[Text] No way to distinguish between a hit to the last character and a hit beyond the end of text

When hitting a Text node, there is no way to distinguish between a hit to the trailing edge of the last character and a hit beyond the end of text. Both return a HitInfo

    charIndex: n-1, isLeading: false

where n is the length of the text. The code to showcase the hit beyond the end of text is below.
For a hit beyond the end of text, I would suggest to return a HitInfo

    charIndex: n, isLeading: true

instead. This resolves to the same insertion index, but provides a way to tell apart the two cases.

Note that making this change also resolves RT-37801.

I realize that impl_* methods are not public API, but I'm using them in RichTextFX [1] anyway because there's no public API for this functionality. If you are planning/willing to expose more public API on Text/TextFlow, I will be happy to summarize what private API is currently used in RichTextFX.


import javafx.geometry.Point2D;
import javafx.scene.text.Text;

import com.sun.javafx.scene.text.HitInfo;

public class HitEndOfText {

    public static void main(String[] args) {
        Text text = new Text("foo");
        HitInfo hit = text.impl_hitTestChar(new Point2D(9999, 1));
        System.out.println(hit);
        // prints: charIndex: 2, isLeading: false
        // expected: charIndex: 3, isLeading: true
    }

}

[1] https://github.com/TomasMikula/RichTextFX