Buffer class

High-level wrapper for OpenTUI's optimized buffer operations.

The Buffer class provides a convenient Dart interface for all OpenTUI drawing operations, including text rendering, shape drawing, and advanced compositing. Buffers represent 2D grids of terminal cells, each containing a character, foreground color, background color, and text attributes.

Lifecycle: Buffer instances obtained from Renderer.nextBuffer are only valid until the next call to Renderer.render(). After render, the buffer is invalidated and all operations will throw StateError.

Use Buffer when:

• Building terminal-based user interfaces
• Creating text-mode games and graphics
• Implementing off-screen rendering for complex layouts
• Building layered rendering systems with multiple buffers

Example:

final buffer = renderer.getNextBuffer();

// Clear to dark background
buffer.clear(Color.fromHex('#1A202C'));

// Draw a bordered panel
buffer.drawBox(5, 2, 30, 15,
    BoxOptions(sides: BorderSides.all(), title: 'Settings'),
    Color.cyan, Color.darkGray);

// Add content text
buffer.drawText('Welcome to OpenTUI!', 10, 5, Color.white);

// Create a progress bar
buffer.fillRect(10, 8, 20, 1, Color.green);

Constructors

Buffer(Pointer<OptimizedBufferHandle> _ptr, OpenTuiBindings _bindings)

Creates a Buffer.

Properties

hashCode → int

The hash code for this object.

no setter, inherited

height → int

Height of the buffer in terminal rows.

no setter

isInvalidated → bool

Whether this buffer has been invalidated.

no setter

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

width → int

Width of the buffer in terminal columns.

no setter

Methods

clear(Color bg) → void

Clears the entire buffer to a uniform background color.

clipped({required int clipX, required int clipY, required int clipWidth, required int clipHeight}) → Buffer

Returns a Buffer view that silently drops draw calls outside the rectangle (clipX, clipY, clipWidth, clipHeight). The view shares the underlying FFI buffer and validity state; invalidating the parent also invalidates every clipped view. Used by scrolling/clipping containers (e.g. ScrollBox).

drawBox(int x, int y, int width, int height, BoxOptions options, Color borderColor, Color backgroundColor) → void

Draws a bordered box with extensive customization options.

drawFrameBuffer(Buffer sourceBuffer, int srcX, int srcY, int srcWidth, int srcHeight, int destX, int destY) → void

Draw another buffer onto this buffer (compositing).

drawText(String text, int x, int y, Color fg, {Color? bg, int attributes = 0}) → void

Draws text at the specified position with styling options.

drawTextBuffer(TextBuffer textBuffer, int x, int y, {int? clipX, int? clipY, int? clipWidth, int? clipHeight}) → void

Draw a TextBuffer to this buffer.

fillRect(int x, int y, int width, int height, Color color) → void

Fills a rectangular region with solid background color.

getDirectAccess() → DirectBufferAccess

Get direct access to internal arrays for performance-critical operations.

invalidate() → void

Invalidate this buffer (and every view created from it via clipped). Called by Renderer after render, resize, or dispose.

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

resize(int newWidth, int newHeight) → void

Resizes the buffer to newWidth by newHeight terminal cells.

setCell(int x, int y, String char, Color fg, Color bg, int attributes) → void

Sets a single cell at (x, y) using alpha blending.

setCellWithAlphaBlending(int x, int y, String char, Color fg, Color bg, int attributes) → void

Sets a cell at (x, y) with full alpha-blending support.

toString() → String

A string representation of this object.

inherited

Operators

operator ==(Object other) → bool

The equality operator.

inherited