Up to date

This page is up to date for Godot 4.2. If you still find outdated information, please open an issue.

RichTextLabel 中的 BBCode

前言

Label nodes are great for displaying basic text, but they have limitations. If you want to change the color of the text, or its alignment, you can only do that to the entire label. You can't make a part of the text have another color, or have a part of the text centered. To get around these limitations, you would use a RichTextLabel.

RichTextLabel allows for complex formatting of text using a markup syntax or the built-in API. It uses BBCodes for the markup syntax, a system of tags that designate formatting rules for a part of the text. You may be familiar with them if you ever used forums (also known as bulletin boards, hence the "BB" in "BBCode").

Unlike Label, RichTextLabel also comes with its own vertical scrollbar. This scrollbar is automatically displayed if the text does not fit within the control's size. The scrollbar can be disabled by unchecking the Scroll Active property in the RichTextLabel inspector.

Note that the BBCode tags can also be used to some extent in the XML source of the class reference. For more information, see 类参考入门.

参见

You can see how BBCode in RichTextLabel works in action using the Rich Text Label with BBCode demo project.

使用 BBCode

By default, RichTextLabel functions like a normal Label. It has the property_text property, which you can edit to have uniformly formatted text. To be able to use BBCode for rich text formatting, you need to turn on the BBCode mode by setting bbcode_enabled. After that, you can edit the text property using available tags. Both properties are located at the top of the inspector after selecting a RichTextLabel node.

../../_images/bbcode_in_richtextlabel_inspector.webp

For example, BBCode [color=green]test[/color] would render the word "test" with a green color.

../../_images/bbcode_in_richtextlabel_basic_example.webp

Most BBCodes consist of 3 parts: the opening tag, the content and the closing tag. The opening tag delimits the start of the formatted part, and can also carry some configuration options. Some opening tags, like the color one shown above, also require a value to work. Other opening tags may accept multiple options (separated by spaces within the opening tag). The closing tag delimits the end of the formatted part. In some cases, both the closing tag and the content can be omitted.

Unlike BBCode in HTML, leading/trailing whitespace is not removed by a RichTextLabel upon display. Duplicate spaces are also displayed as-is in the final output. This means that when displaying a code block in a RichTextLabel, you don't need to use a preformatted text tag.

[tag]content[/tag]
[tag=value]content[/tag]
[tag option1=value1 option2=value2]content[/tag]
[tag][/tag]
[tag]

备注

RichTextLabel doesn't support entangled BBCode tags. For example, instead of using:

[b]bold[i]bold italic[/b]italic[/i]

请使用:

[b]bold[i]bold italic[/i][/b][i]italic[/i]

安全地处理用户输入

In a scenario where users may freely input text (such as chat in a multiplayer game), you should make sure users cannot use arbitrary BBCode tags that will be parsed by RichTextLabel. This is to avoid inappropriate use of formatting, which can be problematic if [url] tags are handled by your RichTextLabel (as players may be able to create clickable links to phishing sites or similar).

Using RichTextLabel's [lb] and/or [rb] tags, we can replace the opening and/or closing brackets of any BBCode tag in a message with those escaped tags. This prevents users from using BBCode that will be parsed as tags – instead, the BBCode will be displayed as text.

Example of unescaped user input resulting in BBCode injection (2nd line) and escaped user input (3rd line)

Example of unescaped user input resulting in BBCode injection (2nd line) and escaped user input (3rd line)

创建一个 Node 节点并附加下面的脚本:

extends RichTextLabel

func _ready():
    append_chat_line("Player 1", "Hello world!")
    append_chat_line("Player 2", "Hello [color=red]BBCode injection[/color] (no escaping)!")
    append_chat_line_escaped("Player 2", "Hello [color=red]BBCode injection[/color] (with escaping)!")


# Returns escaped BBCode that won't be parsed by RichTextLabel as tags.
func escape_bbcode(bbcode_text):
    # We only need to replace opening brackets to prevent tags from being parsed.
    return bbcode_text.replace("[", "[lb]")


# Appends the user's message as-is, without escaping. This is dangerous!
func append_chat_line(username, message):
    append_text("%s: [color=green]%s[/color]\n" % [username, message])


# Appends the user's message with escaping.
# Remember to escape both the player name and message contents.
func append_chat_line_escaped(username, message):
    append_text("%s: [color=green]%s[/color]\n" % [escape_bbcode(username), escape_bbcode(message)])

剥离 BBCode 标签

For certain use cases, it can be desired to remove BBCode tags from the string. This is useful when displaying the RichTextLabel's text in another Control that does not support BBCode (such as a tooltip):

extends RichTextLabel

func _ready():
    var regex = RegEx.new()
    regex.compile("\\[.*?\\]")
    var text_without_tags = regex.sub(text, "", true)
    # `text_without_tags` contains the text with all BBCode tags removed.

