UIAlertView reloads Views that were removed from their superView - ios

I alloc and show an UIAlertView ( standard one button ). On
- (void)willPresentAlertView:(UIAlertView *)alertView{
NSArray *a = [self.view subviews];
}
I get one element. The view that was in effect when I showed the Alert. On
- (void)didPresentAlertView:(UIAlertView *)alertView{
NSArray *a = [self.view subviews];
}
I get 4 elements(??). UIAlertView somehow brings to life views that I previously have removed from their superview. Why??
Thanks, David

Showing an alert is an activity related to UI and it's generally good practice to perform all the UI related tasks on the main thread.
dispatch_async(dispatch_get_main_queue(), ^{
});
Inside the dispatch block, you should display your alert.
Hope this helps..

Related

UIRefreshControl cancel touch on top of custom cell - Objective-c iOS

I have an issue with my UIRefreshControl : after the first time it was triggered, it cancels touch on top of my first custom cell (even if it is hidden), like if it was invisible.
If I remove it from superview, then add it again, the issue is still there.
Actually I have a UITableView that is populated with some data. The user can refresh the table view by pulling it and for that I've added an UIRefreshControl to my table view like this in viewDidLoad()
self.refreshControl = [[UIRefreshControl alloc]init];
self.refreshControl.tintColor = [UIColor colorWithRed:0.35 green:0.78 blue:0.98 alpha:1.0];
[_tableView addSubview:self.refreshControl];
I've not added selector to the refreshControl object because I want the tableView to refresh only when the user stopped touching the screen. So for that I've added this ScrollView's delegate method :
- (void)scrollViewDidEndDecelerating:(UIScrollView*)scrollView {
if (self.refreshControl.isRefreshing) {
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
dispatch_sync(dispatch_get_main_queue(), ^{
[self refreshTable];
});
});
}
}
And here is my refresh method :
- (void)refreshTable {
//refresh code
[self.refreshControl endRefreshing];
}
I don't want to put my app online with this issue, even if this does not block user to use it !
Thanks in advance for your help !
I've found the solution by going to this post
So effectively in my case I did not have to add a selector, just implement those UIScrollViewDelegate's method :)

iOS GUI refresh

I am using setNeedsDisplay on my GUI, but there update is sometimes not done. I am using UIPageControllView, each page has UIScrollView with UIView inside.
I have the following pipeline:
1) application comes from background - called applicationWillEnterForeground
2) start data download from server
2.1) after data download is finished, trigger selector
3) use dispatch_async with dispatch_get_main_queue() to fill labels, images etc. with new data
3.1) call setNeedsDisplay on view (also tried on scroll view and page controller)
Problem is, that step 3.1 is called, but changes apper only from time to time. If I swap pages, the refresh is done and I can see new data (so download works correctly). But without manual page turn, there is no update.
Any help ?
Edit: code from step 3 and 3.1 (removed _needRefresh variables pointed in comments)
-(void)FillData {
dispatch_async(dispatch_get_main_queue(), ^{
NSString *stateID = [DataManager ConvertStateToStringFromID:_activeCity.actual_weather.state];
if ([_activeCity.actual_weather.is_night boolValue] == YES)
{
self.contentBgImage.image = [UIImage imageNamed:[NSString stringWithFormat:#"bg_%#_noc", [_bgs objectForKey:stateID]]];
if (_isNight == NO)
{
_bgTransparencyInited = NO;
}
_isNight = YES;
}
else
{
self.contentBgImage.image = [UIImage imageNamed:[NSString stringWithFormat:#"bg_%#", [_bgs objectForKey:stateID]]];
if (_isNight == YES)
{
_bgTransparencyInited = NO;
}
_isNight = NO;
}
[self.contentBgImage setNeedsDisplay]; //refresh background image
[self CreateBackgroundTransparency]; //create transparent background if colors changed - only from time to time
self.contentView.parentController = self;
[self.contentView FillData]; //Fill UIView with data - set labels texts to new ones
//_needRefresh is set to YES after application comes from background
[self.contentView setNeedsDisplay]; //This do nothing ?
[_grad display]; //refresh gradient
});
}
And here is selector called after data download (in MainViewController)
-(void)FinishDownload:(NSNotification *)notification
{
dispatch_async(dispatch_get_main_queue(), ^{
[_activeViewController FillData]; //call method shown before
//try call some more refresh - also useless
[self.pageControl setNeedsDisplay];
//[self reloadInputViews];
[self.view setNeedsDisplay];
});
}
In AppDelegate I have this for application comes from background:
-(void)applicationWillEnterForeground:(UIApplication *)application
{
MainViewController *main = (MainViewController *)[(SWRevealViewController *)self.window.rootViewController frontViewController];
[main UpdateData];
}
In MainViewController
-(void)UpdateData
{
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(FinishForecastDownload:) name:#"FinishDownload" object:nil]; //create selector
[[DataManager SharedManager] DownloadForecastDataWithAfterSelector:#"FinishDownload"]; //trigger download
}
try this:
[self.view performSelectorOnMainThread:#selector(setNeedsLayout) withObject:nil waitUntilDone:NO];
or check this link:
http://blackpixel.com/blog/2013/11/performselectoronmainthread-vs-dispatch-async.html
setNeedsDisplay triggers drawRect: and is used to "redraw the pixels" of the view , not to configure the view or its subviews.
You could override drawRect: and modify your labels, etc. there but that's not what it is made for and neither setNeedsLayout/layoutSubviews is.
You should create your own updateUI method where you use your fresh data to update the UI and not rely on specialized system calls meant for redrawing pixels (setNeedsDisplay) or adjusting subviews' frames (drawRect:).
You should set all your label.text's, imageView.image's, etc in the updateUI method. Also it is a good idea to try to only set those values through this method and not directly from any method.
None of proposed solutions worked. So at the end, I have simply remove currently showed screen from UIPageControllView and add this screen again. Something like changing the page there and back again programatically.
Its a bit slower, but works fine.

