Bump version 6.5.40 Traffic light in the app bar showing what R is doing

Author: gjwgit

CHANGELOG.md

@@ -17,6 +17,7 @@ Visit [togaware](https://rattle.togaware.com) for details.
 
 ## 6.6 Review and Consolidate
 
++ Traffic light in the app bar showing what R is doing [6.5.40 20260816 gjw]
 + EVALUATE: Interactive prediction of an observation [6.5.39 20260816 gjw]
 + Centre the plot and restore its footer [6.5.38 20260815 gjw]
 + Fix blurry plots and enlarge the plot display [6.5.37 20260815 gjw]

lib/home.dart

@@ -67,6 +67,7 @@ import 'package:rattle/utils/reset.dart';
 import 'package:rattle/utils/show_dataset_alert_dialog.dart';
 import 'package:rattle/utils/show_ok.dart';
 import 'package:rattle/utils/show_settings_dialog.dart';
+import 'package:rattle/widgets/r_status_light.dart';
 import 'package:rattle/widgets/status_bar.dart';
 
 // Define the [NavigationRail] tabs for the home page.
@@ -454,6 +455,12 @@ class RattleHomeState extends ConsumerState<RattleHome>
 
         // Deploy the buttons aligned to the top right for actions.
         actions: [
+          // 20260816 gjw Issue #1173. Show what R is doing, since the app
+          // itself cannot show it: the panels simply have nothing new until R
+          // has finished, which looks the same as an app that has stopped.
+
+          const RStatusLight(),
+
           if (_isVersionLoaded)
             VersionWidget(
               version: _appVersion,

lib/providers/pty.dart

@@ -24,6 +24,7 @@
 /// Authors: Graham Williams
 library;
 
+import 'dart:async';
 import 'dart:convert';
 
 import 'package:flutter/material.dart';
@@ -34,6 +35,7 @@ import 'package:universal_io/io.dart' show Platform;
 import 'package:xterm/xterm.dart';
 
 import 'package:rattle/app.dart';
+import 'package:rattle/providers/r_status.dart';
 import 'package:rattle/providers/stdout.dart';
 import 'package:rattle/providers/terminal.dart';
 import 'package:rattle/utils/clean_string.dart';
@@ -61,12 +63,48 @@ final ptyProvider = StateProvider<Pty>((ref) {
 
   bool missingPackageNotified = false;
 
+  // Drive the traffic light of the app bar from what R actually reports, which
+  // is the only honest account of what R is doing: `rSource()` hands the code
+  // to the pty and returns, so the app itself does not know when R is
+  // finished. (gjw 20260816)
+  //
+  // R prints its `> ` prompt before echoing each statement it reads, so the
+  // console ending with a prompt does not on its own mean R is finished, and
+  // watching for it alone would flicker green all the way through a script.
+  // Instead we wait for R to go quiet: each chunk of output restarts the timer
+  // below, and only when nothing more has arrived for [rIdleDelay], with the
+  // console sitting at a prompt, is R actually waiting for us again.
+  //
+  // The alternative, submitting a marker command after each script and
+  // watching for it to be echoed back, would be exact but would write Rattle's
+  // own bookkeeping into the user's CONSOLE.
+
+  Timer? idleTimer;
+
   pty.output.cast<List<int>>().transform(const Utf8Decoder()).listen((data) {
     terminal.write(data);
     // debugPrint('update stdoutProvider');
-    final String accumulated = ref.read(stdoutProvider) + cleanString(data);
+    final String cleaned = cleanString(data);
+    final String accumulated = ref.read(stdoutProvider) + cleaned;
     ref.read(stdoutProvider.notifier).state = accumulated;
 
+    // An R error leaves the light red until the next script is run. R carries
+    // on with the rest of the submitted code after an error at the top level,
+    // so the prompt returning does not mean all was well.
+
+    if (rErrorReported.hasMatch(cleaned)) {
+      ref.read(rStatusProvider.notifier).state = RStatus.failed;
+    }
+
+    idleTimer?.cancel();
+    idleTimer = Timer(rIdleDelay, () {
+      final bool atPrompt = ref.read(stdoutProvider).endsWith('> ');
+
+      if (atPrompt && ref.read(rStatusProvider) == RStatus.running) {
+        ref.read(rStatusProvider.notifier).state = RStatus.ready;
+      }
+    });
+
     // If R reports a package that is not installed (or fails to load), the
     // downstream objects are never created and the display panel renders blank
     // (the "grey screen"), or throws in debug mode. Catch that here, where all
@@ -112,6 +150,11 @@ final ptyProvider = StateProvider<Pty>((ref) {
 
   pty.exitCode.then((code) {
     terminal.write('the process exited with exit code $code');
+
+    // R is gone, so nothing can run until the app is restarted or reset.
+
+    idleTimer?.cancel();
+    ref.read(rStatusProvider.notifier).state = RStatus.failed;
   });
 
   terminal.onOutput = (data) {

lib/providers/r_status.dart

@@ -0,0 +1,66 @@
+/// A provider of the status of the R process, for the traffic light display.
+///
+/// Time-stamp: "Sunday 2026-08-16 09:20:00 +1000 Graham Williams"
+///
+/// Copyright (C) 2026, Togaware Pty Ltd.
+///
+/// Licensed under the GNU General Public License, Version 3 (the "License");
+///
+/// License: https://opensource.org/license/gpl-3-0
+///
+// This program is free software: you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free Software
+// Foundation, either version 3 of the License, or (at your option) any later
+// version.
+//
+// This program is distributed in the hope that it will be useful, but WITHOUT
+// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+// FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+// details.
+//
+// You should have received a copy of the GNU General Public License along with
+// this program.  If not, see <https://opensource.org/license/gpl-3-0>.
+///
+/// Authors: Graham Williams
+
+library;
+
+import 'package:flutter_riverpod/legacy.dart';
+
+/// What the R process is doing, as shown by the traffic light in the app bar.
+
+enum RStatus {
+  /// R is at its prompt, having completed what was asked of it. Green.
+
+  ready,
+
+  /// R is running our code. Yellow.
+
+  running,
+
+  /// R reported an error, or the R process is gone. Red.
+
+  failed,
+}
+
+/// The R process starts out [RStatus.running] because it is: the R session is
+/// started when the CONSOLE is first built, and the light turns green when R
+/// settles at its prompt, having loaded. (gjw 20260816)
+
+final rStatusProvider = StateProvider<RStatus>((ref) => RStatus.running);
+
+/// How long R has to be quiet before we call it finished.
+///
+/// Long enough that the gap between R printing a prompt and echoing the next
+/// statement of a script does not read as R having finished, and short enough
+/// that the light turns green as soon as it has. (gjw 20260816)
+
+const Duration rIdleDelay = Duration(milliseconds: 400);
+
+/// How R reports an error, being `Error: ...` or `Error in <call> : ...` at the
+/// start of a line.
+///
+/// Anchored so that output which merely mentions an error, such as the
+/// `Overall Error = 16.67%` of the error matrix, is not mistaken for one.
+
+final RegExp rErrorReported = RegExp(r'^Error(:| in )', multiLine: true);

lib/r/source.dart

@@ -48,6 +48,7 @@ import 'package:rattle/providers/normalise.dart';
 import 'package:rattle/providers/number.dart';
 import 'package:rattle/providers/partition.dart';
 import 'package:rattle/providers/pty.dart';
+import 'package:rattle/providers/r_status.dart';
 import 'package:rattle/providers/selected.dart';
 import 'package:rattle/providers/selected2.dart';
 import 'package:rattle/providers/settings.dart';
@@ -621,6 +622,13 @@ Future<void> rSource(
   // was 286 lines of code. It may be char length rather than line count that is
   // important though. (gjw 20250513)
 
+  // 20260816 gjw The traffic light of the app bar goes yellow from here, being
+  // the moment the code is handed to R, and `providers/pty.dart` turns it green
+  // again when R settles back at its prompt, or red if R reports an error. This
+  // also clears a red left by a previous script.
+
+  ref.read(rStatusProvider.notifier).state = RStatus.running;
+
   if (lines.length > 200) {
     String code1 = '${lines.take(200).join('\n')}\n';
     String code2 = lines.skip(200).join('\n');

lib/widgets/r_status_light.dart

@@ -0,0 +1,108 @@
+/// A traffic light in the app bar showing what the R process is doing.
+///
+/// Time-stamp: "Sunday 2026-08-16 09:20:00 +1000 Graham Williams"
+///
+/// Copyright (C) 2026, Togaware Pty Ltd.
+///
+/// Licensed under the GNU General Public License, Version 3 (the "License");
+///
+/// License: https://opensource.org/license/gpl-3-0
+///
+// This program is free software: you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free Software
+// Foundation, either version 3 of the License, or (at your option) any later
+// version.
+//
+// This program is distributed in the hope that it will be useful, but WITHOUT
+// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+// FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+// details.
+//
+// You should have received a copy of the GNU General Public License along with
+// this program.  If not, see <https://opensource.org/license/gpl-3-0>.
+///
+/// Authors: Graham Williams
+
+library;
+
+import 'package:flutter/material.dart';
+
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:markdown_tooltip/markdown_tooltip.dart';
+
+import 'package:rattle/providers/r_status.dart';
+
+/// Show whether R is idle, busy, or has stopped.
+///
+/// Rattle hands our R code to an R session running alongside the app, and until
+/// R has finished with it the panels have nothing new to show. Without some
+/// indication of that, a slow model build is indistinguishable from an app that
+/// has stopped responding. The light reports what R is actually doing.
+
+class RStatusLight extends ConsumerWidget {
+  const RStatusLight({super.key});
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final RStatus status = ref.watch(rStatusProvider);
+
+    final (Color colour, String label, String advice) = switch (status) {
+      RStatus.ready => (
+          Colors.green,
+          'Ready',
+          'R has finished and is waiting for you. Any output is on the panel '
+              'behind, with the detail in the **Console** tab.',
+        ),
+      RStatus.running => (
+          Colors.amber,
+          'Running',
+          'R is running your code. A model over a large dataset can take a '
+              'while, so the panels will not update until this turns green. '
+              'Watch the **Console** tab to see how it is going.',
+        ),
+      RStatus.failed => (
+          Colors.red,
+          'Stopped',
+          'R reported an error, or the R session has stopped. Whatever you '
+              'last asked for may be missing or incomplete. See the '
+              '**Console** tab for what R reported. The light turns green '
+              'again once the next request succeeds.',
+        ),
+    };
+
+    return MarkdownTooltip(
+      message: '''
+
+      **R is $label**
+
+      $advice
+
+      ''',
+      child: Padding(
+        padding: const EdgeInsets.symmetric(horizontal: 12),
+        child: Row(
+          mainAxisSize: MainAxisSize.min,
+          children: [
+            // A ring around the light so that it reads as a light rather than
+            // as a coloured dot, and so it stays visible on any app bar colour.
+
+            Container(
+              width: 16,
+              height: 16,
+              decoration: BoxDecoration(
+                color: colour,
+                shape: BoxShape.circle,
+                border: Border.all(color: Colors.black26),
+              ),
+            ),
+            const SizedBox(width: 8),
+            Text(
+              label,
+              style: const TextStyle(fontSize: 14),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}

pubspec.yaml

@@ -1,7 +1,7 @@
 name: rattle
 description: Rattle Data Science Next Generation
 publish_to: 'none'
-version: 6.5.39+216
+version: 6.5.40+216
 
 environment:
   sdk: '>=3.0.5 <4.0.0'

snap/snapcraft.yaml

@@ -8,7 +8,7 @@
 
 name: rattle
 base: core22
-version: 6.5.39
+version: 6.5.40
 summary: Rattle Next Generation Data Science
 description: |
   Rattle is the data scientists toolkit.