compose: Support images from keyboard for Android

Fixes: zulip#419
Fixes: zulip#1173

Signed-off-by: Zixuan James Li <zixuan@zulip.com>

assets/l10n/app_en.arb

@@ -522,6 +522,14 @@
   "@topicValidationErrorMandatoryButEmpty": {
     "description": "Topic validation error when topic is required but was empty."
   },
+  "errorContentNotInsertedTitle": "Content not inserted",
+  "@errorContentNotInsertedTitle": {
+    "description": "Title for error dialog when an attempt to insert rich content failed."
+  },
+  "errorContentToInsertIsEmpty": "The file to be inserted is empty or cannot be accessed.",
+  "@errorContentToInsertIsEmpty": {
+    "description": "Error message when the rich content to be inserted is empty or cannot be accessed."
+  },
   "errorInvalidApiKeyMessage": "Your account at {url} could not be authenticated. Please try logging in again or use another account.",
   "@errorInvalidApiKeyMessage": {
     "description": "Error message in the dialog for invalid API key.",

test/widgets/compose_box_test.dart

@@ -4,6 +4,7 @@ import 'dart:io';
 
 import 'package:checks/checks.dart';
 import 'package:file_picker/file_picker.dart';
+import 'package:flutter/services.dart';
 import 'package:flutter_checks/flutter_checks.dart';
 import 'package:http/http.dart' as http;
 import 'package:flutter/material.dart';
@@ -831,6 +832,106 @@ void main() {
     // target platform the test is simulating.
     // TODO(upstream): unskip after fix to https://github.com/flutter/flutter/issues/161073
     skip: Platform.isWindows);
+
+    group('attach from keyboard', () {
+      // This is adapted from:
+      //   https://github.com/flutter/flutter/blob/0ffc4ce00/packages/flutter/test/widgets/editable_text_test.dart#L724-L740
+      Future<void> insertContentFromKeyboard(WidgetTester tester, {
+        required List<int>? data,
+        required String attachedFileUrl,
+        required String mimeType,
+      }) async {
+        await tester.showKeyboard(contentInputFinder);
+        // This invokes [EditableText.performAction] on the content [TextField],
+        // which did not expose an API for testing.
+        // TODO(upstream): support a better API for testing this
+        await tester.binding.defaultBinaryMessenger.handlePlatformMessage(
+          SystemChannels.textInput.name,
+          SystemChannels.textInput.codec.encodeMethodCall(
+            MethodCall('TextInputClient.performAction', <dynamic>[
+              -1,
+              'TextInputAction.commitContent',
+              // This fakes data originally provided by the Flutter engine:
+              //   https://github.com/flutter/flutter/blob/0ffc4ce00/engine/src/flutter/shell/platform/android/io/flutter/plugin/editing/InputConnectionAdaptor.java#L497-L548
+              {
+                "mimeType": mimeType,
+                "data": data,
+                "uri": attachedFileUrl,
+              },
+            ])),
+            (ByteData? data) {});
+      }
+
+      testWidgets('success', (tester) async {
+        const fileContent = [1, 0, 1, 0, 0];
+        await prepare(tester);
+        const uploadUrl = '/user_uploads/1/4e/m2A3MSqFnWRLUf9SaPzQ0Up_/test.gif';
+        connection.prepare(json: UploadFileResult(uri: uploadUrl).toJson());
+        await insertContentFromKeyboard(tester,
+          data: fileContent,
+          attachedFileUrl:
+            'content://com.zulip.android.zulipboard.provider'
+            '/root/com.zulip.android.zulipboard/candidate_temp/test.gif',
+          mimeType: 'image/gif');
+
+        await tester.pump();
+        check(controller!.content.text)
+          .equals('see image: [Uploading test.gif…]()\n\n');
+        // (the request is checked more thoroughly in API tests)
+        check(connection.lastRequest!).isA<http.MultipartRequest>()
+          ..method.equals('POST')
+          ..files.single.which((it) => it
+            ..field.equals('file')
+            ..length.equals(fileContent.length)
+            ..filename.equals('test.gif')
+            ..contentType.asString.equals('image/gif')
+            ..has<Future<List<int>>>((f) => f.finalize().toBytes(), 'contents')
+              .completes((it) => it.deepEquals(fileContent))
+          );
+        checkAppearsLoading(tester, true);
+
+        await tester.pump(Duration.zero);
+        check(controller!.content.text)
+          .equals('see image: [test.gif]($uploadUrl)\n\n');
+        checkAppearsLoading(tester, false);
+      });
+
+      testWidgets('data is null', (tester) async {
+        await prepare(tester);
+        await insertContentFromKeyboard(tester,
+          data: null,
+          attachedFileUrl:
+          'content://com.zulip.android.zulipboard.provider'
+          '/root/com.zulip.android.zulipboard/candidate_temp/test.gif',
+          mimeType: 'image/jpeg');
+
+        await tester.pump();
+        check(controller!.content.text).equals('see image: ');
+        check(connection.takeRequests()).isEmpty();
+        checkErrorDialog(tester,
+          expectedTitle: 'Content not inserted',
+          expectedMessage: 'The file to be inserted is empty or cannot be accessed.');
+        checkAppearsLoading(tester, false);
+      });
+
+      testWidgets('data is empty', (tester) async {
+        await prepare(tester);
+        await insertContentFromKeyboard(tester,
+          data: [],
+          attachedFileUrl:
+            'content://com.zulip.android.zulipboard.provider'
+            '/root/com.zulip.android.zulipboard/candidate_temp/test.gif',
+          mimeType: 'image/jpeg');
+
+        await tester.pump();
+        check(controller!.content.text).equals('see image: ');
+        check(connection.takeRequests()).isEmpty();
+        checkErrorDialog(tester,
+          expectedTitle: 'Content not inserted',
+          expectedMessage: 'The file to be inserted is empty or cannot be accessed.');
+        checkAppearsLoading(tester, false);
+      });
+    });
   });
 
   group('error banner', () {