Prompt user before leaving edit profile when any field has been modified.

app/src/main/java/com/keylesspalace/tusky/EditProfileActivity.kt

@@ -25,7 +25,9 @@ import android.view.Menu
 import android.view.MenuItem
 import android.view.View
 import android.widget.ImageView
+import androidx.activity.OnBackPressedCallback
 import androidx.activity.viewModels
+import androidx.appcompat.app.AlertDialog
 import androidx.core.view.isVisible
 import androidx.lifecycle.LiveData
 import androidx.lifecycle.lifecycleScope
@@ -46,9 +48,11 @@ import com.keylesspalace.tusky.di.ViewModelFactory
 import com.keylesspalace.tusky.util.Error
 import com.keylesspalace.tusky.util.Loading
 import com.keylesspalace.tusky.util.Success
+import com.keylesspalace.tusky.util.await
 import com.keylesspalace.tusky.util.show
 import com.keylesspalace.tusky.util.viewBinding
 import com.keylesspalace.tusky.viewmodel.EditProfileViewModel
+import com.keylesspalace.tusky.viewmodel.ProfileData
 import com.mikepenz.iconics.IconicsDrawable
 import com.mikepenz.iconics.typeface.library.googlematerial.GoogleMaterial
 import com.mikepenz.iconics.utils.colorInt
@@ -200,20 +204,37 @@ class EditProfileActivity : BaseActivity(), Injectable {
                 }
             }
         }
+
+        val onBackCallback = object : OnBackPressedCallback(enabled = true) {
+            override fun handleOnBackPressed() {
+                if (!viewModel.hasUnsavedChanges(gatherProfileData())) finish()
+
+                lifecycleScope.launch {
+                    when(showConfirmationDialog()) {
+                        AlertDialog.BUTTON_POSITIVE -> save()
+                        else -> finish()
+                    }
+                }
+            }
+        }
+
+        onBackPressedDispatcher.addCallback(this, onBackCallback)
     }
 
     override fun onStop() {
         super.onStop()
         if (!isFinishing) {
-            viewModel.updateProfile(
-                binding.displayNameEditText.text.toString(),
-                binding.noteEditText.text.toString(),
-                binding.lockedCheckBox.isChecked,
-                accountFieldEditAdapter.getFieldData()
-            )
+            viewModel.updateProfile(gatherProfileData())
         }
     }
 
+    private fun gatherProfileData() = ProfileData(
+        displayName = binding.displayNameEditText.text.toString(),
+        note = binding.noteEditText.text.toString(),
+        locked = binding.lockedCheckBox.isChecked,
+        fields = accountFieldEditAdapter.getFieldData(),
+    )
+
     private fun observeImage(
         liveData: LiveData<Uri>,
         imageView: ImageView,
@@ -287,14 +308,7 @@ class EditProfileActivity : BaseActivity(), Injectable {
         return super.onOptionsItemSelected(item)
     }
 
-    private fun save() {
-        viewModel.save(
-            binding.displayNameEditText.text.toString(),
-            binding.noteEditText.text.toString(),
-            binding.lockedCheckBox.isChecked,
-            accountFieldEditAdapter.getFieldData()
-        )
-    }
+    private fun save() = viewModel.save(gatherProfileData())
 
     private fun onSaveFailure(msg: String?) {
         val errorMsg = msg ?: getString(R.string.error_media_upload_sending)
@@ -306,4 +320,10 @@ class EditProfileActivity : BaseActivity(), Injectable {
         Log.w("EditProfileActivity", "failed to pick media", throwable)
         Snackbar.make(binding.avatarButton, R.string.error_media_upload_sending, Snackbar.LENGTH_LONG).show()
     }
+
+    private suspend fun showConfirmationDialog() = AlertDialog.Builder(this)
+        .setTitle(getString(R.string.title_edit_profile_save_changes_prompt))
+        .setMessage(getString(R.string.message_edit_profile_save_changes_prompt))
+        .create()
+        .await(R.string.action_save, R.string.action_discard)
 }

app/src/main/java/com/keylesspalace/tusky/viewmodel/EditProfileViewModel.kt

@@ -51,6 +51,17 @@ import javax.inject.Inject
 private const val HEADER_FILE_NAME = "header.png"
 private const val AVATAR_FILE_NAME = "avatar.png"
 
