tcell-widgets/helpers/tcell_borders.go

/*
Copyright © Brian Buller <brian@bullercodeworks.com>

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/
package helpers

import (
	"github.com/gdamore/tcell"
)

/*
The Border template starts at North and goes clockwise:
─, ┐, │, ┘, ─, └, │, ┌
Then it has the crossing lines:
├, ─, ┤, ┬, │, ┴
So a full border might look like this:

	[]rune{
		'─', '┐', '│', '┘', '─', '└', '│', '┌',
		'├', '─', '┤', '┬', '│', '┴',
	}

U+250x 	─ 	━ 	│ 	┃ 	┄ 	┅ 	┆ 	┇ 	┈ 	┉ 	┊ 	┋ 	┌ 	┍ 	┎ 	┏
U+251x 	┐ 	┑ 	┒ 	┓ 	└ 	┕ 	┖ 	┗ 	┘ 	┙ 	┚ 	┛ 	├ 	┝ 	┞ 	┟
U+252x 	┠ 	┡ 	┢ 	┣ 	┤ 	┥ 	┦ 	┧ 	┨ 	┩ 	┪ 	┫ 	┬ 	┭ 	┮ 	┯
U+253x 	┰ 	┱ 	┲ 	┳ 	┴ 	┵ 	┶ 	┷ 	┸ 	┹ 	┺ 	┻ 	┼ 	┽ 	┾ 	┿
U+254x 	╀ 	╁ 	╂ 	╃ 	╄ 	╅ 	╆ 	╇ 	╈ 	╉ 	╊ 	╋ 	╌ 	╍ 	╎ 	╏
U+255x 	═ 	║ 	╒ 	╓ 	╔ 	╕ 	╖ 	╗ 	╘ 	╙ 	╚ 	╛ 	╜ 	╝ 	╞ 	╟
U+256x 	╠ 	╡ 	╢ 	╣ 	╤ 	╥ 	╦ 	╧ 	╨ 	╩ 	╪ 	╫ 	╬ 	╭ 	╮ 	╯
U+257x 	╰ 	╱ 	╲ 	╳ 	╴ 	╵ 	╶ 	╷ 	╸ 	╹ 	╺ 	╻ 	╼ 	╽ 	╾ 	╿
*/
const (
	BRD_N = iota
	BRD_NE
	BRD_E
	BRD_SE
	BRD_S
	BRD_SW
	BRD_W
	BRD_NW
	BRD_CROSS_E
	BRD_CROSS_H
	BRD_CROSS_W
	BRD_CROSS_S
	BRD_CROSS_V
	BRD_CROSS_N
	BRD_CROSS_ALL
)

var (
	BRD_SIMPLE           = []rune{'─', '┐', '│', '┘', '─', '└', '│', '┌', '├', '─', '┤', '┬', '│', '┴', '┼'}
	BRD_CSIMPLE          = []rune{'─', '╮', '│', '╯', '─', '╰', '│', '╭', '├', '─', '┤', '┬', '│', '┴', '┼'}
	BRD_DOUBLE           = []rune{'═', '╗', '║', '╝', '═', '╚', '║', '╔', '╠', '═', '╣', '╦', '║', '╩', '╬'}
	BRD_CSIMPLE_DOTSPLIT = []rune{'─', '╮', '│', '╯', '─', '╰', '│', '╭', '├', '┄', '┤', '┬', '┊', '┴', '┼'}
	BRD_BLOCK_SHADOW     = []rune{'░', '░', '▓', '▓', '▓', '░', '░', '░', '░', '░', '░', '░', '░', '░', '░'}
)

// Horizontal/Vertical Rules
const (
	RULE_START = iota
	RULE_FILL
	RULE_END
)

var (
	HRULE_SIMPLE = []rune{'├', '─', '┤'}
	HRULE_DOUBLE = []rune{'╠', '═', '╣'}