Allow User to Cancel MBProgressHUD when JSON call takes too long

I've read and read on SO about this, and I just can't seem to find anything that matches my situation.
I've got MBProgressHUD loading when the view appears, as my app immediately goes to grab some webservice data. My problem is the back button on my navigationcontroller is unresponsive while the HUD is displayed (and therefore while the app gets its data). I want the user to be able to tap to dismiss (or to be able to hit the back button in the worst case) to get the heck out, if it's an endless wait. Here's my code that runs as soon as the view appears:
#ifdef __BLOCKS__
MBProgressHUD *hud = [MBProgressHUD showHUDAddedTo:self.navigationController.view animated:YES];
hud.labelText = #"Loading";
hud.dimBackground = NO;
hud.userInteractionEnabled = YES;
dispatch_async(dispatch_get_global_queue( DISPATCH_QUEUE_PRIORITY_LOW, 0), ^{
// Do a task in the background
NSString *strURL = #"http://WEBSERVICE_URL_HERE";
//All the usual stuff to get the data from the service in here
NSDictionary* responseDict = [json objectForKey:#"data"]; // Get the dictionary
NSArray* resultsArray = [responseDict objectForKey:#"key"];
// Hide the HUD in the main tread
dispatch_async(dispatch_get_main_queue(), ^{
for (NSDictionary* internalDict in resultsArray)
{
for (NSString *key in [internalDict allKeys])
{//Parse everything and display the results
}
}
[MBProgressHUD hideHUDForView:self.navigationController.view animated:YES];
});
});
#endif
Leaving out all the gibberish about parsing the JSON. This all works fine, and the HUD dismisses after the data shows up and gets displayed. How in the world can I enable a way to stop all this on a tap and get back to the (blank) interface? GestureRecognizer? Would I set that up in the MBProgressHUD class? So frustrated...
Kindest thanks for any help. My apologies for the long post. And for my ugly code...
No need to extend MBProgressHUD. Simply add an UITapGestureRecognizer to it.
ViewDidLoad
:
MBProgressHUD *HUD = [MBProgressHUD showHUDAddedTo:self.view animated:NO];
HUD.mode = MBProgressHUDModeAnnularDeterminate;
UITapGestureRecognizer *HUDSingleTap = [[UITapGestureRecognizer alloc]initWithTarget:self action:#selector(singleTap:)];
[HUD addGestureRecognizer:HUDSingleTap];
And then:
-(void)singleTap:(UITapGestureRecognizer*)sender
{
//do what you need.
}
The MBProgressHUD is just a view with a custom drawing to indicate the current progress, which means it is not responsible for any of your app's logic. If you have a long running operation which needs to be canceled at some point, you have to implement this yourself.
The most elegant solution is to extend the MBProgressHUD. You can either draw a custom area which plays the role of a button, add a button programmatically or just wait for a tap event on the whole view. Then you can call a delegate method whenever that button or the view is tapped.
It can look like this:
// MBProgressHUD.h
#protocol MBProgressHUDDelegate <NSObject>
- (void)hudViewWasTapped; // or any other name
#end
// MBProgressHUD.m
// Either this, or some selector you set up for a gesture recognizer
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
if ([self.delegate respondsToSelector:#selector(hudViewWasTapped)]) {
[self.delegate performSelector:#selector(hudViewWasTapped)];
}
}
you have to set your view controller as the delegate for theMBProgressHUD and act accordingly.
Let me know if you need more clarification on this :)
To have extra information:
You could create contentView in your view
And simply show the hud in your contentView (not in your self.view or self.navigationController.view)
in this way your navigationBar's view will not be responsible for your hudView. So, you can go back from your navigationController's view to previous page.

