I'm using core plot and have allowed user interactions. Now it is possible to scroll in all directions using gestures. All directions? No, if the finger is moving from left to right (so I try to scroll from 100 to 0) sometimes nothing or much less than usually expected happens.
So if I scroll in the opposite direction, the same point remains under my finger. If I scroll from left to right, there is much less movement.
I have no idea, where the problem can be. Expecially, since I also tried to implement scrolling by swiping (My own Swiping-Implementation, not the Coreplot implementation) and the result was almost the same: All swipes worked, only right-swipe made trouble.
Well, I have an idea: Right-Swipe is already implemented somehow in the CorePlot-library to do something else, and the gesture is recognized to do something else than desired. ... but I found nothing about it.
Ideas?
Related
I am making an iOS app for remote controlling the lights in my house. I have a list of groups of bulbs (rooms) that can be turned on and off. My problem is selecting a room, I want it to be like this:
You can either press the arrows left or right to switch the room, or you can put your finger, where it says Living Room and swipe left or right to switch it.
Can someone give me a pointer as how to implement a swipe feature like that? I know there are gesture recognizers. I never used them, but I guess they won't automatically make the text I want to swipe follow my finger.
I guess it would be possible to use the gesture recognizer and manually move the text to get the swipe "feeling". It just seems to me like there should be an easier solution.
I've done something similar several times, and the most elementary way to approach it is to override the touches... methods on NSResponder. This will tell you when a user's finger touches the component, when it moves, and when they let go. From that, it's pretty easy to adjust the position of your UIView, do some custom rendering, or whatever else you need.
Another, higher-level, approach is to use a UIScrollView and implement it's delegate methods. Inside the scroll view are three elements which completely fill the viewport: the one you can see, and those to the left and right. You watch the delegate events for the user adjusting the position of the viewport and as they expose an element to the left or right, you can snap the viewport into place when they let go. Then, you adjust the three inner views to show the appropriate new content and reset the viewport to expose the middle element (which would then be showing the appropriate content).
There are undoubtedly many other approaches, but I've used both of these with good effect.
I solved it in the end by using a pangesturerecgonizer attached to the label. It's pretty straight forward, I just didn't know pan is supposed to mean something like drag and drop, I thought pan would be something completely different.
I've scoured the internet and I cannot seem to find any help on this. I want to have an image perform a wipe animation. By that I mean I would like the image itself to fade in from the left to right (not move from left to right, but fade, like reveal itself. I hope that's not a terrible description) I've found material on how to transition the image with a wipe, but it's outdated and I don't want to transition the image, I want to straight up fade it in. If anybody could help me on this I would be incredible grateful. Thank you so much, let me know if I can help clarify anything!
First thing that came to my mind is to have a separate UIImageView, with image something like this: http://www.creativecow.net/articles/ahearn_luke/creating_clouds/images/gradient.jpg (but transparent-to-white).
So - once You want to fade out Your image, You add as a subview a new UIImageView, which has frame like 3 times the width of the original image You want to hide. Once You add it as a subview, visually nothing would change, as the beginning of the hovering UIImageView would be transparent, But then You start animate frame (origin.x) of the hovering UIImageView so that it would be moved to the left side. While this happens, bottom ImageView will be gradually hidden from one side. After animation ends, You remove/hide both UIImageViews.
Not the best solution, but - if You are stuck, and still want the effect... Atleast some option.. Good luck!
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!
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
i want my app to be able to track a person when he moves 2 dimensionally upwards. I already have a vertical scroll view, and it works, but when i press a button i want it to track a little stick figure as he walks vertically, how can i control this? i thought of setting the scrollview.contentoffset to a certain position, but it just changes it one time when i want it to change it fluidly. i suppose i could make a timer that updates the contentOffSet every like .001 seconds or something, but i thought there maybe a better way.
Also, while i was searching the UIScrollView's methods, one of them was an isTracking method, which is a boolean, and I'm assuming it returns yes if the scrollview is tracking something, so given that i assume there is a feature in scrollview so that you can track things. Also, if to track things you have to use some other framework thing that would be helpful to know too
THANKYOU FOR ANY HELP!
The property tracking tells if the scroll view is currently tracking the user's movement. So that definitely won't help you out. (See David H's post for a better explanation for what the property indicates.)
However, you could use setContentOffset:animated: and set animated to YES. That results in a smooth transition to the new content offset.
Instead of calculating a reasonable content offset you might find it easier to specify an area that contains the stick figure. If so use scrollRectToVisible:animated:. Obviously animated should be set to YES.
1) don't use contentOffset = x;, use "- (void)setContentOffset:(CGPoint)contentOffset animated:(BOOL)animated". Experiment how often you need to send this message, but I'm guessing you can do it no more than 10 times a second and get nice results.
2) isTracking means the user has their finger on the scrollView but has not started dragging it. By testing "isTracking" and "isDragging" you can determine if the user is fiddling with your scrollView or not.