PAINTROID-796 Add Clip area tool

lib/core/commands/command_factory/command_factory.dart

@@ -1,5 +1,7 @@
 import 'package:flutter/material.dart';
 import 'package:paintroid/core/commands/command_implementation/graphic/text_command.dart';
+import 'package:paintroid/core/commands/command_implementation/graphic/clip_area_command.dart';
+import 'package:paintroid/core/commands/command_implementation/graphic/clip_path_command.dart';
 import 'package:paintroid/core/commands/command_implementation/graphic/line_command.dart';
 import 'package:paintroid/core/commands/command_implementation/graphic/path_command.dart';
 import 'package:paintroid/core/commands/command_implementation/graphic/shape/ellipse_shape_command.dart';
@@ -16,6 +18,19 @@ class CommandFactory {
   ) =>
       PathCommand(path, paint);
 
+  ClipPathCommand createClipPathCommand(
+    PathWithActionHistory path,
+    Paint paint, {
+    Offset? startPoint,
+    Offset? endPoint,
+  }) =>
+      ClipPathCommand(
+        path,
+        paint,
+        startPoint: startPoint,
+        endPoint: endPoint,
+      );
+
   LineCommand createLineCommand(
     PathWithActionHistory path,
     Paint paint,
@@ -72,4 +87,10 @@ class CommandFactory {
   SprayCommand createSprayCommand(List<Offset> points, Paint paint) {
     return SprayCommand(points, paint);
   }
+
+  ClipAreaCommand createClipAreaCommand(
+    PathWithActionHistory path,
+    Paint paint,
+  ) =>
+      ClipAreaCommand(path, paint);
 }

lib/core/commands/command_implementation/command.dart

@@ -1,4 +1,6 @@
 import 'package:equatable/equatable.dart';
+import 'package:paintroid/core/commands/command_implementation/graphic/clip_area_command.dart';
+import 'package:paintroid/core/commands/command_implementation/graphic/clip_path_command.dart';
 import 'package:paintroid/core/commands/command_implementation/graphic/line_command.dart';
 import 'package:paintroid/core/commands/command_implementation/graphic/path_command.dart';
 import 'package:paintroid/core/commands/command_implementation/graphic/shape/ellipse_shape_command.dart';
@@ -24,6 +26,10 @@ abstract class Command with EquatableMixin {
         return EllipseShapeCommand.fromJson(json);
       case SerializerType.TEXT_COMMAND:
         return TextCommand.fromJson(json);
+      case SerializerType.CLIP_PATH_COMMAND:
+        return ClipPathCommand.fromJson(json);
+      case SerializerType.CLIP_AREA_COMMAND:
+        return ClipAreaCommand.fromJson(json);
       default:
         return PathCommand.fromJson(json);
     }

lib/core/commands/command_implementation/graphic/clip_area_command.dart

@@ -0,0 +1,69 @@
+import 'dart:ui';
+
+import 'package:json_annotation/json_annotation.dart';
+import 'package:paintroid/core/commands/command_implementation/graphic/graphic_command.dart';
+import 'package:paintroid/core/commands/path_with_action_history.dart';
+import 'package:paintroid/core/json_serialization/converter/paint_converter.dart';
+import 'package:paintroid/core/json_serialization/converter/path_with_action_history_converter.dart';
+import 'package:paintroid/core/json_serialization/versioning/serializer_version.dart';
+import 'package:paintroid/core/json_serialization/versioning/version_strategy.dart';
+
+part 'clip_area_command.g.dart';
+
+@JsonSerializable()
+class ClipAreaCommand extends GraphicCommand {
+  @JsonKey(includeToJson: true, includeFromJson: true)
+  final String type;
+  @JsonKey(includeToJson: true, includeFromJson: true)
+  final int version;
+
+  @PathWithActionHistoryConverter()
+  final PathWithActionHistory clipPathData;
+
+  ClipAreaCommand(
+    this.clipPathData,
+    Paint paint, {
+    this.type = SerializerType.CLIP_AREA_COMMAND,
+    int? version,
+  })  : version = version ??
+            VersionStrategyManager.strategy.getClipAreaCommandVersion(),
+        super(paint);
+
+  @override
+  void call(Canvas canvas) {
+    final Rect canvasBounds = canvas.getLocalClipBounds();
+
+    Path areaToClear = Path.combine(
+      PathOperation.difference,
+      Path()..addRect(canvasBounds),
+      clipPathData.path,
+    );
+
+    canvas.drawPath(
+        areaToClear,
+        Paint()
+          ..blendMode = BlendMode.clear
+          ..style = PaintingStyle.fill);
+  }
+
+  @override
+  List<Object?> get props => [paint, clipPathData, type, version];
+
+  factory ClipAreaCommand.fromJson(Map<String, dynamic> json) {
+    int version = json['version'] as int;
+
+    switch (version) {
+      case Version.v1:
+        return _$ClipAreaCommandFromJson(json);
+      case Version.v2:
+      // For different versions of ClipAreaCommand the deserialization
+      // has to be implemented manually.
+      // Autogenerated code can only be used for one version
+      default:
+        return _$ClipAreaCommandFromJson(json);
+    }
+  }
+
+  @override
+  Map<String, dynamic> toJson() => _$ClipAreaCommandToJson(this);
+}

lib/core/commands/command_implementation/graphic/clip_path_command.dart

@@ -0,0 +1,89 @@
+import 'dart:ui';
+
+import 'package:flutter/widgets.dart';
+import 'package:json_annotation/json_annotation.dart';
+import 'package:paintroid/core/commands/command_implementation/graphic/graphic_command.dart';
+import 'package:paintroid/core/commands/path_with_action_history.dart';
+import 'package:paintroid/core/json_serialization/converter/offset_converter.dart';
+import 'package:paintroid/core/json_serialization/converter/path_with_action_history_converter.dart';
+import 'package:paintroid/core/json_serialization/converter/paint_converter.dart';
+import 'package:paintroid/core/json_serialization/versioning/serializer_version.dart';
+import 'package:paintroid/core/json_serialization/versioning/version_strategy.dart';
+import 'package:path_drawing/path_drawing.dart';
+
+part 'clip_path_command.g.dart';
+
+@JsonSerializable()
+class ClipPathCommand extends GraphicCommand {
+  @JsonKey(includeToJson: true, includeFromJson: true)
+  final String type;
+  @JsonKey(includeToJson: true, includeFromJson: true)
+  final int version;
+
+  @PathWithActionHistoryConverter()
+  final PathWithActionHistory path;
+
+  @OffsetConverter()
+  final Offset? startPoint;
+  @OffsetConverter()
+  final Offset? endPoint;
+
+  ClipPathCommand(
+    this.path,
+    super.paint, {
+    this.startPoint,
+    this.endPoint,
+    this.type = SerializerType.CLIP_PATH_COMMAND,
+    int? version,
+  }) : version = version ??
+            VersionStrategyManager.strategy.getClipPathCommandVersion();
+
+  @override
+  void call(Canvas canvas) {
+    final dashLength = paint.strokeWidth * 4;
+    final dashGap = paint.strokeWidth * 2;
+
+    final dashedPath = dashPath(
+      path.path,
+      dashArray: CircularIntervalList<double>([dashLength, dashGap]),
+    );
+    canvas.drawPath(dashedPath, paint);
+
+    if (startPoint != null &&
+        endPoint != null &&
+        (startPoint!.dx != endPoint!.dx || startPoint!.dy != endPoint!.dy)) {
+      final solidPaint = Paint()
+        ..color = paint.color
+        ..style = PaintingStyle.stroke
+        ..strokeWidth = paint.strokeWidth
+        ..isAntiAlias = true;
+
+      final solidPath = Path()
+        ..moveTo(startPoint!.dx, startPoint!.dy)
+        ..lineTo(endPoint!.dx, endPoint!.dy);
+
+      canvas.drawPath(solidPath, solidPaint);
+    }
+  }
+
+  @override
+  List<Object?> get props => [paint, path, startPoint, endPoint, type, version];
+
+  factory ClipPathCommand.fromJson(Map<String, dynamic> json) {
+    int version = json['version'] as int;
+
+    switch (version) {
+      case Version.v1:
+        return _$ClipPathCommandFromJson(json);
+      case Version.v2:
+      // For different versions of ClipPathCommand the deserialization
+      // has to be implemented manually.
+      // Autogenerated code can only be used for one version
+      default:
+        return _$ClipPathCommandFromJson(json);
+    }
+  }
+
+  @override
+  Map<String, dynamic> toJson() => _$ClipPathCommandToJson(this);
+}

lib/core/commands/command_manager/command_manager.dart

@@ -1,6 +1,8 @@
 import 'dart:ui';
 
 import 'package:paintroid/core/commands/command_implementation/command.dart';
+import 'package:paintroid/core/commands/command_implementation/graphic/clip_area_command.dart';
+import 'package:paintroid/core/commands/command_implementation/graphic/clip_path_command.dart';
 import 'package:paintroid/core/commands/command_implementation/graphic/text_command.dart';
 import 'package:paintroid/core/commands/command_implementation/graphic/graphic_command.dart';
 import 'package:paintroid/core/commands/command_implementation/graphic/line_command.dart';
@@ -23,13 +25,19 @@ class CommandManager {
     _undoStack.add(command);
   }
 
+  void removeCommand(Command commandToRemove) {
+    _undoStack.remove(commandToRemove);
+  }
+
   void setUndoStack(List<Command> commands) {
     _undoStack.clear();
     _undoStack.addAll(commands);
   }
 
   void executeLastCommand(Canvas canvas) {
-    if (_undoStack.isEmpty) return;
+    if (_undoStack.isEmpty) {
+      return;
+    }
     final lastCommand = _undoStack.last;
     if (lastCommand is GraphicCommand) {
       lastCommand.call(canvas);
@@ -45,7 +53,9 @@ class CommandManager {
   }
 
   void discardLastCommand() {
-    if (_undoStack.isNotEmpty) _undoStack.removeLast();
+    if (_undoStack.isNotEmpty) {
+      _undoStack.removeLast();
+    }
   }
 
   void clearUndoStack({Iterable<Command>? newCommands}) {
@@ -115,6 +125,9 @@ class CommandManager {
       return ToolData.TEXT;
     } else if (command.runtimeType == SprayCommand) {
       return ToolData.SPRAY;
+    } else if (command.runtimeType == ClipAreaCommand ||
+        command.runtimeType == ClipPathCommand) {
+      return ToolData.CLIPPING;
     } else {
       return ToolData.BRUSH;
     }

lib/core/json_serialization/versioning/serializer_version.dart

@@ -7,6 +7,8 @@ class SerializerVersion {
   static const int ELLIPSE_SHAPE_COMMAND_VERSION = Version.v1;
   static const int TEXT_COMMAND_VERSION = Version.v1;
   static const int SPRAY_COMMAND_VERSION = Version.v1;
+  static const int CLIP_PATH_COMMAND_VERSION = Version.v1;
+  static const int CLIP_AREA_COMMAND_VERSION = Version.v1;
 }
 
 class Version {
@@ -25,4 +27,6 @@ class SerializerType {
   static const String ELLIPSE_SHAPE_COMMAND = 'EllipseShapeCommand';
   static const String TEXT_COMMAND = 'TextCommand';
   static const String SPRAY_COMMAND = 'SprayCommand';
+  static const String CLIP_PATH_COMMAND = 'ClipPathCommand';
+  static const String CLIP_AREA_COMMAND = 'ClipAreaCommand';
 }

lib/core/json_serialization/versioning/version_strategy.dart

@@ -14,6 +14,10 @@ abstract class IVersionStrategy {
   int getTextCommandVersion();
 
   int getSprayCommandVersion();
+
+  int getClipPathCommandVersion();
+
+  int getClipAreaCommandVersion();
 }
 
 class ProductionVersionStrategy implements IVersionStrategy {
@@ -39,6 +43,14 @@ class ProductionVersionStrategy implements IVersionStrategy {
 
   @override
   int getSprayCommandVersion() => SerializerVersion.SPRAY_COMMAND_VERSION;
+
+  @override
+  int getClipPathCommandVersion() =>
+      SerializerVersion.CLIP_PATH_COMMAND_VERSION;
+
+  @override
+  int getClipAreaCommandVersion() =>
+      SerializerVersion.CLIP_AREA_COMMAND_VERSION;
 }
 
 class VersionStrategyManager {