Files
8bitMyGoUI/shop/quantity.go
T
ZacharyZhang-NY 5605d785de Add shop components 436-450; Odometer exact at 15 fps
Fifteen shop components: PriceTag, Wallet, ShopItem, Cart, Receipt,
Checkout, CurrencyConvert, SaleBadge, Quantity, PricingTiers, Coupon,
DailyReward, BidTicker, TradeWindow and VendingMachine.

Receipt prints dot by dot with feed holes and a torn edge; Coupon cuts
real notches; SaleBadge is a sixteen-point starburst; VendingMachine
sells A1 to D4 by code and drops the snack into its tray. Sums are
checked against overflow, TradeWindow withdraws both confirms on any
change to an offer, and a disabled Checkout veils its inert content.

text.Odometer now counts digits as text, steps at 15 fps as S5 asks,
draws exact digits at rest and lands rolls that floats would stall.
2026-10-12 11:15:07 -04:00

95 lines
2.4 KiB
Go
Raw Blame History

This file contains ambiguous Unicode characters
This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.
package shop
import (
"fmt"
"log/slog"
"strconv"
"github.com/egoist/mygo/ui"
"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/icon"
"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/pixel"
)
type QuantityOptions struct {
// Min is the least; Max the most, zero meaning 99.
Min, Max int
Disabled bool
}
type QuantityResult struct {
Element *ui.Element
Changed bool
}
// Quantity steps − n + within its limits.
func Quantity(c *ui.Context, text string, value *int, o QuantityOptions) QuantityResult {
k := pixel.K(c)
lo, hi := o.Min, pixel.Or("Quantity Max", o.Max, 99)
if lo < 0 || hi < lo || *value < lo || *value > hi {
panic(fmt.Sprintf("shop: Quantity %d outside %d to %d", *value, lo, hi))
}
shell, base, st := pixel.Shell(c, func() *ui.Element {
return ui.Box(c).Focusable().Role(ui.RoleStepper).Label(text).Disabled(o.Disabled)
})
old, nw := *value, pixel.Measure(strconv.Itoa(hi))+6
if !base.IsDisabled() {
step := 0
// Enter and Space are taken, so clicks come from pointers.
base.Shortcut(0, ui.KeyEnter)
base.Shortcut(0, ui.KeySpace)
if base.Shortcut(0, ui.KeyLeft) || base.Shortcut(0, ui.KeyDown) {
step--
}
if base.Shortcut(0, ui.KeyRight) || base.Shortcut(0, ui.KeyUp) {
step++
}
if base.Clicked() {
if x, _, _ := base.PointerPosition(); int(x/k.Dot()) < 14 {
step--
} else if int(x/k.Dot()) >= 14+nw {
step++
}
}
// One at a time toward the limit, so nothing overflows.
for ; step > 0 && *value < hi; step-- {
*value++
}
for ; step < 0 && *value > lo; step++ {
*value--
}
if base.Shortcut(0, ui.KeyHome) {
*value = lo
}
if base.Shortcut(0, ui.KeyEnd) {
*value = hi
}
}
n := *value
base.Description(strconv.Itoa(n))
shell.Size(k.D(28+nw), k.D(pixel.LineHeight)).Draw(func(p *ui.Painter, r ui.Rect) {
g := k.Canvas(p, r)
// A side at its limit fades; it goes no further.
for _, b := range []struct {
x int
sp *pixel.Sprite
on bool
}{{0, icon.Minus, n > lo}, {14 + nw, icon.Plus, n < hi}} {
ink := pixel.Faint
if b.on {
ink = pixel.Ink
}
g.Frame(b.x, 1, 14, 14, pixel.Raised, pixel.Face)
g.Sprite(b.x+1, 2, b.sp, 0, ink, 1)
}
s := strconv.Itoa(n)
g.Text(14+(nw-pixel.Measure(s))/2, 0, s, pixel.Ink, 1)
g.Finish(st)
})
res := QuantityResult{Element: shell, Changed: *value != old}
if res.Changed {
slog.Debug("8bit: quantity", "label", text, "value", *value)
}
return res
}