I'm using code to create a detailed view pushed when you press a row of an UITableView, but theres a problem.
The detailed view contain an UITextView and when a detailedView is called (only first time) this make the UITableView row pressed to lose its pressed state. It shouldn't ! It should lose the pressed state only when returning from the detailed view to the list view.
As soon as I remove the UITextView from my code, no problem !
I think it's something like UITextView taking focus?
Is there any way to avoid this ? By subclassing or such?
Hmmm not seeing this in the sandbox I just wrote.
Created a simple navigation-based project.
Added a view controller to the project with XIB; added a UITextField to the XIB.
Made following code changes to the root view controller:
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return 1;
}
in cellForRowAtIndexPath:
cell.text = #"Push me";
in didSelectRowAtIndexPath:
SimpleViewController *detailViewController = [[SimpleViewController alloc] initWithNibName:#"SimpleView" bundle:nil];
in viewDidLoad:
self.navigationItem.title = #"Home";
Selecting the "Push me" row highlights the row and pushes the SimpleViewController onto the stack. Selecting the "Home" back button pops the view off the stack, returning to the table view and deselecting/un-highlighting the selected row. This is true whether or not the textfield in the SimpleViewController is the first responder at the time of the back navigation.
Related
My ViewController is a custom UIViewController <UITableViewDataSource, UITableViewDelegate, UISearchBarDelegate, UISearchDisplayDelegate>. I have set up the UISearchBar to display a scope bar.
I instantiate the view controller once and then show the same view on demand via [self presentModalViewController:mySearchController fromView:self.view];
Now, when I configure the view controller to be displayed as a form sheet, the scope bar appears only the first time the view is shown. The next time the scope bar is not displayed.
Displaying the view as a page sheet works fine. However in this case I observe that the first time the scope bar is already in place, while thereafter it is animated into the search bar as soon as it becomes the first responder.
I fiddled around with the view and controller settings in the inspector without any success.
What is causing this behavior?
How can I make the scope bar appear in the form sheet the next time I am showing the view?
Is there a way to prevent the UISearchBar from going into a different state when its view is hidden/redisplayed?
Set the scope bar titles in search delegate for begin editing and make it nil when the search ends. And add the showScopeBar method right after this method. Try and check if that helps.
For eg:-
- (BOOL)searchBarShouldBeginEditing:(UISearchBar *)searchBar {
[searchBar setScopeButtonTitles:[NSArray arrayWithObjects:#"Title1", #"Title2", nil]];
[searchBar setShowsScopeBar:YES];
//...
}
And in didEndEditing,
- (void)searchBarTextDidEndEditing:(UISearchBar *)searchBar {
[searchBar setScopeButtonTitles:nil];
[searchBar setShowsScopeBar:NO];
//..
}
In addition to this, whenever you want to display the scopebar you can use the above lines to show and hide it.
I have set up a demo application with a simple UITableViewController with no contents, but an 'Add' button in the toolbar. This launches a modal view controller which is again empty other than a 'cancel' button. The cancel button just tells its delegate (the UITableViewController) to dismiss the modal.
I then added an NSLog statement in the UITableViewController's numberOfSectionsInTableView method.
Ordinarily, when the table view controller loads I see two calls to numberOfSectionsInTableView. When I open and dismiss the modal (which returns to the UITableViewController) I see no further calls to numberOfSectionsInTableView.
However, if I return 0 from numberOfSectionsInTableView, in addition to the two calls on display, I also see an additional numberOfSections call when the modal is dismissed.
This only happens when numberOfSectionsInTableView returns 0, and I have added no additional code to my project besides that mentioned. This is easily verifiable by setting up a couple of controllers as I've described and modifying the result from numberOfSectionsInTableView.
My questions:
Why is the UITableView calling numberOfSectionsInTableView on return from a modal view?
Why is it only doing this if numberOfSectionsInTableView returns 0?
In addition to numberOfSectionsInTableView, the UITableViewController is also calling cellForRowAtIndex: when the modal is dismissed. In fact, it is attempting to display the new contents of its dataSource. How am I meant to manually animate a row insertion if the first row added is going to already be updated automatically? Shouldn't it be left to me to make sure that my UITableView is consistent with its dataSource?
What property is the UITableViewController checking to know that there is one or more sections (and therefore ask my delegate how many sections)? It can't be numberOfSectionsInTableView itself, since I would see it called whenever I return from the modal, not only when numberOfSections = 0.
From UITableViewController docs:
When the table view is about to appear the first time it’s loaded, the
table-view controller reloads the table view’s data... The
UITableViewController class implements this in the superclass method
viewWillAppear:
If you watch in the debugger, the second call upon app launch is from UITableViewController's viewWillAppear: implementation - specifically the part referred to above, where tableView is sent the reloadData message.
Now, the first call to numberOfSectionsInTableView: on launch is also from UITableViewController's implementation of viewWillAppear: but not directly from that implementation's call to -[UITableView reloadData]. I'm not sure what the first call is all about.
