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tomo-old/elements/switch.go
2023-05-03 15:40:40 -04:00

217 lines
5.5 KiB
Go

package elements
import "image"
import "git.tebibyte.media/sashakoshka/tomo"
import "git.tebibyte.media/sashakoshka/tomo/input"
import "git.tebibyte.media/sashakoshka/tomo/artist"
import "git.tebibyte.media/sashakoshka/tomo/textdraw"
// Switch is a toggle-able on/off switch with an optional label. It is
// functionally identical to Checkbox, but plays a different semantic role.
type Switch struct {
entity tomo.Entity
drawer textdraw.Drawer
enabled bool
pressed bool
checked bool
text string
onToggle func ()
}
// NewSwitch creates a new switch with the specified label text.
func NewSwitch (text string, on bool) (element *Switch) {
element = &Switch {
checked: on,
text: text,
enabled: true,
}
element.entity = tomo.NewEntity(element).(checkboxEntity)
element.theme.Case = tomo.C("tomo", "switch")
element.drawer.SetFace (element.theme.FontFace (
tomo.FontStyleRegular,
tomo.FontSizeNormal))
element.drawer.SetText([]rune(text))
element.updateMinimumSize()
return
}
// Entity returns this element's entity.
func (element *Switch) Entity () tomo.Entity {
return element.entity
}
// Draw causes the element to draw to the specified destination canvas.
func (element *Switch) Draw (destination artist.Canvas) {
bounds := element.entity.Bounds()
handleBounds := image.Rect(0, 0, bounds.Dy(), bounds.Dy()).Add(bounds.Min)
gutterBounds := image.Rect(0, 0, bounds.Dy() * 2, bounds.Dy()).Add(bounds.Min)
state := tomo.State {
Disabled: !element.Enabled(),
Focused: element.entity.Focused(),
Pressed: element.pressed,
On: element.checked,
}
element.entity.DrawBackground(destination)
if element.checked {
handleBounds.Min.X += bounds.Dy()
handleBounds.Max.X += bounds.Dy()
if element.pressed {
handleBounds.Min.X -= 2
handleBounds.Max.X -= 2
}
} else {
if element.pressed {
handleBounds.Min.X += 2
handleBounds.Max.X += 2
}
}
gutterPattern := element.theme.Pattern (
tomo.PatternGutter, state)
gutterPattern.Draw(destination, gutterBounds)
handlePattern := element.theme.Pattern (
tomo.PatternHandle, state)
handlePattern.Draw(destination, handleBounds)
textBounds := element.drawer.LayoutBounds()
offset := bounds.Min.Add(image.Point {
X: bounds.Dy() * 2 +
element.theme.Margin(tomo.PatternBackground).X,
})
offset.Y -= textBounds.Min.Y
offset.X -= textBounds.Min.X
foreground := element.theme.Color(tomo.ColorForeground, state)
element.drawer.Draw(destination, foreground, offset)
}
func (element *Switch) HandleFocusChange () {
element.entity.Invalidate()
}
func (element *Switch) HandleMouseDown (
position image.Point,
button input.Button,
modifiers input.Modifiers,
) {
if !element.Enabled() { return }
element.Focus()
element.pressed = true
element.entity.Invalidate()
}
func (element *Switch) HandleMouseUp (
position image.Point,
button input.Button,
modifiers input.Modifiers,
) {
if button != input.ButtonLeft || !element.pressed { return }
element.pressed = false
within := position.In(element.entity.Bounds())
if within {
element.checked = !element.checked
}
element.entity.Invalidate()
if within && element.onToggle != nil {
element.onToggle()
}
}
func (element *Switch) HandleKeyDown (key input.Key, modifiers input.Modifiers) {
if key == input.KeyEnter {
element.pressed = true
element.entity.Invalidate()
}
}
func (element *Switch) HandleKeyUp (key input.Key, modifiers input.Modifiers) {
if key == input.KeyEnter && element.pressed {
element.pressed = false
element.checked = !element.checked
element.entity.Invalidate()
if element.onToggle != nil {
element.onToggle()
}
}
}
// OnToggle sets the function to be called when the switch is flipped.
func (element *Switch) OnToggle (callback func ()) {
element.onToggle = callback
}
// Value reports whether or not the switch is currently on.
func (element *Switch) Value () (on bool) {
return element.checked
}
// Focus gives this element input focus.
func (element *Switch) Focus () {
if !element.entity.Focused() { element.entity.Focus() }
}
// Enabled returns whether this switch is enabled or not.
func (element *Switch) Enabled () bool {
return element.enabled
}
// SetEnabled sets whether this switch can be toggled or not.
func (element *Switch) SetEnabled (enabled bool) {
if element.enabled == enabled { return }
element.enabled = enabled
element.entity.Invalidate()
}
// SetText sets the checkbox's label text.
func (element *Switch) SetText (text string) {
if element.text == text { return }
element.text = text
element.drawer.SetText([]rune(text))
element.updateMinimumSize()
element.entity.Invalidate()
}
// SetTheme sets the element's theme.
func (element *Switch) SetTheme (new tomo.Theme) {
if new == element.theme.Theme { return }
element.theme.Theme = new
element.drawer.SetFace (element.theme.FontFace (
tomo.FontStyleRegular,
tomo.FontSizeNormal))
element.updateMinimumSize()
element.entity.Invalidate()
}
// SetConfig sets the element's configuration.
func (element *Switch) SetConfig (new tomo.Config) {
if new == element.config.Config { return }
element.config.Config = new
element.updateMinimumSize()
element.entity.Invalidate()
}
func (element *Switch) updateMinimumSize () {
textBounds := element.drawer.LayoutBounds()
lineHeight := element.drawer.LineHeight().Round()
if element.text == "" {
element.entity.SetMinimumSize(lineHeight * 2, lineHeight)
} else {
element.entity.SetMinimumSize (
lineHeight * 2 +
element.theme.Margin(tomo.PatternBackground).X +
textBounds.Dx(),
lineHeight)
}
}