Set `FlutterDevice.viewFilter` by CLI flag (#23026)

`FlutterDevice.views` is limited by a filter. Pipe this filter up as an
option for the commands that instantiate `FlutterDevice`s. This is the
first change necessary for the CLI tooling to target specific isolates
(#22009).

More work needs to be done after this patch.
* Isolate names are dynamically generated and change every restart.
* This just filters views, not background isolates (`VMService.isolates`).

packages/flutter_tools/lib/src/commands/attach.dart

@@ -37,6 +37,7 @@ final String ipv4Loopback = InternetAddress.loopbackIPv4.address;
 class AttachCommand extends FlutterCommand {
   AttachCommand({bool verboseHelp = false, this.hotRunnerFactory}) {
     addBuildModeFlags(defaultToRelease: false);
+    usesIsolateFilterOption(hide: !verboseHelp);
     usesTargetOption();
     usesFilesystemOptions(hide: !verboseHelp);
     argParser
@@ -122,6 +123,7 @@ class AttachCommand extends FlutterCommand {
         dillOutputPath: argResults['output-dill'],
         fileSystemRoots: argResults['filesystem-root'],
         fileSystemScheme: argResults['filesystem-scheme'],
+        viewFilter: argResults['isolate-filter'],
       );
       flutterDevice.observatoryUris = <Uri>[ observatoryUri ];
       final HotRunner hotRunner = hotRunnerFactory.build(

packages/flutter_tools/lib/src/commands/daemon.dart

@@ -338,6 +338,7 @@ class AppDomain extends Domain {
     String packagesFilePath,
     String dillOutputPath,
     bool ipv6 = false,
+    String isolateFilter,
   }) async {
     if (await device.isLocalEmulator && !options.buildInfo.supportsEmulator) {
       throw '${toTitleCase(options.buildInfo.modeName)} mode is not supported for emulators.';
@@ -351,6 +352,7 @@ class AppDomain extends Domain {
       device,
       trackWidgetCreation: trackWidgetCreation,
       dillOutputPath: dillOutputPath,
+      viewFilter: isolateFilter,
     );
 
     ResidentRunner runner;

packages/flutter_tools/lib/src/commands/fuchsia_reload.dart

@@ -158,6 +158,7 @@ class FuchsiaReloadCommand extends FlutterCommand {
         final FlutterDevice flutterDevice = FlutterDevice(
           device,
           trackWidgetCreation: false,
+          viewFilter: isolateName,
         );
         flutterDevice.observatoryUris = observatoryUris;
           final HotRunner hotRunner = HotRunner(<FlutterDevice>[flutterDevice],
@@ -166,7 +167,7 @@ class FuchsiaReloadCommand extends FlutterCommand {
           projectRootPath: _fuchsiaProjectPath,
               packagesFilePath: _dotPackagesPath);
         printStatus('Connecting to $_modName');
-        await hotRunner.attach(viewFilter: isolateName);
+        await hotRunner.attach();
       } finally {
         await Future.wait<void>(forwardedPorts.map<Future<void>>((_PortForwarder pf) => pf.stop()));
       }

packages/flutter_tools/lib/src/commands/run.dart

@@ -19,6 +19,7 @@ import '../run_hot.dart';
 import '../runner/flutter_command.dart';
 import 'daemon.dart';
 
+// TODO(flutter/flutter#23031): Test this.
 abstract class RunCommandBase extends FlutterCommand {
   // Used by run and drive commands.
   RunCommandBase({ bool verboseHelp = false }) {
@@ -46,6 +47,7 @@ abstract class RunCommandBase extends FlutterCommand {
     usesTargetOption();
     usesPortOptions();
     usesPubOption();
+    usesIsolateFilterOption(hide: !verboseHelp);
   }
 
   bool get traceStartup => argResults['trace-startup'];
@@ -351,6 +353,7 @@ class RunCommand extends RunCommandBase {
         dillOutputPath: argResults['output-dill'],
         fileSystemRoots: argResults['filesystem-root'],
         fileSystemScheme: argResults['filesystem-scheme'],
+        viewFilter: argResults['isolate-filter'],
       );
     }).toList();
 

packages/flutter_tools/lib/src/resident_runner.dart

@@ -34,6 +34,7 @@ class FlutterDevice {
     this.dillOutputPath,
     this.fileSystemRoots,
     this.fileSystemScheme,
+    this.viewFilter,
     ResidentCompiler generator,
   }) : generator = generator ?? ResidentCompiler(
          artifacts.getArtifactPath(Artifact.flutterPatchedSdkPath),
@@ -51,7 +52,7 @@ class FlutterDevice {
   List<String> fileSystemRoots;
   String fileSystemScheme;
   StreamSubscription<String> _loggingSubscription;
-  String viewFilter;
+  final String viewFilter;
 
