Viewer: round icon buttons with backgrounds; plain text follows Edit -> Save too

Edit/Preview and Save are now compact (36px) icon-only NooButtons - primary when
alone, Edit/Preview secondary beside a primary Save, a spinner circle while
saving. Plain text opens read-only like Markdown and gets the same toggle.
NooButton gains an opt-in iconOnly mode.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

.claude/context/styling.md

@@ -391,11 +391,11 @@ blocks are noted where they matter:
 
 ## Text/markdown viewer
 
-`MediaTextPreview` is an editable monospace `TextField` padded clear of the status bar, top bar and action bar; a Save icon button appears in the viewer's top bar when dirty (a spinner while it saves; read-only for offline copies). The preview owns the text, the editing mode and the save; a `TextPreviewController` (owned by `FileViewerScreen`, passed to `MediaTextPreview`) mirrors that state out so the screen's top bar can draw - and trigger - the buttons, which keeps the preview's widget tree unchanged. `NooPersonAccessRow.trailing` replaces the owner label/permission pill (used by share-search results). Sheets whose close button lives in `showNooSheet` children must pop via a `Builder` context, not the caller's.
+`MediaTextPreview` is an editable monospace `TextField` padded clear of the status bar, top bar and action bar; every text file opens read-only (plain text as-is, Markdown rendered) and follows Edit -> Save: an Edit/Preview toggle and, once dirty, a Save button live in the viewer's top bar as round icon-only `NooButton`s (`iconOnly`, 36px; a lone button is primary, with two Edit/Preview is secondary and Save primary; Save becomes a primary circle with a spinner while it saves). Offline copies are read-only with no buttons. The preview owns the text, the editing mode and the save; a `TextPreviewController` (owned by `FileViewerScreen`, passed to `MediaTextPreview`) mirrors that state out so the screen's top bar can draw - and trigger - the buttons, which keeps the preview's widget tree unchanged. `NooPersonAccessRow.trailing` replaces the owner label/permission pill (used by share-search results). Sheets whose close button lives in `showNooSheet` children must pop via a `Builder` context, not the caller's.
 
 `showNooSheet` insets its body by the keyboard (`viewInsets.bottom`) so focused fields stay visible; the body's widget structure must not change when the keyboard opens, or the sheet content is rebuilt and loses focus.
 
-Markdown files (`.md`/`.markdown`) in `MediaTextPreview` open rendered via `flutter_markdown_plus` (`Markdown`, styled from Noo tokens in `_markdownStyle`), with an Edit/Preview icon toggle in the viewer's top bar (hidden for read-only offline copies). Other text files go straight to the editor.
+Markdown files (`.md`/`.markdown`) in `MediaTextPreview` open rendered via `flutter_markdown_plus` (`Markdown`, styled from Noo tokens in `_markdownStyle`), with the same Edit/Preview toggle in the viewer's top bar (hidden for read-only offline copies). Other text files go straight to the editor.
 
 `ShareSheet`: focusing the people search field does not scroll; once the user types, `_revealPeopleSection` animates the "Share with people" section (keyed by `_peopleKey` on the `NooShareSection`, not the inner column) to just below the sheet's top edge with a small gap.
 

lib/views/file_viewer_screen.dart

@@ -759,7 +759,7 @@ class _FileViewerScreenState extends State<FileViewerScreen> {
 
 /// The text viewer's top-bar buttons: Edit/Preview (markdown only) and Save
 /// (once the content changed; a spinner while it saves). Same
-/// [NooTopBarButton] look as the back button next to it.
+/// round [NooButton] look (primary for the main action, secondary beside it).
 class _TextActions extends StatelessWidget {
   final TextPreviewController controller;
 
@@ -767,39 +767,92 @@ class _TextActions extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    final colors = context.nooColors;
+    final toggle = controller.canToggleEditing;
+    final save = controller.saving || controller.showSave;
+    // One button is the primary action; with two, Save is and Edit/Preview
+    // steps back to secondary.
+    final both = toggle && save;
     return Row(
       mainAxisSize: MainAxisSize.min,
       children: [
-        if (controller.canToggleEditing)
-          NooTopBarButton(
+        if (toggle)
+          _ActionButton(
             icon: controller.editing ? LucideIcons.eye : LucideIcons.pencil,
             tooltip: controller.editing ? 'Preview' : 'Edit',
+            variant: both
+                ? NooButtonVariant.secondary
+                : NooButtonVariant.primary,
             onTap: controller.toggleEditing,
           ),
+        if (both) const SizedBox(width: 8),
         if (controller.saving)
-          Semantics(
-            label: 'Saving',
-            child: SizedBox.square(
-              dimension: 48,
-              child: Center(
-                child: SizedBox.square(
-                  dimension: 20,
-                  child: CircularProgressIndicator(
-                    strokeWidth: 2,
-                    color: colors.fg1,
-                  ),
-                ),
-              ),
-            ),
-          )
-        else if (controller.showSave)
-          NooTopBarButton(
+          const _SavingIndicator()
+        else if (save)
+          _ActionButton(
             icon: LucideIcons.save,
             tooltip: 'Save',
+            variant: NooButtonVariant.primary,
             onTap: controller.save,
           ),
       ],
     );
   }
 }
+
+/// A round icon-only [NooButton] with the tooltip and semantic label an
+/// icon-only button needs.
+class _ActionButton extends StatelessWidget {
+  final IconData icon;
+  final String tooltip;
+  final NooButtonVariant variant;
+  final VoidCallback onTap;
+
+  const _ActionButton({
+    required this.icon,
+    required this.tooltip,
+    required this.variant,
+    required this.onTap,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    return Tooltip(
+      message: tooltip,
+      child: Semantics(
+        button: true,
+        label: tooltip,
+        excludeSemantics: true,
+        child: NooButton(
+          icon: icon,
+          iconOnly: true,
+          variant: variant,
+          onTap: onTap,
+        ),
+      ),
+    );
+  }
+}
+
+/// Stands in for the Save button while it saves: the same primary circle,
+/// with a spinner, so it can't be tapped twice.
+class _SavingIndicator extends StatelessWidget {
+  const _SavingIndicator();
+
+  @override
+  Widget build(BuildContext context) {
+    final colors = context.nooColors;
+    return Semantics(
+      label: 'Saving',
+      child: Container(
+        width: 36,
+        height: 36,
+        alignment: Alignment.center,
+        decoration: BoxDecoration(color: colors.accent, shape: BoxShape.circle),
+        child: const SizedBox.square(
+          dimension: 16,
+          child: CircularProgressIndicator(strokeWidth: 2, color: Colors.white),
+        ),
+      ),
+    );
+  }
+}

lib/widgets/noo/core/noo_button.dart

@@ -1,7 +1,15 @@
 import 'package:flutter/material.dart';
 import '../../../theme/design_tokens.dart';
 
-enum NooButtonVariant { primary, tonal, secondary, danger, outline, text, textDanger }
+enum NooButtonVariant {
+  primary,
+  tonal,
+  secondary,
+  danger,
+  outline,
+  text,
+  textDanger,
+}
 
 enum NooButtonSize { cta, card, field, toolbar, compact, xs }
 
@@ -37,6 +45,11 @@ class NooButton extends StatefulWidget {
   final bool disabled;
   final VoidCallback? onTap;
 
+  /// A round, icon-only button (no label) - [icon] centred in a circle as
+  /// wide as the size's height, instead of the pill's side padding. Callers
+  /// are responsible for a tooltip/semantic label, since there's no text.
+  final bool iconOnly;
+
   const NooButton({
     super.key,
     this.variant = NooButtonVariant.primary,
@@ -46,6 +59,7 @@ class NooButton extends StatefulWidget {
     this.fullWidth = false,
     this.disabled = false,
     this.onTap,
+    this.iconOnly = false,
   });
 
   @override
@@ -87,7 +101,8 @@ class _NooButtonState extends State<NooButton> {
     final colors = context.nooColors;
     final s = _sizes[widget.size]!;
     final (bg, fg, border) = _colors(colors);
-    final hasLeadingIcon = widget.icon != null && widget.child != null && !_isTextVariant;
+    final hasLeadingIcon =
+        widget.icon != null && widget.child != null && !_isTextVariant;
 
     final content = Row(
       mainAxisSize: MainAxisSize.min,
@@ -107,7 +122,9 @@ class _NooButtonState extends State<NooButton> {
       child: GestureDetector(
         onTapDown: widget.disabled ? null : (_) => setState(() => _down = true),
         onTapUp: widget.disabled ? null : (_) => setState(() => _down = false),
-        onTapCancel: widget.disabled ? null : () => setState(() => _down = false),
+        onTapCancel: widget.disabled
+            ? null
+            : () => setState(() => _down = false),
         onTap: widget.disabled ? null : widget.onTap,
         child: AnimatedScale(
           scale: _down && !widget.disabled ? NooMotion.pressScale : 1,
@@ -115,8 +132,10 @@ class _NooButtonState extends State<NooButton> {
           curve: NooMotion.ease,
           child: Container(
             height: s.height,
-            width: widget.fullWidth ? double.infinity : null,
-            padding: _isTextVariant
+            width: widget.iconOnly
+                ? s.height
+                : (widget.fullWidth ? double.infinity : null),
+            padding: _isTextVariant || widget.iconOnly
                 ? EdgeInsets.zero
                 : EdgeInsets.only(
                     left: hasLeadingIcon ? s.px - 4 : s.px,
@@ -128,7 +147,9 @@ class _NooButtonState extends State<NooButton> {
             // of shrink-wrapping to it, which is what stretched this button
             // edge-to-edge instead of sizing to its content (see NooFab's
             // doc comment for the same bug).
-            alignment: widget.fullWidth ? Alignment.center : null,
+            alignment: widget.fullWidth || widget.iconOnly
+                ? Alignment.center
+                : null,
             decoration: BoxDecoration(
               color: bg,
               borderRadius: BorderRadius.circular(NooRadii.pill),

lib/widgets/viewer/media_text_preview.dart

@@ -89,8 +89,9 @@ class TextPreviewController extends ChangeNotifier {
 
 /// Text/markdown file preview and editor for [FileViewerScreen]'s static
 /// (non-swipeable) path (`_textPreviewExtensions`). Content is always
-/// editable when online; Save appears once it has changed. Markdown files open
-/// rendered, with an Edit/Preview toggle. Both controls live in the viewer's
+/// editable when online - after tapping Edit; every file opens read-only
+/// (Markdown rendered) with an Edit/Preview toggle - and Save appears once it
+/// has changed. Both controls live in the viewer's
 /// top bar, driven through [controller]. Opened from the Offline tab
 /// ([localPathResolver] set) it is read-only, since the local copy has no
 /// server to write back to.
@@ -125,12 +126,15 @@ class _MediaTextPreviewState extends State<MediaTextPreview> {
   String? _error;
   bool _isSaving = false;
   bool _editing = false;
+  final _focus = FocusNode();
 
   bool get _isMarkdown {
     final name = widget.item.name.toLowerCase();
     return name.endsWith('.md') || name.endsWith('.markdown');
   }
 
+  /// Markdown shows rendered until the user taps Edit. Plain text has no
+  /// rendered form, so it just shows its (read-only) text until then.
   bool get _showRendered => _isMarkdown && !_editing;
 
   bool get _readOnly => widget.localPathResolver != null;
@@ -150,6 +154,7 @@ class _MediaTextPreviewState extends State<MediaTextPreview> {
   @override
   void dispose() {
     widget.controller?._unbind();
+    _focus.dispose();
     _controller.dispose();
     super.dispose();
   }
@@ -159,7 +164,7 @@ class _MediaTextPreviewState extends State<MediaTextPreview> {
   /// initState, where notifying the bar's listeners would be illegal.
   void _syncToolbar() {
     widget.controller?._update(
-      canToggleEditing: _saved != null && _isMarkdown && !_readOnly,
+      canToggleEditing: _saved != null && !_readOnly,
       editing: _editing,
       dirty: _dirty,
       saving: _isSaving,
@@ -169,6 +174,12 @@ class _MediaTextPreviewState extends State<MediaTextPreview> {
   void _toggleEditing() {
     setState(() => _editing = !_editing);
     _syncToolbar();
+    // Tapping Edit should put the cursor in the text, not just unlock it.
+    if (_editing) {
+      WidgetsBinding.instance.addPostFrameCallback(
+        (_) => _focus.requestFocus(),
+      );
+    }
   }
 
   Future<void> _load() async {
@@ -262,7 +273,10 @@ class _MediaTextPreviewState extends State<MediaTextPreview> {
                     padding: padding,
                     child: TextField(
                       controller: _controller,
-                      readOnly: _readOnly,
+                      focusNode: _focus,
+                      // Read-only until Edit is tapped (always, for the
+                      // Offline copy).
+                      readOnly: _readOnly || !_editing,
                       maxLines: null,
                       keyboardType: TextInputType.multiline,
                       style: style,

test/views/file_viewer_screen_test.dart

@@ -9,7 +9,7 @@ import 'package:noo/providers/item_operations.dart';
 import 'package:noo/providers/session_controller.dart';
 import 'package:noo/services/nextcloud_service.dart';
 import 'package:noo/views/file_viewer_screen.dart';
-import 'package:noo/widgets/noo/nav/noo_top_bar.dart';
+import 'package:noo/widgets/noo/core/noo_button.dart';
 import 'package:noo/widgets/viewer/media_action_bar.dart';
 import 'package:provider/provider.dart';
 
@@ -49,9 +49,11 @@ class _Operations implements ItemOperations {
   dynamic noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
 }
 
-Finder _button(String tooltip) => find.byWidgetPredicate(
-  (widget) => widget is NooTopBarButton && widget.tooltip == tooltip,
-);
+Finder _button(String tooltip) => find.byTooltip(tooltip);
+
+/// The [NooButton] behind the top-bar action tagged [tooltip].
+Finder _noo(String tooltip) =>
+    find.descendant(of: _button(tooltip), matching: find.byType(NooButton));
 
 void main() {
   setUpNooTests();
@@ -118,6 +120,12 @@ void main() {
       }
 
       inHeader('Edit');
+      // A lone action is the primary one, and a compact round icon button.
+      expect(
+        tester.widget<NooButton>(_noo('Edit')).variant,
+        NooButtonVariant.primary,
+      );
+      expect(tester.getSize(_noo('Edit')), const Size(36, 36));
       expect(find.byType(Markdown), findsOneWidget);
       await tester.tap(_button('Edit'));
       await tester.pumpAndSettle();
@@ -125,6 +133,15 @@ void main() {
       await tester.enterText(find.byType(TextField), '# Changed');
       await tester.pump();
       inHeader('Save');
+      // With two, Save is primary and the toggle steps back to secondary.
+      expect(
+        tester.widget<NooButton>(_noo('Save')).variant,
+        NooButtonVariant.primary,
+      );
+      expect(
+        tester.widget<NooButton>(_noo('Preview')).variant,
+        NooButtonVariant.secondary,
+      );
       await tester.tap(_button('Preview'));
       await tester.pumpAndSettle();
       expect(tester.widget<Markdown>(find.byType(Markdown)).data, '# Changed');
@@ -156,7 +173,7 @@ void main() {
     });
   }
 
-  testWidgets('plain text has Save without the markdown toggle', (
+  testWidgets('plain text opens read-only and follows Edit -> Save too', (
     tester,
   ) async {
     final service = await mount(
@@ -166,11 +183,35 @@ void main() {
     );
     service.loaded.complete(utf8.encode('Original'));
     await tester.pumpAndSettle();
-    expect(_button('Edit'), findsNothing);
-    expect(_button('Preview'), findsNothing);
+
+    bool readOnly() =>
+        tester.widget<TextField>(find.byType(TextField)).readOnly;
+    expect(readOnly(), isTrue, reason: 'not directly editable');
+    expect(_button('Edit'), findsOneWidget);
+    expect(_button('Save'), findsNothing);
+    expect(
+      tester.widget<NooButton>(_noo('Edit')).variant,
+      NooButtonVariant.primary,
+    );
+
+    await tester.tap(_button('Edit'));
+    await tester.pumpAndSettle();
+    expect(readOnly(), isFalse);
+    expect(_button('Preview'), findsOneWidget);
     await tester.enterText(find.byType(TextField), 'Changed');
     await tester.pump();
     expect(_button('Save'), findsOneWidget);
+    expect(
+      tester.widget<NooButton>(_noo('Save')).variant,
+      NooButtonVariant.primary,
+    );
+
+    // Preview goes back to the read-only view, keeping the change unsaved.
+    await tester.tap(_button('Preview'));
+    await tester.pumpAndSettle();
+    expect(readOnly(), isTrue);
+    expect(find.text('Changed'), findsOneWidget);
+    expect(_button('Save'), findsOneWidget);
     await tester.pumpWidget(const SizedBox.shrink());
   });