Files
prevara/enum.go

83 lines
1.5 KiB
Go

package gel
import (
"image"
"gioui.org/gesture"
l "gioui.org/layout"
"gioui.org/op/clip"
)
type Enum struct {
value string
changed bool
clicks []gesture.Click
values []string
hook func(value string)
}
func (w *Window) Enum() *Enum {
return &Enum{hook: func(string) {}}
}
func (e *Enum) Value() string {
return e.value
}
func (e *Enum) SetValue(value string) *Enum {
e.value = value
return e
}
func (e *Enum) SetOnChange(hook func(value string)) *Enum {
e.hook = hook
return e
}
func index(vs []string, t string) int {
for i, v := range vs {
if v == t {
return i
}
}
return -1
}
// Changed reports whether Value has changed by user interaction since the last call to Changed.
func (e *Enum) Changed() bool {
changed := e.changed
e.changed = false
return changed
}
// Fn adds the event handler for key.
func (e *Enum) Fn(gtx l.Context, key string) l.Dimensions {
defer clip.Rect(image.Rectangle{Max: gtx.Constraints.Min}).Push(gtx.Ops).Pop()
if index(e.values, key) == -1 {
e.values = append(e.values, key)
e.clicks = append(e.clicks, gesture.Click{})
e.clicks[len(e.clicks)-1].Add(gtx.Ops)
} else {
idx := index(e.values, key)
clk := &e.clicks[idx]
for {
ev, ok := clk.Update(gtx.Source)
if !ok {
break
}
switch ev.Kind {
case gesture.KindClick:
if niew := e.values[idx]; niew != e.value {
e.value = niew
e.changed = true
e.hook(e.value)
}
}
}
clk.Add(gtx.Ops)
}
return l.Dimensions{Size: gtx.Constraints.Min}
}