Class LineScrollTextArea

A line-by-line scrolling text display component for terminal and console-style output. Scrolls by discrete logical lines rather than pixels and uses TextMeshProUGUI for rendering.

Inheritance
object
Object
Component
Behaviour
MonoBehaviour
LineScrollTextArea
Inherited Members
MonoBehaviour.IsInvoking()
MonoBehaviour.CancelInvoke()
MonoBehaviour.StopCoroutine(Coroutine)
MonoBehaviour.StopAllCoroutines()
MonoBehaviour.destroyCancellationToken
MonoBehaviour.useGUILayout
MonoBehaviour.didStart
MonoBehaviour.didAwake
MonoBehaviour.runInEditMode
Behaviour.enabled
Behaviour.isActiveAndEnabled
Component.GetComponent<T>()
Component.TryGetComponent<T>(out T)
Component.GetComponentInChildren<T>()
Component.GetComponentsInChildren<T>()
Component.GetComponentInParent<T>()
Component.GetComponentsInParent<T>()
Component.GetComponents<T>()
Component.GetComponentIndex()
Component.CompareTag(TagHandle)
Component.transform
Component.transformHandle
Component.gameObject
Component.tag
Object.GetEntityId()
Object.GetHashCode()
Object.InstantiateAsync<T>(T)
Object.InstantiateAsync<T>(T, Transform)
Object.InstantiateAsync<T>(T, Vector3, Quaternion)
Object.InstantiateAsync<T>(T, Transform, Vector3, Quaternion)
Object.Instantiate(Object, Vector3, Quaternion)
Object.Instantiate(Object, Vector3, Quaternion, Transform)
Object.Instantiate(Object)
Object.Instantiate(Object, Scene)
Object.Instantiate<T>(T, InstantiateParameters)
Object.Instantiate<T>(T, Vector3, Quaternion, InstantiateParameters)
Object.Instantiate(Object, Transform)
Object.Instantiate<T>(T)
Object.Instantiate<T>(T, Vector3, Quaternion)
Object.Instantiate<T>(T, Vector3, Quaternion, Transform)
Object.Instantiate<T>(T, Transform)
Object.Destroy(Object)
Object.DestroyImmediate(Object)
Object.DontDestroyOnLoad(Object)
Object.FindAnyObjectByType<T>()
Object.FindAnyObjectByType<T>(FindObjectsInactive)
Object.FindObjectsByType<T>()
Object.FindObjectsByType<T>(FindObjectsInactive)
Object.ToString()
Object.name
Object.hideFlags
Namespace: Scylla.Core.Util.UI
Assembly: ScyllaCore.dll
Syntax
[RequireComponent(typeof(RectTransform))]
public sealed class LineScrollTextArea : MonoBehaviour
Remarks

LineScrollTextArea manages a LineScrollTextBuffer that tracks content lines, a computed window size (number of fully visible lines), and a TMP rendering component inside a RectMask2D-clipped viewport. The viewport is sized to exactly windowSize * lineHeight pixels so that only whole lines are ever shown.

Partial-line transitions are handled by an overflow mechanism: the buffer can produce one extra line above and below the visible window. Those overflow lines are rendered off-screen and clipped by the viewport mask, while the text rect's anchoredPosition is shifted to reveal a fractional portion during edge bounce animations.

Scroll input is external. The component provides two high-level input methods - HandleScrollInput(bool, bool) and HandlePageScrollInput(bool, bool) - that accept raw boolean button states and internally handle initial-delay and key-repeat timing. Call ResetScrollInputState() when the component loses focus.

An optional edge bounce animation (EdgeBounceEnabled) plays a sine-wave offset when the user tries to scroll past the top or bottom boundary.

Text selection is opt-in via SelectionEnabled. Call HandleSelectionInput(Vector2, bool, bool, bool, bool) every frame to drive line-based selection. Selected text can be retrieved with SelectedText or copied to the clipboard via CopySelectionToClipboard().

Fields

DEFAULT_BUFFER_CAPACITY

Default buffer capacity (maximum logical lines).

Declaration
public const int DEFAULT_BUFFER_CAPACITY = 1000
Field Value
Type Description
int

DEFAULT_EDGE_BOUNCE_AMPLITUDE

Default edge bounce amplitude in pixels.

