outsource line drawing in paint controller

lib/canvas/drawing_page.dart

@@ -1,17 +1,15 @@
 import 'dart:math';
 import 'dart:ui';
-import 'package:adwaita_icons/adwaita_icons.dart';
 import 'package:fluentui_system_icons/fluentui_system_icons.dart';
 import 'package:flutter/material.dart';
-import 'package:iconify_flutter/iconify_flutter.dart';
+import 'my_painter.dart';
-import 'package:iconify_flutter/icons/emojione_monotone.dart';
+import 'paint_controller.dart';
-import 'package:iconify_flutter/icons/jam.dart';
+import 'screen_document_mapping.dart';
-import 'package:notes/canvas/my_painter.dart';
-import 'package:notes/canvas/screen_document_mapping.dart';
 
 import '../icon_material_button.dart';
-import 'document_types.dart';
+import '../tool_bar.dart';
 
+/// Handles input events and draws canvas element
 class DrawingPage extends StatefulWidget {
   const DrawingPage({Key? key}) : super(key: key);
 
@@ -20,15 +18,11 @@ class DrawingPage extends StatefulWidget {
 }
 
 class _DrawingPageState extends State<DrawingPage> {
-  List<Stroke> _strokes = [];
-  bool allowDrawWithFinger = false;
-
   double zoom = .75;
   double basezoom = 1.0;
   Offset offset = const Offset(.0, .0);
 
-  // todo better pen system
+  PaintController controller = PaintController();
-  bool eraseractive = false;
 
   @override
   void initState() {
@@ -37,7 +31,7 @@ class _DrawingPageState extends State<DrawingPage> {
     // todo might be weird behaviour if used with short side
     final screenWidth =
         (window.physicalSize.longestSide / window.devicePixelRatio);
-    _calcNewPageOffset(const Offset(.0, .0), screenWidth);
+    _calcNewPageOffset(const Offset(.0, .0), screenWidth - 45);
   }
 
   @override
@@ -47,68 +41,39 @@ class _DrawingPageState extends State<DrawingPage> {
         IconMaterialButton(
           icon: const Icon(FluentIcons.book_open_48_filled),
           color: const Color.fromRGBO(255, 255, 255, .85),
-          onPressed: () {},
+          onPressed: () {
+            // todo implement
+          },
         ),
         IconMaterialButton(
           icon: const Icon(FluentIcons.document_one_page_24_regular),
           color: const Color.fromRGBO(255, 255, 255, .85),
-          onPressed: () {},
+          onPressed: () {
+            // todo implement
+          },
         ),
         IconMaterialButton(
           icon: const Icon(Icons.attachment_outlined),
           color: const Color.fromRGBO(255, 255, 255, .85),
-          onPressed: () {},
+          onPressed: () {
+            // todo implement
+          },
           rotation: -pi / 4,
         ),
         IconMaterialButton(
           icon: const Icon(Icons.more_vert),
           color: const Color.fromRGBO(255, 255, 255, .85),
-          onPressed: () {},
+          onPressed: () {
+            // todo implement
+          },
         ),
       ]),
       body: Row(
         children: [
-          Container(
+          ToolBar(
-            color: const Color(0xff3f3f3f),
+            onPenChange: (pen) {
-            width: 45,
+              controller.changePen(pen);
-            child: Column(
+            },
-              children: [
-                const SizedBox(
-                  height: 10,
-                ),
-                IconMaterialButton(
-                  icon: const Iconify(EmojioneMonotone.fountain_pen, color: Color.fromRGBO(255, 255, 255, .85),),
-                  color: const Color.fromRGBO(255, 255, 255, .85),
-                  onPressed: () => setState(() => eraseractive = false),
-                  selected: !eraseractive,
-                  iconSize: 24,
-                ),
-                IconMaterialButton(
-                  icon: const Iconify(Jam.highlighter, color: Color.fromRGBO(255, 255, 255, .85),),
-                  color: const Color.fromRGBO(255, 255, 255, .85),
-                  onPressed: () => setState(() => eraseractive = false),
-                  selected: false,
-                  iconSize: 24,
-                ),
-                IconMaterialButton(
-                  icon: Transform.translate(
-                    offset: const Offset(-2.0, .0),
-                    child: const AdwaitaIcon(AdwaitaIcons.eraser2),
-                  ),
-                  color: const Color.fromRGBO(255, 255, 255, .85),
-                  onPressed: () => setState(() => eraseractive = true),
-                  iconSize: 24,
-                  selected: eraseractive,
-                ),
-                IconMaterialButton(
-                  icon: const Icon(FluentIcons.select_object_24_regular),
-                  color: const Color.fromRGBO(255, 255, 255, .85),
-                  onPressed: () => setState(() => eraseractive = false),
-                  selected: false,
-                  iconSize: 24,
-                ),
-              ],
-            ),
           ),
           Expanded(child: RepaintBoundary(child: _buildCanvas())),
         ],
@@ -116,28 +81,6 @@ class _DrawingPageState extends State<DrawingPage> {
     );
   }
 
