Added sliders and made the ADSR controllabe with them

elements/basic/lerpslider.go

@@ -0,0 +1,44 @@
+package basicElements
+
+// Numeric is a type constraint representing a number.
+type Numeric interface {
+	~float32 | ~float64 |
+	~int     | ~int8    | ~int16  | ~int32  | ~int64  |
+	~uint    | ~uint8   | ~uint16 | ~uint32 | ~uint64 | ~uintptr
+}
+
+type LerpSlider[T Numeric] struct {
+	*Slider
+	min T
+	max T
+}
+
+func NewLerpSlider[T Numeric] (min, max T, value T, vertical bool) (element *LerpSlider[T]) {
+	if min > max {
+		temp := max
+		max = min
+		min = temp
+	}
+	element = &LerpSlider[T] {
+		Slider: NewSlider(0, vertical),
+		min: min,
+		max: max,
+	}
+	element.SetValue(value)
+	return
+}
+
+func (element *LerpSlider[T]) SetValue (value T) {
+	value -= element.min
+	element.Slider.SetValue(float64(value) / float64(element.Range()))
+}
+
+func (element *LerpSlider[T]) Value () (value T) {
+	return T (
+		float64(element.Slider.Value()) * float64(element.Range())) +
+		element.min
+}
+
+func (element *LerpSlider[T]) Range () T {
+	return element.max - element.min
+}

elements/basic/slider.go

@@ -0,0 +1,197 @@
+package basicElements
+
+import "image"
+import "git.tebibyte.media/sashakoshka/tomo/input"
+import "git.tebibyte.media/sashakoshka/tomo/theme"
+import "git.tebibyte.media/sashakoshka/tomo/config"
+import "git.tebibyte.media/sashakoshka/tomo/artist"
+import "git.tebibyte.media/sashakoshka/tomo/elements/core"
+
+type Slider struct {
+	*core.Core
+	*core.FocusableCore
+	core core.CoreControl
+	focusableControl core.FocusableCoreControl
+
+	value   float64
+	vertical bool
+	dragging bool
+	dragOffset int
+	track image.Rectangle
+	bar image.Rectangle
+	
+	config config.Wrapped
+	theme  theme.Wrapped
+	
+	onSlide   func ()
+	onRelease func ()
+}
+
+func NewSlider (value float64, vertical bool) (element *Slider) {
+	element = &Slider {
+		value: value,
+		vertical: vertical,
+	}
+	if vertical {
+		element.theme.Case = theme.C("basic", "sliderVertical")
+	} else {
+		element.theme.Case = theme.C("basic", "sliderHorizontal")
+	}
+	element.Core, element.core = core.NewCore(element.draw)
+	element.FocusableCore,
+	element.focusableControl = core.NewFocusableCore(element.redo)
+	element.updateMinimumSize()
+	return
+}
+
+func (element *Slider) HandleMouseDown (x, y int, button input.Button) {
+	if !element.Enabled() { return }
+	element.Focus()
+	if button == input.ButtonLeft {
+		element.dragging = true
+		element.value = element.valueFor(x, y)
+		if element.onSlide != nil {
+			element.onSlide()
+		}
+		element.redo()
+	}
+}
+
+func (element *Slider) HandleMouseUp (x, y int, button input.Button) {
+	if button != input.ButtonLeft || !element.dragging { return }
+	element.dragging = false
+	if element.onRelease != nil {
+		element.onRelease()
+	}
+	element.redo()
+}
+
+func (element *Slider) HandleMouseMove (x, y int) {
+	if element.dragging {
+		element.dragging = true
+		element.value = element.valueFor(x, y)
+		if element.onSlide != nil {
+			element.onSlide()
+		}
+		element.redo()
+	}
+}
+
+func (element *Slider) HandleMouseScroll (x, y int, deltaX, deltaY float64) { }
+
+func (element *Slider) HandleKeyDown (key input.Key, modifiers input.Modifiers) {
+	// TODO: handle left and right arrows
+}
+
+func (element *Slider) HandleKeyUp (key input.Key, modifiers input.Modifiers) { }
+
+func (element *Slider) Value () (value float64) {
+	return element.value
+}
+
+func (element *Slider) SetEnabled (enabled bool) {
+	element.focusableControl.SetEnabled(enabled)
+}
+
+func (element *Slider) SetValue (value float64) {
+	if value < 0 { value = 0 }
+	if value > 1 { value = 1 }
+	
+	if element.value == value { return }
+
+	element.value = value
+	element.redo()
+}
+
+func (element *Slider) OnSlide (callback func ()) {
+	element.onSlide = callback
+}
+
+func (element *Slider) OnRelease (callback func ()) {
+	element.onRelease = callback
+}
+
+// SetTheme sets the element's theme.
+func (element *Slider) SetTheme (new theme.Theme) {
+	if new == element.theme.Theme { return }
+	element.theme.Theme = new
+	element.redo()
+}
+
+// SetConfig sets the element's configuration.
+func (element *Slider) SetConfig (new config.Config) {
+	if new == element.config.Config { return }
+	element.config.Config = new
+	element.updateMinimumSize()
+	element.redo()
+}
+
+func (element *Slider) valueFor (x, y int) (value float64) {
+	if element.vertical {
+		value =
+			float64(y - element.track.Min.Y - element.bar.Dy() / 2) /
+			float64(element.track.Dy() - element.bar.Dy())
+	} else {
+		value =
+			float64(x - element.track.Min.X - element.bar.Dx() / 2) /
+			float64(element.track.Dx() - element.bar.Dx())
+	}
+	
+	if value < 0 { value = 0 }
+	if value > 1 { value = 1 }
+	value = 1 - value
+	return
+}
+
+func (element *Slider) updateMinimumSize () {
+	if element.vertical {
+		element.core.SetMinimumSize (
+			element.config.HandleWidth(),
+			element.config.HandleWidth() * 2)
+	} else {
+		element.core.SetMinimumSize (
+			element.config.HandleWidth() * 2,
+			element.config.HandleWidth())
+	}
+}
+
+func (element *Slider) redo () {
+	if element.core.HasImage () {
+		element.draw()
+		element.core.DamageAll()
+	}
+}
+
+func (element *Slider) draw () {
+	bounds := element.Bounds()
+	element.track = element.theme.Inset(theme.PatternGutter).Apply(bounds)
+	if element.vertical {
+		barSize := element.track.Dx()
+		element.bar = image.Rect(0, 0, barSize, barSize).Add(bounds.Min)
+		barOffset :=
+			float64(element.track.Dy() - barSize) *
+			(1 - element.value)
+		element.bar = element.bar.Add(image.Pt(0, int(barOffset)))
+	} else {
+		barSize := element.track.Dy()
+		element.bar = image.Rect(0, 0, barSize, barSize).Add(bounds.Min)
+		barOffset :=
+			float64(element.track.Dx() - barSize) *
+			element.value
+		element.bar = element.bar.Add(image.Pt(int(barOffset), 0))
+	}
+
+	state := theme.PatternState {
+		Focused:  element.Focused(),
+		Disabled: !element.Enabled(),
+		Pressed:  element.dragging,
+	}
+	artist.FillRectangle (
+		element,
+		element.theme.Pattern(theme.PatternGutter, state),
+		bounds)
+	artist.FillRectangle (
+		element,
+		element.theme.Pattern(theme.PatternHandle, state),
+		element.bar)
+}