Declaration
public const float DEFAULT_EDGE_BOUNCE_AMPLITUDE = 10
Field Value
Type Description
float

DEFAULT_EDGE_BOUNCE_DURATION

Default edge bounce duration in seconds.

Declaration
public const float DEFAULT_EDGE_BOUNCE_DURATION = 0.15
Field Value
Type Description
float

DEFAULT_FONT_SIZE

Default font size for the text area.

Declaration
public const float DEFAULT_FONT_SIZE = 14
Field Value
Type Description
float

DEFAULT_PADDING

Default padding around the text content (in pixels).

Declaration
public const float DEFAULT_PADDING = 0
Field Value
Type Description
float

DEFAULT_SCROLLBAR_AUTO_HIDE_DELAY

Default delay before scrollbar auto-hide starts in seconds.

Declaration
public const float DEFAULT_SCROLLBAR_AUTO_HIDE_DELAY = 0.75
Field Value
Type Description
float

DEFAULT_SCROLLBAR_FADE_DURATION

Default duration for scrollbar fade animation in seconds.

Declaration
public const float DEFAULT_SCROLLBAR_FADE_DURATION = 0.3
Field Value
Type Description
float

DEFAULT_SCROLLBAR_MARGIN

Default margin between scrollbar and viewport edge in pixels.

Declaration
public const float DEFAULT_SCROLLBAR_MARGIN = 2
Field Value
Type Description
float

DEFAULT_SCROLLBAR_MIN_THUMB_HEIGHT

Minimum height for the scrollbar thumb in pixels.

Declaration
public const float DEFAULT_SCROLLBAR_MIN_THUMB_HEIGHT = 20
Field Value
Type Description
float

DEFAULT_SCROLLBAR_THUMB_COLOR

Default scrollbar thumb color (semi-transparent white).

Declaration
public static readonly Color DEFAULT_SCROLLBAR_THUMB_COLOR
Field Value
Type Description
Color

DEFAULT_SCROLLBAR_TRACK_COLOR

Default scrollbar track color (fully transparent).

Declaration
public static readonly Color DEFAULT_SCROLLBAR_TRACK_COLOR
Field Value
Type Description
Color

DEFAULT_SCROLLBAR_WIDTH

Default scrollbar width in pixels.

Declaration
public const float DEFAULT_SCROLLBAR_WIDTH = 6
Field Value
Type Description
float

DEFAULT_SCROLL_INITIAL_DELAY

Default delay before key repeat starts (in seconds).

Declaration
public const float DEFAULT_SCROLL_INITIAL_DELAY = 0.4
Field Value
Type Description
float

DEFAULT_SCROLL_REPEAT_INTERVAL

Default interval between scroll repeats when key is held (in seconds).

Declaration
public const float DEFAULT_SCROLL_REPEAT_INTERVAL = 0.04
Field Value
Type Description
float

Properties

AutoScroll

Gets or sets whether auto-scroll is enabled.

Declaration
public bool AutoScroll { get; set; }
Property Value
Type Description
bool

Buffer

Gets the underlying text buffer that stores and manages all logical content lines. Use this to access line data, total line counts, and buffer-level scroll state directly.

Declaration
public LineScrollTextBuffer Buffer { get; }
Property Value
Type Description
LineScrollTextBuffer

BufferCapacity

Gets or sets the buffer capacity (maximum number of logical lines). Setting this value will recreate the buffer, clearing any existing content.

Declaration
public int BufferCapacity { get; set; }
Property Value
Type Description
int

EdgeBounceEnabled

Gets or sets whether the edge bounce effect is enabled. When enabled, a visual bounce animation plays when scrolling hits the top or bottom boundary.

Declaration
public bool EdgeBounceEnabled { get; set; }
Property Value
Type Description
bool

Font

Gets or sets the font asset.

Declaration
public TMP_FontAsset Font { get; set; }
Property Value
Type Description
TMP_FontAsset

FontSize

Gets or sets the font size.

Declaration
public float FontSize { get; set; }
Property Value
Type Description
float

HasSelection

Gets whether there is an active (non-empty) selection.

Declaration
public bool HasSelection { get; }
Property Value
Type Description
bool

IsAtBottom

Gets whether the view is at the bottom (newest content visible).

