Is it possible to make the table view allow scrolling only in one section and not others OR in other words allowing scrolling only in desired sections of the grouped table?
Many thanks.
Sure, this is entirely possible if you're willing to forego the use of a tableview. If you use a scrollview, you can achieve what you want by defining custom behaviour. It's not going to be easy but here are some suggestions:
Figure out how you want it laid out on the screen
Create a "floating cell" that will hang around, this will be your "not scrolling" section
With respect to #2 above, you'll have to figure out what kind of logic you want to make that floating cell disappear versus the other data.
The rest, you're effectively reimplementing a tableview.
Now, you can probably achieve this with a tableview, but it's be hairy big time.
Related
This implementation is similar to a normal UITableView, but with one caveat that drasticly changes the complexity of the work in my opinion. The ask is that all section headers will be visible at all times, no matter how long the table is.
Explaining the exact UX is a little difficult, but if you follow the link below there is an interactive example of exactly what I would like to accomplish in native iOS:
http://slinky.iclanzan.com/
It is my understanding that utilizing the normal UITableView will not be enough to satisfy this case. Aside from using a mashup of multiple TableViews, ScrollViews, and/or CollectionViews, I was wondering if anyone knew of some existing libraries that already perform this implementation?
Or if anyone has any high level suggestions on how to accomplish this with custom code that would be appreciated as well (Not looking for someone to write this all out for me, just an idea would suffice).
Found a solution after working with some teammates on a POC. I'll at a high level explain the implementation.
We know that a tableview's header and footer will remain static while we scroll. Since we want our sections headers to "stick" to the bottom and top of the tableview, we mimic this by dynamically adding any section header views that would have been hidden to the tableview's own header or footer.
We do this by maintaining an array of section header views, and calculating in layoutSubviews when we need to change the tableview's header and footer.
It seems that my view-based OutlineView try to re-render text every time user scrolling. I think that was because it tried to save memory by re-using rows that fall outside of visible rectangle, then re-render new data to those old views. How can I disable this? I'm willing to sacrifice memory to archive this so that I can get better scrolling performance. (I have tried with various optimize like layer or so, but no luck).
EDIT: There is another question with same purpose as mine here How to make NSTableView not reuse TableCellViews, but no answer yet :(
I think you are confused -- it doesn't re-render the text. The table only shows views for the visible area (caveat below), and pulls in new views as you scroll -- potentially re-using old views.
You provide the view. Use the delegate method viewForTableColumn:row: and return your own cached view for a given row.
But that isn't going to prevent drawing; the view will likely still get marked dirty and draw.
I don't think you are asking the right question. It sounds like you have a performance problem. To help you with that, we'd have to see samples or instrument traces.
Caveat: Responsive Scrolling will pull in views that are in the non visible area. See the AppKit release notes about this.
corbin
If I turn the autocorrection ON, the words get autocompleted, as if I write "wor", I get "word" before I finish writing. I don't want this to happen because I might be writing "world" or any word different than the autocompleted one.
I set Correction off in the Interface Builder and this problem is solved.
The problem now is that I still need the suggestions that appear in a little popover below the incomplete words.
This two features might be different but I don't know how to activate the suggestions.
How can I solve this?
This can be solved with the use of tableview. Create a tableview with the width as of the width of the textfield and height as you like. Place it just below the textfield. Make it hidden initially. When the user starts typing, fetch the array of data that resembles to the typed text and if any exists then, unhide the table view. On the subsequent typing keep on reloading the tableview sections with animations. You should be accurate on hiding, unhiding and then reloading the data on the tableview. I have implemented such thing before. It is really easy and once you get started with it you find it easy.
In the UITextView TextViewDidChange I created a thread that changed the cursor position. This, off course happens after the text view changes. The change of the cursor position triggers the autocomplete without letting me even see that there had been a suggestion.
I have a problem. I want for each record in my core data database to draw an UIImage view on screen. But the problem is that I want to make a sort of grid. On the link below you see what I want to achieve.
picture
So my question is, how do I draw an image on screen in code. And place those images in a sort of a grid. using a collection view is no option, because the app should be running on all IOS devices.
While you could implement a custom UIView and implement the drawRect: method and draw UIImages there, I suggest just using multiple UIImageViews as subviews on your "main" view. Your view might be embedded in a UIScrollView, or you could use a UITableView with custom UITableViewCells. Whichever is easier is probably related to how you can interact with the view.
Building that one huge image view is something that I'd definitely try to avoid - it costs many many (probably unnecessary) memory, and it might be slow as well. Definitely not very flexible to handle, and a pain to update dynamically.
A quick cheat for something like this is to use a Table View and then in each cell to place another TableView but rotated at 90 degrees.
You can then use this second TableView to display the pictures etc...
This will give you a table that scrolls up and down and then each cell can scroll left to right.
I'd suggest subclassing UITableViewCell and setting it up as a UITableViewDelegate and UITableViewDatasource.
You will also have to remember to rotate the content of these "sub"tables by 90 degrees also so that they are the right way up.
This sounds like a lot of work but if you push the management of the sub Tables into the cells then it actually becomes quite easy.
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.