Window Handling

Windows are created using App.NewWindow() and need to be shown using the Show() function. The helper method ShowAndRun() on fyne.Window allows you to show your window and run the application at the same time.

By default a window will be the right size to show its content by checking the MinSize() function (more on that in later examples). You can set a larger size by calling the Window.Resize() method. Into this is passed a fyne.Size which contains a width and height using device independent pixels (meaning that it will be the same across different devices), for example to make a window square by default we could:

	w.Resize(fyne.NewSize(100, 100))

Be aware that the desktop environment may have constraints that cause windows to be smaller than requested. Mobile devices will typically ignore this as they are only displayed at full-screen.

If you wish to show a second window you must only call the Show() function. It can also be helpful to split Window.Show() from App.Run() if you want to open multiple windows when your application starts. The example below shows how to load two windows when starting.

package main

import (

func main() {
	a := app.New()
	w := a.NewWindow("Hello World")

	w.SetContent(widget.NewLabel("Hello World!"))

	w2 := a.NewWindow("Larger")
	w2.SetContent(widget.NewLabel("More content"))
	w2.Resize(fyne.NewSize(100, 100))


The above application will exit when both windows are closed. If your app is arranged so one window is main and the others are accessory views you can set one window to be “master” so that the app exits if that window is closed. To do this use the SetMaster() function on Window.

Windows can be created at any time, we could change the code above so that the content of the second window (w2) is a button that opens a new window. You could also load windows from more complex workflows, but be careful because new windows will normally appear above the current active content.

	w2.SetContent(widget.NewButton("Open new", func() {
		w3 := a.NewWindow("Third")