Declaration
public bool IsAtBottom { get; }
Property Value
Type Description
bool

IsAtTop

Gets whether the view is at the top (oldest content visible).

Declaration
public bool IsAtTop { get; }
Property Value
Type Description
bool

LineCount

Gets the current line count in the buffer.

Declaration
public int LineCount { get; }
Property Value
Type Description
int

LineHeight

Gets the calculated line height in pixels, as determined by the TMP font metrics. Returns 0 if the component has not been initialized yet.

Declaration
public float LineHeight { get; }
Property Value
Type Description
float

NeedsRefresh

Gets whether the component needs a display refresh.

Declaration
public bool NeedsRefresh { get; }
Property Value
Type Description
bool

Padding

Gets or sets the padding around the text content (in pixels).

Declaration
public float Padding { get; set; }
Property Value
Type Description
float

RectTransform

Gets the RectTransform of this component.

Declaration
public RectTransform RectTransform { get; }
Property Value
Type Description
RectTransform

ScrollInitialDelay

Gets or sets the delay before key repeat starts when holding a scroll key (in seconds).

Declaration
public float ScrollInitialDelay { get; set; }
Property Value
Type Description
float

ScrollRepeatInterval

Gets or sets the interval between scroll repeats when key is held (in seconds).

Declaration
public float ScrollRepeatInterval { get; set; }
Property Value
Type Description
float

ScrollbarAutoHide

Gets or sets whether the scrollbar auto-hides when not scrolling.

Declaration
public bool ScrollbarAutoHide { get; set; }
Property Value
Type Description
bool

ScrollbarAutoHideDelay

Gets or sets the delay before scrollbar auto-hide starts in seconds.

Declaration
public float ScrollbarAutoHideDelay { get; set; }
Property Value
Type Description
float

ScrollbarEnabled

Gets or sets whether the scrollbar is enabled. When enabled, a visual scrollbar indicator appears on the right side of the viewport.

Declaration
public bool ScrollbarEnabled { get; set; }
Property Value
Type Description
bool

ScrollbarFadeDuration

Gets or sets the duration for scrollbar fade animation in seconds.

Declaration
public float ScrollbarFadeDuration { get; set; }
Property Value
Type Description
float

ScrollbarMinThumbHeight

Gets or sets the minimum scrollbar thumb height in pixels.

Declaration
public float ScrollbarMinThumbHeight { get; set; }
Property Value
Type Description
float

ScrollbarThumbColor

Gets or sets the scrollbar thumb color.

Declaration
public Color ScrollbarThumbColor { get; set; }
Property Value
Type Description
Color

ScrollbarTrackColor

Gets or sets the scrollbar track color. Set alpha to 0 for an invisible track.

Declaration
public Color ScrollbarTrackColor { get; set; }
Property Value
Type Description
Color

ScrollbarWidth

Gets or sets the scrollbar width in pixels.

Declaration
public float ScrollbarWidth { get; set; }
Property Value
Type Description
float

SelectedText

Gets the currently selected text content.

Declaration
public string SelectedText { get; }
Property Value
Type Description
string

Selection

Gets the current selection range.

Declaration
public TextSelectionRange Selection { get; }
Property Value
Type Description
TextSelectionRange

SelectionColor

Gets or sets the selection highlight color.

Declaration
public Color SelectionColor { get; set; }
Property Value
Type Description
Color

SelectionEnabled

Gets or sets whether text selection is enabled.

Declaration
public bool SelectionEnabled { get; set; }
Property Value
Type Description
bool

TextColor

Gets or sets the text color.

Declaration
public Color TextColor { get; set; }
Property Value
Type Description
Color

TextComponent

Gets the TextMeshProUGUI component used for rendering.

Declaration
public TextMeshProUGUI TextComponent { get; }
Property Value
Type Description
TextMeshProUGUI

WindowSize

Gets the current window size (number of visible lines).

Declaration
public int WindowSize { get; }
Property Value
Type Description
int

Methods

AppendLine(string)

Appends a single line of text to the buffer. If AutoScroll is true, the buffer automatically advances the view to keep the newest content visible.

Declaration
public void AppendLine(string text)
Parameters
Type Name Description
string text

The text to append. May be null or empty.