	VRULE_SIMPLE = []rune{'┬', '│', '┴'}
	VRULE_DOUBLE = []rune{'╦', '║', '╩'}
)

func ValidateBorder(border []rune) []rune {
	for len(border) < BRD_CROSS_ALL+1 {
		border = append(border, ' ')
	}
	return border
}

func ValidateRule(rule []rune) []rune {
	for len(rule) < RULE_END+1 {
		rule = append(rule, ' ')
	}
	return rule
}

func HRule(x1, x2, y int, rule []rune, s tcell.Style, screen tcell.Screen) {
	Fill(x1, y, x2, y, rule[RULE_FILL], s, screen)
	screen.SetContent(x1, y, rule[RULE_START], nil, s)
	screen.SetContent(x2, y, rule[RULE_END], nil, s)
}

func VRule(x, y1, y2 int, rule []rune, s tcell.Style, screen tcell.Screen) {
	Fill(x, y1, x, y2, rule[RULE_FILL], s, screen)
	screen.SetContent(x, y1, rule[RULE_START], nil, s)
	screen.SetContent(x, y2, rule[RULE_END], nil, s)
}

func BorderFilled(x1, y1, x2, y2 int, border []rune, s tcell.Style, screen tcell.Screen) {
	Border(x1, y1, x2, y2, border, s, screen)
	Fill(x1+1, y1+1, x2-1, y2-1, ' ', s, screen)
}

func Border(x1, y1, x2, y2 int, border []rune, s tcell.Style, screen tcell.Screen) {
	border = ValidateBorder(border)
	Fill(x1+1, y1, x2-1, y1, border[BRD_N], s, screen)
	Fill(x2, y1+1, x2, y2-1, border[BRD_E], s, screen)
	Fill(x1+1, y2, x2-1, y2, border[BRD_S], s, screen)
	Fill(x1, y1+1, x1, y2-1, border[BRD_W], s, screen)
	screen.SetContent(x1, y1, border[BRD_NW], nil, s)
	screen.SetContent(x2, y1, border[BRD_NE], nil, s)
	screen.SetContent(x1, y2, border[BRD_SW], nil, s)
	screen.SetContent(x2, y2, border[BRD_SE], nil, s)
}

func TitledBorderFilled(x1, y1, x2, y2 int, ttl string, border []rune, s tcell.Style, screen tcell.Screen) {
	TitledBorder(x1, y1, x2, y2, ttl, border, s, screen)
	Fill(x1+1, y1+1, x2-1, y2-1, ' ', s, screen)
}

func TitledBorder(x1, y1, x2, y2 int, ttl string, border []rune, s tcell.Style, screen tcell.Screen) {
	if ttl == "" {
		Border(x1, y1, x2, y2, border, s, screen)
		return
	}
	border = ValidateBorder(border)
	ttlLength, maxTtlLength := len(ttl), (x2 - x1 - 2)
	if ttlLength > maxTtlLength {
		if maxTtlLength-3 > 0 {
			ttlLength = maxTtlLength
			ttl = ttl[0:maxTtlLength-3] + "..."
		}
	}
	DrawText(x1+1, y1, ttl, s, screen)
	Fill(x1+1+ttlLength, y1, x2-1, y1, border[BRD_N], s, screen)
	Fill(x2, y1+1, x2, y2-1, border[BRD_E], s, screen)
	Fill(x1+1, y2, x2-1, y2, border[BRD_S], s, screen)
	Fill(x1, y1+1, x1, y2-1, border[BRD_W], s, screen)
	screen.SetContent(x1, y1, border[BRD_NW], nil, s)
	screen.SetContent(x2, y1, border[BRD_NE], nil, s)
	screen.SetContent(x1, y2, border[BRD_SW], nil, s)
	screen.SetContent(x2, y2, border[BRD_SE], nil, s)
}

func BorderHasEast(border []rune) bool {
	border = ValidateBorder(border)
	return border[BRD_E] != ' ' || border[BRD_NE] != ' ' || border[BRD_SE] != ' '
}

func BorderHasWest(border []rune) bool {
	border = ValidateBorder(border)
	return border[BRD_W] != ' ' || border[BRD_NW] != ' ' || border[BRD_SW] != ' '
}

func BorderHasNorth(border []rune) bool {
	border = ValidateBorder(border)
	return border[BRD_N] != ' ' || border[BRD_NE] != ' ' || border[BRD_NW] != ' '
}

func BorderHasSouth(border []rune) bool {
	border = ValidateBorder(border)
	return border[BRD_S] != ' ' || border[BRD_NW] != ' ' || border[BRD_SW] != ' '
}