Under my self.view I have a UIScrollView called self.scrollView and under self.scrollView I have two UIViews called self.panedView and self.recordView. My self.panedView has a height of 568 and a Y origin of 0 and my self.recordView has a height of 274 and a Y origin of 568. My self.scrollView has a content size height that is equal to the height of 842 (height of self.panedView + the height of self.recordView). I want to add a UIImageView called self.iconImageView over self.panedView so that when I scroll, the imageView will move up to a certain position in relation to how much I scroll. self.iconImageView has a Y position of 184 is only a subclass of self.view. I was initially moving my self.iconImageView with UIView animationWithDuration whenever an up swipe was detected by doing the following:
- (void)viewDidLoad
{
[self.view insertSubview:self.iconImageView aboveSubview:self.panedView];
}
[UIView animateWithDuration:.25 delay:0 options:UIViewAnimationOptionCurveLinear animations:^{
self.iconImageView.frame = CGRectOffset(self.iconImageView.frame, 0, -85.5);
} completion:nil];
How can I replicated this now that I've switch over to a UIScrollView? I'm thinking something like this might work:
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
if(self.iconImageView.center.y >= 184 && self.iconImageView.center.y <=451)
{
CGPoint newCenter = CGPointMake(self.view.bounds.size.width/2, self.iconImageView.center.y + (self.scrollView.contentOffset.y/self.scrollView.contentOffset.y));
self.iconImageView.center = newCenter;
}
}
Implement UIScrollViewDelegate. Whenever the scroll view is scrolled(even programatically), you get an event.
Related
Code:
-(void)scrollViewWillBeginDecelerating:(UIScrollView *)scrollView{
int diff = end-start;
if (diff>0)
{
k = k + 95;
}
else {
k = k - 95;
}
[scrollView setContentOffset:CGPointMake(k, 0) animated:YES];
}
- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
{
start = scrollView.contentOffset.x;
}
- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate
{
end = scrollView.contentOffset.x;
}
I have a scrollview with 3 labels. leftSide 90 pixels width, center 90 pixels width and rightside 90 pixels width.Each label has 5 pixel gap.when scrollview scroll left or right i align next or previous label center of the screen.Logic is working fine.but animtation is not smooth and also there is a pause after starting animation.How do i solve this problem?.How do i speed up animation?any help will be appreciated.
You can adjust the speed of scrolling by the following way, by adjusting duration value.
[UIView animateWithDuration:0.5 animations:^{
_scrolview.contentOffset = CGPointMake(k, 0);
}];
I think the better way would be to just use UIScrollView's
pagingEnabled = YES;
And you don't need the above delegate methods. Make sure you have set the contentSize.
I want animation like home screen of this app.This screen has a view (with a label on it) on top and a table view under it. When i scroll the table the top view and title on it become small with animation and after a specific point it becomes like navigation bar with title in centre. And the same thing when i scroll down.
Here is what i tried so far
-(void)scrollViewDidScroll:(UIScrollView *)scrollView
{
CGPoint offset = scrollView.contentOffset;
NSLog(#"y is::: %f", offset.y);
if (offset.y > 0 && offset.y < 16 && self.topView.frame.size.height > 64) {
[UIView animateWithDuration:0.8 animations:^{
CGRect rect = self.topView.frame;
rect.size.height = rect.size.height-offset.y;
self.topView.frame = rect;
}completion:^(BOOL finish){
}];
}
else if(offset.y <= 0 && offset.y > -16 && self.topView.frame.size.height < 80)
{
[UIView animateWithDuration:0.8 animations:^{
CGRect rect = self.topView.frame;
rect.size.height = 80;
self.topView.frame = rect;
}completion:^(BOOL finish){
}];
}
}
Note that my top view initial height is 80 and i want to make it 64 when scroll up and vice versa.
with this code the view height animated but it depends upon animation duration.So if i scroll fast then it is not working properly.The original app i mentioned have very smooth animation. How could i achieve that?
Screen shot of original App-
These screen shots showing three different scroll position, please note the "MySurgery" text on top.1- Larger text and right align.
