How to use keyboard in OpenGL es app - ios

Question

I have an OpenGL ES app which uses keyboard. I can make the keyboard pop-up on screen when screen is touched. If I am correct, each time I press a key,
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
should be called. But it doesn't. The app was initially a pure OpenGL Mac game, which I am trying to make an iOS version of, so I am not using storyboard. I prefer to do everything programmatically if possible. Here is my code for ViewController.h:
#import <GLKit/GLKit.h>
#import "KeyboardView.h"
#interface ViewController : GLKViewController {
KeyboardView* keyBoard;
}
#end
relevant parts of ViewController.m:
- (void)viewDidLoad
{
[super viewDidLoad];
self.context = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES2];
if (!self.context) {
NSLog(#"Failed to create ES context");
}
GLKView *view = (GLKView *)self.view;
view.context = self.context;
view.drawableDepthFormat = GLKViewDrawableDepthFormat24;
CGRect viewRect = CGRectMake(0, 0, 100, 100);
keyBoard = [[KeyboardView alloc] initWithFrame:viewRect];
[self setupGL];
}
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
[self.view addSubview:keyBoard];
[keyBoard becomeFirstResponder];
}
KeyboardView.h:
#import <UIKit/UIKit.h>
#interface KeyboardView : UIView <UIKeyInput, UITextFieldDelegate> {
UITextField *field;
}
KeyboardView.m:
#import "KeyboardView.h"
#implementation KeyboardView
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
field = [[UITextField alloc] initWithFrame:CGRectMake(0, 0, 100, 10)];
}
return self;
}
- (void)insertText:(NSString *)text {
}
- (void)deleteBackward {
}
- (BOOL)hasText {
return YES;
}
- (BOOL)canBecomeFirstResponder {
return YES;
}
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string {
NSLog(#"text: %#", textField.text);
NSString *newString = [textField.text stringByReplacingCharactersInRange:range withString:string];
if ([newString length] < 1) {
return YES;
} else
{
textField.text = [newString length] > 1 ? [newString substringToIndex:1] : newString;
[textField resignFirstResponder];
return NO;
}
}
#end
I need to be able to get each character entered by user while keyboard is active. I most confess, I am a little bit confused. I am not sure if my approach is correct, so I really appreciate your help.

Answer 1

The keyboard text input isn't captured through the UITextField's
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
It is indeed captured through UIKeyInput's
- (void)insertText:(NSString *)text;
I am using the soft keyboard to capture text on my GLKView (OpenGLES) app, and I don't even need any UITextField at all
For reference:
UIKeyInput Reference Doc
EDIT:
You need to call your keyboardview's becomeFirstResponder to show your keyboard and call resignFirstResponder to hide it
You also need to override canBecomeFirstResponder and return TRUE