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UITextView Subclass to avoid Long-Press Delays with embedded Links
//
// LinkedTextView.h
//
// Created by Benjamin Bojko on 10/22/14.
//
// The MIT License (MIT)
//
// Copyright (c) 2014 Benjamin Bojko
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//
//
#import <UIKit/UIKit.h>
/**
* This is a subclass of @p UITextView that solves the problem of embedded link requiring a long-press
* before triggering. It uses a tap gesture recognizer to detect the attributes at the tap location and
* checks for embedded links. If a link is detected, it calls @p -[UITextViewDelegate textView:shouldInteractWithTextAttachment:inRange:]
* before calling @p -[UIApplication openURL:].
*/
@interface LinkedTextView : UITextView
@property (nonatomic, strong, readonly) UITapGestureRecognizer *linkTapGestureRecognizer;
@end
//
// LinkedTextView.m
//
// Created by Benjamin Bojko on 10/22/14.
//
// The MIT License (MIT)
//
// Copyright (c) 2014 Benjamin Bojko
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//
//
#import "LinkedTextView.h"
@implementation LinkedTextView
- (instancetype)initWithFrame:(CGRect)frame textContainer:(NSTextContainer *)textContainer {
self = [super initWithFrame:frame textContainer:textContainer];
if (self) {
[self setupLinkedTextView];
}
return self;
}
- (id)initWithCoder:(NSCoder *)aDecoder {
self = [super initWithCoder:aDecoder];
if (self) {
[self setupLinkedTextView];
}
return self;
}
- (void)awakeFromNib {
[super awakeFromNib];
[self setupLinkedTextView];
}
- (void)setupLinkedTextView {
_linkTapGestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleLinkTapGestureRecognizer:)];
_linkTapGestureRecognizer.cancelsTouchesInView = NO;
_linkTapGestureRecognizer.delaysTouchesBegan = NO;
_linkTapGestureRecognizer.delaysTouchesEnded = NO;
[self addGestureRecognizer:_linkTapGestureRecognizer];
}
/**
* Since UITextViews only open links on long-press, we want to check
* if a user pressed a link in the text view right away. We can do this
* by getting the text attributes at the tap location and checking for
* a link in the attributed string.
*/
- (void)handleLinkTapGestureRecognizer:(UITapGestureRecognizer *)tapRecognizer {
UITextView *textView = self;
CGPoint tapLocation = [tapRecognizer locationInView:textView];
// we need to get two positions since attributed links only apply to ranges with a length > 0
UITextPosition *textPosition1 = [textView closestPositionToPoint:tapLocation];
UITextPosition *textPosition2 = [textView positionFromPosition:textPosition1 offset:1];
// check if we're beyond the max length and go back by one
if (!textPosition2) {
textPosition1 = [textView positionFromPosition:textPosition1 offset:-1];
textPosition2 = [textView positionFromPosition:textPosition1 offset:1];
}
// abort if we still don't have a string that's long enough
if (!textPosition2) {
return;
}
// get the offset range of the character we tapped on
UITextRange *range = [textView textRangeFromPosition:textPosition1 toPosition:textPosition2];
NSInteger startOffset = [textView offsetFromPosition:textView.beginningOfDocument toPosition:range.start];
NSInteger endOffset = [textView offsetFromPosition:textView.beginningOfDocument toPosition:range.end];
NSRange offsetRange = NSMakeRange(startOffset, endOffset - startOffset);
if (offsetRange.location == NSNotFound || offsetRange.length == 0) {
return;
}
if (NSMaxRange(offsetRange) > textView.attributedText.length) {
return;
}
// now grab the link from the string
NSAttributedString *attributedSubstring = [textView.attributedText attributedSubstringFromRange:offsetRange];
NSString *link = [attributedSubstring attribute:NSLinkAttributeName atIndex:0 effectiveRange:nil];
if (!link) {
return;
}
NSURL *URL = [NSURL URLWithString:link];
if (self.delegate && [self.delegate respondsToSelector:@selector(textView:shouldInteractWithURL:inRange:)]) {
// abort if the delegate doesn't allow us to open this URL
if (![self.delegate textView:self shouldInteractWithURL:URL inRange:offsetRange]) {
return;
}
}
[[UIApplication sharedApplication] openURL:URL];
}
@end
@xd54622

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@xd54622 xd54622 commented Oct 20, 2015

NSString *link = [attributedSubstring attribute:NSLinkAttributeName atIndex:0 effectiveRange:nil];
This is not a string, it's just a NSURL.

