In a custom UIView I have overridden drawRect and draw several lines.
Then the UIView is scaled with animation:
[UIView animateWithDuration: 1.0
delay: 0.1
animations: ^{
myView.transform = CGAffineTransformMakeScale(zoom, zoom);}
completion:^(BOOL finished) { }
];
The drawn lines obviously change their thickness (width).
How can I force a redraw of the lines to obtain original width? I think that I have to put somewhere the line
[myView setNeedsDisplay]
But I tried different positions to no avail. Or there is another solution?
Related
I have a page in my app in which there is user's profile pic in a circle as its there in Twitter profile page.
I have to add a functionality such that when I tap on it, the image should expand. Animation needs to be added in such a way that a new bigger circle should slowly appear from the centre of the smaller circle and reach the centre of the screen.
Any ideas as to how this can be implemented?
Try UIView Animation block with changing bigger circle's position, size, alpha, and corner radius (if required).
Place your bigger circle (with smaller size initially) on top of smaller circle and hide it initially. Then before animation, un-hide it and animate using a block like this:
[UIView animateWithDuration:1.0 animations:^{
// set bigger circle destination position i.e. centre of screen
// set bigger circle final size
// set other properties like alpha, corner radius etc
} completion:nil];
Use CATransform3DScale transform and UIView Animation
CATransform3D avatarTransform = CATransform3DIdentity;
avatarTransform = CATransform3DScale(avatarTransform, avatarScaleFactor,avatarScaleFactor, 0);
[UIView animateWithDuration:1.0 animations:^{
//Change the frame to reach the center of screen
self.avatar.layer.transform = headerTransform
} completion:nil]
You can simply use CGAffineTransformScale and scale your ImageView inside UIView's animateWithDuration block.
imgV.transform = CGAffineTransformScale(CGAffineTransformIdentity, 0.0, 0.0);
[UIView animateWithDuration:0.5 delay:0 options:UIViewAnimationOptionCurveEaseInOut
animations:^{
imgV.transform = CGAffineTransformScale(CGAffineTransformIdentity, 1.0, 1.0);
}
completion:^(BOOL finished) {
NSLog(#"done");
}];
For further references you can look into these Stackoverflow questions :
Animate a UIImageView
iOS View Transform Animation
- (void)startAnimation {
//reverse - shrinking from full size
if (_reversed == YES) {
//self.transform = CGAffineTransformMakeScale(1.0, 1.0);
[UIView animateWithDuration:1.0f delay:0.0f options:UIViewAnimationOptionCurveLinear animations:^{
self.transform = CGAffineTransformMakeScale(0.1, 0.1); //this line does it instantly
self.alpha = 0;
} completion:^(BOOL finished) {
[self removeFromSuperview];
}];
} else {
//non reverse - expanding from middle
self.transform = CGAffineTransformMakeScale(0.001, 0.001);
[UIView animateWithDuration:1.0f delay:0.0f options:UIViewAnimationOptionCurveLinear animations:^{
self.transform = CGAffineTransformMakeScale(1.0, 1.0);
self.alpha = 0;
} completion:^(BOOL finished) {
[self removeFromSuperview];
}];
}
}
The non reverse piece of code does work fine as I expect, however when I do the _reversed == YES bit, the transformation inside the animation block happens instantly. If I comment that line of code, then the view stays the right size, but if i uncomment it then it shrinks instantly but the alpha still does the fade animation. Why does this happen?
Edit: I figured out what happened but I don't know how to fix it. The view does do the animation, only the size of the view changes instantly but it still 'slides' into the centre as if it is shrinking (what you see is just a small rectangle sliding to the middle as if it's the top left corner of the object). If I scale the view to 2 first, then scale down to 1 the animation works fine, its only when going from 1 to a decimal number that it doesn't work. Also I used draw rect to create an object with core graphics and the transform problem affects that, but not the actual frame if a set background colour.
I was running into a similar issue, where the position of the view would suddenly jump before animating in a change of transform with CGAffineTransformMakeScale. I noticed that the size of the "jump" seemed to be proportional to the scaling that would occur later in the animation.
I could fix this problem by finding that in a viewWillLayoutSubviews() override, I was setting the frame of the view being animated. As a rule, don't set the frames of views that will have a non-identity transform. So in the viewWillLayoutSubviews() override, I set the view's bounds and layer.position instead and now the animation is smooth as silk.
I saw this thread but the solution is not what I'm looking for.
I would like to pop up a UIView with an animation similar to how an app appears from the SpringBoard (it seems it comes closer) and make it disappear moving it away.
I've tried to animate the frame, but the effect is that the content is not resized: unfortunately I cannot assign constraints to the content of the view; the result should be like if the view is shown with the correct sizes and only the "graphics context" is resized.
Help!
This starts at 10% the size and turns to 100 % of the views size
view.transform = CGAffineTransformScale(view.transform, 0.1, 0.1);
[UIView animateWithDuration:0.35 animations:^{
view.transform = CGAffineTransformScale(view.transform, 1.0, 1.0);
} completion:^(BOOL finished) {
}];
also remember to #import <QuartzCore/QuartzCore.h>
You can animate the transform.scale and opacity of the view's layer. See this answer for details: https://stackoverflow.com/a/3463362/550177
During a sliding animation(down, pause, then up back to the original position) of a subview, the device is rotated, so the superview is rotated. I want to keep the subview's width the same as the superview, so I need to resize it during its sliding animation.