But, to your question, the call to numberOfSectionsInTableView: that happens when dismissing the modal has exactly the same call stack as the second call from applicationDidFinishLaunching:withOptions:. My hypothesis then is that UITableView interprets having zero sections as being in a state where it has not loaded at all. That does make some sense actually. I'd consider an "empty" table view to be one without any rows, but one without any sections seems almost "uninitialized" to me. Furthermore the UITableViewDataSource documentation implies UITableView has by default one section. Returning zero from this method would be inconsistent with that assumption of the docs as well.
Now, to your concern about animation - if you give the table an empty section to work with, you will be able to have full control over inserting the first row with whatever animation you'd like, and not be locked in to when you need to reload.
I think the moral of the story is, don't return zero sections unless you really, really need to for some reason. The title of your post refers to this table view being "empty" as well but I think it's clear the framework finds zero sections to not be empty but unloaded.
Hope this helps! And thanks for posting the sample project for me to play around with.
Perhaps the delegate just couldn't believe its eyes. But seriously, since a table view has to have at least one section, passing 0 doesn't make any sense. Why do it? You pass it an invalid argument and it gives you back a weird response. As to why it doesn't ask for number of sections when you pass 1, I think it's because it doesn't need to know at that point (coming back from the modal view controller) -- the table view has already been populated (if there were some data) and you haven't changed anything in the model, so it doesn't need to update.
I added a few lines to your example project to slide in a row each time you return from the modal view controller, which is what I think you're trying to do. I added an int property num for the return value of numberOfRowsInSection, added an array to populate the table, and a call to insertRowsAtIndexPaths from the modal view controller dismissal method.
- (void)viewDidLoad
{
_num = 0;
self.theData = #[#"one",#"two",#"three"];
[super viewDidLoad];
self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAdd
target:self
action:#selector(addRecipe)];
}
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
NSLog(#"# sections requested");
//when 0, this fires on return from the modal. When 1, it does not.
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
NSLog(#"in numberOfRows in section");
return _num;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
NSLog(#"in cellForRowAtIndexPath");
UITableViewCell *cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:nil];
cell.textLabel.text = [self.theData objectAtIndex:indexPath.row];
return cell;
}
- (void)addRecipe
{
//create the modal and suscribe for delegate notifications
AddRecipeViewController *addRecipeController = [[AddRecipeViewController alloc]initWithStyle:UITableViewStyleGrouped];
addRecipeController.delegate = self;
//display the modal in a navigation controller
UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:addRecipeController];
[self.navigationController presentModalViewController:navController animated:YES];
}
- (void)addRecipeVC:(AddRecipeViewController *)addRecipeVC didAddRecipe:(NSString *)recipe
{
[self dismissModalViewControllerAnimated:YES];
_num += 1;
[self performSelector:#selector(addRow) withObject:nil afterDelay:.5];
}
-(void)addRow {
[self.tableView insertRowsAtIndexPaths:#[[NSIndexPath indexPathForRow:_num-1 inSection:0]] withRowAnimation:UITableViewRowAnimationRight];
}
The tableview checks number of sections when it's populating the table view with data!
Since the table can be divided into sections, it has to know specifically how many sections to divide it into.
When you reload the data, the number of sections is also checked.
Because every time the table view has to take action in accessing either the data of the table, like what row you tapped, and in what section, or populating the data table, the number of sections has to be known!
Hope this helped!
So I am trying to add in to my current Xcode project a table view which, whenever you click on a cell, whichever one it is, a new subview is added to the window. I will use global variables and the didSelectRowAtIndexPath to pass data on.
As it stands, I have my table view drawn on screen with the correct data inside. What I want to happen is when I click, a new subview is added but i cannot seem to get this to work.
I have tried adding the "addSubview" inside the didSelectRowAtIndexPath method itself and this did not work and I have tried declaring a separate method that loads a subview called 'loadDetails' then calling it with [self loadDetails] when a cell is selected but it wants an id after the call and I don't know what to pass in.
I have elsewhere in my project used the line:
[rightButton addTarget:self
action:#selector(showDetails:)
forControlEvents:UIControlEventTouchUpInside];
But I can't see how to adapt this to the tableCell unless I could somehow add a new button over the cell? I really don't know.
If anybody has any other ideas of how to solve this problem, that would be great.
Thanks,
Matt
EDIT:
Problem is now solved, was a really stupid mistake, I forgot to link the view on the xib I was moving to, to the view created programmatically in my header file
try using presentModalViewController to show your view, and then dismiss it from the modalViewController:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
DetailView *detailView = [[DetailView alloc] initWithNibName:#"DetailView" bundle:nil];
[self presentModalViewController:detailView animated:YES];
}
I have not yet found any really good examples on how to do this. There is an image that I want to use as the accessory button and when I put it in and click on it doesn't work. So it looks correct but doesn't work...