备注

Removing BBCode tags entirely isn't advised for user input, as it can modify the displayed text without users understanding why part of their message was removed. Escaping user input should be preferred instead.

性能

In most cases, you can use BBCode directly as-is since text formatting is rarely a heavy task. However, with particularly large RichTextLabels (such as console logs spanning thousands of lines), you may encounter stuttering during gameplay when the RichTextLabel's text is updated.

There are several ways to alleviate this:

  • Use the append_text() function instead of appending to the text property. This function will only parse BBCode for the added text, rather than parsing BBCode from the entire text property.

  • Use push_[tag]() and pop() functions to add tags to RichTextLabel instead of using BBCode.

  • Enable the Threading > Threaded property in RichTextLabel. This won't speed up processing, but it will prevent the main thread from blocking, which avoids stuttering during gameplay. Only enable threading if it's actually needed in your project, as threading has some overhead.

使用 push_[标签]() 和 pop() 函数代替 BBCode

If you don't want to use BBCode for performance reasons, you can use functions provided by RichTextLabel to create formatting tags without writing BBCode in the text.

Every BBCode tag (including effects) has a push_[tag]() function (where [tag] is the tag's name). There are also a few convenience functions available, such as push_bold_italics() that combines both push_bold() and push_italics() into a single tag. See the RichTextLabel class reference for a complete list of push_[tag]() functions.

The pop() function is used to end any tag. Since BBCode is a tag stack, using pop() will close the most recently started tags first.

The following script will result in the same visual output as using BBCode [color=green]test [i]example[/i][/color]:

extends RichTextLabel

func _ready():
    append_text("BBCode ")  # Trailing space separates words from each other.
    push_color(Color.GREEN)
    append_text("test ")  # Trailing space separates words from each other.
    push_italics()
    append_text("example")
    pop()  # Ends the tag opened by `push_italics()`.
    pop()  # Ends the tag opened by `push_color()`.

警告

Do not set the text property directly when using formatting functions. Appending to the text property will erase all modifications made to the RichTextLabel using the append_text(), push_[tag]() and pop() functions.

参考

标签

示例

b
Makes {text} use the bold (or bold italics) font of RichTextLabel.

[b]{text}[/b]

i
Makes {text} use the italics (or bold italics) font of RichTextLabel.

[i]{text}[/i]

u
{text} 上显示下划线。

[u]{text}[/u]

s
{text} 上显示删除线。

[s]{text}[/s]

code
{text} 使用 RichTextLabel 的等宽字体。

[code]{text}[/code]

p
Adds new paragraph with {text}. Supports configuration options, see 段落选项.
[p]{text}[/p]
[p {options}]{text}[/p]
center
Makes {text} horizontally centered.
Same as [p align=center].

[center]{text}[/center]

left
Makes {text} horizontally left-aligned.
Same as [p align=left].

[left]{text}[/left]

right
Makes {text} horizontally right-aligned.
Same as [p align=right].

[right]{text}[/right]

fill
Makes {text} fill the full width of RichTextLabel.
Same as [p align=fill].

[fill]{text}[/fill]

indent
Indents {text} once. The indentation width is the same as with [ul] or [ol], but without a bullet point.

[indent]{text}[/indent]

url
Creates a hyperlink (underlined and clickable text). Can contain optional {text} or display {link} as is.
Must be handled with the "meta_clicked" signal to have an effect, see 处理 [url] 标签点击.
[url]{link}[/url]
[url={link}]{text}[/url]
hint
Creates a tooltip hint that is displayed when hovering the text with the mouse. Tooltip text should not be quoted (quotes will appear as-is in the tooltip otherwise).
[hint={tooltip text displayed on hover}]{text}[/hint]
img
Inserts an image from the {path} (can be any valid Texture2D resource).
If {width} is provided, the image will try to fit that width maintaining the aspect ratio.
If both {width} and {height} are provided, the image will be scaled to that size.
If {valign} configuration is provided, the image will try to align to the surrounding text, see 图像的垂直对齐.
Supports configuration options, see 图像选项.
[img]{path}[/img]
[img={width}]{path}[/img]
[img={width}x{height}]{path}[/img]
[img={valign}]{path}[/img]
[img {options}]{path}[/img]
font
Makes {text} use a font resource from the {path}.
Supports configuration options, see 字体选项.
[font={path}]{text}[/font]
[font {options}]{text}[/font]
font_size
Use custom font size for {text}.