How to reload data on a subview if the model is presented using UIModalPresentationFormSheet

I have implemented a UIModalPresentationFormSheet in my iPad application. The new view partially covers the sub view and allows the user to make a choice. This all works great, however...
When the user selects an option I would like to update the underlying view with the new details, but cannot get it to work!
I have tried using setNeedsDisplay or [table reloadData]; in both the viewDidAppear and viewWillAppear methods.
Some code for codes sake:
- (void)viewWillAppear:(BOOL)animated {
[self updateUserDetails];
[self.myTableView reloadData];
}
- (void)viewDidAppear:(BOOL)animated {
[self updateUserDetails];
[self.myTableView reloadData];
}
- (void)updateUserDetails {
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
[defaults setObject:selection forKey:#"userDetail"];
}
My transition is as follows. If this line is commented out then the application functions as expected:
myNavigationController.modalPresentationStyle = UIModalPresentationFormSheet;
Any help appreciated, thanks!
You can set
self.view.autolayoutSubviews = NO;
UI will change your view's size for UIModalPresentationFormSheet. This may be break the reload process.
I think you should put the reloading of data near the code where you detect the selection of the user, not in the viewWillAppear of viewDidAppear.

UISearchDisplayController Without Dimming?

I am writing a SplitView iPad app. Inside the DetailViewController, there's a little view that contains a UITableView and a UISearchBar and its controller. This view does not represent the whole screen space reserved for the DetailViewController. Actually, it uses just half of it. There's an UIImageView on the other half.
And this is where trouble comes in: every time I use the search bar, the displaycontroller (I assume) dims everything present inside the DetailViewController, including the image view. That is not consistent with what someone would expect when running the app. Is there any way to set the frame to be dimmed? Or at least disable dimming for good?
Thanks in advance.
You are correct that it is the UISearchDisplayController that is managing the "dimming" effect that you're seeing.
What the UISearchDisplayController is doing is adding a UIControl as a subview to the view of the searchContentsController (a property of UISearchDisplayController), which is likely your detail-view controller. This UIControl is just an alpha'd view with a gray background. It seems to have a touch-up-inside event handler that ends searching when tapped.
To constrain the dimming effect to your sub-view of the detail-view, you need to do three things. (I'm assuming your detail-view-controller is defined via a xib. If not, these steps can be done in code too.)
1) add a new UIViewController to your detail-view-controller xib. Attach this new view-controller to an IBOutlet of your detail-view-controller. In my example I call this "_searchAreaViewController". This is important, even if you wont ever access the view controller (but remember, you'll have to release it at some point)
#interface DetailViewController : UIViewController <UIPopoverControllerDelegate, UISplitViewControllerDelegate, UITableViewDelegate, UITableViewDataSource> {
UIPopoverController *popoverController;
UIToolbar *toolbar;
id detailItem;
UILabel *detailDescriptionLabel;
IBOutlet UIViewController* _searchAreaViewController;
}
2) make the containing view for your search area the view of this new view-controller. To do this, use Interface Builder to set a new referencing outlet for this view by dragging the outlet to the searchAreaViewController and selecting the "view" outlet. You must have a containing view - it should be a subview of your detail-view, and it should contain the UISearchBar and likely your UITableView.
3) make the searchContentsController property of the UISearchDisplayController refer to this new view controller instead of the detail-view-controller. This can only be done via Interface Builder as the property is read-only (IB has some magic to make this work?) If you need to do this step via code you'll have to subclass the UISearchDisplayController and return the correct value from a property override of "searchContentsController".
