UIScrollView+UIView instead of UITableView+customcells? - ios

I need UIView created automatically when scrolling happens. One UIView disappear and one UIView appear. Invisible UIView should be unloaded from memory like than I use UITableView and loaded back than I scroll back. Is it possible?

Absolutely possible, you can just reference the UITableView,including its datasource and delegate methods

Checkout my example of RecyclingScrollView
https://github.com/iSevenDays/RecyclingScrollView/tree/new

Related

Remove Object out of subview

Hey guys I added a UIImageView to the subview and want to remove it after a couple of seconds.
self.view.addSubview(car)
Now I want to remove the image completely. I tried something like:
self.view.delete(car)
But than I get a really long error when I press the button, which should remove the image.
I hope you can help me out.
-Lukas
removeFromSuperview is your way to go.
car.removeFromSuperview()
Methods to manage the view hierarchy are documented for UIView.

Set layers programmatically

so I have an application with several images, buttons, etc.. Now, I would like to control programmatically which object is in the foreground and which is further in the back. I know that in the storyboard this is possible, but since I declare a button in the AppDelegate (I don't have in the storyboard) I can't use this function.
Now, is there a way to do this?
You have to use the property .zPosition to accomplish that.
Look at the "Managing View Hierachy" section on UIView to accomplish this.
https://developer.apple.com/library/ios/documentation/UIKit/Reference/UIView_Class/index.html#//apple_ref/doc/uid/TP40006816-CH3-SW46
You can bring views to the front or send them to the back or adjust their index among others.
- (void)bringSubviewToFront:(UIView *)view

Button in custom UITableViewCell not responding in iOS 7

This is more or less a continuation of this post: Button in UITableViewCell not responding under ios 7
I am having the same exact issue and have tried every suggestion in the thread. Obviously I don't own that question so I can't edit it to give more info, and thus why I am posting this question now!
Problem:
I have VC nib that I load up that has a tableview in it that I resize based on how many rows are in it. Each row is made from a custom uitableviewcell subclass using a nib file. That class/nib has 4 buttons in it. I can load this code up in iOS 6 or iOS 8 right now and it works perfectly. I don't have a iOS 7 device so I'm bound to the simulator which is at 7.1 (which is the version I'm guess the user that reported this issue was using as well given it was today). Now in the simulator, and the user's phone, I can touch/click everything else on that VC except any of the buttons in the cells. It's as if they had UserInteractionEnabled set to NO, but they don't and neither are any of their parent views (as I'll soon get into).
Tried solutions:
-Completely recreating the nib from scratch both using and not using autolayout
-Calling [self.contentView addSubview:button] in the awakeFromNib of the cell class
-Tried re-adding the buttons to the contentView at runtime with [self.contentView addSubView:button]
-Have ensured four times over that every view in the hierarchy I can find that leads to these buttons have userInteractionEnabled set to YES. (including but not limited to the tableview itself, the cell, the contentView and when I added a "parent view" to the buttons that it was set as well)
-Tried raising all the buttons with a parent view that contains nothing but the buttons
-All buttons are at the top(visually bottom) of the event stack(add and remove are the other two buttons):
-Have set the table cell selection from single to none.
-I am not overriding layoutSubviews in my cell class
-I can not move any views outside of the Content View as Interface Builder takes them completely out of the cell if I do that.
-I have tried disabling the userInteractionEnabled on just the ContentView at runtime with no change
-I tried putting in the cell creation code of the tableview [cell bringSubviewToFront:cell.button]; for the different buttons to the same result.
Hopefully Helpful Facts:
-I tried setting all of the background colors of all of the views in the hierarchy to different colors so I could visually debug it at runtime... it looked exactly as expected. No overlaps or coverings. (This was limited to only views in the cell)
-Here is all of the settings for the TableView:
-I tried to load this in the new XCode 6 to use the visual debugger but the 7.1 simulator included with it actually ran the code perfectly so I could debug it...
-Here is the dequeueing code in the VC:
NiTGroupTimeCell* cell = (NiTGroupTimeCell*)[tableView dequeueReusableCellWithIdentifier:ident forIndexPath:indexPath];
-Here is the code in the viewDidLoad of the VC to set up the cell nib with the table(it's 2 because this is the from scratch one):
[self.timesTable registerNib:[UINib nibWithNibName:#"NiTGroupTimeCell2" bundle:nil] forCellReuseIdentifier:#"GroupTime"];
-All connections were made via IB. These are all using IBAction or IBOutlet.
-I have NSLog statements in all button methods to test if they are actually called, but I have also tested with breakpoints. All are never triggered in testing.
-The only TableView delegate or datasource methods implemented are as follows:
-(int)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
-(UITableViewCell*)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
-(float)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
-As per suggestion I took Revel to it and found that a mystery UILabel and UIImageView were in the view.... but as you can see their frames are all zeros so they shouldn't be getting in the way of anything so back to where we were I'm afraid:
UILabel frame:
UIImageView frame:
IIRC I counted this off as a Simulator bug before, but since it's happening on the user's device it must be an actual issue and it's holding up my pipeline so help would be GREATLY appreciated! Thanks in advance!
PS I'm happy to post whatever, but because of all the shifting in debugging I didn't know exactly what people would want to see and I didn't want to overload this post because I knew it was going to be long with everything else.
So apparently the issue was these lines of code(in diff format from my git diff output):
--(int)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
+-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
and
--(float)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath{
+-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath{
so yeah... seems that in iOS7+ if you have the "old" output types for these datasource methods it'll look fine but bork your tableview functionally... good times, but hey it's fixed now^^ hopefully this helps others.
I would suspect that there's an issue with your custom UITableViewCell subclass, NiTGroupTimeCell, or with the IBAction connections from the nib to the tableViewCell subclass.
I also wonder about the extra empty UILabel and UIImageView. They sound like the default properties declared in UITableViewCell.h, UIImageView *imageView and UILabel *textLabel. The fact that they're getting instantiated (and aren't nil) could be a clue as to the weird, unexpected behavior you're seeing.
Do you have IBOutlets to the UIButtons? What about changing properties (in code) for the buttons (such as background color) to make sure you actually are retaining them in the NiTGroupTimeCell.
You're saying that you tried [self.contentView addSubview:button] but your button in your first image is inside a view inside contentView. Try linking an IBOutlet to that view, then try [nameOfView addSubview];
Throwing a wild guess as it looks like you have covered pretty much everything else.
You said:
I load up that has a tableview in it that I resize based on how many rows are in it
And you posted a screen shot saying the clip subviews is off on the UITableView
Are you setting the frame of the tableview incorrectly but its showing the cells anyway due the the subviews not being clipped?
Load up reveal again and check the height of the UITableView
Not sure if it is the case here. But if you name the custom cell outlets imageView, textLabel or any of the "built-in" UITableViewCell's properties you will get weird results and behavior.
You need to check couple of things:
Make sure all the parent views of the button have User Interaction enabled.
Check AutoSizing in the size inspector and make sure the button lies inside the view so it could receive touch events otherwise touch events will get ignore. You can verify it by changing the colour of the view. Changing colour or NSLog the frame of button and parent views will help you to troubleshoot if this is the problem.
Try to make things simpler and don't addSubView programmatically, if designing from IB.
Make sure some component is not overlapping the button with a clearColor background color.
What worked for me is this:
self.contentView.userInteractionEnabled = NO;
I called this after loading my custom cell from nib / storyboard. Without the userinteractionEnabled set to NO, my buttons haven't been responding to touches somehow. My contentView has received all touches and did not forward them to my buttons.
I've seen code where
[cell bringSubviewToFront:button]
has been used as a workaround, for me it did not solve the issue.
I had a simillar issue, while adding Custom Acions based on Guestures.
I was adding Action Button on runtime in Inherited class of UITableViewCell
The bahaviour was if I add buttons outside the visible rect, after animating buttons inside, I was unable to click / tap. But in My Case I was able to Tap / Click if buttons were added in visible rect.
What Worked for me, I added those buttons in View instead of ContentView of UITableViewCell, then animated only Content View. You may try somthing simillar
-- Vishal
You've said that there are no TouchRecognizers(TapRecognizers?), but I think you should double-check that, and look not only for touch recognizers but for any recognizers in controller that uses that cell,even added to self.view/tableView.
I was recently trying to find out why cells don't select(delegate method wasn't called) only to find out that I've added 2 gesture recognizers(in code, those were necessary for other things, but I had to do that in other way) that would prevent cell selection.
Also the sign of it may be that if you hold button long enough(put breakpoint there so you can make it easier), action will fire.

