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MLEM/MLEM/Input/TextInput.cs

646 lines
30 KiB
C#

using System;
using System.IO;
using System.Linq;
using System.Text;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using MLEM.Font;
using MLEM.Graphics;
using MLEM.Maths;
using MLEM.Misc;
namespace MLEM.Input {
/// <summary>
/// A class that contains all of the necessary tools to create a text input field or box.
/// This text input features single- and <see cref="Multiline"/> input, <see cref="InputRule"/> sets, free caret movement, copying and pasting, and more.
/// To use this class, <see cref="OnTextInput"/>, <see cref="Update"/> and <see cref="Draw"/> have to be called regularly.
/// While this class is used by MLEM.Ui's TextField, it is designed to be used for custom or external UI systems.
/// </summary>
public class TextInput {
/// <summary>
/// A <see cref="Rule"/> that allows any visible character and spaces
/// </summary>
public static readonly Rule DefaultRule = (input, add) => {
foreach (var c in add) {
if (char.IsControl(c) && (!input.Multiline || c != '\n'))
return false;
}
return true;
};
/// <summary>
/// A <see cref="Rule"/> that only allows letters
/// </summary>
public static readonly Rule OnlyLetters = (input, add) => {
foreach (var c in add) {
if (!char.IsLetter(c))
return false;
}
return true;
};
/// <summary>
/// A <see cref="Rule"/> that only allows numerals
/// </summary>
public static readonly Rule OnlyNumbers = (input, add) => {
foreach (var c in add) {
if (!char.IsNumber(c))
return false;
}
return true;
};
/// <summary>
/// A <see cref="Rule"/> that only allows letters and numerals
/// </summary>
public static readonly Rule LettersNumbers = (input, add) => {
foreach (var c in add) {
if (!char.IsLetter(c) || !char.IsNumber(c))
return false;
}
return true;
};
/// <summary>
/// A <see cref="Rule"/> that only allows characters not contained in <see cref="Path.GetInvalidPathChars"/>
/// </summary>
public static readonly Rule PathNames = (input, add) => {
foreach (var c in add) {
if (char.IsControl(c) || Path.GetInvalidPathChars().Contains(c))
return false;
}
return true;
};
/// <summary>
/// A <see cref="Rule"/> that only allows characters not contained in <see cref="Path.GetInvalidFileNameChars"/>
/// </summary>
public static readonly Rule FileNames = (input, add) => {
foreach (var c in add) {
if (char.IsControl(c) || Path.GetInvalidFileNameChars().Contains(c))
return false;
}
return true;
};
/// <summary>
/// This text input's current text
/// </summary>
public string Text => this.text.ToString();
/// <summary>
/// The length that this <see cref="TextInput"/>'s text has.
/// </summary>
public int Length => this.text.Length;
/// <summary>
/// An event that gets called when <see cref="Text"/> changes, either through input, or through a manual change.
/// </summary>
public TextChanged OnTextChange;
/// <summary>
/// The rule used for text input.
/// Rules allow only certain characters to be allowed inside of a text input.
/// </summary>
public Rule InputRule;
/// <summary>
/// The position of the caret within the text.
/// This is always between 0 and the <see cref="string.Length"/> of <see cref="Text"/>
/// </summary>
public int CaretPos {
get => this.caretPos;
set {
var val = (int) MathHelper.Clamp(value, 0F, this.text.Length);
if (this.caretPos != val) {
// ensure that we don't move to a location that is between high and low surrogates
this.caretPos = new CodePointSource(this.text).EnsureSurrogateBoundary(val, val > this.caretPos);
this.caretBlinkTimer = 0;
this.SetTextDataDirty(false);
}
}
}
/// <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 {
this.UpdateTextDataIfDirty();
return this.caretLine;
}
}
/// <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 {
this.UpdateTextDataIfDirty();
return this.caretPosInLine;
}
}
/// <summary>
/// A character that should be displayed instead of this text input'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 inputs or similar.
