objects/button.go

package objects

import "git.tebibyte.media/tomo/tomo"
import "git.tebibyte.media/tomo/tomo/theme"
import "git.tebibyte.media/tomo/tomo/input"
import "git.tebibyte.media/tomo/tomo/event"

// Button is a clickable button.
type Button struct {
	tomo.TextBox
	on struct {
		click event.FuncBroadcaster
	}
}

// NewButton creates a new button with the specified text.
func NewButton (text string) *Button {
	box := &Button { TextBox: tomo.NewTextBox() }
	theme.Apply(box, theme.R("objects", "Button", ""))
	box.SetText(text)
	box.SetAlign(tomo.AlignMiddle, tomo.AlignMiddle)
	box.OnMouseUp(box.handleMouseUp)
	box.OnKeyUp(box.handleKeyUp)
	box.SetFocusable(true)
	return box
}

// OnClick specifies a function to be called when the button is clicked.
func (this *Button) OnClick (callback func ()) event.Cookie {
	return this.on.click.Connect(callback)
}

func (this *Button) handleKeyUp (key input.Key, numberPad bool) {
	if key != input.KeyEnter && key != input.Key(' ') { return }
	this.on.click.Broadcast()
}

func (this *Button) handleMouseUp (button input.Button) {
	if button != input.ButtonLeft { return }
	if this.MousePosition().In(this.Bounds()) {
		this.on.click.Broadcast()
	}
}