Okay, I made an app that has a list of items as a main view, and when you select an item it pushes a detail view controller. In this detail view controller you can switch between items. I want to be able to push a view, scroll a few items, and pop the view as if the current item was initially selected. I want to push a view, and then when i pop it, i want it to look like a different view was initially pushed.
Any ideas on how to do this?
Take a look at UITableView's selectRowAtIndexPath:animated:scrollPosition: method. You can call it from within your view controller's viewDidAppear method to achieve the illustrated effect, I believe.
Consider that this is probably not what you really want to do. Leaving a table cell highlighted after a return from a detail view has been condemned by Apple and will be jarring to users unless you have a really good reason for it.
So far, to achieve this effect, I have used this to mask the original UITableViewCell from highlighting.
I have added this in the -(void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated method
[self.tableView selectRowAtIndexPath:selectedRow animated:NO scrollPosition:UITableViewScrollPositionNone];
[self.tableView deselectRowAtIndexPath:selectedRow animated:NO];
Where selectedRow is the Index Path of the original cell selected. I have also added the code below to scoll to and highlight the correct UITableViewCell.
[self.tableView scrollToRowAtIndexPath:tempPath atScrollPosition:UITableViewScrollPositionMiddle animated:NO];
[self.tableView selectRowAtIndexPath:tempPath animated:NO scrollPosition:UITableViewScrollPositionMiddle];
[self.tableView deselectRowAtIndexPath:tempPath animated:YES];
Related
on the main screen on my project I have a a TableView, with a navigationBar on top and toolBar on the bottom. The thing is, one of the buttons in the toolbar needs to slide up an UISegmentedControl from the toolbar. I have already implemented this control in a custom UIView, BUT, if i just add it to my rootviewcontroller.view and slide it into place, it will scroll with the rest of the table, which is undesired (I would like it to appear as an extension of the toolbar).
So, what do I do? In rootViewController I do
self.filterView = [[FilterView alloc] initWithTarget:self.tableView reloadDataSelector:#selector(reloadData)];
[[self.view superview] addSubview:self.filterView];
[[self.view superview] bringSubviewToFront:self.filterView];
I add the control view (self.filterView) to my view's superview, and that puts it above the tableview's scroll.
BUT, now the problem. As soon as the tableView goes out of view (I push another view on the navigationController, or specially if the app goes to background) this view gets re layed-out, and my controller view gets moved to (0,0).
The thing is, as far as pushing new views on the navigationController, I can kind of control it by repositioning it in viewWillAppear and viewWillDisappear in my rootViewController. But when the app goes to background and comes back those functions don't get called.
So, is there any way to
(a)prevent my controller view from being moved
(b)detecting when it has been moved unintentionally
(c)detecting coming and going from background from rootViewController
???
I know I can detect passes to background in appDelegate, but I wouldn't feel comfortable dealing with layout issues there.
Thanks!!
EDIT:
To add some info, if I do
NSLog(#"%#",[self.view superview]);
//I get <UIViewControllerWrapperView: 0x61589d0; frame = (0 64; 320 372); autoresize = W+H; layer = <CALayer: 0x615d9c0>>
EDIT2: I guess I could create my own wrapper UIView first, load all my current view hierarchy in it, and put the controller view there. Do you guys think that would be worth the trouble? isn't there a simpler way?
EDIT3: Ended up opting for changing my rootViewController from UITableViewController to UIViewController, and added the tableView programatically, as Phil suggested below. I can now control my main view as I like, and since I am putting my segmentedControl view there I can control how it is positioned, as opposed to before, when I was placing it in an UIViewControllerWrapperView, which I am not too sure who controls or what it does to it's subviews.
SO, just out of curiosity, does anyone know why the UIViewControllerWrapperView that was wrapping my UITableViewController's view was moving my UIView on coming back from background??
To clarify, the setup was like so:
UIViewControllerWrapperView
|
|UITableView
|Custom SegmentedControl UIView
As a side note, you have a pattern in your code that looks like that view is going to leak and addSubview will automatically put the view on the top of the view order.
However, the reason your view is scrolling is because it is being added as a subview of the UITableView, which is a subclass of UIScrollView. When the scroll view scrolls, it will move any subviews up or down by the contentOffset property. As the UIScrollView scrolls it will repeatedly layout its subviews. Since the table view isn't aware of your custom subview, it appears it is just moving it to the 0,0.
I assume you are using UITableViewController. If you plan to have more than just a table view for this view controller, then you should implement a standard view controller instead. This controller would have a normal view that contains the tableview and your other views. UITableViewController is merely for convenience for a very common case.
It's very easy to duplicate UITableViewController's functionality if you are worried about that. It is actually very clearly documented.
When the table view is about to appear
the first time it’s loaded, the
table-view controller reloads the
table view’s data. It also clears its
selection (with or without animation,
depending on the request) every time
the table view is displayed. The
UITableViewController class implements
this in the superclass method
viewWillAppear:. You can disable this
behavior by changing the value in the
clearsSelectionOnViewWillAppear
property.
