[mob][photos] Fix issues with single tap and some other issues when dragging and selecting + use better names

mobile/lib/states/pointer_position_provider.dart

@@ -1,68 +0,0 @@
-import "dart:async";
-
-import "package:flutter/widgets.dart";
-
-class PointerPositionProvider extends StatefulWidget {
-  final Widget child;
-  const PointerPositionProvider({
-    super.key,
-    required this.child,
-  });
-
-  @override
-  State<PointerPositionProvider> createState() =>
-      _PointerPositionProviderState();
-}
-
-class _PointerPositionProviderState extends State<PointerPositionProvider> {
-  @override
-  void dispose() {
-    PointerPosition.of(context).pointerPositionStreamController.close();
-    super.dispose();
-  }
-
-  @override
-  Widget build(BuildContext context) {
-    return PointerPosition(
-      child: Builder(
-        builder: (context) {
-          return Listener(
-            onPointerMove: (PointerMoveEvent event) {
-              PointerPosition.of(context)
-                  .pointerPositionStreamController
-                  .add(event.localPosition);
-            },
-            child: widget.child,
-          );
-        },
-      ),
-    );
-  }
-}
-
-class PointerPosition extends InheritedWidget {
-  PointerPosition({super.key, required super.child});
-
-  final StreamController<Offset> pointerPositionStreamController =
-      StreamController.broadcast();
-
-  Future<dynamic> closeController() {
-    debugPrint("dragToSelect: Closing stream controller");
-    return pointerPositionStreamController.close();
-  }
-
-  static PointerPosition? maybeOf(BuildContext context) {
-    return context.dependOnInheritedWidgetOfExactType<PointerPosition>();
-  }
-
-  static PointerPosition of(BuildContext context) {
-    final PointerPosition? result = maybeOf(context);
-    assert(result != null, 'No PointerPositionProvider found in context');
-    return result!;
-  }
-
-  @override
-  bool updateShouldNotify(PointerPosition oldWidget) =>
-      pointerPositionStreamController !=
-      oldWidget.pointerPositionStreamController;
-}

mobile/lib/states/pointer_provider.dart

@@ -0,0 +1,98 @@
+import "dart:async";
+
+import "package:flutter/widgets.dart";
+
+class PointerProvider extends StatefulWidget {
+  final Widget child;
+  const PointerProvider({
+    super.key,
+    required this.child,
+  });
+
+  @override
+  State<PointerProvider> createState() => _PointerProviderState();
+}
+
+class _PointerProviderState extends State<PointerProvider> {
+  @override
+  void dispose() {
+    Pointer.of(context).closePositionController();
+    Pointer.of(context).closeDownEventController();
+    Pointer.of(context).upDownEventController();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Pointer(
+      child: Builder(
+        builder: (context) {
+          return Listener(
+            onPointerMove: (event) {
+              if (event.delta.distance > 0) {
+                Pointer.of(context)
+                    .positionStreamController
+                    .add(event.localPosition);
+              }
+            },
+            onPointerDown: (event) {
+              Pointer.of(context)
+                  .downEventStreamController
+                  .add(event.localPosition);
+            },
+            onPointerUp: (event) {
+              Pointer.of(context)
+                  .upEventStreamController
+                  .add(event.localPosition);
+            },
+            child: widget.child,
+          );
+        },
+      ),
+    );
+  }
+}
+
+class Pointer extends InheritedWidget {
+  Pointer({super.key, required super.child});
+
+  final StreamController<Offset> positionStreamController =
+      StreamController.broadcast();
+
+  final StreamController<Offset> downEventStreamController =
+      StreamController.broadcast();
+
+  final StreamController<Offset> upEventStreamController =
+      StreamController.broadcast();
+
+  Future<dynamic> closePositionController() {
+    debugPrint("dragToSelect: Closing position stream controller");
+    return positionStreamController.close();
+  }
+
+  Future<dynamic> closeDownEventController() {
+    debugPrint("dragToSelect: Closing down event stream controller");
+    return downEventStreamController.close();
+  }
+
+  Future<dynamic> upDownEventController() {
+    debugPrint("dragToSelect: Closing up event stream controller");
+    return upEventStreamController.close();
+  }
+
+  static Pointer? maybeOf(BuildContext context) {
+    return context.dependOnInheritedWidgetOfExactType<Pointer>();
+  }
+
+  static Pointer of(BuildContext context) {
+    final Pointer? result = maybeOf(context);
+    assert(result != null, 'No PointerPositionProvider found in context');
+    return result!;
+  }
+
+  @override
+  bool updateShouldNotify(Pointer oldWidget) =>
+      positionStreamController != oldWidget.positionStreamController ||
+      downEventStreamController != oldWidget.downEventStreamController ||
+      upEventStreamController != oldWidget.upEventStreamController;
+}