2- small text and near centre position
3- smaller text and centralised(like navigation bar)
I think you dont need animation for this, you just need some calculations and setting frame of the top view. like,
-(void)scrollViewDidScroll:(UIScrollView *)scrollView
{
CGPoint offset = scrollView.contentOffset;
if (offset.y>0 && offset.y<64) {
[topView layoutIfNeeded];
CGRect viewFrame = topView.frame;
viewFrame.size.height--;
topView.frame = viewFrame;
}
}
Note that layoutIfNeeded is required if your view is using autolayout
I have this code below who move my UIView to left:
- (void)viewDidLoad {
[super viewDidLoad];
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:4];
int xOriginal = 91;
CGRect rect = imagem.frame;
int x = rect.origin.x;
int y = rect.origin.y;
int w = rect.size.width;
int h = rect.size.height;
if(x == xOriginal){
imagem.frame = CGRectMake(x+100, y, w, h);
}else{
imagem.frame = CGRectMake(x-100, y, w, h);
}
[UIView commitAnimations];
}
My coordinate of my view is x = 91 (Center of the superView), When I start my app my UIView start left and go to center, instead of center and go to right, Why this is happening?
How to make my UIView start in center (x=91) and go to right (91+100), instead of left to center?
[UIImageView animateWithDuration:0.5 delay:0 options:UIViewAnimationOptionCurveLinear animations:^{
imagem.frame=CGRectMake(imagem.frame.origin.x+100, imagem.frame.origin.y, imagem.frame.size.width, imagem.frame.size.height);
} completion:^(BOOL finished) {
//code for completion
NSLog(#"Animation complete");
}];
Autolayout and frame animations are not good friends. Try to animate constraints instead of directly the frame.
You can create outlets of your constraints, and set the constant property of the constraint in your code to move your views.
You also call -[view layoutIfNeeded] to refresh your constraints while in an animation block.
Else you can remove all of your view constraints and animate its frame fearlessly.
Initially image.frame = CGRectMake(91,100,20,20);
So imageview starting point is 0
[UIView animateWithDuration:5.0
animations:^{
//Animation code goes here
image.frame = CGRectMake(191,100,20,20); //Now imageview moves from 0 to 100
} completion:^(BOOL finished) {
//Code to run once the animation is completed goes here
}];
As the other poster says, you can't animate a view's frame in XIBs/storyboards that use AutoLayout.
Instead you have to animate a constraint that's attached to the view.
What you do is to create a constraint (or multiple constraints) and connect it to an IBOutlet. Then, in your animation code, you calculate the changes to the constraint(s) and change the constant for the appropriate constraints.
For example, if you wanted to shift the vertical position of a view, set up a constraint that sets the vertical position of your view, and link it to an IBOutlet called viewConstraint. Then you'd use code like this:
[myView animateWithDuration: .25
animations: ^
{
viewConstraint.constant -= shiftAmount;
[self.view layoutIfNeeded];
}
];
I have a UIScrollView with a number of rectangular subviews lined up, of equal sizes. Then I need to be able to pass a CGPoint to that UIScrollView and I want it to give me the rectangular subview that contains the CGPoint. That's basically hitTest:event, except hitTest:event: doesn't work with UIScrollView once CGPoint goes beyond the UIScrollView bounds and doesn't look into its actual content.
What's everyone been doing about this? How to "hit test" on a UIScrollView content view?
