ExpandableTextView

ExpandableTextView is a UITextView subclass that is able to hide part of the text if it is too long. In this case, it will show a link (e.g., More). Once the link is touched, it will expand to show the entire content. The idea and most code is ported from ExpandableLabel. One benefit of UITextView is to detect links by setting dataDetectorTypes.

Installation

Carthage

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github "tianzhuqiao/ExpandableTextView"

Swift Package Manager

• xcode->file->Add Package Dependency
  1. url: https://github.com/tianzhuqiao/ExpandableTextView
  2. branch: main

Usage

1. import the package

import ExpandableTextView

2. Create an ExpandableTextView instance and customization

lazy var notesTextView : ExpandableTextView = {
        let v = ExpandableTextView()
        v.font = UIFont(name: "HelveticaNeue", size: 16)
        v.textColor = UIColor(red:0x22/255, green: 0x22/255, blue: 0x22/255, alpha: 1)
        v.backgroundColor = .clear
        v.moreText = "Read More"
        v.lessText = "Read Less"
        v.delegateExppanable = self
        v.numberOfLines = 3
        v.linkPosition = .automatic // the More/Less button position: .space, .newline or .automatic
        v.textAlignment = .left
        return v
    }()

3. Update the protocol

    func willExpandTextView(_ textView: ExpandableTextView) {
        // before expanding
    }
    
    func didExpandTextView(_ textView: ExpandableTextView) {
        // finished expanding, update the layout if needed as the textview height may have changed
        ...
    }
    
    func willCollapseTextView(_ textView: ExpandableTextView) {
        // before collapsing
    }
    func didCollapseTextView(_ textView: ExpandableTextView) {
        // finished collapsing, update the layout if needed as the textview height may have changed
        ...
    }

    func expandableTextViewUpdateHeight(_ textView: ExpandableTextView) {
        // the ExpandableTextView height has changed (i.e., by setting its text)
        ...
    }
  
    func expandableTextView(_ textView: ExpandableTextView, shouldInteractWith URL: URL, in characterRange: NSRange, interaction: UITextItemInteraction) -> Bool {
        // check whether the specified text view allows the user interaction with the URL in the range of text
        return true
    }

And expandableTextView is same as TextView; but the tap is ignored if it is not inside a link by following the way here.