I'm trying to implement the answer to this SO question. The problem is: -[drawTextInRect] is apparently not called, and setting the shadow in -[drawRect] doesn't make the UITextField's text shadowed.
Another weird thing is that even if my subclass implementations of -[drawTextInRect] and -[drawRect] are completely empty (not even a call to super), the textfield's text is drawn.
This is a bug in the UITextField API documentation. The documentation indicates that overriding drawTextInRect: can be used to customize behaviour. This is not the case.
In fact, drawTextInRect: will never be called on an UITextField (drawPlaceholderInRect: will be called neither by the way).
See also http://discussions.apple.com/thread.jspa?threadID=1727596.
Overriding the method on UILabel works though.
I guess the method you are looking for is:
- (CGRect)textRectForBounds:(CGRect)bounds
or possibly
- (CGRect)editingRectForBounds:(CGRect)bounds
I note that -[drawTextInRect] is called once when the UITextField loses focus. Not what I wanted.
UITextField does not respond to a - drawTextInRect: message. The code on the page you reference subclasses a UILabel not a UITextField, which is why it didn't work for you.
If you don't call super, the compiler might be removing the method during optimization of your code. Effectively meaning that UILabel's implementation is getting called.
Update:
If you are using a nib to create the textfield, be sure you have set the class of the textfield in the nib to your custom subclass, otherwise your custom code will not be called.
Related
Loading a custom input view into a UITextField, I can arbitrarily change the keyboard type of the standard keyboard between UIKeyboardTypeAlphabet and UIKeyboardTypeNumberPad. Just call something like:
[editingField setKeyboardType:UIKeyboardTypeNumberPad];
[editingField reloadInputViews];
And viola! There is your number pad.
Without changing this block of code, but just making editingField a UITextView instead of a UITextField, it no longer works. According to the docs, these are both compliant with the UITextInput and UITextInputTraits protocols.
It is worth mentioning that the above code actually does work, but only after the user leaves the textView in question and later reselects it. It is almost like reloadInputViews does nothing, and then the textView loads its input views when it becomeFirstResponder.
I have tried all sorts of performSelector: etc and cannot force the issue. Any ideas? How do you make UITextView obey reloadInputViews and dynamically change its inputView?
Are you setting inputView of UITextView to nil before calling?
[editingField setKeyboardType:UIKeyboardTypeNumberPad];
[editingField reloadInputViews];
In Objective-C, I have a category for a class:
#interface UILabel(CustomInit)
- (id)initWithCoder:(NSCoder *)coder;
#end
What I'm doing is writing a custom init function that does some extra stuff, and what I'd like to do, is in this custom init function, call the UILabel's base initWithCoder. Is this possible? How so?
EDIT
Thanks. Ok, so my plans moot. Can't just overload initWithCoder. Is there a way to achieve the same functionality (where all UILabels get this added initialization step) without overloading initWithCoder? Or perhaps is there sample code for the UILabel's initWithCoder that I can just rewrite with the added code?
EDIT
Ok, so to be clear about what I'm trying:
Can I embed a custom font in an iPhone application?
has an answer in which someone manually adds a custom font on the iphone using the private GraphicServices function GSFontAddFromFile. I tried this code and it worked great for manually setting the font of a label. However, if you try setting the font in Interface Builder, it doesn't load properly, it just drops down to the system font. What I wanted to do was load the font manually and set the label's font automatically with the chosen font in IB. This way I don't need to make an outlet for every label I put down. I also don't have to write a ridiculous label subclass (which was also suggested in that thread and does a large amount of custom drawing) which I found rather grotesque. Now I could still make a subclass for all my labels, but then there's the case of embedded labels in other UI objects, ie UIButtons. I'd like the embedded labels to also not be broken.
Any suggestions would be great. Thanks.
From the Mac OS X Reference Library:
When a category overrides an inherited
method, the method in the category
can, as usual, invoke the inherited
implementation via a message to super.
However, if a category overrides a
method that already existed in the
category's class, there is no way to
invoke the original implementation.
How do you guys feel about this?
Grab the original method address for initWithCoder at runtime and store it in a static variable. Do a method swizzle on it to replace the classes implementation with the my initWithCoder. And then in my initWithCoder, I would call the original method stored in the static variable.
You can put it in a category and call this class initialization step at the start of the program, making sure it can't be called twice, or if it is it does nothing.
It seems dangerous, but I feel like it should work.
Method swizzling should work as kidnamedlox suggested .
Your exact same question was discussed in this Stanford itunes class by Evan Doll
https://podcasts.apple.com/us/podcast/iphone-application-programming-spring-2009/id384233222
I have a UIViewController that is initialised with a correct frame, however somewhere in my code the frame gets mangled and I'm having difficulty finding out where.
In situations like this it is usually handy to watch a variable in the debugger, however I have no way of accessing the controller->view->frame property in my variable view, since it isn't a variable, it's a property (surprisingly enough)
Drilling into the UIView in the variables display shows a few things but nothing I can relate to the frame, I thought perhaps that would be in layer but it isn't.
Is there any way to watch for changes in a private API? I guess not, since the variables are essentially 'hidden' and so you can't specify exactly what to watch.
Alternatively, what other approach could I use? I already tried subclassing UIView, setting my UIViewController's view to point to this subclass and breaking on the setFrame method but it didn't seem to work.
