I've been following a tutorial that manipulates a uitableview from a uiviewcontroller to generate nicely styled cells.
I was wondering is it possible to do same to a class that subclasses uitablewcontroller instead of uiviewcontroller. The user uses code like:
tableView.rowHeight = 50;
tableView.backgroundColor = [UIColor clearColor];
In the viewdidload method. I would like to do the same but again in a uitableview sub class. I tried to do
self.rowHeight = 50;
But this didn't work. Does anyone know how I can implement this?
Thanks a million!
This is the actual tutorial site: http://blog.atrexis.com/index.cfm/2009/1/6/iPhone--Customize-the-UITableCellView
The Cocoa design patterns encourage using a controller object to configure views, but there's no reason why you can't subclass like you're describing, especially if you need to add functionality that can't be done any other way. You can use properties and methods just how you're describing, so there's a problem somewhere else. What method are you subclassing to assign the row height? Have you checked in the debugger to make sure your subclass is being allocated instead of a regular table view?
A UITableViewController IS a subclass of UIViewController.
The only diffference is that it conforms to the UITableViewDelegateDataSource and UITableViewDelegate protocols and it has an additional instance variable: tablview.
In viewDidLoad, you can set any table properties you like except for style (style has to be set in the initializer or in IB)
- (void)viewDidLoad{
[[self tableView] setRowHeight:kCellHeight];
[[self tableView] setTableHeaderView:myView];
//etc...
}
Related
I have a subclass of UIViewController that I want to add from the storyboard.
So I'm using what seems the standard methodology:
SubViewController *svc = [self.storyboard instantiateViewControllerWithIdentifier:#"SubViewControllerID"];
[self addChildViewController:svc];
[self.view addSubview:svc.view];
Which is fine but what if I want to call a custom init method on the subview?
I can do something like:
svc = [svc initWithFoo:#"Hello"];
Which seems to have to go after the addSubview call inorder for it to work.
Is this the best way to do this?
Seems a bit unorthodox. Calling an init method on an object that has already been created seems like its no longer truly an init method.
Maybe I should call it setWithFoo: or something and not have it return anything?
SubViewController *svc = [self.storyboard instantiateViewControllerWithIdentifier:#"SubViewControllerID"];
will cause the SubViewController to be inited with it's - (id)initWithCoder:(NSCoder *)decoder {} method.
Override that method (don't forget to call super)
If you want to do additional setup to your view controller after you instantiate it form the storyboard you can create some methods in the view controller's class and call them after the instantiate method fo the storyboard.
But be careful, if you try to make changes on any UI component in those methods, they wont be applied, and probably the app will crash. So use those methods to set params to the View Controller like array of objects, or any kind of data, and apply the UI changes for the view controller's view in viewDidLoad/viewWillAppear/viewDidAppear methods of your view controller.
Essentially I think the answer is that you can't use custom initialisers on ViewControllers added from the storyboard. Instead you have to set properties directly or through a method at the appropriate time in the life cycle as stated above.
Also as mentioned, the VC will be instantiated through initWithCoder, so calling an additional initialiser might be superfluous(?).
I encountered problems trying to use a custom initialiser that contains a call to super if I called it before the subview was added. I would just get a blank view added, I think because the superclass doesn't seem to know about the storyboard at that point. I had more success removing the call to super but that seems wrong.
This case would be more pertinent when adding subviews to a scrollview. For simplicity I left this out of my example.
I want to add a tableview-look-a-like-login to my app, but it seems to be not that easy to implement. I tried to accomplish my goal using more then one approach, but i am not sure about which solution is the best.
For example, Dropbox and Facebook have a login page like this.
Here are my 3 approaches :
I added 2 UITextfields to my View (no border) and placed a . png behind, which looks like a tableviewcell. ( Not the best approach cause i want to use real tableviews )
I added a Container View to my ViewController placed a tableview with static Table Views inside. The Problem here is, that i dont know how to access the information inside my viewcontroller?
I added a tableview to my ViewController and used dynamic cells with it. Connected the outlets for delegate and datasource to my viewcontroller and initialized them with the delegate and datasource methods. The Problem here is, that i can not use static table views inside a uiviewcontroller.
Is there any better way of solving this problem ?
I would really like to know how to do this in a more elegant way.
EDIT:
A ContainerViewController basically solved this issue for me some month ago.
After embedding one into the main controller you can access it through the prepareForSegue function and define a protocol-based interface for that specific controller to interact with the embedded controller.
