Buffer

Buffer is a 2D grid of cells representing terminal content. The framework creates buffers automatically; components write into them during Render.

Creating Buffers

go
buf := tui.NewBuffer(width, height)

Typically you receive a buffer from the framework rather than creating one.

Writing Content

Method	Description
`SetChar(x, y, rune, Style)`	Set a single character
`SetString(x, y, string, Style) int`	Write a string, returns cells written
`SetStringInRect(string, Rect, Style) int`	Write with wrapping, returns lines used
`Fill(Rect, Cell)`	Fill area with a cell
`FillStyle(Rect, Style)`	Apply style to area, preserving characters
`DrawHLine(x, y, width, rune, Style)`	Draw horizontal line
`DrawVLine(x, y, height, rune, Style)`	Draw vertical line

Reading Content

Method	Description
`Get(x, y) Cell`	Read cell at position (emptyCell if out of bounds)

Buffer Operations

Method	Description
`Clear()`	Reset all cells to empty
`Resize(width, height)`	Change dimensions, discard content
`Merge(other, offsetX, offsetY)`	Overlay another buffer at offset
`AddImage(ImagePlacement)`	Register an image for KGP rendering

Diff-Based Rendering

The framework uses Diff internally to produce minimal terminal updates:

go
output := current.Diff(previous)  // only changed cells
output := current.RenderFull()     // full redraw

Cell

go
type Cell struct {
    Char  rune
    Style Style
}

Rect

go
type Rect struct {
    X, Y, Width, Height int
}

Method	Description
`Right() int`	X + Width
`Bottom() int`	Y + Height
`Area() int`	Width * Height
`IsEmpty() bool`	Width or Height is zero
`Contains(x, y) bool`	Point inside rectangle
`Inner(margin) Rect`	Inset by margin on all sides
`InnerPadding(t, r, b, l) Rect`	Inset by individual sides
`SplitVertical(x) (Rect, Rect)`	Split into left and right
`SplitHorizontal(y) (Rect, Rect)`	Split into top and bottom
`Intersect(Rect) Rect`	Intersection of two rectangles

Block

Block draws a border and optional title:

go
type Block struct {
    Border BorderStyle
    Title  string
    Style  Style
}

go
block := tui.NewBlock()           // single-line border
block.Border = tui.BorderRounded  // change border style
block.Title = "Panel"
inner := block.Render(buf, area)  // returns inner area for content

Border styles: BorderSingle, BorderDouble, BorderRounded, BorderThick, BorderASCII, BorderNone.