Here is the sliding animation code:
[UIView animateWithDuration:0.3 animations:^{
self.frame = finalFrame;
} completion:^(BOOL finished) {
[UIView animateWithDuration:0.3 delay:3 options:0 animations:^{
self.frame = initFrame;
} completion:^(BOOL finished) {
[self removeFromSuperview];
}];
}];
This is the method that is called when I detect rotation:
- (void)rotate:(NSNotification *)notif {
// What to do here to adjust the width but also keep the sliding animation going.
}
It seems there is no auto-resizing magic that can be used here. One must:
Record the progress of the animations.
On detection of rotations, cancel the old animations, adjust the view size, and add new animations starting from the current progress.
Here is a sample project for reference: http://d.pr/f/M4UW.
You can animate the bounds of the layer to change the width. Just make the height the same and apply an animation for the bounds.
If you want both animations to have the same duration, timing function etc. then you could add them both to an animation group and add that group to the layer you are animating.
I have set up the following animation to rotate between views of different sizes. The midpoint of the animation seems to have a flicker as the new, taller view comes into view. Is there anything I can do to smoothen the transition.
newView.layer.transform = CATransform3DMakeRotation(M_PI_2, 0.0, 1.0, 0.0);
[UIView animateWithDuration:0.5
delay:0
options:UIViewAnimationOptionCurveLinear
animations:^{oldView.layer.transform = CATransform3DMakeRotation(M_PI_2, 0.0, -1.0, 0.0);}
completion:^(BOOL finished) {
[oldView removeFromSuperview];
[UIView animateWithDuration:0.5
delay:0
options:UIViewAnimationOptionCurveLinear
animations:^{newView.layer.transform = CATransform3DMakeRotation(M_PI_2, 0.0, 0.0, 0.0);}
completion:nil];
}];
Got this working thanks to this thread, so I thought I'd share my to-from 3D transform using the m34 matrix.
UIView *toView = // show this
UIView *fromView = // hide this one
// set up from
CATransform3D fromViewRotationPerspectiveTrans = CATransform3DIdentity;
fromViewRotationPerspectiveTrans.m34 = -0.003; // 3D ish effect
fromViewRotationPerspectiveTrans = CATransform3DRotate(fromViewRotationPerspectiveTrans, M_PI_2, 0.0f, -1.0f, 0.0f);
// set up to
CATransform3D toViewRotationPerspectiveTrans = CATransform3DIdentity;
toViewRotationPerspectiveTrans.m34 = -0.003;
toViewRotationPerspectiveTrans = CATransform3DRotate(toViewRotationPerspectiveTrans, M_PI_2, 0.0f, 1.0f, 0.0f);
toView.layer.transform = toViewRotationPerspectiveTrans;
[UIView animateWithDuration:1.0
delay:0
options:UIViewAnimationOptionCurveLinear
animations:^{fromView.layer.transform = fromViewRotationPerspectiveTrans; }
completion:^(BOOL finished) {
[fromView removeFromSuperview];
[UIView animateWithDuration:1.0
delay:0
options:UIViewAnimationOptionCurveLinear
animations:^{toView.layer.transform = CATransform3DMakeRotation(M_PI_2, 0.0, 0.0, 0.0);}
completion:nil];
}];
I was halfway there, but the missing piece, setting the m34 cell value of the transformation matrix, did the trick.
As David pointed out, your code doesn't make sense as written. You're setting the final rotation of your newView to a rotation around nothing, which will PROBABLY be equivalent to the identity matrix, but I'm not sure.
Here's what I would try (I'm tired, so let's see if I can explain this coherently...)
Animate the oldView from 0 to pi/2 as animation step 1. Set the newView to -pi/2 before beginning the second animation (rotated 90 degrees the other way.)
In the completion method, remove the old view and start an animation to set the new view's rotation back to zero. That will cause the new view to look like it's continuing to flip around in a 180 degree flip.
Here's the tricky part. Calculate the difference in size (horizontal and vertical) between the old and new views. Add (concatenate) a scale transform along with the rotation, so that when the first part of the rotation is finished, it is scaled to the average of the old and new size. Pseudocode might look like this:
//Scale to apply to oldView for the first part of the animation:
scale height = ((oldView.size.height+newView.size.height)/2) / oldView.size.height
scale width = ((oldView.size.width+newView.size.width)/2) / oldView.size.width
/*
Before beginning the second part of the animation, rotate newView to -pi/2,
and scale it by an amount that makes it the same size that oldView will be
at the end of the first animation (the average of the sizes of both views)
*/
newView scale height = ((oldView.size.height+newView.size.height)/2) /
newView.size.height
newView scale width = ((oldView.size.width+newView.size.width)/2) /
newView.size.width
in the completion block, remove oldView from it's superview,
and animate newView back to the identity transform.
If my approach is right, at the end of the first animation, oldView should be scaled to a size halfway between the sizes of oldView and newView.
The second animation, triggered in the completion block of the first, will start out with newView being the same size that oldView was scaled to at the end of the first animation. The second animation will end with the new view rotating into place and scaling back to it's original size.