If you want to use static cells inside a regular UIViewController, just add the static cells and design them the way you like in interface builder, then connect the table cells as strong IB outlets (weak won't work, make sure they are strongly referenced). This will work flawlessly if you have a few table cells. Then set the view controller as the data source of the tablet view, implement -(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section to return the number of cells and implement -(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath to return your strongly referenced cell instance for the specified index path. I've used this method for a simple table view in my view controller that had four cells and it is working perfectly. For a large-dynamic data set, I definitely do not recommend this approach but for small, static tables, this does the job right.
I have an idea how to solve this. I think it's a clean way to do so. You do not need storyboard for this controller.
Make your controller subclass UITableViewController like so:
#interface YourViewController : UITableViewController
Then in your viewDidLoad you create the instances of the cells:
- (void) viewDidLoad {
usernameCell = [YourTextFieldCell new];
passwordCell = [YourTextFieldCell new];
}
The YourTextFieldCell is of course your own subclass of a UITableViewCell, which could be something like this:
#implementation YourTextFieldCell {
UITextField textField;
}
- (id) init {
self = [super init];
if (self) {
// Adjust the text's frame field to your liking
textField = [[UITextField alloc] initWithFrame:CGRectMake(0, 0, 200, 20)];
[self addSubview:textField];
}
}
// A getter method to access the textfield from the outside
- (UITextField *) textField {
return textField;
}
#end
Back in YourViewController:
- (NSInteger) tableView:(UITableView *) tv numberOfRowsInSection:(NSInteger) section {
return 2;
}
- (UITableViewCell *) tableView:(UITableView *) tv cellForRowAtIndexPath:(NSIndexPath *) indexPath {
if (indexPath.row == 0) {
return usernameCell;
} else if (indexPath.row == 1) {
return passwordCell;
}
return nil;
}
Do you get where I am going with this? This is how I think you should do it! Good luck!
I think your approach 2 is the best. If you need to access information in the table view controller, from your UIViewController (which will be the parent view controller), you can get a reference to that table view controller with self.childViewControllers.lastObject. In the viewDidLoad method of the UIViewController subclass, you could set yourself as the delegate of the table view with this line if you want:
[[(UITableViewController *)self.childViewControllers.lastObject tableView] setDelegate:self];
That way, you could implement the tableView:didSelectRowAtIndexPath: method in the view controller, which will get the information I'm guessing you need.
If you go with your option 2) using a storyboard and have a ContainerView containing your own subclass of UITableViewController with static cells then you can implement the prepareForSegue: method in your parent ViewController to take a reference to the UITableViewController (it'll be the destinationController of the segue) and also to pass itself down to the UITableViewController subclass if necessary (which should hold onto it with a weak reference).
Disclaimer - This answer will work for any size of UITableView, but if you're just making a login view, Tom's answer will work quite well.
I'm not sure if this will help, but what I did for this was create my own UITableView-esque subclass with a UITableViewCell-esque subclass as well.
This may not be what you want to hear, but I find what I made to be really helpful, since I've used it a number of times now. Basically, you have a UIView with the stylistic approach for the different types (10.0f - 20.0f cornerRadius and a 1px border (divide by UIScreen's scale property for retina). As for the cell, you'll want to have a full sized UIButton on it that responds to your table view for the touch events either with a delegate or by setting the target and tag inside your table view's class.
Last, you'll have a delegate system just like the UITableView for your information for building the specific tables.
In short, you'll need:
2 UIView subclasses (TableView and TableViewCell)
2 Delegates/Protocols (TableViewDataSource and TableViewDelegate)
Optionally
1 Delegate (TableViewCellResponseDelegate)
1 NSObject Subclass (Contains all of the information needed in each cell - Ease of use)
I found Can's solution to be the best / easiest, but unfortunately it breaks in XCode 5.1 --
I found a workaround which builds off the same basic idea, but unfortunately requires a little more involvement: http://www.codebestowed.com/ios-static-tableview-in-uiviewcontroller/
To summarize, you can add TableViewCells directly to views (and create IBOutlets from them, etc), but in order for them to get "moved" to the TableView properly, you need to remove them from the view in code, and you also need to set Auto-Layout constraints in IB.
I have a UITableView in view controller. I want to set up the view, properties etc for the table view without setting a UITableViewDelegate or UITableViewDataSource delegate.
