Add documentation for Slider

input.go

@@ -52,7 +52,7 @@ func (this *TextInput) handleKeyDown (key input.Key, numpad bool) {
 	word      := modifiers.Control
 	sel       := modifiers.Shift
 	changed   := false
-	
+
 	switch {
 	case key == input.KeyEnter:
 		this.on.enter.Broadcast()
@@ -87,7 +87,7 @@ func (this *TextInput) handleKeyDown (key input.Key, numpad bool) {
 		this.text, dot = text.Type(this.text, dot, rune(key))
 		changed = true
 	}
-	
+
 	this.Select(dot)
 	if changed { this.SetText(string(this.text)) }
 }

scrollbar.go

@@ -33,12 +33,12 @@ func newScrollbar (orient string) *Scrollbar {
 
 	this.Add(this.handle)
 	this.SetFocusable(true)
-	
+
 	this.CaptureDND(true)
 	this.CaptureMouse(true)
 	this.CaptureScroll(true)
 	this.CaptureKeyboard(true)
-	
+
 	this.OnKeyDown(this.handleKeyDown)
 	this.OnMouseDown(this.handleMouseDown)
 	this.OnMouseUp(this.handleMouseUp)
@@ -80,6 +80,13 @@ func (this *Scrollbar) SetValue (value float64) {
 // right/bottom.
 func (this *Scrollbar) Value () float64 {
 	// TODO
+	return 0
+}
+
+// OnValueChange specifies a function to be called when the position of the
+// scrollbar changes.
+func (this *Slider) OnValueChange (callback func ()) event.Cookie {
+	return this.on.valueChange.Connect(callback)
 }
 
 func (this *Scrollbar) handleKeyDown (key input.Key, numpad bool) {

slider.go

@@ -6,6 +6,7 @@ import "git.tebibyte.media/tomo/tomo/theme"
 import "git.tebibyte.media/tomo/tomo/input"
 import "git.tebibyte.media/tomo/tomo/event"
 
+// Slider is a control that selects a numeric value between 0 and 1.
 type Slider struct {
 	tomo.ContainerBox
 	handle     *SliderHandle
@@ -18,6 +19,8 @@ type Slider struct {
 	}
 }
 
+// SliderHandle is a simple object that serves as a handle for sliders and
+// scrollbars. It is completely inert.
 type SliderHandle struct {
 	tomo.Box
 }
@@ -35,12 +38,12 @@ func newSlider (orient string, value float64) *Slider {
 
 	this.Add(this.handle)
 	this.SetFocusable(true)
-	
+
 	this.CaptureDND(true)
 	this.CaptureMouse(true)
 	this.CaptureScroll(true)
 	this.CaptureKeyboard(true)
-	
+
 	this.SetValue(value)
 	this.OnKeyDown(this.handleKeyDown)
 	this.OnMouseDown(this.handleMouseDown)
@@ -51,14 +54,17 @@ func newSlider (orient string, value float64) *Slider {
 	return this
 }
 
+// NewVerticalSlider creates a new vertical slider with the specified value.
 func NewVerticalSlider (value float64) *Slider {
 	return newSlider("vertical", value)
 }
 
+// NewHorizontalSlider creates a new horizontal slider with the specified value.
 func NewHorizontalSlider (value float64) *Slider {
 	return newSlider("horizontal", value)
 }
 
+// SetValue sets the value of the slider between 0 and 1.
 func (this *Slider) SetValue (value float64) {
 	if value < 0 { value = 0 }
 	if value > 1 { value = 1 }
@@ -68,10 +74,13 @@ func (this *Slider) SetValue (value float64) {
 	this.on.valueChange.Broadcast()
 }
 
+// Value returns the value of the slider between 0 and 1.
 func (this *Slider) Value () float64 {
 	return this.layout.value
 }
 
+// OnValueChange specifies a function to be called when the slider's value
+// changes.
 func (this *Slider) OnValueChange (callback func ()) event.Cookie {
 	return this.on.valueChange.Connect(callback)
 }