I made a sample app to demonstrate this and the only line of code I had to add to the SplitView template was the one listed in step 1 above. Everything else was just adding the views/controllers and connecting them properly in IB.
good luck!
iOS 8+
[[UIView appearanceWhenContainedInInstancesOfClasses:#[NSClassFromString(#"UISearchDisplayControllerContainerView")]] setHidden:YES];
iOS 7
[View appearanceWhenContainedIn:NSClassFromString(#"UISearchDisplayControllerContainerView"), nil] setHidden:YES];
I know, that UISearchDisplayController is deprecated for now, but if you still need to use it, you can solve your issue with one line of code perfectly. Add it to viewDidLoad method.
Could you clarify what you mean by "use the search bar" and "dims everything present"? I interpret what you wrote in such a way that the keyboard pops up when you are about to enter text in the text field of the search bar. And that at this point the detail view is dimmed out, preventing user interaction.
The cause is that the search bar implements a modal dialog which prevents user interaction with the view as long as the keyboard is shown. Unfortunately, there doesn't seem to be any way to configure the search bar to prevent this behavior. On the other hand I am not sure that the user won't expect this behavior since search bars are modal consistently and behave like this in general under iOS.
I have tried two work-arounds:
1.) There is a property of the UIViewController called modalPresentationStyle which produces exactly the behavior you describe if it has the value UIModalPresentationFormSheet ("All uncovered areas are dimmed to prevent the user from interacting with them.", see the Apple documentation). But setting this property to a different values does not change the result (at least for me it didn't work).
2.) You would need to write your own non-modal search bar replacement since a standard UITextField is non-modal and thus does not dim out any other UI elements. This approach works, but you might need a little more work to make it look like a "regular" search bar. But, again, since this search bar behaves differently from the modal normal search bars in iOS this might not really be what the users expect.
I know I am late and this is a horrible idea here, but 'setHidden:No' did not work for me.
-(void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText
{
BOOL hasBeenremoved = NO;
hasBeenremoved = [[[[NSThread mainThread] threadDictionary] objectForKey:#"hasBeenremoved"] boolValue];
if (hasBeenremoved)
{
UIView* dimmingView = nil;
dimmingView = [[[NSThread mainThread] threadDictionary] objectForKey:#"dimmingView"];
UIView* dimmingViewSuperView = nil;
dimmingViewSuperView = [[[NSThread mainThread] threadDictionary] objectForKey:#"dimmingViewSuperView"];
[dimmingViewSuperView addSubview:dimmingView];
[[[NSThread mainThread] threadDictionary] setObject:#NO forKey:#"hasBeenremoved"];
}
if ([searchText length] == 0 || [searchText isEqualToString:#""] )
{
[searchBar becomeFirstResponder];
[[[self primarySearchDisplayController] searchResultsTableView] reloadData];
[[[self primarySearchDisplayController] searchResultsTableView] setHidden:NO];
for( UIView *subview in self.view.subviews )
{
if([subview isMemberOfClass:[UIControl class]] ||
([[[subview class] description] isEqualToString:#"UISearchDisplayControllerContainerView"]))
{
for(UIView *subView2 in subview.subviews)
{
for(UIView *subView3 in subView2.subviews)
{
if (subView3.alpha < 1)
{
if ([[[subView3 class] description] isEqualToString:#"_UISearchDisplayControllerDimmingView"])
{
[[[NSThread mainThread] threadDictionary] setObject:subView3 forKey:#"dimmingView"];
[[[NSThread mainThread] threadDictionary] setObject:subView3.superview forKey:#"dimmingViewSuperView"];
[[[NSThread mainThread] threadDictionary] setObject:#YES forKey:#"hasBeenremoved"];
[subView3 removeFromSuperview];
}
}
}
}
}
}
}
}

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