library/ui/ui.go

325 lines
7.5 KiB
Go

package ui
import (
"strings"
"git.yetaga.in/alazyreader/library/book"
"github.com/gdamore/tcell"
)
type Drawable interface {
Draw(tcell.Screen)
SetSize(x, y, h, w int)
}
type Offsets struct {
Top int
Bottom int
Left int
Right int
Percent int
}
type Contents []struct {
Offsets Offsets
Container Drawable
}
const (
LayoutUnmanaged = iota
LayoutHorizontalEven
LayoutVerticalEven
LayoutHorizontalPercent
LayoutVerticalPercent
)
// A Container has no visible UI of its own, but arranges sub-components on the screen.
// layoutMethod manages how subcomponents are organized. If `LayoutUnmanaged`, it just uses the offsets
// in contents to paint on the screen. Otherwise, `LayoutHorizontalEven` and `LayoutVerticalEven` will
// have it compute even distributions of space for all components either horizontally or vertically,
// filling the container.
type Container struct {
x, y int
h, w int
layoutMethod int
contents Contents
}
func NewContainer(contents Contents, layoutMethod int) *Container {
return &Container{
layoutMethod: layoutMethod,
contents: contents,
}
}
func (c *Container) Draw(s tcell.Screen) {
for i := range c.contents {
c.contents[i].Container.Draw(s)
}
}
func (c *Container) SetSize(x, y, h, w int) {
c.x, c.y, c.h, c.w = x, y, h, w
carry := 0
if c.layoutMethod == LayoutVerticalEven {
num := len(c.contents)
extra := c.h % num
for r := range c.contents {
w := c.w
h := c.h / num
x := c.x
y := c.y + (h * r) + carry
if extra > 0 { // distribute "extra" space to containers as we have some left
h++
extra--
carry++
}
c.contents[r].Container.SetSize(x, y, h, w)
}
} else if c.layoutMethod == LayoutHorizontalEven {
num := len(c.contents)
extra := c.w % num
for r := range c.contents {
w := c.w / num
h := c.h
x := c.x + (w * r) + carry
y := c.y
if extra > 0 { // distribute "extra" space to containers as we have some left
w++
extra--
carry++
}
c.contents[r].Container.SetSize(x, y, h, w)
}
} else if c.layoutMethod == LayoutHorizontalPercent {
// first, work out overall distribution
total := 0
for r := range c.contents {
// `0` or negatives are set as minimum
if c.contents[r].Offsets.Percent < 1 {
total += 1
} else {
total += c.contents[r].Offsets.Percent
}
}
carry := 0
// push around containers
for r := range c.contents {
ratio := (float64(c.contents[r].Offsets.Percent) / float64(total))
w := int(float64(c.w) * ratio)
h := c.h
x := c.x + carry
y := c.y
carry += w
// and add any remaining space to the last container
if r == len(c.contents)-1 {
w += (c.w - carry)
}
c.contents[r].Container.SetSize(x, y, h, w)
}
} else if c.layoutMethod == LayoutVerticalPercent {
// first, work out overall distribution
total := 0
for r := range c.contents {
// `0` or negatives are set as minimum
if c.contents[r].Offsets.Percent < 1 {
total += 1
} else {
total += c.contents[r].Offsets.Percent
}
}
carry := 0
// push around containers
for r := range c.contents {
ratio := (float64(c.contents[r].Offsets.Percent) / float64(total))
w := c.w
h := int(float64(c.h) * ratio)
x := c.x
y := c.y + carry
carry += h
// and add any remaining space to the last container
if r == len(c.contents)-1 {
h += (c.h - carry)
}
c.contents[r].Container.SetSize(x, y, h, w)
}
} else {
for r := range c.contents {
x := c.x + c.contents[r].Offsets.Left
y := c.y + c.contents[r].Offsets.Top
h := c.h - c.contents[r].Offsets.Bottom
w := c.w - c.contents[r].Offsets.Right
c.contents[r].Container.SetSize(x, y, h, w)
}
}
}
func (c *Container) Contents() Contents {
return c.contents
}
func (c *Container) SetContents(con Contents) {
c.contents = con
}
// A Box draws a ASCII box around its contents, with an optional title and footer.