@fnazarios

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@fnazarios fnazarios commented Oct 24, 2015

handle method in swift ;)

    func tappedOnLink(tapGesture: UITapGestureRecognizer) {
        let textView: UITextView = tapGesture.view as! UITextView
        let tapLocation = tapGesture.locationInView(tapGesture.view)

        var textPosition1 = textView.closestPositionToPoint(tapLocation)
        var textPosition2:UITextPosition?
        if let _ = textPosition1 {
            textPosition2 = textView.positionFromPosition(textPosition1!, offset: 1)
            if let _ = textPosition2 {
                textPosition1 = textView.positionFromPosition(textPosition1!, offset: -1)
                textPosition2 = textView.positionFromPosition(textPosition1!, offset: 1)
            } else  {
                return
            }
        }

        let range = textView.textRangeFromPosition(textPosition1!, toPosition: textPosition2!)
        let startOffset = textView.offsetFromPosition(textView.beginningOfDocument, toPosition: range!.start)
        let endOffset = textView.offsetFromPosition(textView.beginningOfDocument, toPosition: range!.end)
        let offsetRange = NSMakeRange(startOffset, endOffset - startOffset)
        if offsetRange.location == NSNotFound || offsetRange.length == 0 {
            return
        }

        if NSMaxRange(offsetRange) > textView.attributedText.length {
            return
        }

        let attributedSubstring = textView.attributedText .attributedSubstringFromRange(offsetRange)
        let link = attributedSubstring.attribute(NSLinkAttributeName, atIndex: 0, effectiveRange: nil)

        if let _ = link {
            return
        }

        debugPrint(link)
    }
@dmcgloin

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@dmcgloin dmcgloin commented May 17, 2016

@fnazarios Thanks for this. Unfortunately, it looks like the Swift code will very occasionally crash because textPosition1 is nil.

Looking into fix - but first need to understand the code a bit better.

I had to tap the link about 10 to 20 times to get the exact right condition for the crash.

Using Xcode version 7.3.1 (7D1014)

@deya-eldeen

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@deya-eldeen deya-eldeen commented Jun 30, 2016

@fnazarios : how to use this?

@arixegal

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@arixegal arixegal commented Dec 6, 2017

xd54622 is correct.
This is the needed modification beginning line 102:

// now grab the link from the string
NSAttributedString *attributedSubstring = [textView.attributedText attributedSubstringFromRange:offsetRange];
NSURL *link = [attributedSubstring attribute:NSLinkAttributeName atIndex:0 effectiveRange:nil];

if (!link) {
	return;
}

if (self.delegate && [self.delegate respondsToSelector:@selector(textView:shouldInteractWithURL:inRange:)]) {
	// abort if the delegate doesn't allow us to open this URL
	if (![self.delegate textView:self shouldInteractWithURL:link inRange:offsetRange]) {
		return;
	}
}

[[UIApplication sharedApplication] openURL:link];
@grigorye

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@grigorye grigorye commented Dec 27, 2017

Thanks! I tried it and it worked well except for the case when the link is at the beginning of a line and tap is at the empty space at the end of the previous line - in such a case the link is triggered while it should not. After investigation it looks like it's due to closestPositionToPoint that in such a case returns the position at the end of the previous line, and the fact that attribute is retrieved from the range next to such a position - in this case it's the beginning of the line containing the link.

The text is flowed like below:

bla-bla-bla <tap here>
[link]

I tried switching from range calculated from closestPosition (and next position) to range obtained from textView.characterRange(at: location) and so far it worked like expected for me, in all the cases.

@vatsal1992

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@vatsal1992 vatsal1992 commented Jun 9, 2018

i've another solution for "Disabled Selection in UITextView and still you want Link selection"
i will show you what i tried,
checkout this StackOverflow answer

@OscarApeland

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@OscarApeland OscarApeland commented Nov 6, 2018

I posted a Swift 4 solution over here for anyone else looking at this in 2018:) https://stackoverflow.com/a/53171516/1278026

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