-  double _calcTiltedWidth(double baseWidth, double tilt) {
-    if (tilt == .0) return baseWidth;
-    return baseWidth * tilt;
-  }
-
-  double _calcAngleDependentWidth(Point pt1, Point pt2, double basetickness) {
-    double dx = pt2.point.dx - pt1.point.dx;
-    double dy = pt2.point.dy - pt1.point.dy;
-
-    // todo those deltas to small to get an accurate direction!
-
-    double alpha = atan(dx / dy);
-    // alpha has range from 0 - 2pi
-    // we want 0.5 -1;
-
-    alpha /= (2 * pi * 2);
-    alpha += .5;
-
-    double thickness = basetickness * alpha;
-    return thickness;
-  }
-
   // calculate new page offset from mousepointer delta
   void _calcNewPageOffset(Offset delta, double canvasWidth) {
     if (zoom > 1.0) {
@@ -175,96 +118,28 @@ class _DrawingPageState extends State<DrawingPage> {
       return;
     }
 
-    // todo outsource this eraser pen
+    controller.pointMoveEvent(pos, event.kind, event.tilt);
-    if (eraseractive) {
-      // todo dynamic eraser size
-      final eraserrect = Rect.fromCircle(center: pos, radius: 3);
-      for (final stroke in _strokes) {
-        // check if delete action was within bounding rect of stroke
-        if (stroke.getBoundingRect().contains(pos)) {
-          // check if eraser hit an point within its range
-          for (final pt in stroke.points) {
-            if (eraserrect.contains(pt.point)) {
-              setState(() {
-                _strokes = List.from(_strokes)..remove(stroke);
-              });
-              return;
-            }
-          }
-        }
-      }
-      return;
-    }
 
-    if (allowDrawWithFinger || event.kind != PointerDeviceKind.touch) {
+    if (event.kind == PointerDeviceKind.touch) {
-      final pts = _strokes.last.points;
-
-      if (pts.last.point == pos) return;
-
-      double newWidth = _calcTiltedWidth(5.0, event.tilt);
-      if (_strokes.last.points.length > 1) {
-        newWidth =
-            _calcAngleDependentWidth(pts.last, pts[pts.length - 2], newWidth);
-      }
-
-      setState(() {
-        _strokes = List.from(_strokes, growable: false)
-          ..last.addPoint(Point(pos, newWidth));
-      });
-    } else {
       _calcNewPageOffset(event.delta, size.width);
     }
   }
 
   Widget _buildCanvas() {
     final size = MediaQuery.of(context).size;
-
     final canvasSize = Size(size.width - 45, size.height);
 
