My problem is that I am using nested scrollviews. One for the horizontal paging and second to show the content with vertical scrolling (cuz content, which is text, is more than the available space). Actually there are multiple copies of this vertical scrollview like:
MainScrollView (Horizontal)
VerticalScrollView1
VerticalScrollView2
VerticalScrollView3
Besides these the vertical scrollviews contains label that are draggable, I implemented dragging using touchesBegan: and moved: events. I developed the whole thing using only one vertical scrollview and it's working just fine and I thought, to my dismay, that it'll work exactly the same for the rest but when I added more vertical scrollviews, only the last one is allowing dragging of the labels. The first two ain't allowing dragging, besides, they are also not responding to the vertical scrolling event, which was perfect earlier. I tried it with two vertical scrollviews and even then only the last one was allowing dragging. Ain't sure about the vertical scrolling cuz right now only the first one has enough content to be scrolled rest need not to. I can try that out too but it's kinda late here, so, if someone can guide me with the provided info. would be much helpful. Else I can try that out tomorrow and post you with the result.
Thanks for your time.
I had similar issues with nesting UIScrollviews. I found this video from WWDC 2010 to be really helpful in showing how to work with scrollviews inside a paging scrollview, and I managed to fix the bugs I had by following the steps in this video and looking at the sample code.
Designing Apps with Scroll Views
Sample code
Related
I'm trying to understand how autolayout works under XCode6, but there's a lot of mysterious things that runs away from my mind. Autolayout and constraints philosofy can be very hard to learn, but I realized that life can be easier using these tools...
For your information, I need to build a chat view with a table (the messages) and a view containing a text field (the send message pane) nested in a UIView that is again nested in a UIScrollView, so I can shift up the scroll view as the keyboard appears under the textfield.
I read a lot of tutorials and watched a lot of video until I found the useful tutorial Using UIScrollView with Auto Layout in iOS. There's a Xcode project in Github of what the tutorial explains, too.
In his tutorial, Mike Woelmer tells that
One of the big pain points with the old way of setting up a
UIScrollView was communicating the content size to the scroll view. It
was fairly straightforward to calculate your content size if the
content in the UIScrollView was an image. But it was not as easy if
your scroll view included a mixed bag of buttons, labels, custom
views, and text fields. Lengthy code adjustments were needed to
reflect constant changes in device rotations and phone size
differences.
So Mike explains the way to adapt the UIView, using placeholder and forcing the view inside the scrollview to fits the device's screen, creating in viewDidLoad some NSLayoutConstraint:
The solution is to look outside the scroll view and attach a
constraint to the view controller’s main view. This cannot be done in
interface builder, so we will have to write some code. Interface
builder is still complaining, though, so we have to add a placeholder
width constraint to make it happy.
I tried to use parts of the code of the tutorial for my project, but I cannot get a working view controller for my needs (I always get errors). Which is the best approach to do this? Am I on the right road?
Last but not least, I'm italian, so pardon for my english. If something is not clear enough, please leave me a comment.
Basically you have to set both alignment and size constraints in order for Autolayout to take care of the rest for you. If you don't provide enough information you get warning. If you provide conflicting information you get errors.
You need basically to provide enough information for Autolayout to calculate the UIView frame property (i.e., x-position, y-position, width, height).
For example, by providing the distance constraints from the top, right, bottom, and left edges, Autolayout has enough information to draw that UIView's frame rectangle. But you could also provide just the distance constraints from the top and left edges and then provide a size and height constraint.
You can also configure the key constraints you need and then click 'resolve auto layout issues' and choose 'add missing constraints' though sometimes it doesn't give you what you want. It is better to understand that how Autolayout accomplishes what I described above.
If you mess up, it's usually easier to clear all the constraints and start over. Do it a few times and you'll get the hang of it.
I am trying to initiate a scroll view in my UITextView and even though I seem to have selected the appropriate boxes, I can't seem to get the scrolling working. I have gone through multiple questions similar to this but none seem to have the answer.
I included an image of Xcode below:
Question 2: When I scroll down the majority of my text shows but the scrolling stops with two sentences or so left and I have to scroll down and hold it there to read. Any way I can fix this so it scrolls all the way to the bottom of the text?