+
+/**
+ * Conveniently groups Profile Data users can modify in the UI.
+ */
+internal data class ProfileData(
+    val displayName: String,
+    val note: String,
+    val locked: Boolean,
+    val fields: List<StringField>,
+)
+
 class EditProfileViewModel @Inject constructor(
     private val mastodonApi: MastodonApi,
     private val eventHub: EventHub,
@@ -96,29 +107,73 @@ class EditProfileViewModel @Inject constructor(
         headerData.value = getHeaderUri()
     }
 
-    fun save(newDisplayName: String, newNote: String, newLocked: Boolean, newFields: List<StringField>) {
+    internal fun save(newProfileData: ProfileData) {
         if (saveData.value is Loading || profileData.value !is Success) {
             return
         }
 
         saveData.value = Loading()
 
-        val displayName = if (oldProfileData?.displayName == newDisplayName) {
-            null
-        } else {
-            newDisplayName.toRequestBody(MultipartBody.FORM)
+        val encoded = encodeChangedProfileFields(newProfileData)
+        if (encoded.allFieldsAreNull()) {
+            // if nothing has changed, there is no need to make a network request
+            saveData.postValue(Success())
+            return
         }
 
-        val note = if (oldProfileData?.source?.note == newNote) {
+        viewModelScope.launch {
+            mastodonApi.accountUpdateCredentials(
+                encoded.displayName, encoded.note, encoded.locked, encoded.avatar, encoded.header,
+                encoded.field1?.first, encoded.field1?.second, encoded.field2?.first, encoded.field2?.second, encoded.field3?.first, encoded.field3?.second, encoded.field4?.first, encoded.field4?.second
+            ).fold(
+                { newProfileData ->
+                    saveData.postValue(Success())
+                    eventHub.dispatch(ProfileEditedEvent(newProfileData))
+                },
+                { throwable ->
+                    saveData.postValue(Error(errorMessage = throwable.getServerErrorMessage()))
+                }
+            )
+        }
+    }
+
+    // cache activity state for rotation change
+    internal fun updateProfile(newProfileData: ProfileData) {
+        if (profileData.value is Success) {
+            val newProfileSource = profileData.value?.data?.source?.copy(note = newProfileData.note, fields = newProfileData.fields)
+            val newProfile = profileData.value?.data?.copy(
+                displayName = newProfileData.displayName,
+                locked = newProfileData.locked,
+                source = newProfileSource
+            )
+
+            profileData.postValue(Success(newProfile))
+        }
+    }
+
+    internal fun hasUnsavedChanges(newProfileData: ProfileData) : Boolean {
+        val encoded = encodeChangedProfileFields(newProfileData)
+        // If all fields are null, there are no changes.
+        return !encoded.allFieldsAreNull()
+    }
+
+    private fun encodeChangedProfileFields(newProfileData: ProfileData): EncodedProfileData {
+        val displayName = if (oldProfileData?.displayName == newProfileData.displayName) {
             null
         } else {
-            newNote.toRequestBody(MultipartBody.FORM)
+            newProfileData.displayName.toRequestBody(MultipartBody.FORM)
         }
 
-        val locked = if (oldProfileData?.locked == newLocked) {
+        val note = if (oldProfileData?.source?.note == newProfileData.note) {
             null
         } else {
-            newLocked.toString().toRequestBody(MultipartBody.FORM)
+            newProfileData.note.toRequestBody(MultipartBody.FORM)
+        }
+
+        val locked = if (oldProfileData?.locked == newProfileData.locked) {
+            null
+        } else {
+            newProfileData.locked.toString().toRequestBody(MultipartBody.FORM)
         }
 
         val avatar = if (avatarData.value != null) {
@@ -136,48 +191,15 @@ class EditProfileViewModel @Inject constructor(
         }
 