Here's some code to illustrate the problem:
NSArray *rectangles = [self getBeautifulRectangles];
CGFloat rectangleLength;
rectangleLength = 100;
// add some rectangle subviews
for (int i = 0; i < rectangles.count; i++) {
UIView *rectangle = [rectangles objectAtIndex:i];
[rectangle setFrame:CGRectMake(i * rectangleLength, 0, rectangleLength, rectangleLength)];
[_scrollView addSubview:rectangle];
}
[_scrollView setContentSize:CGSizeMake(rectangleLength * rectangles.count, rectangleLength)];
// add scroll view to parent view
UIView *containerView = [[UIView alloc] initWithFrame:CGRectMake(0,0,320, rectangleLength)];
[containerView addSubview:_scrollView];
// compute CGPoint to center of first rectangle
CGPoint number1RectanglePoint = CGPointMake(0 * rectangleLength + 50, 50);
// compute CGPoint to center of fifth rectangle
CGPoint number5RectanglePoint = CGPointMake(4 * rectangleLength + 50, 50);
UIView *firstSubview = [containerView hitTest:number1RectanglePoint withEvent:nil];
UIView *fifthSubview = [containerView hitTest:number5RectanglePoint withEvent:nil];
if (firstSubview) NSLog(#"first rectangle OK");
if (fifthSubview) NSLog(#"fifth rectangle OK");
output: first rectangle OK
You should be able to loop through the scrollview subviews
+(UIView *)touchedViewIn:(UIScrollView *)scrollView atPoint:(CGPoint)touchPoint {
CGPoint actualPoint = CGPointMake(touchPoint.x + scrollView.contentOffset.x, scrollView.contentOffset.y + touchPoint.y);
for (UIView * subView in scrollView.subviews) {
if(CGRectContainsPoint(subView.frame, actualPoint)) {
NSLog(#"THIS IS THE ONE");
return subView;
}
}
//Nothing touched
return nil;
}
I guess you pass the wrong CGPoint coordinate to the hitTest:withEvent: method causing wrong behavior if the scroll view is scrolled.
The coordinate you pass to this method must be in the target views coordinate system. I guess your coordinate is in the UIScrollView's superview's coordinate system.
You can convert the coordinate prior to using it for the hit test using CGPoint hitPoint = [scrollView convertPoint:yourPoint fromView:scrollView.superview].
In your example you let the container view perform the hit testing, but the container can only see & hit the visible portion of the scroll view and thus your hit fails.
In order to hit subviews of the scroll view which are outside of the visible area you have to perform the hit test on the scroll view directly:
UIView *firstSubview = [_scrollView hitTest:number1RectanglePoint withEvent:nil];
UIView *fifthSubview = [_scrollView hitTest:number5RectanglePoint withEvent:nil];
I have view with UITableView. Above this list I have UIButton. I need to implement an animation what will move button vertically according to scrolling on list and return to base location when scrolling is finished. I show scrolling down in pictures bellow:
This is not scrolled list:
This is list scrolled to half:
This is list fully scrolled:
For now I detect start and stop scrolling list events and do animation like that:
-(void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
{
CGRect screenRect = [[UIScreen mainScreen] bounds];
CGFloat screenWidth = screenRect.size.width;
CGRect newFrame = button.frame;
newFrame.origin.y = screenHeight - (newFrame.size.height/2.0);
[UIView animateWithDuration:2
animations:^{
button.frame = newFrame;
}];
}
-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
CGRect newFrame = storedButtonFrame;
[UIView animateWithDuration:2
animations:^{
button.frame = newFrame;
}];
}
I have few issues with this First is that when I scrolling down my animation is animating to then end and I want to animate based on scrolled list eg. when I scroll down list for 10px I would like to move button only for 10px not to the end of list. Second is that I get stop scroll event when begin scroll animation is still running the start animation is blink to the end and the end animation is start animating what is definitly what I dont want. I dont have to much experiance in iOS and I really dont have any ide how can I do this. Have any idea how can I do something like this?
Instead of using scrollViewWillBeginDragging: you could use scrollViewDidScroll: like so:
/// Animate the button position as the scroll view scrolls
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
CGFloat percentage = scrollView.contentOffset.y / scrollView.contentSize.height;
CGRect frame = _button.frame;
frame.origin.y = scrollView.contentOffset.y + percentage * self.tableView.frame.size.height;
_button.frame = frame;
}
/// Animate the button back to the top-right corner
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
CGRect frame = _button.frame;
frame.origin.y = scrollView.contentOffset.y;
[UIView animateWithDuration:0.4f
animations:^{
_button.frame = frame;
}];
}
This makes the button follow the scroll indicator as you scroll the list. scrollViewDidScroll: fires very often so the movement is smooth.
When the list stops, it goes back to its default position at the top-right, which you get from contentOffset.y.