gregoryv/draw

package design

import "fmt"

// Return adds a link between from and to indicating a return signal.
func (d *SequenceDiagram) Return(from, to, text string) *Link {
    l := d.Link(from, to, text)
    l.Class = "dashed-arrow"
    return l
}

// Link adds a link between from and to indicating a func call or data
// flow.
func (d *SequenceDiagram) Link(from, to, text string) *Link {
    fromIndex := -1
    toIndex := -1
    for i, column := range d.columns {
        if column == from {
            fromIndex = i
            break
        }
    }
    for i, column := range d.columns {
        if column == to {
            toIndex = i
            break
        }
    }
    lnk := &Link{
        fromIndex: fromIndex,
        toIndex:   toIndex,
        text:      text,
    }
    d.links = append(d.links, lnk)
    if fromIndex == -1 {
        panic(fmt.Sprintf("Missing %q column", from))
    }
    if toIndex == -1 {
        panic(fmt.Sprintf("Missing %q column", to))
    }
    return lnk
}

// Skip adds dotted distance on all columns
func (d *SequenceDiagram) Skip() {
    d.links = append(d.links, skip)
}

func (d *SequenceDiagram) ClearLinks() {
    d.links = make([]*Link, 0)
}

var skip *Link = &Link{}

// Link represents an arrow in a sequence diagram
type Link struct {
    fromIndex, toIndex int
    text               string
    Class              string
    TextClass          string
}

func (l *Link) toSelf() bool {
    return l.fromIndex == l.toIndex
}

func (l *Link) class() string {
    if l.Class == "" {
        return "arrow"
    }
    return l.Class
}