[font_size={size}]{text}[/font_size]

dropcap
Use a different font size and color for {text}, while making the tag's contents span multiple lines if it's large enough.
A drop cap is typically one uppercase character, but [dropcap] supports containing multiple characters. margins values are comma-separated and can be positive, zero or negative. Negative top and bottom margins are particularly useful to allow the rest of the paragraph to display below the dropcap.

[dropcap font_size={size} color={color} margins={left},{top},{right},{bottom}]{text}[/dropcap]

opentype_features
{text} 启用自定义 OpenType 字体特性。{list} 中的特性必须以英文逗号分隔。
[opentype_features={list}]
{text}
[/opentype_features]
lang
Overrides the language for {text} that is set by the BiDi > Language property in RichTextLabel. {code} must be an ISO language code. This can be used to enforce the use of a specific script for a language without starting a new paragraph. Some font files may contain script-specific substitutes, in which case they will be used.

[lang={code}]{text}[/lang]

color
修改 {text} 的颜色。设置的颜色必须使用通用名称(见 具名颜色)或十六进制格式(例如 #ff00ff,见 十六进制颜色代码)。

[color={code/name}]{text}[/color]

bgcolor
{text} 背后绘制的颜色。可以用来高亮文本。接受的值和 color 标签一致。

[bgcolor={code/name}]{text}[/bgcolor]

fgcolor
{text} 前方绘制的颜色。使用不透明的前景色可以“遮盖”文本。接受的值和 color 标签一致。

[fgcolor={code/name}]{text}[/fgcolor]

outline_size
{text} 使用自定义字体轮廓大小。
[outline_size={size}]
{text}
[/outline_size]
outline_color
{text} 使用自定义轮廓颜色。接受的值和 color 标签一致。
[outline_color={code/name}]
{text}
[/outline_color]
table
创建列数为 {number} 的表格。定义表格中的单元格请使用 cell 标签。

[table={number}]{cells}[/table]

cell
向表格中添加一个文本为 {text} 的单元格。
If {ratio} is provided, the cell will try to expand to that value proportionally to other cells and their ratio values.
Supports configuration options, see 单元格选项.
[cell]{text}[/cell]
[cell={ratio}]{text}[/cell]
[cell {options}]{text}[/cell]
ul
添加无序列表。列表项 {item} 必须以一行一个的形式提供。
项目符号可以使用 {bullet} 参数自定义,见 无序列表项目符号
[ul]{items}[/ul]
[ul bullet={bullet}]{items}[/ul]
ol
添加有序(编号)列表,类型由 {type} 给定(见 有序列表类型)。列表项 {items} 必须以一行一个的形式提供。

[ol type={type}]{items}[/ol]

lbrb
分别添加 []。用于转义 BBCode 标记。
这些是自闭合标签,不需要手动关闭(不存在 [/lb][/rb] 这种关闭标签)。
[lb]b[rb]text[lb]/b[rb] 会被显示为 [b]text[/b]
部分 Unicode 控制字符可以使用对应的自闭合标签添加。
相比于直接在文本中粘贴这些控制字符,
这种方法更方便维护。
[lrm] (left-to-right mark), [rlm] (right-to-left mark), [lre] (left-to-right embedding),
[rle] (right-to-left embedding), [lro] (left-to-right override), [rlo] (right-to-left override),
[pdf] (pop directional formatting), [alm] (Arabic letter mark), [lri] (left-to-right isolate),
[rli] (right-to-left isolate), [fsi] (first strong isolate), [pdi] (pop directional isolate),
[zwj] (zero-width joiner), [zwnj] (zero-width non-joiner), [wj] (word joiner),
[shy] (soft hyphen)

备注

Tags for bold ([b]) and italics ([i]) formatting work best if the appropriate custom fonts are set up in the RichTextLabelNode's theme overrides. If no custom bold or italic fonts are defined, faux bold and italic fonts will be generated by Godot. These fonts rarely look good in comparison to hand-made bold/italic font variants.

The monospaced ([code]) tag only works if a custom font is set up in the RichTextLabel node's theme overrides. Otherwise, monospaced text will use the regular font.

目前还没有用于控制文本垂直居中的BBCode标签.

Options can be skipped for all tags.

段落选项

  • align

    leftcenterright