     return Listener(
       behavior: HitTestBehavior.opaque,
-      onPointerMove: (e) => _onPointerMove(e, size),
+      onPointerMove: (e) => _onPointerMove(e, canvasSize),
-      onPointerSignal: (event) {
-        print('Button: ${event.buttons}');
-      },
       onPointerDown: (event) {
-        print('Button: ${event.buttons}');
+        Offset pos = event.localPosition;
-
+        final scale = calcPageDependentScale(zoom, a4Page, canvasSize);
-        if (allowDrawWithFinger || event.kind != PointerDeviceKind.touch) {
+        pos = translateScreenToDocumentPoint(pos, scale, offset);
-          Offset pos = event.localPosition;
+        controller.pointDownEvent(pos, event.kind, event.tilt);
-          final scale = calcPageDependentScale(zoom, a4Page, size);
-          pos = translateScreenToDocumentPoint(pos, scale, offset);
-
-          // todo line drawn on edge where line left page
-          if (!a4Page.contains(pos)) return;
-
-          if (eraseractive) return;
-
-          setState(() {
-            _strokes = List.from(_strokes)
-              ..add(Stroke.fromPoints(
-                  [Point(pos, _calcTiltedWidth(3.0, event.tilt))]));
-          });
-        }
       },
       onPointerUp: (event) {
-        if (eraseractive) return;
+        controller.pointUpEvent(event.kind);
-
-        if (allowDrawWithFinger || event.kind != PointerDeviceKind.touch) {
-          if (_strokes.last.points.length <= 1) {
-            // if the line consists only of one point (point) add endpoint as the same to allow drawing a line
-            // todo maybe solve this in custompainter in future
-            setState(() {
-              _strokes = List.from(_strokes, growable: false)
-                ..last.points.add(_strokes.last.points.last);
-            });
-          } else {
-            setState(() {});
-          }
-
-          print(_strokes.length);
-          print(_strokes.last.points.length);
-        }
       },
       child: GestureDetector(
         onScaleUpdate: (details) {
@@ -277,18 +152,12 @@ class _DrawingPageState extends State<DrawingPage> {
         onScaleEnd: (details) {
           basezoom = zoom;
         },
-        onSecondaryTap: () {
-          print('secctab');
-        },
-        onTertiaryTapDown: (details) {
-          print('tertiary button');
-        },
         child: CustomPaint(
           painter: MyPainter(
-              strokes: _strokes,
               offset: offset,
               zoom: zoom,
-              canvasSize: canvasSize),
+              canvasSize: canvasSize,
+              controller: controller),
           size: canvasSize,
         ),
       ),

lib/canvas/my_painter.dart

@@ -1,24 +1,32 @@
 import 'dart:math';
 
 import 'package:flutter/material.dart';
+import 'package:notes/canvas/paint_controller.dart';
 import 'package:notes/canvas/screen_document_mapping.dart';
 
-import 'document_types.dart';
-
 final Rect a4Page =
     Rect.fromPoints(const Offset(.0, .0), const Offset(210, 210 * sqrt2));
 
 class MyPainter extends CustomPainter {
-  List<Stroke> strokes;
   double zoom;
   Offset offset;
   Size canvasSize;
+  PaintController controller;
+
+  late Pen activePen;
 
   MyPainter(
-      {required this.strokes,
+      {required this.zoom,
-      required this.zoom,
       required this.offset,
-      required this.canvasSize});
+      required this.canvasSize,
+      required this.controller})
+      : super(repaint: controller) {
+    activePen = controller.activePen;
+
+    controller.addListener(() {
+      activePen = controller.activePen;
+    });
+  }
 
   Offset _translatept(Offset pt, Size canvasSize) {
     final scale = calcPageDependentScale(zoom, a4Page, canvasSize);
@@ -42,7 +50,7 @@ class MyPainter extends CustomPainter {
             _translatept(a4Page.bottomRight, size)),
         backgroundPaint);
 
-    for (final stroke in strokes) {
+    for (final stroke in controller.strokes) {
       for (int i = 0; i < stroke.points.length - 1; i++) {
         Offset pt1 = stroke.points[i].point;
         pt1 = _translatept(pt1, size);
@@ -58,8 +66,6 @@ class MyPainter extends CustomPainter {
 
   @override
   bool shouldRepaint(MyPainter oldDelegate) {
-    return oldDelegate.strokes != strokes ||
+    return oldDelegate.zoom != zoom || oldDelegate.offset != offset;
-        oldDelegate.zoom != zoom ||
-        oldDelegate.offset != offset;
   }
 }

