Text Input & Area

Brine2D provides two editable text controls:

UITextInput: single-line field with horizontal scrolling
UITextArea: multi-line editor with vertical scrolling

Both support text selection, clipboard operations, undo/redo, character filtering, and read-only mode. Both implement IUIComponent and IAnchoredUIComponent.

UITextInput

Constructor

C#

var input = new UITextInput(new Vector2(100, 50), new Vector2(240, 32));
_canvas.Add(input);

Properties

Property	Type	Default	Description
`Text`	`string`	`""`	Current text value
`Placeholder`	`string`	`"Enter text..."`	Shown when empty
`MaxLength`	`int`	`0`	Max character count; `0` = unlimited
`CursorPosition`	`int`	`0`	Cursor position as a character index
`Font`	`IFont?`	`null`	Custom font
`IsFocused`	`bool`	`false`	Read-only: whether the field has input focus
`ReadOnly`	`bool`	`false`	Display only; navigation and Ctrl+C still work
`IsPassword`	`bool`	`false`	Masks text with `MaskChar`
`MaskChar`	`char`	`'●'`	Password mask character
`CharacterFilter`	`Func<char, bool>?`	`null`	Accept only characters where delegate returns `true`
`CursorHeight`	`float`	`16`	Height of the cursor bar and selection highlight in pixels
`UndoStackLimit`	`int`	`100`	Max undo steps; `0` = unlimited

Colors

Property	Type	Default
`TextColor`	`Color`	White
`PlaceholderColor`	`Color`	`(150,150,150)`
`BackgroundColor`	`Color`	`(40,40,40)`
`FocusedBackgroundColor`	`Color`	`(50,50,50)`
`BorderColor`	`Color`	`(100,100,100)`
`FocusedBorderColor`	`Color`	`(120,180,255)`
`SelectionColor`	`Color`	`(80,120,200,180)`

Events

Event	Signature	Fires when
`OnTextChanged`	`Action<string>`	Text changes on any keystroke or paste
`OnSubmit`	`Action<string>`	Enter key pressed
`OnFocusGained`	`Action`	Field gains keyboard focus
`OnFocusLost`	`Action`	Field loses keyboard focus

Keyboard shortcuts

Key	Action
Arrow keys	Move cursor
Shift + Arrow	Extend selection
Ctrl + A	Select all
Ctrl + C / X / V	Copy / cut / paste
Ctrl + Z / Y	Undo / redo
Home / End	Jump to start / end of line
Backspace / Delete	Delete character
Enter	Fire `OnSubmit`

Example: username field

C#

var usernameInput = new UITextInput(new Vector2(120, 100), new Vector2(200, 30))
{
    Placeholder          = "Username",
    MaxLength            = 24,
    FocusedBorderColor   = new Color(100, 200, 255),
    TabIndex             = 0,
};
usernameInput.OnSubmit += text => Login(text);
_canvas.Add(usernameInput);

Example: password field

C#

var passwordInput = new UITextInput(new Vector2(120, 140), new Vector2(200, 30))
{
    Placeholder = "Password",
    IsPassword  = true,
    TabIndex    = 1,
};

Example: numeric only

C#

var portInput = new UITextInput(new Vector2(120, 180), new Vector2(80, 30))
{
    Placeholder     = "Port",
    CharacterFilter = c => char.IsDigit(c),
    MaxLength       = 5,
    TabIndex        = 2,
};

UITextArea

Constructor

C#

var area = new UITextArea(new Vector2(20, 60), new Vector2(400, 200));
_canvas.Add(area);

Properties

Property	Type	Default	Description
`Text`	`string`	`""`	Current text (`'\n'` as line separator)
`Placeholder`	`string`	`"Enter text..."`	Shown when empty and unfocused
`MaxLength`	`int`	`0`	Max character count; `0` = unlimited
`CursorPosition`	`int`	`0`	Cursor as a character index into `Text`
`Font`	`IFont?`	`null`	Custom font
`LineHeight`	`float`	`20`	Pixel height of each text line
`IsFocused`	`bool`	`false`	Read-only
`ReadOnly`	`bool`	`false`	Display only
`TabInsertsTab`	`bool`	`false`	When `true`, Tab inserts `'\t'` instead of advancing focus
`CharacterFilter`	`Func<char, bool>?`	`null`	Per-character acceptance filter
`UndoStackLimit`	`int`	`100`	Max undo steps

Colors

Property	Type	Default
`TextColor`	`Color`	White
`PlaceholderColor`	`Color`	`(150,150,150)`
`BackgroundColor`	`Color`	`(40,40,40)`
`FocusedBackgroundColor`	`Color`	`(50,50,50)`
`BorderColor`	`Color`	`(100,100,100)`
`FocusedBorderColor`	`Color`	`(120,180,255)`
`SelectionColor`	`Color`	`(80,120,200,180)`

Events

Event	Signature	Fires when
`OnTextChanged`	`Action<string>`	Text changes
`OnFocusGained`	`Action`	Area gains keyboard focus
`OnFocusLost`	`Action`	Area loses keyboard focus

Note

UITextArea does not have an OnSubmit event: Enter inserts a new line. Use OnFocusLost or a separate submit button if you need to detect "done editing".

Example: console / log input

C#

var consoleInput = new UITextArea(new Vector2(10, 400), new Vector2(780, 120))
{
    Placeholder    = "Enter command…",
    TabInsertsTab  = true,
    LineHeight     = 18f,
    FocusedBorderColor = new Color(0, 200, 100),
};
consoleInput.OnTextChanged += text => _livePreview.Text = text;

Choosing between the two

Scenario	Use
Single line (name, search, port number)	`UITextInput`
Submit on Enter	`UITextInput` with `OnSubmit`
Password field	`UITextInput` with `IsPassword = true`
Multi-line notes, scripts, config	`UITextArea`
In-game chat or console	`UITextArea`