. Instead you need to animate the constraints of the view, which you can set up in the storyboard and then animate like this:
[self.view layoutIfNeeded];
[UIView animateWithDuration:0.3 delay:0 options:UIViewAnimationOptionCurveEaseInOut animations:^{
self.bottomViewY.constant = -196;
[self.view layoutIfNeeded];
} completion:nil];
self.bottomViewY is a constraint which is assigned as an IBOulet. You need to call layoutIfNeeded as it will update the constraints.

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