type Box struct {
x, y int
h, w int
title Drawable
menuItems Drawable
contents Contents
}
func NewBox(title string, menuItems []string, contents Contents) *Box {
return &Box{
title: NewPaddedText(title),
menuItems: NewPaddedText(strings.Join(menuItems, " ")),
contents: contents,
}
}
func (b *Box) SetSize(x, y, h, w int) {
b.x, b.y, b.h, b.w = x, y, h, w
b.title.SetSize(b.x+2, b.y, 0, 0)
b.menuItems.SetSize(b.x+2, b.y+b.h-1, 0, 0)
for c := range b.contents {
x := b.x + b.contents[c].Offsets.Left
y := b.y + b.contents[c].Offsets.Top
h := b.h - b.contents[c].Offsets.Bottom
w := b.w - b.contents[c].Offsets.Right
b.contents[c].Container.SetSize(x, y, h, w)
}
}
func (b *Box) Draw(s tcell.Screen) {
for m := b.x + 1; m < b.x+b.w-1; m++ {
s.SetContent(m, b.y, tcell.RuneHLine, nil, tcell.StyleDefault)
s.SetContent(m, b.y+b.h-1, tcell.RuneHLine, nil, tcell.StyleDefault)
}
for m := b.y + 1; m < b.y+b.h-1; m++ {
s.SetContent(b.x, m, tcell.RuneVLine, nil, tcell.StyleDefault)
s.SetContent(b.x+b.w-1, m, tcell.RuneVLine, nil, tcell.StyleDefault)
}
s.SetContent(b.x, b.y, tcell.RuneULCorner, nil, tcell.StyleDefault)
s.SetContent(b.x+b.w-1, b.y, tcell.RuneURCorner, nil, tcell.StyleDefault)
s.SetContent(b.x, b.y+b.h-1, tcell.RuneLLCorner, nil, tcell.StyleDefault)
s.SetContent(b.x+b.w-1, b.y+b.h-1, tcell.RuneLRCorner, nil, tcell.StyleDefault)
if b.title != nil {
b.title.Draw(s)
}
if b.menuItems != nil {
b.menuItems.Draw(s)
}
for c := range b.contents {
b.contents[c].Container.Draw(s)
}
}
func (b *Box) Contents() Contents {
return b.contents
}
func (b *Box) SetContents(c Contents) {
b.contents = c
}
// A List is a scrollable, pageable list with a selector token.
type List struct {
x, y int
h, w int
selected int
listItems []string
}
func NewList(listItems []string, initialSelected int) *List {
return &List{
listItems: listItems,
selected: initialSelected,
}
}
func (l *List) SetSize(x, y, h, w int) {
l.x, l.y, l.h, l.w = x, y, h, w
}
func (l *List) Draw(s tcell.Screen) {
for i := range l.listItems {
for j, r := range l.listItems[i] {
s.SetContent(l.x+j, l.y+i, r, nil, tcell.StyleDefault)
}
if i == l.selected {
s.SetContent(l.x+len(l.listItems[i])+1, l.y+i, '<', nil, tcell.StyleDefault)
}
}
}
func (l *List) Selected() int {
return l.selected
}
func (l *List) SetSelected(i int) {
l.selected = i
}
func (l *List) ListMembers() []string {
return l.listItems
}
// A List is a scrollable, pageable list with a selector token.
type BookDetails struct {
x, y int
h, w int
selected int
book book.Book
}
func NewBookDetails() *BookDetails {
return &BookDetails{}
}
func (l *BookDetails) SetSize(x, y, h, w int) {
l.x, l.y, l.h, l.w = x, y, h, w
}
func (l *BookDetails) Draw(s tcell.Screen) {
items := []string{"title", "authors", "isbn-10", "isbn-13"}
for i := range items {
for j, r := range items[i] {
s.SetContent(l.x+j, l.y+i, r, nil, tcell.StyleDefault)
}
s.SetContent(l.x+len(items[i]), l.y+i, ':', nil, tcell.StyleDefault)
}
}
// PaddedText outputs strings with a space on both sides.
// Useful for generating headings, footers, etc. Used by Box.
type PaddedText struct {
x, y int
h, w int
text string
}
func NewPaddedText(text string) *PaddedText {
return &PaddedText{text: text}
}
func (p *PaddedText) SetSize(x, y, _, _ int) {
p.x, p.y, p.h, p.w = x, y, 1, len(p.text)+2
}
func (p *PaddedText) Draw(s tcell.Screen) {
if p.text == "" {
return
}
t := p.x
s.SetContent(t, p.y, ' ', nil, tcell.StyleDefault)
t++
for _, r := range p.text {
s.SetContent(t, p.y, r, nil, tcell.StyleDefault)
t++
}
s.SetContent(t, p.y, ' ', nil, tcell.StyleDefault)
}