In your implementation:
- (void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
if ([self.tableView numberOfSections] == 0) {
[self.tableView reloadData];
} else {
[self.tableView deselectRowAtIndexPath:[self.tableView indexPathForSelectedRow] animated:animated];
}
}
When the table view has appeared, the
controller flashes the table view’s
scroll indicators. The
UITableViewController class implements
this in the superclass method
viewDidAppear:.
In your implementation:
- (void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
[self.tableView flashScrollIndicators];
}
It implements the superclass method
setEditing:animated: so that if a user
taps an Edit|Done button in the
navigation bar, the controller toggles
the edit mode of the table.
In your implementation:
- (void)setEditing:(BOOL)editing animated:(BOOL)animated {
[super setEditing:editing animated:animated];
[self.tableView setEditing:editing animated:animated];
}
I have an app I am working on, that has a table view with a few cells, and when you hit a cell, the nav controller pushes a new view. Pretty simple stuff. The problem is that when I hit on a row, the whole row highlights blue, and then remains blue all while the view is being presented by the controller, and then if I hit back to go back to the table view, the row is just still completely highlighted Even though I'm not pressing it or anything.
I have made a few apps with the table view before, and have never seen this behavior before, so I am at a loss as to what is going on. Is there some setting that I have set wrong somewhere?
Thanks
You need to deselect cell manually (probably in tableView:didSelectRowAtIndexPath: method):
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{
[tableView deselectRowAtIndexPath:indexPath animated:YES];
// Your code
...
}
If your view controller is a subclass of UITableViewController, it will automatically deselect the row after you hit the back button. If you don't subclass UITableViewController, you need to call deselectRowAtIndexPath:animated: when you want it deselected.
I have a cell with a few lines of text which changes colour when selected/highlighted. The problem is that as the new viewController is being pushed, the deselection animation occurs which is visually distracting as the text suddenly reverts to the unselected state. I have moved the deselectRowAtIndexPath statement after the line where the new view controller is pushed, but this has no effect.
How can I prevent the user seeing the cell deselection (without implementing a timer)? Any help would be appreciated please.
If you're using a UITableViewController, you won't need to call deselectRowAtIndexPath:. This will be done for you automatically when your table view becomes visible again.
If you're not using a UITableViewController because you have a more complicated interface, you would need to call deselectRowAtIndexPath: manually from the viewWillAppear:animated: method.
I think the general paradigm used with table views and pushing new VCs is that you deselect the table row in your viewWillAppear:animated method. Then as the VC is popped, they see which row had been used to navigate to that VC.
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
[self.myTableView deselectRowAtIndexPath:[myTableView indexPathForSelectedRow] animated:YES];
}
so remove deselectRow from your didSelectRowAtIndexPath method.
I have a UITableView on a view. This UITableView has cells which are made up of a checkbox custom control, a label and a disclosure accessory. When I select a row in the tableview it selects correctly (blue highlight shows 100% correctly).
I then created a didSelectRowAtIndexPath delegate to push a detail view controller onto the navigation stack using the following code:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
MyDetailsViewController *detailsViewController = [[MyDetailsViewController alloc] initWithNibName:#"MyDetailsView" bundle:nil];
[[self navigationController] pushViewController:detailsViewController animated:YES];
[detailsViewController release];
}
This works - in so far as that it pushes the view controller onto the navigation stack and presents the view. The problem I'm having is that the animation is really "flickery" and the row that was selected doesn't even get highlighted before the animation starts.
I've done this before (but never with custom cells) and I know that the procedure should be as follows: row highlights, detail view animates in, (edit details), detail view animates out, row gets deselected.
I'm not sure why my row automatically gets deselected (or de-highlighted) when I select it and why the animation is flickery.
Has anyone had this before?
Ugh, I so hate it when I find the answer to my own question about a minute after posting it. The problem was that I was doing all kinds of things in viewWillDisappear that was modifying my table data. ****grin****
When a button is pushed in one of my app's table view cells, I need to push a certain view controller onto the navigation stack.
This could be done by using an instance of NSNotification to inform the table view's controller of the button press. But that would be awfully heavyweight, especially since selections in a tab bar in the app could cause the table view to appear or disappear, creating additional overhead as the various table views register and unregister themselves whenever they are tabbed onto or off of the screen.
Can anyone think of a better solution?
Why not put
[[self navigationController] pushViewController:targetViewController animated:YES];
in the method called by the button?
Make your UITableViewController use the UITableViewDelegate Protocol and implement this method:
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
From the indexPath you can get which row has been pressed and then you know which cell is being selected. The purpose of the UITableViewController is to know about the cells and the cell itself does not need a button to trigger an event to push a new view.
What I did was set the table view's delegate to be the same as its controller. Then:
UITableView *myTableView = (UITableView *)self.superview;
NSIndexPath *indexPath = [myTableView indexPathForCell: self];
MyTableViewController *myTableViewController = (MyTableViewController *)(myTableView.delegate);
[myTableViewController buttonWasPressedOnCellWithIndexPath: indexPath];