EDIT: the subclassing UIView method DID work, I just had to set the view to point to my test subclass in viewDidLoad and not the init method. Leaving this question open as I'm not sure if this is the best way of approaching this kind of problem...
Subclass your the view you want to track and rewrite the setFrame method:
#implementation MyTableView
- (void)setFrame:(CGRect)frame;
{
NSLog(#"%#", frame);
[super setFrame:frame];
}
#end
Then use the debugger to add a breakpoint to it and check when it gets called. Eventually, you'll see when the frame gets changed and where does the change comes from.
I discovered this can be done using key value observers.
http://developer.apple.com/library/ios/#documentation/cocoa/conceptual/KeyValueObserving/KeyValueObserving.html
You could create an ivar, view2, and just assigned it to your view in your loadView method. That should enable you to watch it like a normal variable.
I am having quite a issue trying to change the cut/copy/paste behavior of the UITextView.
What I want to achieve is: detect when the user has pasted some text into the UITextView. When I detect this I will then check the data and do my thing.
According to the documents, I found out about UIResponder.
So I created an simple class that inherits UITextView.
in the .m file I create 1 function called.
-(void) paste:(id)sender{
NSLog(#"paste button was pressed do something");
}
But for some reason it never seems to fire. I could get the select statement working and tracing data.
-(void) select:(id)sender
1. Is this the correct way to detect Paste in a UITextView?
2. Right now I am tracking buy how many Characters UITextView changes and if its greater than one char then I suspect that it could be a paste operation. But since the iPhone can autocomplete words eg Wedn (goes to Wednesday) its possibly not a paste operation.
In Interface Builder, I selected my textView in my NIB file, and selected its "Class Identity" to my nearly created class before and I know that this file was working as a subclass but it just would not respond to the Paste event.
thanks.
UITextView has a view that handles the cut, copy, paste. It's UIWebDocumentView. So if UITextView is the first responder, UIWebDocumentView will get it first instead of your implementation. I would like to overwrite these functions so this is very frustrating.
Same thing happens to me too. Select (and copy sometimes) gets called but paste never.
I have simulated the behavior using textViewDidChange where I always verify the difference between the current text and the previous one. If there are more letters different and the text.length is bigger than it must have been pasted.
Hope Apple will fix this.
In case somebody still needs short and easy solution I'll share mine. I use wonderfull NSObject+REResponder category from REKit project. The solution is as easy as this:
- (void)hookMessageTextFieldPasteAction
{
void (^textFieldDidPasteBlock)(id receiver, id sender) = ^(id receiver, id sender)
{
NSLog(#"paste hook");
};
[self.messageTextField respondsToSelector:#selector(paste:) withKey:nil usingBlock:textFieldDidPasteBlock];
}
Yes your above code for paste is correct according to Apple's Documentation which refers to it here.
- (void)paste:(id)sender
I suspect you are implementing it in the wrong file. You should be implementing it in a file that is part of the 1st Responder chain. Have you subclassed the UITextView or are you using a vanilla one in your ViewController?
Hmmm I think the problem is that you may need to make your UITextView subclass become the delegate in order for the delegate method to work, because it's not by the looks of things. I'll try to find how i did that before.
Okay think i found it. I think you need to do this on your subclassed UITextField class:
#interface mySpecialTextFieldClass : NSObject <UITextFieldDelegate>
{
}
Adding that onto the end should work, give it a try!
What it does is makes your subclass become an object of a type that the delegate can send a notification to...it's polymorphism, unless someone wants to correct me here :)
One last thing to try John, in the ViewController which contains the IBOutlet to the UITextView, try calling this method on the instance of the UITextView:
[myUITextView setDelegate:self];
Just to throw something completely random in there try setting it to become first responder.
[myUITextView becomeFirstResponder];
This is called programming in the dark kiddies! And is a very bad way to program, but I admit I do it and sometimes it pays off :P lol.
I have a pretty simple UIViewController. It's initialized with a view I've created in Interaface Builder, which contains only a UIImageView. When the user touches the screen, I want the touchesBegan message of UIViewController to get called. So, I override it and added some logging, but nothing has happened.
I haven't done anything "special" at all, as since UIViewController inherits from UIResponder, I expect this to work right out of the box. From what I understand UIImageViews have user interaction disabled by default, so I have enabled it, both via InterfaceBuilder and in my UIViewcontroller's viewDidLoad method (I have tied the UIImageView to an IBOutlet). I also am ensuring that userInteraction is enabled in the parent view in Interface Builder.
Anything else that I am forgetting here?
OK, I'm a dummy. It works fine. The problem was, I didn't realize I was sending a release message to the UIViewController without having retained it elsewhere first. So that was causing the problem.
It is hard to say what your problem is, I don't know what you mean by overriding it?
Make sure you are connecting the touchesBegan event with an IBAction in Interface Builder?
You must create a IBAction function to handle the event, and explicitly connect the even to the IBAction. It is not as simple as simply overriding a method.
Although you have the View tied to an IBOutlet, you need to connect the event using an IBAction, or else you won't get any of those events.
Please ignore the first answer. It is, in fact, as easy as overriding the method in the custom view. The most common reason for not receiving touchesBegan is the canBecomeFirstResponder method not being implemented. This is not an IB hookup, these are the standard methods for touch handling.