Files
FlaxEngine/Source/Engine/UI/GUI/Common/RichTextBox.Parsing.cs
2024-02-18 19:48:43 +01:00

313 lines
11 KiB
C#

// Copyright (c) 2012-2023 Wojciech Figat. All rights reserved.
using System.Collections.Generic;
using System.Runtime.InteropServices;
using FlaxEngine.Utilities;
namespace FlaxEngine.GUI
{
partial class RichTextBox
{
/// <summary>
/// Rich Text parsing context.
/// </summary>
public struct ParsingContext
{
/// <summary>
/// Text box control.
/// </summary>
public RichTextBox Control;
/// <summary>
/// HTML tags parser.
/// </summary>
public HtmlParser Parser;
/// <summary>
/// Current caret location for the new text blocks origin.
/// </summary>
public Float2 Caret;
/// <summary>
/// Index of the current line start character.
/// </summary>
public int LineStartCharacterIndex;
/// <summary>
/// Index of the current line start text block.
/// </summary>
public int LineStartTextBlockIndex;
/// <summary>
/// Text styles stack (new tags push modified style and pop on tag end).
/// </summary>
public Stack<TextBlockStyle> StyleStack;
/// <summary>
/// Adds the text block to the control
/// </summary>
/// <param name="textBlock">The text block to add.</param>
public void AddTextBlock(ref TextBlock textBlock)
{
// Post-processing
Control.PostProcessBlock?.Invoke(ref this, ref textBlock);
// Add to the text blocks
Control._textBlocks.Add(textBlock);
}
}
/// <summary>
/// The delegate for text blocks post-processing.
/// </summary>
/// <param name="context">The parsing context.</param>
/// <param name="textBlock">The text block (not yet added to the text box - during parsing).</param>
public delegate void PostProcessBlockDelegate(ref ParsingContext context, ref TextBlock textBlock);
/// <summary>
/// The custom callback for post-processing text blocks.
/// </summary>
[HideInEditor]
public PostProcessBlockDelegate PostProcessBlock;
/// <summary>
/// The delegate for HTML tag processing.
/// </summary>
/// <param name="context">The parsing context.</param>
/// <param name="tag">The tag.</param>
public delegate void ProcessTagDelegate(ref ParsingContext context, ref HtmlTag tag);
/// <summary>
/// Collection of HTML tags processors.
/// </summary>
public static Dictionary<string, ProcessTagDelegate> TagProcessors = new Dictionary<string, ProcessTagDelegate>
{
{ "br", ProcessBr },
{ "color", ProcessColor },
{ "alpha", ProcessAlpha },
{ "style", ProcessStyle },
{ "font", ProcessFont },
{ "b", ProcessBold },
{ "i", ProcessItalic },
{ "size", ProcessSize },
{ "img", ProcessImage },
{ "valign", ProcessVAlign },
{ "align", ProcessAlign },
{ "center", ProcessCenter },
};
private HtmlParser _parser = new HtmlParser();
private Stack<TextBlockStyle> _styleStack = new Stack<TextBlockStyle>();
/// <inheritdoc />
protected override void OnParseTextBlocks()
{
if (ParseTextBlocks != null)
{
ParseTextBlocks(_text, _textBlocks);
return;
}
// Setup parsing
_parser.Reset(_text);
_styleStack.Clear();
_styleStack.Push(_textStyle);
var context = new ParsingContext
{
Control = this,
Parser = _parser,
Caret = Float2.Zero,
LineStartCharacterIndex = 0,
LineStartTextBlockIndex = 0,
StyleStack = _styleStack,
};
// Parse text with HTML tags
int testStartPos = 0;
while (_parser.ParseNext(out var tag))
{
// Insert text found before the tag
OnAddTextBlock(ref context, testStartPos, tag.StartPosition);
// Move the text pointer after the tag
testStartPos = tag.EndPosition;
// Process the tag
OnParseTag(ref context, ref tag);
}
// Insert remaining text (and line)
OnAddTextBlock(ref context, testStartPos, _text.Length);
if (context.LineStartTextBlockIndex != _textBlocks.Count)
{
context.Caret.X = 0;
OnLineAdded(ref context, _text.Length - 1);
}
}
/// <summary>
/// Parses HTML tag.
/// </summary>
/// <param name="context">The parsing context.</param>
/// <param name="tag">The tag.</param>
protected virtual void OnParseTag(ref ParsingContext context, ref HtmlTag tag)
{
// Get tag processor matching the tag name
if (!TagProcessors.TryGetValue(tag.Name, out var process))
TagProcessors.TryGetValue(tag.Name.ToLower(), out process);
if (process != null)
{
process(ref context, ref tag);
}
}
/// <summary>
/// Inserts parsed text block using the current style and state (eg. from tags).