Issue with overlapping text: iOS7

I normally post source code and examples of UI but I think its more related to an iOS7 change and I cant see it being a code bug (yet). I would have to post so much code and UI that it would be counter productive. So here is my best non-visual description:
Since upgrading a project to iOS7 I am finding that if I put call to change a UILabel or calling setText of a UIButton in a ViewDidAppear or ViewWillAppear it puts the new text right on top of the old text.
Since developing for iOS I have never had to do anything different. If I do this:
lblMyHours.text = #"12";
It shouldnt just throw that on top of my existing label.
This especially happens inside of a UITableView where I have created an iVar for a UILabel thats in a UITableViewCell. If a user makes an adjustment to a value after clicking on a cell (it takes them to a detail screen to edit), when I pop back I have it recalculate in ViewDidAppear. In that recalculating I am resetting a label like the above. But it doesnt clear out the old.
You might be adding a new label every time you return a new cell.
You should just replace the text of the current label instead.
There are two way to achieve this, one you are already doing and as #Guilherme rightly pointed out. The other way is to create a custom tableview cell and put the UILabel property in there. As for the viewDidAppear scenario, you can create a uilabel in ther .h file (in the #interface declaration) and then initialize it in ViewDidLoad method and simple use in ViewDidAppear method without having to declare it again.
I would suggest that you follow the way I described for ViewDidAppear issue, and for the UITableView issue, search for UILabels in subview of the cell everytime cellForRowAtIndex method is called and remove it from the subview, something like this before adding a new label
for(UIView *view in cell.subviews)
{
if([view isKindOfClass:[UILabel class]])
{
[view removeFromSuperview];
}
}
Hope this helps.

UIwebview does not respond to touchesBegan

I have subclass of UIViewController which has UIWebview as a subview added.
I'm trying to detect touch events on webview but failing to do so.
-(void)touchesBegan
is the method which should get called.
Can anyone help me in this.
Thanks in advance.
Detecting touches on UIWebView is not trivial.
Check this tutorial : http://mithin.in/2009/08/26/detecting-taps-and-events-on-uiwebview-the-right-way/
BTW - If you need only to detect a touch on a links or buttons and add a custom action you can do it to. look here:
http://dblog.com.au/iphone-development/iphone-sdk-tip-firing-custom-events-when-a-link-is-clicked-in-a-uiwebview/
Good Luck
Make sure your UIWebView is the first responder. When you add it, use becomeFirstResponder on the web view (I've linked the documentation at Apple for you).
Also make sure becomeFirstResponder returns YES.
Lastly, make sure your view controller's UIView userInteractionEnabled property is set to YES.

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