/// </summary>
public char? MaskingCharacter {
get => this.maskingCharacter;
set {
if (this.maskingCharacter != value) {
this.maskingCharacter = value;
this.SetTextDataDirty(false);
}
}
}
/// <summary>
/// The maximum amount of characters that can be input into this text input.
/// If this is set, the length of <see cref="Text"/> will never exceed this value.
/// </summary>
public int? MaximumCharacters;
/// <summary>
/// Whether this text input should support multi-line editing.
/// 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 input's bounds will be hidden.
/// </summary>
public bool Multiline {
get => this.multiline;
set {
if (this.multiline != value) {
this.multiline = value;
this.SetTextDataDirty(false);
}
}
}
/// <summary>
/// The font that this text input is currently using.
/// </summary>
public GenericFont Font {
get => this.font;
set {
if (this.font != value) {
this.font = value;
this.SetTextDataDirty(false);
}
}
}
/// <summary>
/// The scale that this text input's text has.
/// In <see cref="Draw"/>, this is multiplied with the drawScale parameter.
/// </summary>
public float TextScale {
get => this.textScale;
set {
if (this.textScale != value) {
this.textScale = value;
this.SetTextDataDirty(false);
}
}
}
/// <summary>
/// The size of this text input, which is the size that this text input's <see cref="Text"/> will be bounded to in <see cref="Draw"/>.
/// Note that <see cref="TextScale"/> gets applied to the text for calculations involving this size.
/// </summary>
public Vector2 Size {
get => this.size;
set {
if (this.size != value) {
this.size = value;
this.SetTextDataDirty(false);
}
}
}
/// <summary>
/// The maximum amount of lines that can be visible in this text input, based on its <see cref="Size"/>, the used <see cref="Font"/> and its <see cref="TextScale"/>.
/// Note that this may return a number higher than 1 even if this is not a <see cref="Multiline"/> text input.
/// </summary>
public int MaxDisplayedLines => (this.Size.Y / (this.Font.LineHeight * this.TextScale)).Floor();
/// <summary>
/// The index of the first line that is currently visible.
/// This value can be changed using <see cref="ShowLine"/>.
/// </summary>
public int FirstVisibleLine { get; private set; }
/// <summary>
/// The total amount of lines of text that this text input currently has, including additional lines added by automatic wrapping.
/// If this is not a <see cref="Multiline"/> text input, this value is always 1.
/// </summary>
public int Lines { get; private set; }
/// <summary>
/// A function that is invoked when a string of text should be copied to the clipboard.
/// MLEM.Ui uses the TextCopy package for this, but other options are available.
/// </summary>
public Action<string> CopyToClipboardFunction;
/// <summary>
/// A function that is invoked when a string of text should be pasted from the clipboard.
/// MLEM.Ui uses the TextCopy package for this, but other options are available.
/// </summary>
public Func<string> PasteFromClipboardFunction;
private readonly StringBuilder text = new StringBuilder();
private char? maskingCharacter;
private double caretBlinkTimer;
private string visibleText;
private string[] multilineSplitText;
private int textOffset;
private int caretPos;
private int caretLine;
private int caretPosInLine;
private float caretDrawOffset;
private bool multiline;
private GenericFont font;
private float textScale;
private Vector2 size;
private bool textDataDirty;
/// <summary>
/// Creates a new text input with the given settings.
