Fix pressing back on AuthenticationFragment

If login request isn't disabled when user presses
back then they might get navigated back to
authentication again.

app/src/main/java/gq/kirmanak/mealient/extensions/FragmentExtensions.kt

@@ -0,0 +1,30 @@
+package gq.kirmanak.mealient.extensions
+
+import androidx.activity.OnBackPressedDispatcher
+import androidx.activity.addCallback
+import androidx.fragment.app.Fragment
+import androidx.lifecycle.lifecycleScope
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.channels.awaitClose
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.callbackFlow
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.launch
+
+fun Fragment.executeOnceOnBackPressed(action: () -> Unit) {
+    val onBackPressedDispatcher = requireActivity().onBackPressedDispatcher
+    lifecycleScope.launch {
+        onBackPressedDispatcher.backPressedFlow().first()
+        action()
+        onBackPressedDispatcher.onBackPressed() // Execute other callbacks now
+    }
+}
+
+@OptIn(ExperimentalCoroutinesApi::class)
+fun OnBackPressedDispatcher.backPressedFlow(): Flow<Unit> = callbackFlow {
+    val callback = addCallback { trySend(Unit) }
+    awaitClose {
+        callback.isEnabled = false
+        callback.remove()
+    }
+}

app/src/main/java/gq/kirmanak/mealient/extensions/ViewExtensions.kt

@@ -0,0 +1,112 @@
+package gq.kirmanak.mealient.extensions
+
+import android.app.Activity
+import android.os.Build
+import android.view.View
+import android.view.WindowInsets
+import android.widget.EditText
+import android.widget.TextView
+import androidx.annotation.RequiresApi
+import androidx.appcompat.app.AppCompatActivity
+import androidx.core.widget.doAfterTextChanged
+import androidx.lifecycle.LifecycleCoroutineScope
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.asLiveData
+import androidx.swiperefreshlayout.widget.SwipeRefreshLayout
+import com.google.android.material.textfield.TextInputLayout
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.channels.ChannelResult
+import kotlinx.coroutines.channels.awaitClose
+import kotlinx.coroutines.channels.onClosed
+import kotlinx.coroutines.channels.onFailure
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.callbackFlow
+import kotlinx.coroutines.flow.filterNotNull
+import kotlinx.coroutines.flow.first
+import timber.log.Timber
+
+@OptIn(ExperimentalCoroutinesApi::class)
+fun SwipeRefreshLayout.refreshesLiveData(): LiveData<Unit> {
+    val callbackFlow: Flow<Unit> = callbackFlow {
+        val listener = SwipeRefreshLayout.OnRefreshListener {
+            Timber.v("Refresh requested")
+            trySend(Unit).logErrors("refreshesFlow")
+        }
+        Timber.v("Adding refresh request listener")
+        setOnRefreshListener(listener)
+        awaitClose {
+            Timber.v("Removing refresh request listener")
+            setOnRefreshListener(null)
+        }
+    }
+    return callbackFlow.asLiveData()
+}
+
+fun Activity.setSystemUiVisibility(isVisible: Boolean) {
+    Timber.v("setSystemUiVisibility() called with: isVisible = $isVisible")
+    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) setSystemUiVisibilityV30(isVisible)
+    else setSystemUiVisibilityV1(isVisible)
+}
+
+@Suppress("DEPRECATION")
+private fun Activity.setSystemUiVisibilityV1(isVisible: Boolean) {
+    Timber.v("setSystemUiVisibilityV1() called with: isVisible = $isVisible")
+    window.decorView.systemUiVisibility = if (isVisible) 0 else View.SYSTEM_UI_FLAG_FULLSCREEN
+}
+
+@RequiresApi(Build.VERSION_CODES.R)
+private fun Activity.setSystemUiVisibilityV30(isVisible: Boolean) {
+    Timber.v("setSystemUiVisibilityV30() called with: isVisible = $isVisible")
+    val systemBars = WindowInsets.Type.systemBars()
+    window.insetsController?.apply { if (isVisible) show(systemBars) else hide(systemBars) }
+        ?: Timber.w("setSystemUiVisibilityV30: insets controller is null")
+}
+
+fun AppCompatActivity.setActionBarVisibility(isVisible: Boolean) {
+    Timber.v("setActionBarVisibility() called with: isVisible = $isVisible")
+    supportActionBar?.apply { if (isVisible) show() else hide() }
+        ?: Timber.w("setActionBarVisibility: action bar is null")
+}
+
+@OptIn(ExperimentalCoroutinesApi::class)
+fun TextView.textChangesFlow(): Flow<CharSequence?> = callbackFlow {
+    Timber.v("textChangesFlow() called")
+    val textWatcher = doAfterTextChanged {
+        trySend(it).logErrors("textChangesFlow")
+    }
+    awaitClose {
+        Timber.d("textChangesFlow: flow is closing")
+        removeTextChangedListener(textWatcher)
+    }
+}
+
+fun <T> ChannelResult<T>.logErrors(methodName: String): ChannelResult<T> {
+    onFailure { Timber.e(it, "$methodName: can't send event") }
+    onClosed { Timber.e(it, "$methodName: flow has been closed") }
+    return this
+}
+
+fun EditText.checkIfInputIsEmpty(
+    inputLayout: TextInputLayout,
+    lifecycleCoroutineScope: LifecycleCoroutineScope,
+    errorText: () -> String
+): String? {
+    Timber.v("checkIfInputIsEmpty() called with: input = $this, inputLayout = $inputLayout, errorText = $errorText")
+    val text = text?.toString()
+    Timber.d("Input text is \"$text\"")
+    if (text.isNullOrEmpty()) {
+        inputLayout.error = errorText()
+        lifecycleCoroutineScope.launchWhenResumed {
+            waitUntilNotEmpty()
+            inputLayout.error = null
+        }
+        return null
+    }
+    return text
+}
+
+suspend fun EditText.waitUntilNotEmpty() {
+    Timber.v("waitUntilNotEmpty() called with: input = $this")
+    textChangesFlow().filterNotNull().first { it.isNotEmpty() }
+    Timber.v("waitUntilNotEmpty() returned")
+}