   /// If the [reloadSources] parameter is not null the 'reloadSources' service
   /// will be registered.
@@ -618,14 +619,12 @@ abstract class ResidentRunner {
 
   /// If the [reloadSources] parameter is not null the 'reloadSources' service
   /// will be registered
-  Future<void> connectToServiceProtocol({String viewFilter,
-      ReloadSources reloadSources, CompileExpression compileExpression}) async {
+  Future<void> connectToServiceProtocol({ReloadSources reloadSources, CompileExpression compileExpression}) async {
     if (!debuggingOptions.debuggingEnabled)
       return Future<void>.error('Error the service protocol is not enabled.');
 
     bool viewFound = false;
     for (FlutterDevice device in flutterDevices) {
-      device.viewFilter = viewFilter;
       await device._connect(reloadSources: reloadSources,
           compileExpression: compileExpression);
       await device.getVMs();

packages/flutter_tools/lib/src/run_cold.dart

@@ -12,6 +12,7 @@ import 'globals.dart';
 import 'resident_runner.dart';
 import 'tracing.dart';
 
+// TODO(flutter/flutter#23031): Test this.
 class ColdRunner extends ResidentRunner {
   ColdRunner(
     List<FlutterDevice> devices, {

packages/flutter_tools/lib/src/run_hot.dart

@@ -41,6 +41,7 @@ HotRunnerConfig get hotRunnerConfig => context[HotRunnerConfig];
 
 const bool kHotReloadDefault = true;
 
+// TODO(flutter/flutter#23031): Test this.
 class HotRunner extends ResidentRunner {
   HotRunner(
     List<FlutterDevice> devices, {
@@ -152,13 +153,10 @@ class HotRunner extends ResidentRunner {
   Future<int> attach({
     Completer<DebugConnectionInfo> connectionInfoCompleter,
     Completer<void> appStartedCompleter,
-    String viewFilter,
   }) async {
     _didAttach = true;
     try {
-      await connectToServiceProtocol(viewFilter: viewFilter,
-          reloadSources: _reloadSourcesService,
-          compileExpression: _compileExpressionService);
+      await connectToServiceProtocol(reloadSources: _reloadSourcesService, compileExpression: _compileExpressionService);
     } catch (error) {
       printError('Error connecting to the service protocol: $error');
       return 2;
@@ -285,6 +283,12 @@ class HotRunner extends ResidentRunner {
         // occurred and tighten this message.
         printStatus('Try again after fixing the above error(s).', emphasis: true);
       }
+    } else if (lower == 'l') {
+      final List<FlutterView> views = flutterDevices.expand((FlutterDevice d) => d.views).toList();
+      printStatus('Connected ${pluralize('view', views.length)}:');
+      for (FlutterView v in views) {
+        printStatus('${v.uiIsolate.name} (${v.uiIsolate.id})', indent: 2);
+      }
     }
   }
 

packages/flutter_tools/lib/src/runner/flutter_command.dart

@@ -166,6 +166,14 @@ abstract class FlutterCommand extends Command<void> {
         valueHelp: 'x.y.z');
   }
 
+  void usesIsolateFilterOption({@required bool hide}) {
+    argParser.addOption('isolate-filter',
+      defaultsTo: null,
+      hide: hide,
+      help: 'Restricts commands to a subset of the available isolates (running instances of Flutter).\n'
+            'Normally there\'s only one, but when adding Flutter to a pre-existing app it\'s possible to create multiple.');
+  }
+
   void addBuildModeFlags({bool defaultToRelease = true, bool verboseHelp = false}) {
     defaultBuildMode = defaultToRelease ? BuildMode.release : BuildMode.debug;
 

packages/flutter_tools/lib/src/vmservice.dart

@@ -102,6 +102,7 @@ const Duration kLongRequestTimeout = Duration(minutes: 1);
 /// Used for RPC requests that should never take a long time.
 const Duration kShortRequestTimeout = Duration(seconds: 5);
 
+// TODO(flutter/flutter#23031): Test this.
 /// A connection to the Dart VM Service.
 class VMService {
   VMService._(