I was able to put together a utility script for detecting hyperlinks in UI.Text, all thanks to @Stephan_B who pointed me in the right direction. Thanks, Stephan!
I am laying it out here for people looking to do this with UI.Text.
using System.Text.RegularExpressions;
using UnityEngine;
using UnityEngine.UI;
public class UITextUtilities : MonoBehaviour
{
/// <summary>
/// Given an input string returns if it is a URL
/// </summary>
/// <param name="str">Input string.</param>
/// <returns>Whether or not input string is a URL.</returns>
public static bool hasLinkText(string str)
{
string strWOHTMLTags = RemoveHtmlLikeTags(str);
string URL_WO_HTTP_PATTERN = @"(^|[\n ])(?<url>(www|ftp)\.[^ ,""\s<]*)";
string URL_WITH_HTTP_PATTERN = @"(^|[\n ])(?<url>(http://www\.|http://|https://)[^ ,""\s<]*)";
Regex urlregex = new Regex(URL_WO_HTTP_PATTERN, RegexOptions.IgnoreCase);
Regex httpurlregex = new Regex(URL_WITH_HTTP_PATTERN, RegexOptions.IgnoreCase);
return urlregex.IsMatch(strWOHTMLTags) || httpurlregex.IsMatch(strWOHTMLTags);
}
/// <summary>
/// Given an input string returns a string without any HTML like tags
/// </summary>
/// <param name="str">Input string.</param>
/// <returns>String without any HTML like tags.</returns>
public static string RemoveHtmlLikeTags(string str)
{
string HTML_LIKE_TAGS_PATTERN = @"<[^>]+>| ";
return Regex.Replace(str, HTML_LIKE_TAGS_PATTERN, "").Trim();
}
/// <summary>
/// Given an input Text component, clicked position in local space and UI camera returns the word in the value of the Text component that was got clicked
/// </summary>
/// <param name="textComp">Text component.</param>
/// <param name="position">Click position.</param>
/// <param name="camera">UI camera.</param>
/// <returns>Word in the value of the Text component that was clicked.</returns>
public static string FindIntersectingWord(Text textComp, Vector3 position, Camera camera)
{
Vector2 localPosition;
RectTransformUtility.ScreenPointToLocalPointInRectangle(textComp.GetComponent<RectTransform>(),
position, camera, out localPosition);
int characterIndex = GetCharacterIndexFromPosition(textComp, localPosition);
if (!string.IsNullOrWhiteSpace(GetCharFromIndex(textComp, characterIndex)))
{
return GetWordFromCharIndex(textComp.text, characterIndex);
}
return "";
}
private static string GetCharFromIndex(Text textComp, int index)
{
var tempArr = textComp.text.ToCharArray();
if (index != -1 && index < tempArr.Length)
{
return tempArr[index] + "";
}
return "";
}
private static int GetCharacterIndexFromPosition(Text textComp, Vector2 pos)
{
TextGenerator gen = textComp.cachedTextGenerator;
if (gen.lineCount == 0)
return 0;
int line = GetUnclampedCharacterLineFromPosition(textComp, pos, gen);
if (line < 0)
return 0;
if (line >= gen.lineCount)
return gen.characterCountVisible;
int startCharIndex = gen.lines[line].startCharIdx;
int endCharIndex = GetLineEndPosition(gen, line);
for (int i = startCharIndex; i < endCharIndex; i++)
{
if (i >= gen.characterCountVisible)
break;
UICharInfo charInfo = gen.characters[i];
Vector2 charPos = charInfo.cursorPos / textComp.pixelsPerUnit;
float distToCharStart = pos.x - charPos.x;
float distToCharEnd = charPos.x + (charInfo.charWidth / textComp.pixelsPerUnit) - pos.x;
if (distToCharStart < distToCharEnd)
return i;
}
return endCharIndex;
}
private static int GetUnclampedCharacterLineFromPosition(Text textComp, Vector2 pos, TextGenerator generator)
{
// transform y to local scale
float y = pos.y * textComp.pixelsPerUnit;
float lastBottomY = 0.0f;
for (int i = 0; i < generator.lineCount; ++i)
{
float topY = generator.lines[i].topY;
float bottomY = topY - generator.lines[i].height;
// pos is somewhere in the leading above this line
if (y > topY)
{
// determine which line we're closer to
float leading = topY - lastBottomY;
if (y > topY - 0.5f * leading)
return i - 1;
else
return i;
}
if (y > bottomY)
return i;
lastBottomY = bottomY;
}
// Position is after last line.
return generator.lineCount;
}
private static int GetLineStartPosition(TextGenerator gen, int line)
{
line = Mathf.Clamp(line, 0, gen.lines.Count - 1);
return gen.lines[line].startCharIdx;
}
private static int GetLineEndPosition(TextGenerator gen, int line)
{
line = Mathf.Max(line, 0);
if (line + 1 < gen.lines.Count)
return gen.lines[line + 1].startCharIdx - 1;
return gen.characterCountVisible;
}
private static string GetWordFromCharIndex(string str, int characterIndex)
{
string firstPartOfStr = str.Substring(0, characterIndex);
string secondPartOfStr = str.Substring(characterIndex);
string firstPart = firstPartOfStr;
//Check for last index of space in first part of str and get text till that
int lastIndexOfSpace = firstPartOfStr.LastIndexOf(' ');
if (lastIndexOfSpace != -1)
{
firstPart = firstPartOfStr.Substring(lastIndexOfSpace);
}
string secondPart = secondPartOfStr;
//Check for first index of space in second part of str and get text till that
int firstIndexOfSpace = secondPartOfStr.IndexOf(' ');
if (firstIndexOfSpace != -1)
{
secondPart = secondPartOfStr.Substring(0, firstIndexOfSpace);
}
//Check for new lines in first and second parts of the word and trim it
int IndexOfNewLineInFirstPart = firstPart.IndexOf('\n');
if (IndexOfNewLineInFirstPart != -1)
{
firstPart = firstPart.Substring(firstPart.IndexOf('\n'));
}
int IndexOfNewLineInSecondPart = secondPart.IndexOf('\n');
if (IndexOfNewLineInSecondPart != -1)
{
secondPart = secondPart.Substring(0, secondPart.IndexOf('\n'));
}
return firstPart.Replace("\n", "").Replace("\r", "") + secondPart.Replace("\n", "").Replace("\r", "");
}
}
Put this utility script in your project and then add an EventTrigger on the Text component where you want to detect the click event on a hyperlink inside the text value. Then in OnPointerClick, you can have something like this:
public void OnPointerClick(PointerEventData eventData)
{
string clickedWord = UITextUtilities.FindIntersectingWord(textComp, eventData.position, UICamera);
if (!string.IsNullOrEmpty(clickedWord) && UITextUtilities.hasLinkText(clickedWord))
{
string actualUrl = UITextUtilities.RemoveHtmlLikeTags(clickedWord);
Debug.Log("Opening link: " + actualUrl);
Application.OpenURL(actualUrl);
}
}
*Please Note:
The UICamera mentioned above is an Orthographic Camera rendering the corresponding UI Canvas of the Text component. I have not tested it for other scenarios. Feel free to modify it as per your needs!
