Merge pull request #385 from Vorstenbosch/added-example-for-ui-update

Added an example that shows how to update the UI

Author: andlabs

examples/updateui.go

@@ -0,0 +1,115 @@
+package main
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/andlabs/ui"
+)
+
+// Example showing how to update the UI using the QueueMain function
+// especially if the update is coming from another goroutine
+//
+// see QueueMain in 'main.go' for detailed description
+
+var countLabel *ui.Label
+var count int
+
+func setupUI() {
+	mainWindow := ui.NewWindow("libui Updating UI", 640, 480, true)
+	mainWindow.OnClosing(func(*ui.Window) bool {
+		ui.Quit()
+		return true
+	})
+	ui.OnShouldQuit(func() bool {
+		mainWindow.Destroy()
+		return true
+	})
+
+	vbContainer := ui.NewVerticalBox()
+	vbContainer.SetPadded(true)
+
+	inputGroup := ui.NewGroup("Input")
+	inputGroup.SetMargined(true)
+
+	vbInput := ui.NewVerticalBox()
+	vbInput.SetPadded(true)
+
+	inputForm := ui.NewForm()
+	inputForm.SetPadded(true)
+
+	message := ui.NewEntry()
+	message.SetText("Hello World")
+	inputForm.Append("What message do you want to show?", message, false)
+
+	showMessageButton := ui.NewButton("Show message")
+	clearMessageButton := ui.NewButton("Clear message")
+
+	vbInput.Append(inputForm, false)
+	vbInput.Append(showMessageButton, false)
+	vbInput.Append(clearMessageButton, false)
+
+	inputGroup.SetChild(vbInput)
+
+	messageGroup := ui.NewGroup("Message")
+	messageGroup.SetMargined(true)
+
+	vbMessage := ui.NewVerticalBox()
+	vbMessage.SetPadded(true)
+
+	messageLabel := ui.NewLabel("")
+
+	vbMessage.Append(messageLabel, false)
+
+	messageGroup.SetChild(vbMessage)
+
+	countGroup := ui.NewGroup("Counter")
+	countGroup.SetMargined(true)
+
+	vbCounter := ui.NewVerticalBox()
+	vbCounter.SetPadded(true)
+
+	countLabel = ui.NewLabel(fmt.Sprintf("%d", count))
+
+	vbCounter.Append(countLabel, false)
+	countGroup.SetChild(vbCounter)
+
+	vbContainer.Append(inputGroup, false)
+	vbContainer.Append(messageGroup, false)
+	vbContainer.Append(countGroup, false)
+
+	mainWindow.SetChild(vbContainer)
+
+	showMessageButton.OnClicked(func(*ui.Button) {
+		// Update the UI directly as it is called from the main thread
+		messageLabel.SetText(message.Text())
+	})
+
+	clearMessageButton.OnClicked(func(*ui.Button) {
+		// Update the UI directly as it is called from the main thread
+		messageLabel.SetText("")
+	})
+
+	mainWindow.Show()
+
+	// Counting and updating the UI from another goroutine
+	go counter()
+}
+
+func counter() {
+	for {
+		time.Sleep(1 * time.Second)
+		count++
+
+		// Update the UI using the QueueMain function
+		ui.QueueMain(func() {
+			countLabel.SetText(fmt.Sprintf("%d", count))
+		})
+	}
+}
+
+func main() {
+	count = 0
+
+	ui.Main(setupUI)
+}