mobile/lib/ui/viewer/gallery/component/gallery_file_widget.dart

@@ -9,7 +9,7 @@ import "package:photos/core/constants.dart";
 import 'package:photos/models/file/file.dart';
 import "package:photos/models/selected_files.dart";
 import "package:photos/services/app_lifecycle_service.dart";
-import "package:photos/states/pointer_position_provider.dart";
+import "package:photos/states/pointer_provider.dart";
 import "package:photos/theme/ente_theme.dart";
 import "package:photos/ui/viewer/file/detail_page.dart";
 import "package:photos/ui/viewer/file/thumbnail_widget.dart";
@@ -46,9 +46,11 @@ class GalleryFileWidget extends StatefulWidget {
 
 class _GalleryFileWidgetState extends State<GalleryFileWidget> {
   final _globalKey = GlobalKey();
-  bool _insideBbox = false;
+  bool _pointerInsideBbox = false;
   bool _insideBboxPrevValue = false;
   late StreamSubscription<Offset> _pointerPositionStreamSubscription;
+  late StreamSubscription<Offset> _pointerDownEventStreamSubscription;
+  late StreamSubscription<Offset> _pointerUpEventStreamSubscription;
   final _logger = Logger("GalleryFileWidget");
 
   @override
@@ -76,24 +78,42 @@ class _GalleryFileWidgetState extends State<GalleryFileWidget> {
               size.width,
               size.height,
             );
-            _pointerPositionStreamSubscription = PointerPosition.of(context)
-                .pointerPositionStreamController
+
+            _pointerUpEventStreamSubscription = Pointer.of(context)
+                .upEventStreamController
+                .stream
+                .listen((event) {
+              if (bbox.contains(event)) {
+                if (_pointerInsideBbox) _pointerInsideBbox = false;
+              }
+            });
+
+            _pointerDownEventStreamSubscription = Pointer.of(context)
+                .downEventStreamController
+                .stream
+                .listen((event) {
+              if (bbox.contains(event)) {
+                // widget.selectedFiles!.toggleSelection(widget.file);
+                // _insideBbox = true;
+              }
+            });
+
+            _pointerPositionStreamSubscription = Pointer.of(context)
+                .positionStreamController
                 .stream
                 .listen((event) {
               if (widget.selectedFiles?.files.isEmpty ?? true) return;
-              _insideBboxPrevValue = _insideBbox;
+              _insideBboxPrevValue = _pointerInsideBbox;
 
               if (bbox.contains(event)) {
-                _insideBbox = true;
+                _pointerInsideBbox = true;
               } else {
-                _insideBbox = false;
+                _pointerInsideBbox = false;
               }
 
-              if (_insideBbox == true && _insideBboxPrevValue == false) {
+              if (_pointerInsideBbox == true && _insideBboxPrevValue == false) {
                 // print('Entered ${widget.file.displayName}');
                 widget.selectedFiles!.toggleSelection(widget.file);
-              } else if (_insideBbox == false && _insideBboxPrevValue == true) {
-                // print('Exited ${widget.index}');
               }
             });
           } catch (e) {
@@ -107,6 +127,8 @@ class _GalleryFileWidgetState extends State<GalleryFileWidget> {
   @override
   void dispose() {
     _pointerPositionStreamSubscription.cancel();
+    _pointerDownEventStreamSubscription.cancel();
+    _pointerUpEventStreamSubscription.cancel();
     super.dispose();
   }
 
@@ -210,6 +232,7 @@ class _GalleryFileWidgetState extends State<GalleryFileWidget> {
             GalleryContextState.of(context)!.inSelectionMode;
     if (shouldToggleSelection) {
       _toggleFileSelection(file);
+      _pointerInsideBbox = true;
     } else {
       if (AppLifecycleService.instance.mediaExtensionAction.action ==
           IntentAction.pick) {
@@ -228,6 +251,7 @@ class _GalleryFileWidgetState extends State<GalleryFileWidget> {
         IntentAction.main) {
       HapticFeedback.lightImpact();
       _toggleFileSelection(file);
+      _pointerInsideBbox = true;
     }
   }
 

mobile/lib/ui/viewer/gallery/component/group/lazy_group_gallery.dart

@@ -7,7 +7,7 @@ import 'package:photos/core/constants.dart';
 import 'package:photos/events/files_updated_event.dart';
 import 'package:photos/models/file/file.dart';
 import 'package:photos/models/selected_files.dart';
-import "package:photos/states/pointer_position_provider.dart";
+import "package:photos/states/pointer_provider.dart";
 import 'package:photos/theme/ente_theme.dart';
 import "package:photos/ui/viewer/gallery/component/grid/place_holder_grid_view_widget.dart";
 import "package:photos/ui/viewer/gallery/component/group/group_gallery.dart";
@@ -235,7 +235,7 @@ class _LazyGroupGalleryState extends State<LazyGroupGallery> {
                   ),
           ],
         ),
-        PointerPositionProvider(
+        PointerProvider(
           child: GroupGalleryGlobalKey(
             globalKey: _groupGalleryGlobalKey,
             child: SizedBox(