objects/swatch.go

package objects

import "log"
import "image"
import "image/color"
import "git.tebibyte.media/tomo/tomo"
import "git.tebibyte.media/tomo/tomo/input"
import "git.tebibyte.media/tomo/tomo/event"
import "git.tebibyte.media/tomo/tomo/canvas"
import "git.tebibyte.media/tomo/objects/layouts"
import "git.tebibyte.media/tomo/objects/internal"

// Swatch displays a color, allowing the user to edit it by clicking on it.
type Swatch struct {
	tomo.CanvasBox
	value color.Color
	editing bool
	label string
	on struct {
		valueChange event.FuncBroadcaster
		confirm     event.FuncBroadcaster
	}
}

// NewSwatch creates a new swatch with the given color.
func NewSwatch (value color.Color) *Swatch {
	swatch := &Swatch {
		CanvasBox: tomo.NewCanvasBox(),
	}
	swatch.SetRole(tomo.R("objects", "Swatch"))
	swatch.SetDrawer(swatch)
	swatch.SetValue(value)
	
	swatch.OnButtonDown(swatch.handleButtonDown)
	swatch.OnButtonUp(swatch.handleButtonUp)
	swatch.OnKeyDown(swatch.handleKeyDown)
	swatch.OnKeyUp(swatch.handleKeyUp)
	swatch.SetFocusable(true)
	return swatch
}

// Value returns the color of the swatch.
func (this *Swatch) Value () color.Color {
	return this.value
}

// SetValue sets the color of the swatch.
func (this *Swatch) SetValue (value color.Color) {
	this.value = value
	if value == nil { value = color.Transparent }
	this.Invalidate()
}

// OnValueChange specifies a function to be called when the swatch's color
// is changed by the user.
func (this *Swatch) OnValueChange (callback func ()) event.Cookie {
	return this.on.valueChange.Connect(callback)
}

// RGBA satisfies the color.Color interface
func (this *Swatch) RGBA () (r, g, b, a uint32) {
	if this.value == nil { return }
	return this.value.RGBA()
}

// OnConfirm specifies a function to be called when the user selects "OK" in the
// color picker.
func (this *Swatch) OnConfirm (callback func ()) event.Cookie {
	return this.on.confirm.Connect(callback)
}

// Choose creates a modal that allows the user to edit the color of the swatch.
func (this *Swatch) Choose () {
	if this.editing { return }

	var err    error
	var window tomo.Window
	if parent := this.Window(); parent != nil {
		window, err = parent.NewChild(image.Rectangle { })
	} else {
		window, err = tomo.NewWindow(image.Rectangle { })
	}
	if err != nil {
		log.Println("objects: could not create swatch modal:", err)
		return
	}
	if this.label == "" {
		window.SetTitle("Select Color")
	} else {
		window.SetTitle(this.label)
	}
	
	committed := false
	
	colorPicker  := NewHSVAColorPicker(this.Value())
	colorMemory  := this.value
	hexInput     := NewTextInput("")
	hexInput.SetFocused(true)
	cancelButton := NewButton("Cancel")
	cancelButton.SetIcon(tomo.IconDialogCancel)
	okButton     := NewButton("OK")
	okButton.SetIcon(tomo.IconDialogOkay)
	
	updateHexInput := func () {
		nrgba := color.NRGBAModel.Convert(colorPicker.Value()).(color.NRGBA)
		hexInput.SetValue(internal.FormatNRGBA(nrgba))
	}
	updateHexInput()
	commit := func () {
		committed = true
		window.Close()
	}
	colorPicker.OnValueChange(func () {
		this.userSetValue(colorPicker.Value())
		updateHexInput()
	})
	hexInput.OnConfirm(commit)
	hexInput.OnValueChange(func () {
		nrgba := internal.ParseNRGBA(hexInput.Value())
		this.userSetValue(nrgba)
		colorPicker.SetValue(nrgba)
	})
	cancelButton.OnClick(func () {
		window.Close()
	})
	okButton.OnClick(commit)
	
	controlRow := NewInnerContainer (
		layouts.ContractHorizontal,
		cancelButton,
		okButton)
	controlRow.SetAttr(tomo.AAlign(tomo.AlignEnd, tomo.AlignMiddle))
	window.SetRoot(NewOuterContainer (
		layouts.Column { true, false },
		colorPicker,
		NewInnerContainer(layouts.Row { false, true },
			NewLabel("Hex"),
			hexInput),
		controlRow))
	window.OnClose(func () {
		if committed {
			this.on.confirm.Broadcast()
		} else {
			this.userSetValue(colorMemory)
		}
		this.editing = false
	})
	this.editing = true
	window.SetVisible(true)
}

func (this *Swatch) Draw (can canvas.Canvas) {
	pen := can.Pen()
	
	// transparency slash
	pen.Stroke(color.RGBA { R: 255, A: 255 })
	pen.StrokeWeight(1)
	pen.Path(this.Bounds().Min, this.Bounds().Max)
	
	// color
	if this.value != nil {
		pen.StrokeWeight(0)
		pen.Fill(this.value)
		pen.Rectangle(this.Bounds())
	}
}

func (this *Swatch) userSetValue (value color.Color) {
	this.SetValue(value)
	this.on.valueChange.Broadcast()
}

func (this *Swatch) handleKeyDown (key input.Key, numberPad bool) bool {
	if !isClickingKey(key) { return false }
	this.Choose()
	return true
}

func (this *Swatch) handleKeyUp (key input.Key, numberPad bool) bool {
	if !isClickingKey(key) { return false }
	return true
}

func (this *Swatch) handleButtonDown (button input.Button) bool {
	if !isClickingButton(button) { return false }
	return true
}

func (this *Swatch) handleButtonUp (button input.Button) bool {
	if !isClickingButton(button) { return false }
	if this.Window().MousePosition().In(this.Bounds()) {
		this.Choose()
	}
	return true
}