I have an UIScrollView with many buttons and some labels. My question is: How can I easily zoom UIScrollView content (with two fingers)?
Thank you very much.
UIScrollViews already support zoom using pinch gesture, you just need to implement the delegate method
- (UIView*)viewForZoomingInScrollView:(UIScrollView *)scrollView {
// Return the view that you want to zoom
return self.viewZoom;
}
Returning the view you want to zoom.
As Andrea pointed out the UIScrollView already supports zoom feature.
Follow these steps:
Add a UIView (say viewZoom) to the scrollView by giving same width and height as that of scroll view.
Add all UI components (Buttons etc) to viewZoom.
Set maximumZoomScale property of scroll view to '2' (or any other value as per your requirement).
Set your view controller as delegate to ScrollView(scrollView.delegate = self).
Implement - (UIView*)viewForZoomingInScrollView:(UIScrollView *)scrollViewin view controller and return the "viewZoom" you added to the scroll view from this method.
Related
I have a scrollview where I have added different views (like tutorial).
What I wanted to have is slider with below design where on scroll I will see previous tut on left side and next on right side.
For this what I have added is scrollview with paging enabled and adding UILabel (for now) in for loop. After adding label in scrollview below is what I had.
To see the data on the left & right, what I did is uncheck clip subviews from storyboard.
However what I noticed is I can scroll only in scrollview area and not outside.
Any idea how can I make UILabel make scrolling outside & inside scrollview.
As of now to make it working, what I have done is added swipe gesture on view and making scrolling programmatically. However what I was looking is if I scroll outside scrollview, it should scroll scrollview little too.
Phewww...
Finally I managed to make it done..
What I did is added one more scrollview (dummyScrollView) with full screen width above main scrollview (mainScrollView) (which I am using to show label).
Now I enabled paging for the dummyScrollView too and implement below where I am scrolling my mainScrollView based on the factor calculation for the dummyScrollView
#pragma mark - UIScrollView Delegate
- (void) scrollViewDidScroll:(UIScrollView *)sender
{
float myFactor = 0;
// 44232 is tag for new scrollview
if (sender.tag==44232) {
myFactor = mainScrollView.frame.size.width/duplicateSV.frame.size.width;
myFactor = duplicateSV.contentOffset.x*myFac;
CGRect mCC = CGRectMake(myFactor, 0, mainScrollView.frame.size.width, mainScrollView.frame.size.height);
[mainScrollView scrollRectToVisible:mCC animated:NO]; // NO is very important... YES will not work
}
// 44231 is main scrollview tag where I won't be doing anything...
if (sender.tag==44231) {
}
}
I am currently making an application that uses UIScrollView. On scrollview i am showing short descriptions of items. For one item i have four to five descriptions and a doc type at the right side.As shown in image on scrolling top in need to scroll doc file to bottom till the end of particular item description.
How can I achieve this one?
Here are the basic steps -- you need to figure out the details based on your code.
In the VC with this scrollview, implement UIScrollViewDelegate
set the UIScrollView.delegate to the VC (e.g. in viewDidLoad) -- something like self.scrollView.delegate = self; (assuming your IBOutlet to the scrollview is called scrollView
In the VC add this code (fill in actual code to do what comments say):
-(void)scrollViewDidScroll:(UIScrollView *)scrollView {
// scrollView.contentOffset is the scroll position of the scroll view
// Look at that and where your label sections are
// set the AgendaLabel.center or AgendaLabel.frame appropriately
}
I currently have a view controller that is comprised of a Navigation bar, followed by a UIView that has two UIButtons added as subViews. There is then a UITableView underneath that begins at the bottom of the container UIView.
At the moment, when the user scrolls the UITableView it goes behind the UIView and UIButtons. What I actually want to happen is for the UIView and UIButtons to move up with the table view but only by the value of their height which in this case is 58 pixels. The flow would be like this...
1) Table scrolls and the UIView moves with it for the first 58 pixels.
2) The user continues to scroll the table but the UIView "pins" itself just out of view under the navigation bar.
3) When the user scrolls the table back down the UIView is then picked up and dragged back into view. I believe the new Facebook app does something similar in the timeline.
I don't want to set the UIView as the TableHeaderView of the table as I also have a pull-to-refresh which then sits above the buttons and looks terrible. I've tried playing around with the contentOffset properties of the underlying scrollview of the table but have hit a brick wall.
Any advice on where to start would be appreciated.
Thanks
EDIT: I am gotten a little further and using this code to move the frame of the UIView.
