fix(flterm): preserve tracked pointer and touch state

packages/flterm/CHANGELOG.md

@@ -1,5 +1,12 @@
 # Changelog
 
+## Unreleased
+
+### Added
+
+- **Tracked touch policy**: `TerminalGestureSettings.touchMouseTracking` can
+  preserve terminal taps while routing touch and stylus drags to scrolling.
+
 ## 0.0.4
 
 ### Breaking

packages/flterm/lib/flterm.dart

@@ -37,7 +37,8 @@ export 'src/foundation/terminal_gesture_settings.dart'
         GestureModifier,
         LineSelectMode,
         TerminalGestureSettings,
-        TerminalSelectionShape;
+        TerminalSelectionShape,
+        TouchMouseTracking;
 export 'src/foundation/terminal_theme.dart'
     show
         CursorTheme,

packages/flterm/lib/src/foundation/callbacks.dart

@@ -28,7 +28,7 @@ typedef OnResize = void Function(int cols, int rows);
 /// ```
 typedef TerminalMouseEvent = ({
   MouseAction action,
-  MouseButton button,
+  MouseButton? button,
   double pixelX,
   double pixelY,
 });

packages/flterm/lib/src/foundation/terminal_gesture_settings.dart

@@ -19,12 +19,9 @@ enum LineSelectMode {
   full,
 }
 
-/// Controls which terminal selection affordances are enabled and how press
-/// gestures behave.
+/// Controls terminal selection and tracked-pointer gesture behavior.
 ///
-/// Passed to [TerminalView.gestureSettings]. Only affects selection
-/// behavior: mouse tracking (for terminal programs) and focus gestures
-/// work regardless of these settings.
+/// Passed to [TerminalView.gestureSettings].
 ///
 /// ```dart
 /// TerminalView(
@@ -61,6 +58,14 @@ final class TerminalGestureSettings {
   /// [TerminalController.selectAll] still selects programmatically.
   final bool selectAllShortcut;
 
+  /// How touch-like pointers interact with terminal mouse tracking.
+  ///
+  /// [TouchMouseTracking.direct] (default) forwards touch down, motion, and up
+  /// events directly to the terminal program. [TouchMouseTracking.tapAndScroll]
+  /// forwards recognized taps as clicks while leaving drags to terminal
+  /// scrolling.
+  final TouchMouseTracking touchMouseTracking;
+
   /// How triple-click line selection determines the end column.
   ///
   /// [LineSelectMode.content] (default) trims trailing empty cells.
@@ -103,6 +108,7 @@ final class TerminalGestureSettings {
     this.dragSelection = true,
     this.selectAllShortcut = true,
     this.longPressSelection = true,
+    this.touchMouseTracking = .direct,
     this.lineSelectMode = .content,
     this.blockSelectionModifier = .alt,
     this.selectionBehaviors = .standard,
@@ -121,6 +127,7 @@ final class TerminalGestureSettings {
     dragSelection,
     longPressSelection,
     selectAllShortcut,
+    touchMouseTracking,
     wordBoundaries,
   );
 
@@ -140,9 +147,19 @@ final class TerminalGestureSettings {
           dragSelection == other.dragSelection &&
           longPressSelection == other.longPressSelection &&
           selectAllShortcut == other.selectAllShortcut &&
+          touchMouseTracking == other.touchMouseTracking &&
           wordBoundaries == other.wordBoundaries;
 }
 
+/// How touch-like pointers interact with terminal mouse tracking.
+enum TouchMouseTracking {
+  /// Forwards touch down, motion, and up as terminal mouse events.
+  direct,
+
+  /// Forwards recognized taps as clicks and leaves drags to scrolling.
+  tapAndScroll,
+}
+
 /// Selection shape used for gestures that start without a keyboard modifier.
 enum TerminalSelectionShape {
   /// Selects contiguous terminal text.

packages/flterm/lib/src/widgets/terminal_controller_impl.dart

@@ -35,7 +35,6 @@ class TerminalControllerImpl extends TerminalController
 
   @override
   final Terminal terminal;
-  final _renderState = RenderState();
   final _keyEncoder = KeyEncoder();
   final _mouseEncoder = MouseEncoder();
   late final SelectionGestureDriver _selectionGesture;
@@ -52,6 +51,7 @@ class TerminalControllerImpl extends TerminalController
   var _cursorKeyApplication = false;
   Brightness _brightness = .dark;
   var _cursorBlinking = true;
+  var _mouseButtonPressed = false;
   var _wasFocused = false;
   var _selectionMutationDepth = 0;
 
