Preferences not saved in Android Emulator (Linux)

[akzincsystems]

Checklist

• I have searched the issue tracker for open issues that relate to the same problem, before opening a new one.
• This issue only relates to a single bug. I will open new issues for any other problems.

Describe the bug

When running my application in Android Emulator on Linux, preferences do not get saved.

They get saved running in web mode and as a Desktop application

Android Debug Bridge version 1.0.41
Version 35.0.0-11411520
Running on Linux 6.8.0-88-generic (x86_64)

Android Emulator V36.2.12-14214601

fyne cli version: v1.6.2
fyne library version: v2.7.1

How to reproduce

1. Create application
2. Uninstall previous version (Make command ${ADB} shell cmd package uninstall -k ${APP_ID})
3. Build new version (Make command export ANDROID_NDK_HOME=${NDK_HOME} && fyne package -os android)
4. Install new version to emulator (Make command ${ADB} install ${APP_NAME}.apk)
5. Start app in emulator
6. Go to settings screen, enter values and click on save button
7. See confirmation dialog that settings have been saved
8. Exit app and restart
9. Go to settings screen. See that previously entered values have not been saved

Screenshots

No response

Example code

My code contains a Prefs struct (global params variable) which handles all operations for preferences. The prefs.Save() method is called in the OnSubmit callback for the settings screen.

// Save stores the configuration in the preference store
func (cfg *Prefs) Save() {
	p := fyne.CurrentApp().Preferences()
	p.SetString(awsKey, cfg.AwsAccessKey)
	p.SetString(awsSecret, cfg.AwsSecret)
	p.SetString(currentInstance, cfg.CurrenInstance)
	for i := 0; i < 10; i++ {
		slot := fmt.Sprintf("%s%d", "slot", i+1)
		p.SetString(fmt.Sprintf("ins%s", slot), cfg.Instances[slot])
		p.SetString(fmt.Sprintf("ids%s", slot), cfg.Ids[slot])
		p.SetString(fmt.Sprintf("reg%s", slot), cfg.Regions[slot])
	}
	cfg.Saved = true
}

        accessKey := binding.NewString()
	secretKey := binding.NewString()
	if err := accessKey.Set(params.AwsAccessKey); err != nil {
		panic(err)
	}
	if err := secretKey.Set(params.AwsSecret); err != nil {
		panic(err)
	}
	accessKeyItem := widget.NewFormItem("AWS Access Key", widget.NewEntryWithData(accessKey))
	secretKeyItem := widget.NewFormItem("AWS Secret Key", widget.NewEntryWithData(secretKey))

	form := &widget.Form{
		Items: []*widget.FormItem{
			accessKeyItem,
			secretKeyItem,
		},
		OnSubmit: func() {
	                params.Saved = false
			v, err := accessKey.Get()
			if err == nil {
				params.AwsAccessKey = v
			}
			v, err = secretKey.Get()
			if err == nil {
				params.AwsSecret = v
			}
			params.Save()
			dialog := dialog2.NewInformation("Success", "Settings saved", myWindow)
			dialog.Show()
		},
		OnCancel:    func() {},
		SubmitText:  "Save",
		CancelText:  "Cancel",
		Orientation: 0,
	}

Fyne version

2.7.1

Go compiler version

1.23.4

Operating system and version

Ubuntu 24.04.3 LTS

Additional Information

No response

[andydotxyz]

Can you create a small example showing the problem? I cannot replicate with the basic Fyne demo app which uses preferences.

In theory it should be just a few lines of code but it will help to identify where the cause may lie.

[akzincsystems]

@andydotxyz Yes, I can do that. Will take a couple of days as I have to work for next few. Actually, what will do is push all my code onto github. It's an OS app anyway, or will be. All working nicely except this one glitch and some layout/theme issues. But I'll raise other tickets for those.

[andydotxyz]

A code dump won't help us to quickly fix the issue - but a minimal example we can use as a test case will.

For clarity here... The android emulator preference is working in other apps - by distilling down to a code sample that replicates the problem you will be able to figure what is different about your app that causes this bug.