Here is my code:
[cell setAccessoryType:UITableViewCellAccessoryDetailDisclosureButton];
cell.accessoryView = [[UIImageView alloc]
initWithImage:[UIImage imageNamed:#"TableView_Green_Disclosure.png"]];
So how do I get my UIImageView to call accessoryButtonTappedForRowWithIndexPath whenever it is tapped?
A thorough reading of accessoryView and accessoryType would reveal that they are mutually exclusive ways to customize a cell.
Setting the accessoryType will cause the table view delegate method to be called when it is tapped.
Setting the accessoryView will ignore the setting of accessoryType and give you something to display. If you want to receive a callback from the custom view you've put in place, it should be a control that is wired up to do so. (Or any view with a gesture recognizer.)
If you use a button, and set its action to accessoryTapped:, you will receive the button as the "sender" argument. You can walk up the view hierarchy until you find a table view cell, and then ask your table view what the indexPath of that cell is. This will then get you an index into your model objects and you be able to act on it appropriately.
Alternate to the button, you can enable interaction on the UIImageView above, and add a gesture recognizer to it.
To make the button actually do something, you'll need to implement - (void)tableView:(UITableView *)tableView accessoryButtonTappedForRowWithIndexPath:(NSIndexPath *)indexPath from UITableViewDelegate.
When an accessory button is tapped in a row, this method will be called and you'll have the chance to act appropriately using the passed in index path to determine which row's accessory was tapped.
Check the blog post hdr->cmdline for creating custom accessory view for UITableView.
The author used UIButton objects with images for custom accessory view.
To make use of the accessoryView - you would need to set the cell's accessoryType to UITableViewCellAccessoryNone deposit a UIButton (with associated image) into the cell and then wire it up to receive user touches. You might use something like the code below as the IBAction response to the cell's UIButton being touched:
- (IBAction) accessoryButtonPressed:(id) sender
{
NSUInteger pathInts[] = { 0,0 };
pathInts[1] = self.currentselectedrow; // ivar set when tableview row last selected
NSIndexPath* indexPath = [NSIndexPath indexPathWithIndexes:pathInts length:2];
[self tableView:mytableview accessoryButtonTappedForRowWithIndexPath:indexPath];
}
The UIButton would be wired to execute this glue code by way of a line inside your tableview's "cellForRowAtIndexPath:" function
[thecell setButtonTarget:self action:#selector(accessoryButtonPressed:)];
One thing I noticed is that the UIButton seems to want a 'swipe right' versus a simple 'tap' touch in order to trigger the event - but it could be my beta iOS that's the problem. Note that I had added a UIButton* object named 'cell_accessoryButton' to the Custom Cell source.
In the cell's source you'd support the 'setButtonTarget' call with code like this:
- (void) setButtonTarget:(MyViewController*)inTarget action:(SEL) inAction
{
[self.cell_accessoryButton addTarget: inTarget
action: (SEL) inAction
forControlEvents: UIControlEventTouchUpInside];
}
It's so much easier to just use the accessoryType reference and let iOS do the heavy lifting - but, if you want a custom graphic, etc - this is another path that works.
This one is probably something simple, still learning the ins-and-outs on this but I've run out of searches for this one with no available answer.
I've got a UIViewController with several elements displayed on it, one such element is a UITableView. The UITableView has it's own class and is allocated in the UIViewControllers viewWillAppear
- (void)viewWillAppear:(BOOL)animated
{
UITableView *insideTableView = [[UITableView alloc] init];
tableView.delegate = insideTableView;
tableView.dataSource = insideTableView;
}
Everything is working fine in regards to the tableview. Today I am experimenting with a few additions, one of which is a new view popup on cell selection within that tableview.
Inside my TableView Class, I have the following:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
NSLog(#"Cell Pressed, Present View");
PopupView *popupView = [[PopupView alloc] initWithNibName:#"PopupView" bundle:nil];
popupView.modalTransitionStyle = UIModalTransitionStyleCoverVertical;
[self presentModalViewController:popupView animated:YES];
}
Now it gets called fine, verified by the NSLog, however the view doesn't appear. I know the problem is related to the fact that I want PopUp to appear over the TableViews Parent rather than itself.
I'm just not sure how to properly call it in this instance.
The delegate is a UIViewController which doesn't have its view property set, which is why presentModalViewController:: doesn't work.
You need the view controller containing the table view to present the modal view controllers, but note that that view controller is not the parent of the table view delegate. This is because you have no view controller hierarchy in place.
The easiest way to fix this is to put those methods inside the view controller whose view contains the table view. Alternatively the table view delegate needs to hold a reference to the view controller so it can call presentModalViewController:: on it.
The latter approach can lead to retain cycle, so you have to use a non-retaining reference. The nicest implementation is the delegate pattern.
Also, you don't want to do the instantiation in viewWillAppear: because that can be called multiple times during the lifecycle of a view controller. Put the code in viewDidLoad and balance it in dealloc. Right now you are leaking memory every time your view appears, which when your modal view controller is working will be every time the modal view controller is presented and dismissed.