AppendLines(params string[])

Appends multiple lines of text to the buffer in a single batch. Auto-scroll behavior follows the same rules as AppendLine(string).

Declaration
public void AppendLines(params string[] lines)
Parameters
Type Name Description
string[] lines

The lines to append. The method is a no-op if this array is null.

Clear()

Clears all content from the buffer.

Declaration
public void Clear()

ClearSelection()

Clears the current selection.

Declaration
public void ClearSelection()

CopySelectionToClipboard()

Copies selected text to the system clipboard.

Declaration
public void CopySelectionToClipboard()

ForceRefresh()

Immediately recalculates display metrics (window size, line height) and redraws the text content without waiting for the next Update. Use this when external layout changes have resized the component and the next frame update is too late.

Declaration
public void ForceRefresh()

HandlePageScrollInput(bool, bool)

Handles page scroll input with key repeat support. Call this method every frame with the current state of page scroll inputs. The component will handle timing for initial delay and repeat interval.

Declaration
public void HandlePageScrollInput(bool pageUpPressed, bool pageDownPressed)
Parameters
Type Name Description
bool pageUpPressed

Whether the page up input is currently pressed.
bool pageDownPressed

Whether the page down input is currently pressed.

HandleScrollInput(bool, bool)

Handles scroll input with key repeat support. Call this method every frame with the current state of scroll inputs. The component will handle timing for initial delay and repeat interval.

Declaration
public void HandleScrollInput(bool scrollUpPressed, bool scrollDownPressed)
Parameters
Type Name Description
bool scrollUpPressed

Whether the scroll up input is currently pressed.
bool scrollDownPressed

Whether the scroll down input is currently pressed.

HandleSelectionInput(Vector2, bool, bool, bool, bool)

Handles selection input. Call every frame when selection is enabled. Selection is line-based: clicking and dragging with modifier key selects full lines. When modifier key is not held, normal interaction should be used instead.

Declaration
public bool HandleSelectionInput(Vector2 mousePosition, bool leftButtonPressed, bool leftButtonPressedThisFrame, bool leftButtonReleasedThisFrame, bool modifierPressed)
Parameters
Type Name Description
Vector2 mousePosition

The current mouse position in screen coordinates.
bool leftButtonPressed

Whether the left mouse button is currently pressed.
bool leftButtonPressedThisFrame

Whether the left mouse button was pressed this frame.
bool leftButtonReleasedThisFrame

Whether the left mouse button was released this frame.
bool modifierPressed

Whether the selection modifier key (e.g., Shift) is held.
Returns
Type Description
bool

True if selection is being handled.

ResetScrollInputState()

Resets the scroll input state. Call this when the component loses focus or input context changes.

Declaration
public void ResetScrollInputState()

ScrollDownLine()

Scrolls down by one line.

Declaration
public void ScrollDownLine()

ScrollDownPage()

Scrolls down by one page (the number of visible lines in the window).

Declaration
public void ScrollDownPage()

ScrollToBottom()

Scrolls to the bottom (newest content).

Declaration
public void ScrollToBottom()

ScrollToTop()

Scrolls to the top (oldest content).

Declaration
public void ScrollToTop()

ScrollUpLine()

Scrolls up by one line.

Declaration
public void ScrollUpLine()

ScrollUpPage()

Scrolls up by one page (the number of visible lines in the window).

Declaration
public void ScrollUpPage()

SelectAll()

Selects all text in the buffer.

Declaration
public void SelectAll()

SetEventPublishing(bool)

Enables or disables Scylla event publishing for the buffer. When enabled, buffer-level events such as line-added notifications are published via ScyllaEvents. Event publishing is disabled by default for performance.

Declaration
public void SetEventPublishing(bool enabled)
Parameters
Type Name Description
bool enabled

true to enable event publishing; false to suppress all events.

TryGetLineIndexFromScreenPoint(Vector2, out int)

Attempts to get the logical line index at a screen position. Used for line-based selection.

Declaration
public bool TryGetLineIndexFromScreenPoint(Vector2 screenPos, out int lineIndex)
Parameters
Type Name Description
Vector2 screenPos

The screen position.
int lineIndex

The logical line index if successful.
Returns
Type Description
bool

True if the conversion was successful.

Extension Methods