Catzie.net Blog

Category: Coding

  • Exception: No signature of method android() is applicable for argument types, Build Gradle // Dev Diary

    Today I wanted to make a data class a Parcelable so that I could pass it as an argument in Navigation component.

    Parcelables, though better in performance than Serializables, take more time to implement! To help us out, there’s a “kotlin-parcelize” plugin that can generate the boilerplate code for us.

    There were issues though.

    After applying the kotlin-parcelize plugin, I was getting the error:

    'kotlin-parcelize' can't be applied together with 'kotlin-android-extensions'

    So kotlin-parcelize is like a “successor” to the now deprecated 'kotlin-android-extensions' that I’m still using. So I replaced 'kotlin-android-extensions' with ‘kotlin-parcelize’.

    I got another error after attempting to sync with my Gradle files:

    org.gradle.api.GradleScriptException: A problem occurred evaluating project ':app'
[...]
Caused by: groovy.lang.MissingMethodException: No signature of method: build_54gmhuqjm83le8li4fspjsxlu.android() is applicable for argument types: (build_54gmhuqjm83le8li4fspjsxlu$_run_closure1) values: [build_54gmhuqjm83le8li4fspjsxlu$_run_closure1@3c374eea]
	at build_54gmhuqjm83le8li4fspjsxlu.run([...]\app\build.gradle:11)

    The solution was to remove the following code from my android{} block:

    androidExtensions {
    experimental = true
}

    After removing that, Gradle synced successfull!

    References:
    Parcelable implementation generator
    How to use @Parcelize now that kotlin-android-extensions is being deprecated?

  • Two-way data binding with StateFlow & BindingAdapters //Dev Diary

    I created BindingAdapters for an EditText like so:

    @BindingAdapter("android:text")
fun setText(editText: EditText, inputAmount: MutableStateFlow<Double>) {
    if (editText.text.toString() != inputAmount.value.toString()) {
        editText.setText(inputAmount.value.toString())
        editText.setSelection(editText.text.length)
    }
}

@InverseBindingAdapter(attribute = "android:text")
fun getText(editText: EditText): Double {
    if (editText.text.isEmpty()) return 0.0
    return editText.text.toString().toDouble()
}

    My XML layout element looks like this:

                <com.google.android.material.textfield.TextInputEditText
                android:id="@+id/tiet_input_amount"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:hint="@string/input_hint_amount"
                android:inputType="numberDecimal"
                android:text="@={viewModel._inputAmount}" />

    And in my ViewModel, the inputAmount is set up this way:

        val _inputAmount: MutableStateFlow<Double> = MutableStateFlow(0.0)
    val inputAmount: StateFlow<Double> = _inputAmount

  • Fix coroutine error: Cannot access database on the main thread // Android Dev Diary

    As I was running a test for a ViewModel function, I encountered the following error:

    [...] Main Thread @coroutine java.lang.IllegalStateException: Cannot access database on the main thread since it may potentially lock the UI for a long period of time.

    I think it may be caused by the viewModelScope from viewModelScope.launch {} being used by the running test, which may not be accessible during unit tests.

    What I did to fix this error on my unit test was to enable main thread operations in my in-memory Room database test instance. I simply added .allowMainThreadQueries() while building the database instance like so:

    db = Room.inMemoryDatabaseBuilder(
    context, MyRoomDatabase::class.java)
    .allowMainThreadQueries()
    .build()

    Is that the best way to do it? If you got a better suggestion, please comment! I’d love to hear about it.

  • Grant, revoke permissions via Android Studio Terminal (ADB Shell) // Android Dev Diary

    To grant and revoke permissions via Terminal (ADB Shell), run your app on an emulator (I haven’t personally tried on a device but it should work there too).

    Open your Terminal, and then enter the following command:

    adb shell

    Once you’re in, you may use the following syntax for granting or revoking your Android device’s permissions:

    pm grant <package-name> <permission>

    For example, to grant a permission:

    pm grant net.catzie.myapp android.permission.READ_EXTERNAL_STORAGE

    pm grant net.catzie.myapp android.permission.WRITE_EXTERNAL_STORAGE

    And to revoke a permission:

    pm revoke net.catzie.myapp android.permission.READ_EXTERNAL_STORAGE

    pm revoke net.catzie.myapp android.permission.WRITE_EXTERNAL_STORAGE

    Now there’s no need to open the settings screen on your device to play with your Android permissions!

  • Remove room database on app uninstall // Android Dev Diary

    The problem:

    Installing on an Android device that has an old version of an app I’m developing triggers an error:

    Room Database Migration: java.lang.IllegalStateException: Migration didn't properly handle

    Problem persists despite uninstalling the Android app and deleting all app data.

    The solution:

    Very simple. I set allowBackup to false in my AndroidManifest.xml file like so:

    android:allowBackup="false"

    Then I reinstalled the app on the Android device. Error was still triggered on first install, but after one more round of uninstall and reinstall, the error finally went away!

    Side Note / Quick Life Update:

    I have been working on an app, with me as its first user. I tentatively call it “bodymonitor”. It should let me log foods I ate, meds/supplements I took, and body sensations. My brain does not do a good job of monitoring these things so I shall get an app to help me do it. There are existing apps out there that do more or less the same thing, but I want one that caters to my specific needs. Doesn’t hurt to practice Android app development as I make the app, too!

    This weekend I’ll undergo endoscopy again, but this time it’s called a “flexible nasopharyngolaryngoscopy” which will pass through the nose instead of the mouth, to be done under local anesthesia. From the sound of it I don’t expect to be put to sleep, which makes me less anxious, but still anxious. XD It’s gonna be done because of my throat issues.

  • Get Navigation Component destinations in back stack // Android Kotlin Dev Diary

    It’s simple to get the list of destinations that’s currently in your back stack. The only thing you need is a reference to the Navigation Component’s NavController.

    The NavController object has a backQueue property that you can inspect.

    backQueue is an array, and each item’s destination property is what you’re probably looking for!

    To show my current Navigation’s back stack, I use Android Studio’s Debugger, and create watches such as the following:

    Screenshot taking when no frames were available, and thus the texts are red…

    I haven’t literally tried, but logging them programmatically like so should work too:

    for(item in navController.backQueue){
    Log.d("MyNavigationBackStack", "item.destination.displayName: ${item.destination.displayName}")
}
Log.d("MyNavigationBackStack", "navController.backQueue: ${navController.backQueue}")
Log.d("MyNavigationBackStack", "navController.currentBackStackEntry.destination.displayName: ${navController.currentBackStackEntry.destination.displayName}")
Log.d("MyNavigationBackStack", "navController.currentDestination: ${navController.currentDestination}")

    Lemme know if these work, or if you have relevant tips that haven’t been mentioned!

  • A working shared ViewModel between parent and child Fragments //Android Kotlin Dev Diary

    I initially had a problem with the shared ViewModel because the child fragments were creating a new instance from the one held by the parent fragment.

    The ViewModel instantiations below work for me:

    CreateLogFragment.kt (parent)

    CreateLogFoodFragment.kt (child)

    CreateLogNotesFragment.kt (another child)

    by activityViewModels turned things around!