/// </summary>
/// <param name="font">The <see cref="Font"/> to use.</param>
/// <param name="size">The <see cref="Size"/> to set.</param>
/// <param name="textScale">The <see cref="TextScale"/> to set.</param>
/// <param name="inputRule">The <see cref="InputRule"/> to set.</param>
/// <param name="copyToClipboardFunction">The <see cref="CopyToClipboardFunction"/>to set.</param>
/// <param name="pasteFromClipboardFunction">The <see cref="PasteFromClipboardFunction"/> to set.</param>
public TextInput(GenericFont font, Vector2 size, float textScale, Rule inputRule = null, Action<string> copyToClipboardFunction = null, Func<string> pasteFromClipboardFunction = null) {
this.InputRule = inputRule ?? TextInput.DefaultRule;
this.CopyToClipboardFunction = copyToClipboardFunction;
this.PasteFromClipboardFunction = pasteFromClipboardFunction;
this.Font = font;
this.Size = size;
this.TextScale = textScale;
}
/// <summary>
/// A method that should be called when the given text should be entered into this text input.
/// This method is designed to be used with <see cref="MlemPlatform.AddTextInputListener"/> or the TextInput event provided by MonoGame and FNA.
/// </summary>
/// <param name="key">The key that was pressed.</param>
/// <param name="character">The character that the <paramref name="key"/> represents.</param>
/// <returns>Whether text was successfully input.</returns>
public bool OnTextInput(Keys key, char character) {
// FNA's text input event doesn't supply keys, so we handle this in Update
#if !FNA
if (key == Keys.Back) {
if (this.CaretPos > 0) {
this.CaretPos--;
this.RemoveText(this.CaretPos, 1);
return true;
}
} else if (key == Keys.Delete) {
return this.RemoveText(this.CaretPos, 1);
} else if (this.Multiline && key == Keys.Enter) {
return this.InsertText('\n');
} else {
return this.InsertText(character);
}
return false;
#else
return this.InsertText(character);
#endif
}
/// <summary>
/// Updates this text input, including querying input using the given <see cref="InputHandler"/> and updating the caret's blink timer.
/// </summary>
/// <param name="time">The current game time.</param>
/// <param name="input">The input handler to use for input querying.</param>
public void Update(GameTime time, InputHandler input) {
this.UpdateTextDataIfDirty();
#if FNA
// FNA's text input event doesn't supply keys, so we handle this here
if (this.CaretPos > 0 && input.TryConsumePressed(Keys.Back)) {
this.CaretPos--;
this.RemoveText(this.CaretPos, 1);
} else if (this.CaretPos < this.text.Length && input.TryConsumePressed(Keys.Delete)) {
this.RemoveText(this.CaretPos, 1);
} else if (this.Multiline && input.TryConsumePressed(Keys.Enter)) {
this.InsertText('\n');
} else
#endif
if (this.CaretPos > 0 && input.TryConsumePressed(Keys.Left)) {
this.CaretPos--;
} else if (this.CaretPos < this.text.Length && input.TryConsumePressed(Keys.Right)) {
this.CaretPos++;
} else if (this.Multiline && input.IsPressedAvailable(Keys.Up) && (input.IsModifierKeyDown(ModifierKey.Control) ? this.ShowLine(this.FirstVisibleLine - 1) : this.MoveCaretToLine(this.CaretLine - 1))) {
input.TryConsumePressed(Keys.Up);
} else if (this.Multiline && input.IsPressedAvailable(Keys.Down) && (input.IsModifierKeyDown(ModifierKey.Control) ? this.ShowLine(this.FirstVisibleLine + 1) : this.MoveCaretToLine(this.CaretLine + 1))) {
input.TryConsumePressed(Keys.Down);
} else if (this.CaretPos != 0 && input.TryConsumePressed(Keys.Home)) {
this.CaretPos = 0;
} else if (this.CaretPos != this.text.Length && input.TryConsumePressed(Keys.End)) {
this.CaretPos = this.text.Length;
} else if (input.IsModifierKeyDown(ModifierKey.Control)) {
if (input.IsPressedAvailable(Keys.V)) {
var clip = this.PasteFromClipboardFunction?.Invoke();
if (clip != null) {
this.InsertText(clip, true);
input.TryConsumePressed(Keys.V);
}
} else if (input.TryConsumePressed(Keys.C)) {
// until there is text selection, just copy the whole content
this.CopyToClipboardFunction?.Invoke(this.Text);
}
}
this.caretBlinkTimer += time.ElapsedGameTime.TotalSeconds;
if (this.caretBlinkTimer >= 1)
this.caretBlinkTimer = 0;
}
/// <summary>
/// Draws this text input's displayed <see cref="Text"/> along with its caret, if <paramref name="caretWidth"/> is greater than 0.
/// </summary>
/// <param name="batch">The sprite batch to draw with.</param>
/// <param name="textPos">The position to draw the text at.</param>
/// <param name="drawScale">The draw scale, which is multiplied with <see cref="TextScale"/> before drawing.</param>
/// <param name="caretWidth">The width that the caret should have, which is multiplied with <paramref name="drawScale"/> before drawing.</param>
/// <param name="textColor">The color to draw the text and caret with.</param>
public void Draw(SpriteBatch batch, Vector2 textPos, float drawScale, float caretWidth, Color textColor) {
this.UpdateTextDataIfDirty();
var scale = this.TextScale * drawScale;
this.Font.DrawString(batch, this.visibleText, textPos, textColor, 0, Vector2.Zero, scale, SpriteEffects.None, 0);
if (caretWidth > 0 && this.caretBlinkTimer < 0.5F) {
var caretDrawPos = textPos + new Vector2(this.caretDrawOffset * scale, 0);
if (this.Multiline)
caretDrawPos.Y += this.Font.LineHeight * (this.CaretLine - this.FirstVisibleLine) * scale;
batch.Draw(batch.GetBlankTexture(), new RectangleF(caretDrawPos, new Vector2(caretWidth * drawScale, this.Font.LineHeight * scale)), null, textColor);
}
}
/// <summary>
/// Replaces this text input's text with the given text.
/// If the resulting <see cref="Text"/> exceeds <see cref="MaximumCharacters"/>, the end will be cropped to fit.
/// </summary>
/// <param name="text">The new text</param>
/// <param name="removeMismatching">If any characters that don't match the <see cref="InputRule"/> should be left out</param>
public void SetText(object text, bool removeMismatching = false) {
var strg = text?.ToString() ?? string.Empty;
if (!this.FilterText(ref strg, removeMismatching))
return;
if (this.MaximumCharacters != null && strg.Length > this.MaximumCharacters)
strg = strg.Substring(0, new CodePointSource(strg).EnsureSurrogateBoundary(this.MaximumCharacters.Value, false));
this.text.Clear();
this.text.Append(strg);
this.CaretPos = this.text.Length;
this.SetTextDataDirty();
}
/// <summary>
/// Inserts the given text at the <see cref="CaretPos"/>.
/// If the resulting <see cref="Text"/> exceeds <see cref="MaximumCharacters"/>, the end will be cropped to fit.
/// </summary>
/// <param name="text">The text to insert</param>
/// <param name="removeMismatching">If any characters that don't match the <see cref="InputRule"/> should be left out</param>
public bool InsertText(object text, bool removeMismatching = false) {
var strg = text?.ToString() ?? string.Empty;
if (!this.FilterText(ref strg, removeMismatching))
return false;
if (this.MaximumCharacters != null && this.text.Length + strg.Length > this.MaximumCharacters)
strg = strg.Substring(0, new CodePointSource(strg).EnsureSurrogateBoundary(this.MaximumCharacters.Value - this.text.Length, false));
this.text.Insert(this.CaretPos, strg);
this.CaretPos += strg.Length;
this.SetTextDataDirty();
return true;
}
/// <summary>
/// Removes the given amount of text at the given index
/// </summary>
/// <param name="index">The index</param>
/// <param name="length">The amount of text to remove</param>
public bool RemoveText(int index, int length) {
if (index < 0 || index >= this.text.Length)
return false;
var source = new CodePointSource(this.text);
this.text.Remove(source.EnsureSurrogateBoundary(index, false), source.EnsureSurrogateBoundary(index + length, true) - index);
// ensure that caret pos is still in bounds
this.CaretPos = this.CaretPos;
this.SetTextDataDirty();
return true;
}
/// <summary>
/// Moves the <see cref="CaretPos"/> to the given line, if it exists.
/// Additionally maintains the <see cref="CaretPosInLine"/> roughly based on the visual distance that the caret has from the left border of the current <see cref="CaretLine"/>.
/// </summary>
/// <param name="line">The line to move the caret to</param>
/// <returns>True if the caret was moved, false if it was not (which indicates that the line with the given <paramref name="line"/> index does not exist)</returns>
public bool MoveCaretToLine(int line) {
this.UpdateTextDataIfDirty();
var (destStart, destEnd) = this.GetLineBounds(line);
if (destEnd > 0) {
// find the position whose distance from the start is closest to the current distance from the start
var destAccum = "";
while (destAccum.Length < destEnd - destStart) {
if (this.Font.MeasureString(destAccum).X >= this.caretDrawOffset) {
this.CaretPos = destStart + destAccum.Length;
return true;
}
destAccum += CodePointSource.ToString(new CodePointSource(this.text).GetCodePoint(destStart + destAccum.Length).CodePoint);
}
// if we don't find a proper position, just move to the end of the destination line
this.CaretPos = destEnd;
return true;
}
return false;
}
/// <summary>
/// Moves visual focus into such bounds that the given line will be the first visible line of this text input.
/// </summary>
/// <param name="line">The first line that should be visible.</param>
/// <returns>Whether the line can be the fist visible line, and wasn't already the first visible line.</returns>
public bool ShowLine(int line) {
if (this.FirstVisibleLine != line && line >= 0 && line < this.Lines - (this.MaxDisplayedLines - 1)) {
this.FirstVisibleLine = line;
// move the caret into visible bounds if necessary
var clampedCaretLine = (int) MathHelper.Clamp(this.CaretLine, line, line + this.MaxDisplayedLines - 1F);
if (clampedCaretLine != this.CaretLine)
this.MoveCaretToLine(clampedCaretLine);
this.SetTextDataDirty(false);
return true;
}
return false;
}
private bool FilterText(ref string text, bool removeMismatching) {
var result = new StringBuilder();
foreach (var codePoint in new CodePointSource(text)) {
var character = char.ConvertFromUtf32(codePoint);
if (this.InputRule(this, character)) {
result.Append(character);
} else if (!removeMismatching) {
// if we don't remove mismatching characters, we just fail
return false;
}
}
text = result.ToString();
return true;
}
private void SetTextDataDirty(bool textChanged = true) {
this.textDataDirty = true;
if (textChanged)
this.OnTextChange?.Invoke(this, this.Text);
}
private void UpdateTextDataIfDirty() {
if (!this.textDataDirty || this.Font == null)
return;
this.textDataDirty = false;
var visualText = this.text;
if (this.MaskingCharacter != null)
visualText = new StringBuilder(visualText.Length).Append(this.MaskingCharacter.Value, visualText.Length);
if (this.Multiline) {
// soft wrap if we're multiline
this.multilineSplitText = this.Font.SplitStringSeparate(visualText, this.Size.X, this.TextScale).ToArray();
this.visibleText = string.Join("\n", this.multilineSplitText);
this.Lines = this.visibleText.Count(c => c == '\n') + 1;
this.UpdateCaretData();
if (this.Font.MeasureString(this.visibleText).Y * this.TextScale > this.Size.Y) {
if (this.FirstVisibleLine > this.CaretLine) {
// if we're moving up
this.FirstVisibleLine = this.CaretLine;
} else if (this.CaretLine >= this.MaxDisplayedLines) {
// if we're moving down
var limit = this.CaretLine - (this.MaxDisplayedLines - 1);
if (limit > this.FirstVisibleLine)
this.FirstVisibleLine = limit;
}
// calculate resulting string
var ret = new StringBuilder();
var lines = 0;
var originalIndex = 0;
for (var i = 0; i < this.visibleText.Length; i++) {
if (lines >= this.FirstVisibleLine) {
if (ret.Length <= 0)
this.textOffset = originalIndex;
ret.Append(this.visibleText[i]);
}
if (this.visibleText[i] == '\n') {
lines++;
if (visualText[originalIndex] == '\n')
originalIndex++;
} else {
originalIndex++;
}
if (lines - this.FirstVisibleLine >= this.MaxDisplayedLines)
break;
}
this.visibleText = ret.ToString();
} else {
this.FirstVisibleLine = 0;
this.textOffset = 0;
}
} else {
this.multilineSplitText = null;
this.FirstVisibleLine = 0;
this.Lines = 1;
// not multiline, so scroll horizontally based on caret position
if (this.Font.MeasureString(visualText).X * this.TextScale > this.Size.X) {
if (this.textOffset > this.CaretPos) {
// if we're moving the caret to the left
this.textOffset = this.CaretPos;
} else {
// if we're moving the caret to the right
var importantArea = visualText.ToString(this.textOffset, Math.Min(this.CaretPos, visualText.Length) - this.textOffset);
var bound = this.CaretPos - this.Font.TruncateString(importantArea, this.Size.X, this.TextScale, true).Length;
if (this.textOffset < bound)
this.textOffset = bound;
}
var visible = visualText.ToString(this.textOffset, visualText.Length - this.textOffset);
this.visibleText = this.Font.TruncateString(visible, this.Size.X, this.TextScale);
} else {
this.visibleText = visualText.ToString();
this.textOffset = 0;
}
this.UpdateCaretData();
}
}
private void UpdateCaretData() {
if (this.multilineSplitText != null) {
// the code below will never execute if our text is empty, so reset our caret position fully
if (this.multilineSplitText.Length <= 0) {
this.caretLine = 0;
this.caretPosInLine = 0;
this.caretDrawOffset = 0;
return;
}
var line = 0;
var index = 0;
for (var d = 0; d < this.multilineSplitText.Length; d++) {
var startOfLine = 0;
var split = this.multilineSplitText[d];
for (var i = 0; i <= split.Length; i++) {
if (index == this.CaretPos) {
this.caretLine = line;
this.caretPosInLine = i - startOfLine;
this.caretDrawOffset = this.Font.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.visibleText != null) {
this.caretLine = 0;
this.caretPosInLine = this.CaretPos;
this.caretDrawOffset = this.Font.MeasureString(this.visibleText.Substring(0, this.CaretPos - this.textOffset)).X;
}
}
private (int, int) GetLineBounds(int boundLine) {
if (this.multilineSplitText != null) {
var line = 0;
var index = 0;
var startOfLineIndex = 0;
for (var d = 0; d < this.multilineSplitText.Length; d++) {
var split = this.multilineSplitText[d];
for (var i = 0; i < split.Length; i++) {
index++;
if (split[i] == '\n') {
if (boundLine == line)
return (startOfLineIndex, index - 1);
line++;
startOfLineIndex = index;
}
}
if (boundLine == line)
return (startOfLineIndex, index - 1);
line++;
startOfLineIndex = index;
}
}
return default;
}
/// <summary>
/// A delegate method used for <see cref="TextInput.OnTextChange"/>
/// </summary>
/// <param name="input">The text input whose text changed</param>
/// <param name="text">The new text</param>
public delegate void TextChanged(TextInput input, string text);
/// <summary>
/// A delegate method used for <see cref="InputRule"/>.
/// It should return whether the given text can be added to the text input.
/// </summary>
/// <param name="input">The text input</param>
/// <param name="textToAdd">The text that is tried to be added</param>
public delegate bool Rule(TextInput input, string textToAdd);
}
}