/// </summary>
/// <param name="context">The parsing context.</param>
/// <param name="start">Start position (character index).</param>
/// <param name="end">End position (character index).</param>
protected virtual void OnAddTextBlock(ref ParsingContext context, int start, int end)
{
if (start >= end)
return;
// Setup text block
var textBlock = new TextBlock
{
Style = context.StyleStack.Peek(),
Range = new TextRange
{
StartIndex = start,
EndIndex = end,
},
};
// Process text into text blocks (handle newlines etc.)
var font = textBlock.Style.Font.GetFont();
if (!font)
return;
var lines = font.ProcessText(_text, ref textBlock.Range);
if (lines == null || lines.Length == 0)
return;
for (int i = 0; i < lines.Length; i++)
{
ref var line = ref lines[i];
textBlock.Range = new TextRange
{
StartIndex = start + line.FirstCharIndex,
EndIndex = start + line.LastCharIndex,
};
if (i != 0)
{
context.Caret.X = 0;
OnLineAdded(ref context, textBlock.Range.StartIndex - 1);
}
textBlock.Bounds = new Rectangle(context.Caret, line.Size);
textBlock.Bounds.X += line.Location.X;
context.AddTextBlock(ref textBlock);
}
// Update the caret location
ref var lastLine = ref lines[lines.Length - 1];
if (lines.Length == 1)
{
context.Caret.X += lastLine.Size.X;
}
else
{
context.Caret.X = lastLine.Size.X;
}
}
private void OnLineAdded(ref ParsingContext context, int lineEnd)
{
// Calculate size of the line
var textBlocks = CollectionsMarshal.AsSpan(_textBlocks);
var lineOrigin = textBlocks[context.LineStartTextBlockIndex].Bounds.Location;
var lineSize = Float2.Zero;
var lineAscender = 0.0f;
for (int i = context.LineStartTextBlockIndex; i < _textBlocks.Count; i++)
{
ref TextBlock textBlock = ref textBlocks[i];
var textBlockSize = textBlock.Bounds.BottomRight - lineOrigin;
var ascender = textBlock.Ascender;
//if (ascender <= 0)
{
var textBlockFont = textBlock.Style.Font.GetFont();
if (textBlockFont)
ascender = textBlockFont.Ascender;
}
lineAscender = Mathf.Max(lineAscender, ascender);
lineSize = Float2.Max(lineSize, textBlockSize);
}
// Organize text blocks within line
var horizontalAlignments = TextBlockStyle.Alignments.Baseline;
for (int i = context.LineStartTextBlockIndex; i < _textBlocks.Count; i++)
{
ref TextBlock textBlock = ref textBlocks[i];
var vOffset = lineSize.Y - textBlock.Bounds.Height;
horizontalAlignments |= textBlock.Style.Alignment & TextBlockStyle.Alignments.HorizontalMask;
switch (textBlock.Style.Alignment & TextBlockStyle.Alignments.VerticalMask)
{
case TextBlockStyle.Alignments.Baseline:
{
// Match the baseline of the line (use ascender)
var ascender = textBlock.Ascender;
if (ascender <= 0)
{
var textBlockFont = textBlock.Style.Font.GetFont();
if (textBlockFont)
ascender = textBlockFont.Ascender;
}
vOffset = lineAscender - ascender;
textBlock.Bounds.Location.Y += vOffset;
break;
}
case TextBlockStyle.Alignments.Top:
{
textBlock.Bounds.Location.Y = lineOrigin.Y;
break;
}
case TextBlockStyle.Alignments.Middle:
{
textBlock.Bounds.Location.Y = lineOrigin.Y + vOffset * 0.5f;
break;
}
case TextBlockStyle.Alignments.Bottom:
{
textBlock.Bounds.Location.Y = lineOrigin.Y + vOffset;
break;
}
}
}
var hOffset = Width - lineSize.X;
if ((horizontalAlignments & TextBlockStyle.Alignments.Center) == TextBlockStyle.Alignments.Center)
{
hOffset *= 0.5f;
for (int i = context.LineStartTextBlockIndex; i < _textBlocks.Count; i++)
{
ref TextBlock textBlock = ref textBlocks[i];
textBlock.Bounds.Location.X += hOffset;
}
}
else if ((horizontalAlignments & TextBlockStyle.Alignments.Right) == TextBlockStyle.Alignments.Right)
{
for (int i = context.LineStartTextBlockIndex; i < _textBlocks.Count; i++)
{
ref TextBlock textBlock = ref textBlocks[i];
textBlock.Bounds.Location.X += hOffset;
}
}
// Move to the next line
context.LineStartCharacterIndex = lineEnd + 1;
context.LineStartTextBlockIndex = _textBlocks.Count;
context.Caret.Y += lineSize.Y;
}
}
}