gregoryv/draw

package shape

import (
    "io"

    "github.com/gregoryv/draw"
    "github.com/gregoryv/draw/xy"
    "github.com/gregoryv/nexus"
)

// NewHexagon with a title. Radius must be > 0 and is the distance from
// left/right corners to imaginary vertical line.
func NewHexagon(title string, width, height, radius int) *Hexagon {
    if radius < 1 {
        radius = 1
    }
    return &Hexagon{
        Title:  title,
        Font:   draw.DefaultFont,
        Pad:    draw.DefaultTextPad,
        class:  "hexagon",
        width:  width,
        height: height,
        radius: radius,
    }
}

type Hexagon struct {
    x, y  int
    Title string

    Font  draw.Font
    Pad   draw.Padding
    class string

    width, height, radius int // radius is the left/right corner distance

    textAlign string
}

func (r *Hexagon) Position() (x int, y int) { return r.x, r.y }
func (r *Hexagon) SetX(x int)               { r.x = x }
func (r *Hexagon) SetY(y int)               { r.y = y }

func (r *Hexagon) Direction() Direction { return DirectionRight }
func (r *Hexagon) SetClass(c string)    { r.class = c }

func (r *Hexagon) WriteSVG(out io.Writer) error {
    w, err := nexus.NewPrinter(out)
    x, y := r.Position()
    rad := r.radius
    hlen := r.width - 2*rad
    h2 := r.height / 2

    w.Printf(`<path class="%s" d="M%v,%v l %v,%v %v,%v %v,%v %v,%v %v,%v %v,%v" />`,
        r.class,
        x+rad, y,
        hlen, 0,
        rad, h2, // far right corner
        -rad, h2,
        -hlen, 0,
        -rad, -h2, // far left corner
        rad, -h2,
    )

    w.Printf("\n")
    r.title().WriteSVG(w)
    return *err
}

func (r *Hexagon) title() *Label {
    label := &Label{
        Font:  r.Font,
        text:  r.Title,
        class: r.class + "-title",
    }
    label.Font.LineHeight = draw.DefaultFont.Height - 4
    align := Aligner{}
    align.VAlignCenter(r, label)
    align.HAlignCenter(r, label)
    return label
}

func (r *Hexagon) SetFont(f draw.Font)         { r.Font = f }
func (r *Hexagon) SetTextPad(pad draw.Padding) { r.Pad = pad }
func (r *Hexagon) Width() int                  { return r.width }
func (r *Hexagon) Height() int                 { return r.height }
func (r *Hexagon) SetWidth(w int)              { r.width = w }
func (r *Hexagon) SetHeight(h int)             { r.height = h }

// Edge returns intersecting position of a line starting at start and
// pointing to the rect center.
func (r *Hexagon) Edge(start xy.Point) xy.Point {
    return boxEdge(start, r)
}