-(void) scrollViewDidScroll:(UIScrollView *)scrollView
{
NSLog (#"Content Offset: %f", self.tableView.contentOffset.y);
NSLog (#"Button Frame: %f", self.btnBackground.frame.origin.y);
if (self.tableView.contentOffset.y > 0)
{
CGRect newFrame = self.btnBackground.frame;
newFrame.origin.x = 0;
newFrame.origin.y = -self.tableView.contentOffset.y;
[self.btnBackground setFrame: newFrame];
}
}
The problem now is that the scrollViewDidScroll delegate method doesn't get fired quickly enough if the table view is scrolled fast. The result is that the UIView doesn't quite make all way back to its original position when scroll quickly.
The scroll content offset is a good idea. Also if you tableview has only one section one approach is to do a custom header view representing the top level widgets. If there is more than one sections create an additional empty section which would return your custom header.
You can refer to this stack overflow post.
Customize UITableview Header Section
Well Asked Question (y)
well , for me i would first : use a main UIScrollView that contains both your topView and the tableView under it and that has the same width as your top UIView and UITableView and set its height to be height(tableView) + height(topView).
Second : since UITableView is a subClass of UISCrollView you can use scrollViewDidScroll delegate to know if the tableview is scrolled up or down.
in this cas you will have Two cases :
1) tableview is scrolled up = > you set the content offset of the main scrollView to be
[scrollView setContentOffset:CGPointMake(0, 58) animated:YES];
2) when the table view is scrolled down you can reset the content offset again
[scrollView setContentOffset:CGPointMake(0, 0) animated:YES];
This question already has answers here:
UICollectionView: paging like Safari tabs or App Store search
(6 answers)
Closed 9 years ago.
I've got a collection view whose content is scrolled horizontally and needs to be visible for the full width of the device. The collection view has clipsToBounds set to NO and it's frame is 600 wide with pagingEnabled set to YES.
The effect I'm looking for is that content would appear to slide under another view, however when the cell is scrolled outside the frame of the collection view then it is removed so that it can be reused.
Anyone know how I might get this to work, or achieve a similar effect?
Below is the simplest way that I've found to get this effect. It involves your collection view and an extra secret scroll view.
Set up your collection views
Set up your collection view and all its data source methods.
Frame the collection view; it should span the full width that you want to be visible.
Set the collection view's contentInset:
_collectionView.contentInset = UIEdgeInsetsMake(0, (self.view.frame.size.width-pageSize)/2, 0, (self.view.frame.size.width-pageSize)/2);
This helps offset the cells properly.
Set up your secret scrollview
Create a scrollview, place it wherever you like. You can set it to hidden if you like.
Set the size of the scrollview's bounds to the desired size of your page.
Set yourself as the delegate of the scrollview.
Set its contentSize to the expected content size of your collection view.
Move your gesture recognizer
Add the secret scrollview's gesture recognizer to the collection view, and disable the collection view's gesture recognizer:
[_collectionView addGestureRecognizer:_secretScrollView.panGestureRecognizer];
_collectionView.panGestureRecognizer.enabled = NO;
Delegate
- (void) scrollViewDidScroll:(UIScrollView *)scrollView {
CGPoint contentOffset = scrollView.contentOffset;
contentOffset.x = contentOffset.x - _collectionView.contentInset.left;
_collectionView.contentOffset = contentOffset;
}
As the scrollview moves, get its offset and set it to the offset of the collection view.
I blogged about this here, so check this link for updates: http://khanlou.com/2013/04/paging-a-overflowing-collection-view/
I need to place a photo in the screen and it should be able to be scrolled or zoomed,
I know UIScrollView does these, so I alloced one, but how about my photo?
I guess I should not just set the photo as the backgroundColor of my UIScrollView, and I haven't found any property of UIScrollView, in the document, to hold an image, such as "imageView", "contentView", or something like that.
So, what should I do to make a picture in my screen and make it able to respond to finger touches?
Thanks a lot!
Add the UIImageView to the UIScrollView and set the min/max scale value to it.
Then implement the following UIScrollViewDelegate function.
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView {
return yourImageView;
}
If you want to have multiple items scaled, add all the view into a UIView, and put that UIView inside the UIScrollView. Of course you have to change the return view to that UIView in the above function.
Just add your UIImageView as a subview of the UIScrollView. Also, set the scroll view's contentSize property to be equal to the size of the image view's frame.
THe scrollView is the first step.
Then you should add a UIImageView and load an image inside.
You need also to set the max e min zoomScale properties of the scrollview
And you must implement the scrollview delegate method – viewForZoomingInScrollView: