Reload pause (#6459)

* add a pause parameter to the reload command

* encode OperationResult as json

* reverse isOk logic

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

@@ -72,6 +72,8 @@ class DaemonCommand extends FlutterCommand {
   dynamic _jsonEncodeObject(dynamic object) {
     if (object is Device)
       return _deviceToMap(object);
+    if (object is OperationResult)
+      return _operationResultToMap(object);
     return object;
   }
 
@@ -81,7 +83,7 @@ class DaemonCommand extends FlutterCommand {
   }
 }
 
-typedef void DispatchComand(Map<String, dynamic> command);
+typedef void DispatchCommand(Map<String, dynamic> command);
 
 typedef Future<dynamic> CommandHandler(Map<String, dynamic> args);
 
@@ -109,7 +111,7 @@ class Daemon {
   AppDomain appDomain;
   DeviceDomain deviceDomain;
 
-  final DispatchComand sendCommand;
+  final DispatchCommand sendCommand;
   final DaemonCommand daemonCommand;
   final NotifyingLogger notifyingLogger;
 
@@ -381,16 +383,17 @@ class AppDomain extends Domain {
     };
   }
 
-  Future<bool> restart(Map<String, dynamic> args) async {
+  Future<OperationResult> restart(Map<String, dynamic> args) async {
     String appId = _getStringArg(args, 'appId', required: true);
     bool fullRestart = _getBoolArg(args, 'fullRestart') ?? false;
+    bool pauseAfterRestart = _getBoolArg(args, 'pause') ?? false;
 
     AppInstance app = _getApp(appId);
     if (app == null)
       throw "app '$appId' not found";
 
     return app._runInZone(this, () {
-      return app.restart(fullRestart: fullRestart);
+      return app.restart(fullRestart: fullRestart, pauseAfterRestart: pauseAfterRestart);
     });
   }
 
@@ -567,11 +570,20 @@ Map<String, dynamic> _deviceToMap(Device device) {
   };
 }
 
+Map<String, dynamic> _operationResultToMap(OperationResult result) {
+  return <String, dynamic>{
+    'code': result.code,
+    'message': result.message
+  };
+}
+
 dynamic _toJsonable(dynamic obj) {
   if (obj is String || obj is int || obj is bool || obj is Map<dynamic, dynamic> || obj is List<dynamic> || obj == null)
     return obj;
   if (obj is Device)
     return obj;
+  if (obj is OperationResult)
+    return obj;
   return '$obj';
 }
 
@@ -615,8 +627,8 @@ class AppInstance {
 
   _AppRunLogger _logger;
 
-  Future<bool> restart({ bool fullRestart: false }) {
-    return runner.restart(fullRestart: fullRestart);
+  Future<OperationResult> restart({ bool fullRestart: false, bool pauseAfterRestart: false }) {
+    return runner.restart(fullRestart: fullRestart, pauseAfterRestart: pauseAfterRestart);
   }
 
   Future<Null> stop() => runner.stop();

packages/flutter_tools/lib/src/hot.dart

@@ -452,16 +452,16 @@ class HotRunner extends ResidentRunner {
   }
 
   @override
-  Future<bool> restart({ bool fullRestart: false }) async {
+  Future<OperationResult> restart({ bool fullRestart: false, bool pauseAfterRestart: false }) async {
     if (fullRestart) {
       await _restartFromSources();
-      return true;
+      return OperationResult.ok;
     } else {
-      return _reloadSources();
+      return _reloadSources(pause: pauseAfterRestart);
     }
   }
 
-  Future<bool> _reloadSources() async {
+  Future<OperationResult> _reloadSources({ bool pause: false }) async {
     if (currentView.uiIsolate == null)
       throw 'Application isolate not found';
     FirstFrameTimer firstFrameTimer = new FirstFrameTimer(vmService);
@@ -471,28 +471,31 @@ class HotRunner extends ResidentRunner {
     Status reloadStatus = logger.startProgress('Performing hot reload...');
     try {
       Map<String, dynamic> reloadReport =
-          await currentView.uiIsolate.reloadSources();
+          await currentView.uiIsolate.reloadSources(pause: pause);
       reloadStatus.stop(showElapsedTime: true);
       if (!_printReloadReport(reloadReport)) {
         // Reload failed.
         flutterUsage.sendEvent('hot', 'reload-reject');
-        return false;
+        return new OperationResult(1, 'reload rejected');
       } else {
         flutterUsage.sendEvent('hot', 'reload');
       }
     } catch (error, st) {
       int errorCode = error['code'];
+      String errorMessage = error['message'];
+
+      reloadStatus.stop(showElapsedTime: true);
+
       if (errorCode == Isolate.kIsolateReloadBarred) {
         printError('Unable to hot reload app due to an unrecoverable error in '
                    'the source code. Please address the error and then use '
                    '"R" to restart the app.');
         flutterUsage.sendEvent('hot', 'reload-barred');
-        return false;
+        return new OperationResult(errorCode, errorMessage);
       }
-      String errorMessage = error['message'];
-      reloadStatus.stop(showElapsedTime: true);
+
       printError('Hot reload failed:\ncode = $errorCode\nmessage = $errorMessage\n$st');
-      return false;
+      return new OperationResult(errorCode, errorMessage);
     }
     // Reload the isolate.
     await currentView.uiIsolate.reload();
@@ -501,7 +504,7 @@ class HotRunner extends ResidentRunner {
     if ((pauseEvent != null) && (pauseEvent.isPauseEvent)) {
       // Isolate is paused. Stop here.
       printTrace('Skipping reassemble because isolate is paused.');
-      return true;
+      return OperationResult.ok;
     }
     await _evictDirtyAssets();
     printTrace('Reassembling application');
@@ -510,7 +513,7 @@ class HotRunner extends ResidentRunner {
       waitForFrame = (await currentView.uiIsolate.flutterReassemble() != null);
     } catch (_) {
       printError('Reassembling application failed.');
-      return false;
+      return new OperationResult(1, 'error reassembling application');
     }
     try {
       /* ensure that a frame is scheduled */
@@ -530,7 +533,7 @@ class HotRunner extends ResidentRunner {
       }
       flutterUsage.sendTiming('hot', 'reload', firstFrameTimer.elapsed);
     }
-    return true;
+    return OperationResult.ok;
   }
 
   @override

packages/flutter_tools/lib/src/resident_runner.dart

@@ -38,7 +38,7 @@ abstract class ResidentRunner {
     bool shouldBuild: true
   });
 
-  Future<bool> restart({ bool fullRestart: false });
+  Future<OperationResult> restart({ bool fullRestart: false, bool pauseAfterRestart: false });
 
   Future<Null> stop() async {
     await stopEchoingDeviceLog();
@@ -209,6 +209,17 @@ abstract class ResidentRunner {
   Future<Null> handleTerminalCommand(String code);
 }
 
+class OperationResult {
+  static final OperationResult ok = new OperationResult(0, '');
+
+  OperationResult(this.code, this.message);
+
+  final int code;
+  final String message;
+
+  bool get isOk => code == 0;
+}
+
 /// Given the value of the --target option, return the path of the Dart file
 /// where the app's main function should be.
 String findMainDartFile([String target]) {

packages/flutter_tools/lib/src/run.dart

@@ -64,10 +64,10 @@ class RunAndStayResident extends ResidentRunner {
   }
 
   @override
-  Future<bool> restart({ bool fullRestart: false }) async {
+  Future<OperationResult> restart({ bool fullRestart: false, bool pauseAfterRestart: false }) async {
     if (vmService == null) {
       printError('Debugging is not enabled.');
-      return false;
+      return new OperationResult(1, 'debugging not enabled');
     } else {
       Status status = logger.startProgress('Re-starting application...');
 
@@ -79,7 +79,7 @@ class RunAndStayResident extends ResidentRunner {
           .first;
       }
 
-      bool restartResult = await device.restartApp(
+      bool result = await device.restartApp(
         _package,
         _result,
         mainPath: _mainPath,
@@ -89,12 +89,11 @@ class RunAndStayResident extends ResidentRunner {
 
       status.stop(showElapsedTime: true);
 
-      if (restartResult && extensionAddedEvent != null) {
-        // TODO(devoncarew): We should restore the route here.
+      if (result && extensionAddedEvent != null) {
         await extensionAddedEvent;
       }
 
-      return restartResult;
+      return result ? OperationResult.ok : new OperationResult(1, 'restart error');
     }
   }
 
@@ -229,9 +228,9 @@ class RunAndStayResident extends ResidentRunner {
       mainFile.writeAsBytesSync(mainFile.readAsBytesSync());
 
       Stopwatch restartTime = new Stopwatch()..start();
-      bool restarted = await restart();
+      OperationResult result = await restart();
       restartTime.stop();
-      writeRunBenchmarkFile(startTime, restarted ? restartTime : null);
+      writeRunBenchmarkFile(startTime, result.isOk ? restartTime : null);
       await new Future<Null>.delayed(new Duration(seconds: 2));
       stop();
     }

packages/flutter_tools/lib/src/vmservice.dart

@@ -754,9 +754,11 @@ class Isolate extends ServiceObjectOwner {
 
   static final int kIsolateReloadBarred = 1005;
 
-  Future<Map<String, dynamic>> reloadSources() async {
+  Future<Map<String, dynamic>> reloadSources({ bool pause: false }) async {
     try {
-      Map<String, dynamic> response = await invokeRpcRaw('_reloadSources');
+      Map<String, dynamic> response = await invokeRpcRaw(
+        '_reloadSources', <String, dynamic>{ 'pause': pause }
+      );
       return response;
     } on rpc.RpcException catch(e) {
       return new Future<Map<String, dynamic>>.error(<String, dynamic>{