Is it possible programmatically? (something like [tableView setNumberOfSections:2])
No it's not possible. But maybe it's an option for you to use a static tableview? There you don't need a delegate, but your number of rows / sections is fixed.
No, but you can set
myTableView.delegate = self;
myTableView.dataSource = self;
and then add the code for the methods in the same class (so you don't need to create new custom classes).
You can't, and why would you want to do that? The system of using delegates is there to give you the most flexible solution possible, you don't have to use all the delegate and datasource methods. It's just the way it works to make it possible to completely customise your table should you choose to, but a basic implementation is almost no work.
You can use any class as the delegate just by adopting the UITableViewDelegate and UITableViewDataSource protocols, so you don't need to create any specialised class. Just use your viewController for example.
So, I'm trying to change the UILabel on a UIButton to an instance of an FXLabel instead. Check out the link for more on FXLabel (https://github.com/nicklockwood/FXLabel). I know by using class extensions (Subclass UIButton to add a property), I could always add another property, in my case, an FXLabel by just adding a subview basically. However, I like the convenience and features of the titleLabel property already present.
Is there some method to "switch" the UILabel for an FXLabel by subclass or category?
I do know I could do this, but it's such a hack and isn't future proof. And I don't know how to then change the class type (Get UILabel out of UIButton).
UILabel *label;
for (NSObject *view in button.subviews) {
if ([view isKindOfClass:[UILabel class]]) {
label = (UILabel *)view;
break;
}
}
Thoughts?? Thanks.
Here's another way you could at least access the label. Create a subclass of UIButton, and in that subclass override layoutSubviews. From there you can access the label directly:
- (void)layoutSubviews {
[super layoutSubviews];
UILabel *titleLabel = [self titleLabel];
}
Now we're still stuck with the problem of changing that label to be a subclass. I guess you could try to dynamically swap the UILabel's class with your FXLabel subclass (as detailed here), but to be honest that's pretty risky.
I'd say you're better off just creating your own UIControl that you can customize to your hearts content. No risk, just pure goodness. It shouldn't be too hard to imitate a simple UIButton. Good luck!
Sorry to say it but I don't think you can do this in any reliable way. Even if you subclassed UIButton and overrode the titleLabel methods you'd also have to handle the state settings. And you never know when the internal code refers directly to a private ivar for the label.
I created a subclass of UIButton for my apps to do something similar (custom button layouts & subviews), sorry I can't share it right now, it's owned by a client. It's not too difficult to create your own state handling code for your own subviews.
So I just have a standard UIViewController with a UIWebView in it that displays a pdf. For the app functionality, I have need to be able to respond to the UIWebView's nested UIScrollView events like scrollViewWillBeginDragging, scrollViewDidScroll, etc.
The only way I can get access to the scrollView is to (it seems like a hack) go in and get it by the subviews array:
for (id subview in webView.subviews){
if ([[subview class] isSubclassOfClass: [UIScrollView class]]) {
UIScrollView * s = (UIScrollView*)subview;
s.delegate = self;
s.tag = 1;
scrollView = s;
}
}
But that seems to introduce more problems than it's worth, because I lose native UIScrollView stuff like zooming.
So to sum up what I'm needing:
What is the best way to set my UIViewController class as the delegate of the UIScrollView inside of the UIWebView? Is there something I need to do with subclassing my own UIWebView so that it handles events from it's built in UIWebView a certain way and then pass it along somehow to the UIViewController? How does that passing thing work anyway?
Please advise!
Thank you!
Have you checked there is only one UIScrollView subclass in the subviews? Bung in a log in your loop to see. If there is more than one, then you'll only pick up the last one using your code.
If there is just one UIScrollView subclass, you could try saving a reference to its delegate and then in your own delegate methods passing messages on after you have done your business.
So, in your loop, something like
originalDelegate = s.delegate
And then for the delegate methods, something like:
- (void) scrollViewDidScroll: (UIScrollView*) scrollView;
{
// do your stuff
[originalDelegate scrollViewDidScroll: scrollView];
}
You might need to check whether originalDelegate responds to the selector before calling it, i.e. if ([originalDelegate respondsToSelector: #selector(scrollViewDidScroll:)) etc. If it were me, I'd start by implementing all twelve delegate methods defined in the UIScrollView delegate protocol.
Not tested this, so will be interested to know if it can be made to work. Do note, the docs explicitly say that UIWebView "should not be subclassed"