Add export button to account settings (#54)

app/src/main/AndroidManifest.xml

@@ -3,8 +3,8 @@
     xmlns:tools="http://schemas.android.com/tools">
 
     <application
-        android:allowBackup="true"
         android:name=".MainApplication"
+        android:allowBackup="true"
         android:dataExtractionRules="@xml/data_extraction_rules"
         android:fullBackupContent="@xml/backup_rules"
         android:icon="@mipmap/ic_launcher"
@@ -23,7 +23,17 @@
 
                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
+
         </activity>
+        <provider
+            android:name="androidx.core.content.FileProvider"
+            android:authorities="${applicationId}.fileprovider"
+            android:exported="false"
+            android:grantUriPermissions="true">
+            <meta-data
+                android:name="android.support.FILE_PROVIDER_PATHS"
+                android:resource="@xml/file_paths" />
+        </provider>
     </application>
 
 </manifest>

app/src/main/java/com/jocmp/basilreader/OPMLExporter.kt

@@ -0,0 +1,46 @@
+package com.jocmp.basilreader
+
+import android.content.Context
+import android.content.Intent
+import android.net.Uri
+import androidx.core.content.FileProvider
+import com.jocmp.basil.Account
+import java.io.File
+import java.nio.file.Files
+import java.nio.file.StandardCopyOption
+
+class OPMLExporter(
+    private val context: Context,
+) {
+    fun export(account: Account) {
+        val exports = File(context.filesDir, "exports")
+        exports.mkdirs()
+        val export = File(exports, "${account.displayName}.xml")
+
+        val source = File(account.opmlFile.path).toPath()
+        val target = export.toPath()
+
+        val result = Files.copy(source, target, StandardCopyOption.REPLACE_EXISTING)
+
+        return try {
+            val uri = context.fileURI(result.toFile())
+            val shareIntent = Intent(Intent.ACTION_SEND).apply {
+                type = "text/xml"
+                putExtra(Intent.EXTRA_STREAM, uri)
+                addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)
+            }
+
+            context.startActivity(
+                Intent.createChooser(
+                    shareIntent,
+                    context.getString(R.string.opml_exporter_chooser_title, account.displayName)
+                )
+            )
+        } catch (e: IllegalArgumentException) {
+            // return
+        }
+    }
+}
+
+private fun Context.fileURI(file: File) =
+    FileProvider.getUriForFile(this, "${packageName}.fileprovider", file)

app/src/main/java/com/jocmp/basilreader/ui/accounts/AccountSettingsScreen.kt

@@ -1,19 +1,28 @@
 package com.jocmp.basilreader.ui.accounts
 
+import android.content.Context
 import androidx.compose.runtime.Composable
+import androidx.compose.ui.platform.LocalContext
+import com.jocmp.basil.Account
+import com.jocmp.basilreader.OPMLExporter
 import org.koin.androidx.compose.koinViewModel
 
 @Composable
 fun AccountSettingsScreen(
     viewModel: AccountSettingsViewModel = koinViewModel(),
     goBack: () -> Unit,
 ) {
+    val context = LocalContext.current
+
     AccountSettingsView(
         defaultDisplayName = viewModel.displayName,
         removeAccount = {
             viewModel.removeAccount()
             goBack()
         },
-        submit = viewModel::submitName
+        submit = viewModel::submitName,
+        exportOPML = {
+            context.exportOPML(account = viewModel.account)
+        }
     )
 }

app/src/main/java/com/jocmp/basilreader/ui/accounts/AccountSettingsView.kt

@@ -27,6 +27,7 @@ fun AccountSettingsView(
     defaultDisplayName: String,
     removeAccount: () -> Unit,
     submit: (displayName: String) -> Unit,
+    exportOPML: () -> Unit,
 ) {
     val scope = rememberCoroutineScope()
     val snackbarHostState = remember { SnackbarHostState() }
@@ -70,6 +71,11 @@ fun AccountSettingsView(
             ) {
                 Text(stringResource(R.string.account_settings_submit))
             }
+            Button(
+                onClick = exportOPML
+            ) {
+                Text("Export")
+            }
             Button(onClick = { setRemoveDialogOpen(true) }) {
                 Text(stringResource(R.string.account_settings_delete_account_button))
             }
@@ -109,6 +115,7 @@ fun AccountSettingsViewPreview() {
     AccountSettingsView(
         defaultDisplayName = "Feedbin",
         removeAccount = {},
-        submit = {}
+        submit = {},
+        exportOPML = {}
     )
 }

app/src/main/java/com/jocmp/basilreader/ui/accounts/AccountSettingsViewModel.kt

@@ -1,8 +1,11 @@
 package com.jocmp.basilreader.ui.accounts
 
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.neverEqualPolicy
 import androidx.lifecycle.SavedStateHandle
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
+import com.jocmp.basil.Account
 import com.jocmp.basil.AccountManager
 import com.jocmp.basilreader.AppPreferences
 import kotlinx.coroutines.flow.Flow
@@ -13,13 +16,20 @@ class AccountSettingsViewModel(
 ): ViewModel() {
     private val args = AccountSettingsArgs(savedStateHandle)
 
-    private val account = accountManager.findByID(args.accountID)!!
+   private val _account = mutableStateOf(
+       accountManager.findByID(args.accountID)!!,
+       policy = neverEqualPolicy()
+   )
+
+    val account: Account
+        get() = _account.value
 
     val displayName: String
         get() = account.displayName
 
     fun submitName(displayName: String) {
         account.displayName = displayName
+        _account.value = account
     }
 
     fun removeAccount() {

app/src/main/java/com/jocmp/basilreader/ui/accounts/ContextExportOPMLExt.kt

@@ -0,0 +1,9 @@
+package com.jocmp.basilreader.ui.accounts
+
+import android.content.Context
+import com.jocmp.basil.Account
+import com.jocmp.basilreader.OPMLExporter
+
+fun Context.exportOPML(account: Account) {
+    OPMLExporter(this).export(account)
+}

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

@@ -34,4 +34,5 @@
     <string name="account_settings_delete_account_message">Are you sure you want to delete the account \"%1$s\"? This cannot be undone.</string>
     <string name="account_settings_delete_account_submit">Delete</string>
     <string name="account_settings_save_success_message">Settings saved</string>
+    <string name="opml_exporter_chooser_title">Export %1$s Feeds</string>
 </resources>

app/src/main/res/xml/file_paths.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<paths>
+    <files-path name="exports" path="exports/"/>
+</paths>