package progress
const (
prefix = "processing (" // prepended to each progress status line rendered to the terminal
suffix = "%): " // appended to each percentage status calculation rendered to the terminal
minWidth = 80 // fallback for pipes, redirects, and non-tty outputs
pctFieldLen = 3 // the fixed length of the percentage displayed (e.g., "0.0", " 37", "100")
colorBlockFactor = 23 // 23 bytes per column for 24-bit color gradient blocks
maxBytesPerCol = 4 // 4 bytes per column for worst-case UTF-8 status text truncation thresholds
)
// layout encapsulates the terminal-specific rendering layout configuration.
type layout struct {
staticWidth int // the static width reserved for the prefix prepended to each status message, e.g., "processing (7.4%): "
colorBlockFactor int // the number of bytes to allocate to the rendering buffer per each terminal column
prefix string // prepended to each progress status line rendered to the terminal
suffix string // appended to each status percentage calculation rendered to the terminal, e.g., "%): " or "%)"
clearSeq string // ANSI escape sequence used to clear the current terminal line
doneSeq string // ANSI escape sequence used to restore the terminal cursor
lineTerminator string // output line terminator: "" when *Progress.output (nominally os.Stderr) is a terminal; "\n" otherwise
finalStatus string // status message to display upon completion (e.g., "done")
}
layout := layout{
prefix: prefix,
suffix: suffix,
colorBlockFactor: 1, // conditionally overridden in prepareTerminal
clearSeq: "", // conditionally overridden in prepareTerminal
doneSeq: "\n", // conditionally overridden in prepareTerminal
lineTerminator: "\n", // conditionally overridden in prepareTerminal
finalStatus: "done",
}
layout.staticWidth = len(layout.prefix) + pctFieldLen + len(layout.suffix)
return layout
}
return (maxBytesPerCol * termWidth) +
(l.colorBlockFactor * termWidth) +
len(l.prefix ) +
len(l.suffix ) +
len(l.clearSeq ) +
len(l.lineTerminator )
}