guiconfig.go

package dynamic_gui_config

import (
	"log"
	"os"

	"github.com/andlabs/ui"
)

var (
	// window configuration, set during Start
	windowName   string
	windowWidth  int
	windowHeight int

	window *ui.Window           = nil
	tab    *ui.Tab              = nil
	closer *ControlCloseWrapper = nil
)

// perform a check on global variables, panic if check fails
func check() {
	if window == nil || tab == nil || closer == nil {
		panic("window pointer is nil, did you call Start()?")
	}
}

func setup() {
	ui.OnShouldQuit(func() bool {
		window.Destroy()
		window = nil
		tab = nil
		closer = nil
		return true
	})

	window = ui.NewWindow(windowName, windowWidth, windowHeight, true)
	tab = ui.NewTab()
	closer = NewControlCloseWrapper(tab)
	window.SetMargined(true)
	window.SetChild(closer)

	window.OnClosing(func(w *ui.Window) bool {
		ui.Quit()
		return true
	})
}

func uithread(setupdone chan<- bool) {
	if err := ui.Main(func() {
		setup()
		// signal setup done
		setupdone <- true
	}); err != nil {
		log.Println(err)
		os.Exit(1)
	}
	os.Exit(0)
}

// StartDefaults is an alias for Start("config", 640, 400)
func StartDefaults() {
	Start("config", 640, 400)
}

// Start starts the configuration thread and sets up the window handles
// it returns when setup is done and the handles are initialized
func Start(windowname string, width, height int) {
	windowName = windowname
	windowWidth = width
	windowHeight = height

	done := make(chan bool)

	// start the goroutine with ui.Main
	go uithread(done)

	// wait for setup task completion
	<-done
}

// Register adds the given struct pointer to the graphical interface as a new tab
func Register(name string, config interface{}) error {
	// check ui instances
	check()

	fields, err := MakeValueControl(config)
	if err != nil {
		return err
	}

	// add a new tab to the window and add controls based on struct field
	NewTab(name, fields)

	return nil
}

// NewTab creates a new tab in the configuration window
func NewTab(name string, handle ValueControl) {
	ui.QueueMain(func() {
		ctrl := handle.Create()
		if ctrl != nil {
			tab.Append(name, ctrl)
		}
	})
}

// Show displays the configuration window
func Show() {
	check()
	ui.QueueMain(window.Show)
}

// Hide hides the configuration window
func Hide() {
	ui.QueueMain(window.Hide)
}

// Stop triggers the program to quit
func Stop() {
	ui.QueueMain(ui.Quit)
}