how to get selected text from uitextfield in iphone? - ios

Question

I am working on Text to speech application in iPhone,
in which have a text field that takes input, i want user to select some portion of text from text field and my application will convert that selected text into speech.
my problem is how would i get the text that user has selected from text field?

Answer 1

-[UITextField selectedText]
Although UITextField doesn't have a selectedText method, it conforms to the UITextInput protocol. So, you can use the required properties & methods of the UITextInput protocol to determine the selectedText of a UITextField *textField (or any object that conforms to the UITextInput protocol, such as a UITextView).
NSString *selectedText = [textField textInRange:textField.selectedTextRange];
NSLog(#"selectedText: %#", selectedText);
As an aside, you can also use the required properties & methods of the UITextInput to calculate the selectedRange of a UITextField *textField.
UITextRange *selectedTextRange = textField.selectedTextRange;
NSUInteger location = [textField offsetFromPosition:textField.beginningOfDocument
toPosition:selectedTextRange.start];
NSUInteger length = [textField offsetFromPosition:selectedTextRange.start
toPosition:selectedTextRange.end];
NSRange selectedRange = NSMakeRange(location, length);
NSLog(#"selectedRange: %#", NSStringFromRange(selectedRange));
-[UITextFieldDelegate textFieldDidChangeSelection:]
Although, UITextFieldDelegate doesn't declare a textFieldDidChangeSelection: delegate method like -[UITextViewDelegate textViewDidChangeSelection:], you can still hook into when the selection of a UITextField has changed. To do so, subclass UITextField and use method swizzling to add your own code to the textField.inputDelegate's native implementation of -[UITextInputDelegate selectionDidChange:].
// MyTextField.h
#import <UIKit/UIKit.h>
#interface MyTextField : UITextField
#end
// MyTextField.m
#import <objc/runtime.h>
#import "MyTextField.h"
UIKIT_STATIC_INLINE void mySelectionDidChange(id self, SEL _cmd, id<UITextInput> textInput);
#implementation MyTextField {
BOOL swizzled;
}
#pragma mark - UIResponder
// Swizzle here because self.inputDelegate is set after becomeFirstResponder gets called.
- (BOOL)becomeFirstResponder {
if ([super becomeFirstResponder]) {
[self swizzleSelectionDidChange:YES];
return YES;
} else {
return NO;
}
}
// Unswizzle here because self.inputDelegate may become the inputDelegate for another UITextField.
- (BOOL)resignFirstResponder {
if ([super resignFirstResponder]) {
[self swizzleSelectionDidChange:NO];
return YES;
} else {
return NO;
}
}
#pragma mark - Swizzle -[UITextInput selectionDidChange:]
// Swizzle selectionDidChange: to "do whatever you want" when the text field's selection has changed.
// Only call this method on the main (UI) thread because it may not be thread safe.
- (void)swizzleSelectionDidChange:(BOOL)swizzle {
if (swizzle == swizzled || ![self respondsToSelector:#selector(inputDelegate)]) return; // 4.3
Class inputDelegateClass = object_getClass(self.inputDelegate);
SEL mySelector = #selector(mySelectionDidChange:);
class_addMethod(inputDelegateClass, mySelector, (IMP)mySelectionDidChange, "v#:#");
Method myMethod = class_getInstanceMethod(inputDelegateClass, mySelector);
Method uiKitMethod = class_getInstanceMethod(inputDelegateClass, #selector(selectionDidChange:));
method_exchangeImplementations(uiKitMethod, myMethod);
swizzled = swizzle;
// NSLog(#"swizzled? %i", method_getImplementation(uiKitMethod) == (IMP)venmo_selectionDidChange);
}
#end
UIKIT_STATIC_INLINE void mySelectionDidChange(id self, SEL _cmd, id<UITextInput> textInput) {
// Call the native implementation of selectionDidChange:.
[self performSelector:#selector(mySelectionDidChange:) withObject:textInput];
// "Do whatever you want" with the selectedText below.
NSString *selectedText = [textInput textInRange:textInput.selectedTextRange];
NSLog(#"selectedText: %#", selectedText);
}

Answer 2

I did solve my query as follow :
I implement UITextView's delegate and implement following method
- (void)textViewDidChangeSelection:(UITextView *)textView {
NSRange r = textView.selectedRange;
NSLog(#"Start from : %d",r.location); //starting selection in text selection
NSLog(#"To : %d",r.length); // end position in text selection
NSLog([tv.text substringWithRange:NSMakeRange(r.location, r.length)]); //tv is my text view
}
That's it!

Answer 3

Swift
In Swift, getting the selected text from a UITextField is done like this:
if let textRange = myTextField.selectedTextRange {
let selectedText = myTextField.textInRange(textRange)
}
where textRange is a UITextRange that is used to get the actual selected text.

Answer 4

A similar topic is discussed here: Can I select a specific block of text in a UITextField?
AFAIK there is no event if text is selected. However, you could setup an NSTimer to watch your textfield and check the _selectedRange. If it changes, go fire up your text-to-speech code.
EDIT: I was wrong about the selection. UITextField cannot do what you want to achieve. But if you use UITextView instead, you can implement its UITextViewDelegate and override
- (void)textViewDidChangeSelection:(UITextView *)textView
In there, you can use the selectedRange poperty to get the selection. See this reference for details:
https://developer.apple.com/library/ios/documentation/UIKit/Reference/UITextView_Class/Reference/UITextView.html#//apple_ref/doc/uid/TP40006898-CH3-SW13

Answer 5

UITextField don't have delegate to get the selection range change. We can use KVO to observe selectedTextRange property of UITextfield.
[textField addObserver:self forKeyPath:#"selectedTextRange" options:NSKeyValueObservingOptionNew context:NULL];
Or create UITextField subclass and override setSelectedTextRange method.