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improved text field multi line handling

This commit is contained in:
Ell 2021-10-12 18:28:06 +02:00
parent 9aef994c51
commit a47318c0a2

View file

@ -1,5 +1,6 @@
using System;
using System.IO;
using System.Linq;
using System.Text;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
@ -146,6 +147,16 @@ namespace MLEM.Ui.Elements {
}
}
/// <summary>
/// The line of text that the caret is currently on.
/// This can only be only non-0 if <see cref="Multiline"/> is true.
/// </summary>
public int CaretLine { get; private set; }
/// <summary>
/// The position in the current <see cref="CaretLine"/> that the caret is currently on.
/// If <see cref="Multiline"/> is false, this value is always equal to <see cref="CaretPos"/>.
/// </summary>
public int CaretPosInLine { get; private set; }
/// <summary>
/// A character that should be displayed instead of this text field's <see cref="Text"/> content.
/// The amount of masking characters displayed will be equal to the <see cref="Text"/>'s length.
/// This behavior is useful for password fields or similar.
@ -167,6 +178,9 @@ namespace MLEM.Ui.Elements {
/// If this is true, pressing <see cref="Keys.Enter"/> will insert a new line into the <see cref="Text"/> if the <see cref="InputRule"/> allows it.
/// Additionally, text will be rendered with horizontal soft wraps, and lines that are outside of the text field's bounds will be hidden.
/// </summary>
/// <remarks>
/// Moving up and down through the text field, and clicking on text to start editing at the mouse's position, are currently not supported.
/// </remarks>
public bool Multiline {
get => this.multiline;
set {
@ -180,9 +194,11 @@ namespace MLEM.Ui.Elements {
private char? maskingCharacter;
private double caretBlinkTimer;
private string displayedText;
private string[] splitText;
private int textOffset;
private int lineOffset;
private int caretPos;
private float caretDrawOffset;
private bool multiline;
/// <summary>
@ -239,38 +255,26 @@ namespace MLEM.Ui.Elements {
var maxWidth = this.DisplayArea.Width / this.Scale - this.TextOffsetX * 2;
if (this.Multiline) {
// soft wrap if we're multiline
this.displayedText = this.Font.Value.SplitString(this.text.ToString(), maxWidth, this.TextScale);
this.splitText = this.Font.Value.SplitStringSeparate(this.text.ToString(), maxWidth, this.TextScale).ToArray();
this.displayedText = string.Join("\n", this.splitText);
this.UpdateCaretData();
var maxHeight = this.DisplayArea.Height / this.Scale - this.TextOffsetX * 2;
if (this.Font.Value.MeasureString(this.displayedText).Y * this.TextScale > maxHeight) {
var maxLines = (maxHeight / (this.Font.Value.LineHeight * this.TextScale)).Floor();
// calculate what line the caret is on
var caretLine = 0;
var originalIndex = 0;
var addedLineBreaks = 0;
for (var i = 0; i <= this.CaretPos + addedLineBreaks - 1 && i < this.displayedText.Length; i++) {
if (this.displayedText[i] == '\n') {
caretLine++;
if (this.text[originalIndex] != '\n') {
addedLineBreaks++;
continue;
}
}
originalIndex++;
}
// when we're multiline, the text offset is measured in lines
if (this.lineOffset > caretLine) {
if (this.lineOffset > this.CaretLine) {
// if we're moving up
this.lineOffset = caretLine;
} else if (caretLine >= maxLines) {
this.lineOffset = this.CaretLine;
} else if (this.CaretLine >= maxLines) {
// if we're moving down
var limit = caretLine - (maxLines - 1);
var limit = this.CaretLine - (maxLines - 1);
if (limit > this.lineOffset)
this.lineOffset = limit;
}
// calculate resulting string
var ret = new StringBuilder();
var lines = 0;
originalIndex = 0;
var originalIndex = 0;
for (var i = 0; i < this.displayedText.Length; i++) {
if (lines >= this.lineOffset) {
if (ret.Length <= 0)
@ -311,6 +315,7 @@ namespace MLEM.Ui.Elements {
this.displayedText = this.Text;
this.textOffset = 0;
}
this.UpdateCaretData();
}
if (this.MaskingCharacter != null)
@ -320,6 +325,39 @@ namespace MLEM.Ui.Elements {
this.OnTextChange?.Invoke(this, this.Text);
}
private void UpdateCaretData() {
if (this.splitText != null) {
var line = 0;
var index = 0;
for (var d = 0; d < this.splitText.Length; d++) {
var startOfLine = 0;
var split = this.splitText[d];
for (var i = 0; i <= split.Length; i++) {
if (index == this.CaretPos) {
this.CaretLine = line;
this.CaretPosInLine = i - startOfLine;
this.caretDrawOffset = this.Font.Value.MeasureString(split.Substring(startOfLine, this.CaretPosInLine)).X;
return;
}
if (i < split.Length) {
// manual splits
if (split[i] == '\n') {
startOfLine = i + 1;
line++;
}
index++;
}
}
// max width splits
line++;
}
} else if (this.displayedText != null) {
this.CaretLine = 0;
this.CaretPosInLine = this.CaretPos;
this.caretDrawOffset = this.Font.Value.MeasureString(this.displayedText.Substring(0, this.CaretPos - this.textOffset)).X;
}
}
/// <inheritdoc />
public override void Update(GameTime time) {
base.Update(time);
@ -376,28 +414,9 @@ namespace MLEM.Ui.Elements {
this.Font.Value.DrawString(batch, this.displayedText, textPos, textColor * alpha, 0, Vector2.Zero, this.TextScale * this.Scale, SpriteEffects.None, 0);
if (this.IsSelected && this.caretBlinkTimer < 0.5F) {
var caretDrawPos = textPos;
if (this.Multiline) {
var lines = 0;
var lastLineBreak = 0;
var originalIndex = 0;
var addedLineBreaks = 0;
for (var i = 0; i <= this.CaretPos - this.textOffset + addedLineBreaks - 1 && i < this.displayedText.Length; i++) {
if (this.displayedText[i] == '\n') {
lines++;
lastLineBreak = i;
if (this.text[originalIndex] != '\n') {
addedLineBreaks++;
continue;
}
}
originalIndex++;
}
var sub = this.displayedText.Substring(lastLineBreak, this.CaretPos - this.textOffset + addedLineBreaks - lastLineBreak);
caretDrawPos += new Vector2(this.Font.Value.MeasureString(sub).X * this.TextScale * this.Scale, lineHeight * lines);
} else {
caretDrawPos.X += this.Font.Value.MeasureString(this.displayedText.Substring(0, this.CaretPos - this.textOffset)).X * this.TextScale * this.Scale;
}
var caretDrawPos = textPos + new Vector2(this.caretDrawOffset * this.TextScale * this.Scale, 0);
if (this.Multiline)
caretDrawPos.Y += this.Font.Value.LineHeight * (this.CaretLine - this.lineOffset) * this.TextScale * this.Scale;
batch.Draw(batch.GetBlankTexture(), new RectangleF(caretDrawPos, new Vector2(this.CaretWidth * this.Scale, lineHeight)), null, textColor * alpha);
}
} else if (this.PlaceholderText != null) {