refactor: rework password dialog to avoid memory leak

Author: msfjarvis

app/src/main/java/app/passwordstore/ui/autofill/AutofillDecryptActivity.kt

@@ -11,6 +11,7 @@ import android.content.IntentSender
 import android.os.Build
 import android.os.Bundle
 import android.view.autofill.AutofillManager
+import androidx.fragment.app.setFragmentResultListener
 import androidx.lifecycle.lifecycleScope
 import app.passwordstore.R
 import app.passwordstore.data.crypto.PGPPassphraseCache
@@ -35,7 +36,6 @@ import dagger.hilt.android.AndroidEntryPoint
 import java.io.ByteArrayOutputStream
 import java.io.File
 import javax.inject.Inject
-import kotlinx.coroutines.flow.collectLatest
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import logcat.LogPriority.ERROR
@@ -120,16 +120,15 @@ class AutofillDecryptActivity : BasePGPActivity() {
 
   private fun askPassphrase(filePath: String, clientState: Bundle, action: AutofillAction) {
     val dialog = PasswordDialog()
-    lifecycleScope.launch {
-      withContext(dispatcherProvider.main()) {
-        dialog.password.collectLatest { value ->
-          if (value != null) {
-            decryptWithPassphrase(File(filePath), clientState, action, value)
-          }
+    dialog.show(supportFragmentManager, "PASSWORD_DIALOG")
+    dialog.setFragmentResultListener(PasswordDialog.PASSWORD_RESULT_KEY) { key, bundle ->
+      if (key == PasswordDialog.PASSWORD_RESULT_KEY) {
+        val value = bundle.getString(PasswordDialog.PASSWORD_RESULT_KEY)!!
+        lifecycleScope.launch(dispatcherProvider.main()) {
+          decryptWithPassphrase(File(filePath), clientState, action, value)
         }
       }
     }
-    dialog.show(supportFragmentManager, "PASSWORD_DIALOG")
   }
 
   private suspend fun decryptWithPassphrase(

app/src/main/java/app/passwordstore/ui/crypto/DecryptActivity.kt

@@ -9,6 +9,7 @@ import android.content.Intent
 import android.os.Bundle
 import android.view.Menu
 import android.view.MenuItem
+import androidx.fragment.app.setFragmentResultListener
 import androidx.lifecycle.lifecycleScope
 import app.passwordstore.R
 import app.passwordstore.crypto.PGPIdentifier
@@ -35,7 +36,6 @@ import java.io.File
 import javax.inject.Inject
 import kotlin.time.Duration.Companion.seconds
 import kotlinx.coroutines.delay
-import kotlinx.coroutines.flow.collectLatest
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
@@ -189,9 +189,11 @@ class DecryptActivity : BasePGPActivity() {
     if (isError) {
       dialog.setError()
     }
-    lifecycleScope.launch(dispatcherProvider.main()) {
-      dialog.password.collectLatest { value ->
-        if (value != null) {
+    dialog.show(supportFragmentManager, "PASSWORD_DIALOG")
+    dialog.setFragmentResultListener(PasswordDialog.PASSWORD_RESULT_KEY) { key, bundle ->
+      if (key == PasswordDialog.PASSWORD_RESULT_KEY) {
+        val value = bundle.getString(PasswordDialog.PASSWORD_RESULT_KEY)!!
+        lifecycleScope.launch(dispatcherProvider.main()) {
           when (val result = decryptWithPassphrase(value, gpgIdentifiers)) {
             is Ok -> {
               val entry = passwordEntryFactory.create(result.value.toByteArray())
@@ -210,7 +212,6 @@ class DecryptActivity : BasePGPActivity() {
         }
       }
     }
-    dialog.show(supportFragmentManager, "PASSWORD_DIALOG")
   }
 
   private suspend fun decryptWithCachedPassphrase(

app/src/main/java/app/passwordstore/ui/crypto/PasswordDialog.kt

@@ -10,24 +10,21 @@ import android.content.DialogInterface
 import android.os.Bundle
 import android.view.KeyEvent
 import android.view.WindowManager
+import androidx.core.os.bundleOf
 import androidx.core.widget.doOnTextChanged
 import androidx.fragment.app.DialogFragment
+import androidx.fragment.app.setFragmentResult
 import app.passwordstore.R
 import app.passwordstore.databinding.DialogPasswordEntryBinding
 import app.passwordstore.util.extensions.finish
 import app.passwordstore.util.extensions.unsafeLazy
 import com.google.android.material.dialog.MaterialAlertDialogBuilder
-import kotlinx.coroutines.flow.MutableStateFlow
-import kotlinx.coroutines.flow.asStateFlow
-import kotlinx.coroutines.flow.update
 
 /** [DialogFragment] to request a password from the user and forward it along. */
 class PasswordDialog : DialogFragment() {
 
   private val binding by unsafeLazy { DialogPasswordEntryBinding.inflate(layoutInflater) }
   private var isError: Boolean = false
-  private val _password = MutableStateFlow<String?>(null)
-  val password = _password.asStateFlow()
 
   override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
     val builder = MaterialAlertDialogBuilder(requireContext())
@@ -66,7 +63,12 @@ class PasswordDialog : DialogFragment() {
   }
 
   private fun setPasswordAndDismiss() {
-    _password.update { binding.passwordEditText.text.toString() }
+    val password = binding.passwordEditText.text.toString()
+    setFragmentResult(PASSWORD_RESULT_KEY, bundleOf(PASSWORD_RESULT_KEY to password))
     dismissAllowingStateLoss()
   }
+
+  companion object {
+    const val PASSWORD_RESULT_KEY = "password_result"
+  }
 }