@@ -78,6 +78,8 @@ class TerminalControllerImpl extends TerminalController
         maxScrollback: config.scrollbackLimit,
       ),
       super.base() {
+    _lastCols = config.cols;
+    _lastRows = config.rows;
     _selectionGesture = SelectionGestureDriver(terminal);
     installDefaultKittyPngDecoder();
     _textInput
@@ -258,7 +260,6 @@ class TerminalControllerImpl extends TerminalController
     _selectionGesture.dispose();
     _keyEncoder.dispose();
     _mouseEncoder.dispose();
-    _renderState.dispose();
     terminal.dispose();
     super.dispose();
   }
@@ -332,16 +333,32 @@ class TerminalControllerImpl extends TerminalController
 
   @override
   void handleMouseEvent(TerminalMouseEvent event) {
+    final button = event.button;
     _mouseEvent
       ..action = event.action
-      ..button = event.button
       ..mods = _currentMods()
       ..setPosition(
         x: event.pixelX * _lastDevicePixelRatio,
         y: event.pixelY * _lastDevicePixelRatio,
       );
+    if (button == null) {
+      _mouseEvent.clearButton();
+    } else {
+      _mouseEvent.button = button;
+    }
+    if (event.action == .press &&
+        button != .four &&
+        button != .five &&
+        button != null) {
+      _mouseButtonPressed = true;
+    }
     _mouseEncoder.sync(terminal);
+    _mouseEncoder.setAnyButtonPressed(pressed: _mouseButtonPressed);
     final result = _mouseEncoder.encode(_mouseEvent);
+    if (event.action == .release) {
+      _mouseButtonPressed = false;
+      _mouseEncoder.setAnyButtonPressed(pressed: false);
+    }
     if (result.isEmpty) return;
     _emitOutput(utf8.encode(result));
   }
@@ -386,10 +403,11 @@ class TerminalControllerImpl extends TerminalController
   }
 
   @override
-  void handleScroll(int lines) {
+  void handleScroll(int lines, {Offset? localPosition}) {
     if (_activeScreen != .alternate || lines == 0) return;
 
     if (_mouseTracking != .none) {
+      if (localPosition == null) return;
       final button = lines < 0 ? MouseButton.four : MouseButton.five;
       final count = lines.abs();
 
@@ -400,7 +418,10 @@ class TerminalControllerImpl extends TerminalController
           ..action = .press
           ..button = button
           ..mods = _currentMods()
-          ..setPosition(x: 0, y: 0);
+          ..setPosition(
+            x: localPosition.dx * _lastDevicePixelRatio,
+            y: localPosition.dy * _lastDevicePixelRatio,
+          );
         final result = _mouseEncoder.encode(_mouseEvent);
         if (result.isNotEmpty) _emitOutput(utf8.encode(result));
       }
@@ -716,10 +737,8 @@ class TerminalControllerImpl extends TerminalController
   void _emitOutput(Uint8List bytes) => onOutput?.call(bytes);
 
   void _ensureGridSize() {
-    if (_lastRows > 0 && _lastCols > 0) return;
-    _renderState.update(terminal);
-    _lastRows = _renderState.rows;
-    _lastCols = _renderState.cols;
+    if (_lastRows <= 0) _lastRows = _config.rows;
+    if (_lastCols <= 0) _lastCols = _config.cols;
   }
 
   bool _extendSelection(LogicalKeyboardKey arrowKey) {
@@ -791,10 +810,10 @@ class TerminalControllerImpl extends TerminalController
   }
 
   TerminalSizeInfo _handleSizeQuery() {
-    _renderState.update(terminal);
+    _ensureGridSize();
     return TerminalSizeInfo(
-      rows: _renderState.rows,
-      columns: _renderState.cols,
+      rows: _lastRows,
+      columns: _lastCols,
       cellWidth: (_lastMetrics.cellWidth * _lastDevicePixelRatio).round(),
       cellHeight: (_lastMetrics.cellHeight * _lastDevicePixelRatio).round(),
     );