cview/util.go

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package tview
import "github.com/gdamore/tcell"
// Text alignment within a box.
const (
AlignLeft = iota
AlignCenter
AlignRight
)
// Print prints text onto the screen at position (x,y). "align" is one of the
// Align constants and will affect the direction starting at (x,y) into which
// the text is printed. The screen's background color will be maintained. The
// number of runes printed will not exceed "maxWidth".
//
// Returns the number of runes printed.
func Print(screen tcell.Screen, text string, x, y, maxWidth, align int, color tcell.Color) int {
// We deal with runes, not with bytes.
runes := []rune(text)
if maxWidth < 0 {
return 0
}
// Shorten text if it's too long.
if len(runes) > maxWidth {
switch align {
case AlignCenter:
trim := (len(runes) - maxWidth) / 2
runes = runes[trim : maxWidth+trim]
case AlignRight:
runes = runes[len(runes)-maxWidth:]
default: // AlignLeft.
runes = runes[:maxWidth]
}
}
// Adjust x-position.
if align == AlignCenter {
x -= len(runes) / 2
} else if align == AlignRight {
x -= len(runes) - 1
}
// Draw text.
for _, ch := range runes {
_, _, style, _ := screen.GetContent(x, y)
style = style.Foreground(color)
screen.SetContent(x, y, ch, nil, style)
x++
}
return len(runes)
}