Catzie.net Blog

Tag: programming

  • 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!

  • My Fave Android Studio Keyboard Shortcuts

    I have been working on small Android apps, and I just want to share some of my favorite keyboard shortcuts. Some of them were manually added by me.

    Keyboard shortcuts are one of my must-haves for productivity as a programmer, as they let me navigate through code faster, allowing me to focus on creating new modules and solving problems.

    Note: I am using Windows.

    Move between Code, Split, and Design when working on an XML layout file

    Alt + Shift + Left/Right Directional Button
    (If it doesn’t work, click on the layout file’s code/design first, then retry.)

    Run app in test device or emulator

    Shift + F10

    Run app in test device or emulator with Debugger

    Shift + F9

    Navigate between open tabs (no split):

    Navigate between points/screens that you’re viewing:

    Ctrl + Alt + Left/Right

    Show Parameter Info while filling in a function call

    Ctrl + P

    Maximize/minimize editor

    Ctrl + Shift + F12

    Created a custom shortcut for Close All Tabs:

    Ctrl + Alt + Shift + F4

    Created a custom shortcut for Rebuild Project:

    Ctrl + Alt + Shift + F10

    Created a custom shortcut to toggle Distraction-Free Mode on/off:

    Ctrl + Alt + Shift + D

    Created a custom shortcut to toggle ZenMode on/off:

    Ctrl + Alt + Shift + Z

    Other keyboard shortcuts: https://developer.android.com/studio/intro/keyboard-shortcuts

  • Dao Error: Not sure how to handle query method’s return type //Android Kotlin Dev Diary

    As I brush up on my Room database knowlege I came upon the following error while building my app:

    WordDao.java:21: error: Not sure how to handle query method's return type (java.lang.Object). DELETE query methods must either return void or int (the number of deleted rows).

    The solution:

    Set Kotlin version to 1.6.10 then Room to 2.4.2 (Or use more recent compatible versions) in my top-level build.gradle file.

    Reference: Android Room Kotlin throws Delete Query error

  • Error: Type mismatch. Required: ActivityMainBinding. Found: ViewDataBinding! //Android Kotlin Dev Diary

    The problem is that this line of code is producing an error:

            binding = DataBindingUtil.setContentView(this, R.layout.activity_main)

    And the error says:

    Type mismatch.
    Required:
    ActivityMainBinding
    Found:
    ViewDataBinding!

    The solution is to add a <layout> tag in the layout file that you are inflating!