Can you check the two boxes: Bounce Horizontally and Bounce Vertically and see what's happening? Sometimes your content are actually way bigger than your view, and they are touching a invisible outer box. If you can see they actually move, that means there is nothing wrong with touch or scroll, is just the view layout problem.
For the content issue, my guess is that the content size is not right, you can programmatically adjust it with textView.frame property, set it to a proper size, such as the frame of the window or the frame of the content, which are CGRect classes. Comment below to see if this can solve your second problem.
The text view will not scroll in storyboard, only the app. And the text view will scroll once the content in the text view exceeds the frame size.
If you're using iOS 7+, you can just turn on auto layout, pin each of the sides of the text view to the edge of its parent view, and it works fine without needing to do anything in code.
I've got an NSCollectionView which houses three columns of NSCollectionViewItems. In each of the NSCollectionViewItem prototype views, I have a single NSImageView. As far as I'm aware, this is a fairly standard setup. I think the problem stems from my use of a popover to present the collection view, but I'm honestly not sure. Basically, the problem I'm having is that when I click on one of the aforementioned NSCollectionViewItems to mark it as "selected," every once in awhile it flickers/flashes. It's not a total deal-breaker, but it's annoying enough to make me post this question.
Coming from the HTML/CSS/JS game, I started to think of all the ways I would prevent the flicker when building stuff with web technologies. My first thought was to make certain parts of the NSCollectionView (and subviews) layer-backed. I figured that by doing the drawing via layers or just setting the collection view to be layer-backed period, it would render better, kind of like GPU-enhanced animations in CSS (e.g. no sub-pixel antialiasing, enables z-depth, etc.).
So, I subclassed NSCollectionView and added a [self setWantsLayer:YES] in the
-(id)initWithCoder:aDecoder method. I was right! It removed the flickering altogether. Also, the scrolling became much smoother. However, in the process of making the flicker go away, everything else started messing up. The popover would take about 10s to load (vs. ~500ms originally), items would do weird overlapping things, etc.
My question to you all is this: what should I do? If anyone could help a brother out, I'd really appreciate it.
I'm trying to mimic the functionality of the NetFlix app, with a strip on the left that collapses on scrolling, I had to offset the tiles on the GridView a bit to the right so that they can accomodate that behavior. They seem to work alright in keyboard and scroll completely to the right (although I noticed the scrollbar suddenly grows in size when I hit the left boundaries. this totally changes when I use it on touch - I seem to have a limit on the right and the scrolling doesnt scroll past the last 100 pixels or so. how do I take care of this.
I'm assuming it is related to the bug here, but didn't seem to solve the problem with that solution there.
"Sticky scrolling" issue in WinRT XAML GridView control
Jay, I bet you solved it in the meantime. But I'll add my solution here anyway; it might save time for other fellows.
This effect - not being able to scroll to the very right end horizontally with touch - did go away when I either:
*) changed the VirtualizingStackPanel to a StackPanel
OR
*) Grouped the GridView (with VirtualizingStackPanel in the ItemsPanelTemplate) into a simple ScrollViewer
Hope that helps!
I've a window with a horizontal split view. On the bottom pane of the split view, I have a nssegmentedcontrol, aligned to the center. On the bottom of the nssegmentedcontrol I have 5 tabs that are controlled by the segmented control - click in one of the cells and the corresponding tab opens.
My problem is, if I completely minimize the bottom pane, to the point where the dividing line touches the bottom of the window, the segmented control gets pushed on top of the table header and never goes back to its original place.
I've tried fiddling with IB to get this to work, but no luck. Has anyone experienced this?
Following what's on the comments, I replaced the default split view with the one found in BWToolkit that allows for the definition of minimum and maximum height of each view.
BWTookit is a no go, the framework leakes a lot.
You should use RBSplitView (google it), it also gives you option for min and max height
and I started using it because of a bug in the split view as well, I used it for a chat window
but the split view didn't autosave as it should, every time it got like 2px smaller,
RBSplitView is great, and doesn't leak.