How to switch view in split screen mode programatically in Android?

Question

How to switch view in split screen mode programatically in Android? Any code I can use? Thanks!

Answer 1

For Android Studio 4.1.1, click Split.

Answer 2

First don't forget to add the permissions for querying all apps in the AndroidManifest file:

  <uses-permission android:name="android.permission.QUERY_ALL_PACKAGES"/>
  <queries>
    <intent>
      <action android:name="android.intent.action.MAIN" />
      <category android:name="android.intent.category.LAUNCHER" />
    </intent>
  </queries>

This is the Kotlin method that shows all apps installed on the device in a popup and when the user picks someone from the list it gets launched in a split screen if it supports.

 private fun showAppPickerDialog() {
    val pm = packageManager

    val filteredApps = mutableListOf<ResolveInfo>()

    val allAppIntent = Intent(Intent.ACTION_MAIN, null)
    intent.addCategory(Intent.CATEGORY_LAUNCHER)
    val allApps = pm.queryIntentActivities(allAppIntent, 0)
    filteredApps.addAll(allApps)

    // Remove duplicates and ensure they are resizable
    val apps = filteredApps.distinctBy { it.activityInfo.packageName }
        .filter {
            isResizeable(it.activityInfo.metaData) &&
                    isNotSystemApp(it.activityInfo.applicationInfo.flags) &&
                    it.activityInfo.exported
        }

    if (apps.isEmpty()){
        Toast.makeText(this, "No Apps", Toast.LENGTH_SHORT).show()
        return
    }

    val appNames = mutableListOf<String>()
    val appIcons = mutableListOf<Drawable>()

    for (resolveInfo in apps) {
        val name = resolveInfo.loadLabel(pm).toString()
        val icon = resolveInfo.loadIcon(pm)

        appNames.add(name)
        appIcons.add(icon)
    }

    val builder = AlertDialog.Builder(this)
    val adapter = object : ArrayAdapter<String>(this, android.R.layout.select_dialog_item, android.R.id.text1, appNames) {
        override fun getView(position: Int, convertView: View?, parent: ViewGroup): View {
            val view = super.getView(position, convertView, parent)
            val textView = view.findViewById<TextView>(android.R.id.text1)
            textView.setCompoundDrawablesWithIntrinsicBounds(appIcons[position], null, null, null)
            textView.compoundDrawablePadding = 50
            return view
        }
    }

    builder.setAdapter(adapter) { _, which ->
        val packageName = apps[which].activityInfo.packageName
        val className = apps[which].activityInfo.name

        val launchIntent = Intent()
        launchIntent.component = android.content.ComponentName(packageName, className)
        launchIntent.flags = Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_LAUNCH_ADJACENT
        try {
            startActivity(launchIntent)
        } catch (e: ActivityNotFoundException) {
            Toast.makeText(this, "Something went wrong", Toast.LENGTH_SHORT).show()
        }
    }

    builder.show()
}

These are the functions used in the code above:

private fun isNotSystemApp(flags: Int) =
    (flags and ApplicationInfo.FLAG_SYSTEM) == 0 &&
        (flags and ApplicationInfo.FLAG_UPDATED_SYSTEM_APP == 0)

// For some reason this does not work very well... but I did not find a better way
private fun isResizeable(metaData: Bundle?) =
    metaData?.getBoolean("android.resizeableActivity") != false