         // when one field changed, all have to be sent or they unchanged ones would get overridden
-        val fieldsUnchanged = oldProfileData?.source?.fields == newFields
-        val field1 = calculateFieldToUpdate(newFields.getOrNull(0), fieldsUnchanged)
-        val field2 = calculateFieldToUpdate(newFields.getOrNull(1), fieldsUnchanged)
-        val field3 = calculateFieldToUpdate(newFields.getOrNull(2), fieldsUnchanged)
-        val field4 = calculateFieldToUpdate(newFields.getOrNull(3), fieldsUnchanged)
+        val fieldsUnchanged = oldProfileData?.source?.fields == newProfileData.fields
+        val field1 = calculateFieldToUpdate(newProfileData.fields.getOrNull(0), fieldsUnchanged)
+        val field2 = calculateFieldToUpdate(newProfileData.fields.getOrNull(1), fieldsUnchanged)
+        val field3 = calculateFieldToUpdate(newProfileData.fields.getOrNull(2), fieldsUnchanged)
+        val field4 = calculateFieldToUpdate(newProfileData.fields.getOrNull(3), fieldsUnchanged)
 
-        if (displayName == null && note == null && locked == null && avatar == null && header == null &&
-            field1 == null && field2 == null && field3 == null && field4 == null
-        ) {
-            /** if nothing has changed, there is no need to make a network request */
-            saveData.postValue(Success())
-            return
-        }
-
-        viewModelScope.launch {
-            mastodonApi.accountUpdateCredentials(
-                displayName, note, locked, avatar, header,
-                field1?.first, field1?.second, field2?.first, field2?.second, field3?.first, field3?.second, field4?.first, field4?.second
-            ).fold(
-                { newProfileData ->
-                    saveData.postValue(Success())
-                    eventHub.dispatch(ProfileEditedEvent(newProfileData))
-                },
-                { throwable ->
-                    saveData.postValue(Error(errorMessage = throwable.getServerErrorMessage()))
-                }
-            )
-        }
-    }
-
-    // cache activity state for rotation change
-    fun updateProfile(newDisplayName: String, newNote: String, newLocked: Boolean, newFields: List<StringField>) {
-        if (profileData.value is Success) {
-            val newProfileSource = profileData.value?.data?.source?.copy(note = newNote, fields = newFields)
-            val newProfile = profileData.value?.data?.copy(
-                displayName = newDisplayName,
-                locked = newLocked,
-                source = newProfileSource
-            )
-
-            profileData.postValue(Success(newProfile))
-        }
+        return EncodedProfileData(
+            displayName, note, locked, field1, field2, field3, field4, header, avatar
+        )
     }
 
     private fun calculateFieldToUpdate(newField: StringField?, fieldsUnchanged: Boolean): Pair<RequestBody, RequestBody>? {
@@ -193,4 +215,20 @@ class EditProfileViewModel @Inject constructor(
     private fun getCacheFileForName(filename: String): File {
         return File(application.cacheDir, filename)
     }
+
+    private data class EncodedProfileData(
+        val displayName: RequestBody?,
+        val note: RequestBody?,
+        val locked: RequestBody?,
+        val field1: Pair<RequestBody, RequestBody>?,
+        val field2: Pair<RequestBody, RequestBody>?,
+        val field3: Pair<RequestBody, RequestBody>?,
+        val field4: Pair<RequestBody, RequestBody>?,
+        val header: MultipartBody.Part?,
+        val avatar: MultipartBody.Part?,
+    ) {
+        fun allFieldsAreNull() = displayName == null && note == null && locked == null
+            && avatar == null && header == null && field1 == null && field2 == null
+            && field3 == null && field4 == null
+    }
 }

app/src/main/res/values/strings.xml

@@ -820,4 +820,6 @@
     <string name="error_media_playback">Playback failed: %s</string>
     <string name="dialog_delete_filter_text">Delete filter \'%1$s\'?"</string>
     <string name="dialog_delete_filter_positive_action">Delete</string>
+    <string name="title_edit_profile_save_changes_prompt">Unsaved Changes</string>
+    <string name="message_edit_profile_save_changes_prompt">Do you want to save your profile changes?</string>
 </resources>