lib/canvas/paint_controller.dart

@@ -0,0 +1,116 @@
+import 'dart:math';
+import 'dart:ui';
+
+import 'package:flutter/foundation.dart';
+
+import 'document_types.dart';
+import 'my_painter.dart';
+
+enum Pen { eraser, pen, highlighter, selector }
+
+class PaintController extends ChangeNotifier {
+  Pen activePen = Pen.pen;
+  List<Stroke> strokes = [];
+  final bool _allowDrawWithFinger = false;
+
+  void changePen(Pen pen) {
+    activePen = pen;
+    notifyListeners();
+  }
+
+  double _calcTiltedWidth(double baseWidth, double tilt) {
+    if (tilt == .0) return baseWidth;
+    return baseWidth * tilt;
+  }
+
+  double _calcAngleDependentWidth(Point pt1, Point pt2, double basetickness) {
+    double dx = pt2.point.dx - pt1.point.dx;
+    double dy = pt2.point.dy - pt1.point.dy;
+
+    // todo those deltas to small to get an accurate direction!
+
+    double alpha = atan(dx / dy);
+    // alpha has range from 0 - 2pi
+    // we want 0.5 -1;
+
+    alpha /= (2 * pi * 2);
+    alpha += .5;
+
+    double thickness = basetickness * alpha;
+    return thickness;
+  }
+
+  void pointDownEvent(Offset offset, PointerDeviceKind pointer, double tilt) {
+    if (_allowDrawWithFinger || pointer != PointerDeviceKind.touch) {
+      // todo line drawn on edge where line left page
+      if (!a4Page.contains(offset)) return;
+
+      // todo handle other pens
+      if (activePen != Pen.pen) return;
+
+      strokes
+          .add(Stroke.fromPoints([Point(offset, _calcTiltedWidth(3.0, tilt))]));
+      notifyListeners();
+    }
+  }
+
+  void pointUpEvent(PointerDeviceKind pointer) {
+    if (activePen == Pen.eraser) return;
+
+    if (_allowDrawWithFinger || pointer != PointerDeviceKind.touch) {
+      if (strokes.last.points.length <= 1) {
+        // if the line consists only of one point (point) add endpoint as the same to allow drawing a line
+        // todo maybe solve this in custompainter in future
+        strokes.last.points.add(strokes.last.points.last);
+        notifyListeners();
+      }
+    }
+  }
+
+  void pointMoveEvent(Offset offset, PointerDeviceKind pointer, double tilt) {
+    if (!a4Page.contains(offset)) {
+      return;
+    }
+
+    if (_allowDrawWithFinger || pointer != PointerDeviceKind.touch) {
+      switch (activePen) {
+        case Pen.eraser:
+          // todo dynamic eraser size
+          final eraserrect = Rect.fromCircle(center: offset, radius: 3);
+          for (final stroke in strokes) {
+            // check if delete action was within bounding rect of stroke
+            if (stroke.getBoundingRect().contains(offset)) {
+              // check if eraser hit an point within its range
+              for (final pt in stroke.points) {
+                if (eraserrect.contains(pt.point)) {
+                  strokes.remove(stroke);
+                  notifyListeners();
+                  return;
+                }
+              }
+            }
+          }
+          break;
+        case Pen.pen:
+          final pts = strokes.last.points;
+          if (pts.last.point == offset) return;
+
+          double newWidth = _calcTiltedWidth(5.0, tilt);
+          if (strokes.last.points.length > 1) {
+            newWidth = _calcAngleDependentWidth(
+                pts.last, pts[pts.length - 2], newWidth);
+          }
+
+          strokes.last.addPoint(Point(offset, newWidth));
+          break;
+        case Pen.highlighter:
+          // TODO: Handle this case.
+          break;
+        case Pen.selector:
+          // TODO: Handle this case.
+          break;
+      }
+      notifyListeners();
+    }
+  }
+}

lib/tool_bar.dart

@@ -0,0 +1,86 @@
+import 'package:adwaita_icons/adwaita_icons.dart';
+import 'package:fluentui_system_icons/fluentui_system_icons.dart';
+import 'package:flutter/material.dart';
+import 'package:iconify_flutter/iconify_flutter.dart';
+import 'package:iconify_flutter/icons/emojione_monotone.dart';
+import 'package:iconify_flutter/icons/jam.dart';
+
+import 'canvas/paint_controller.dart';
+import 'icon_material_button.dart';
+
+class ToolBar extends StatefulWidget {
+  const ToolBar({Key? key, required this.onPenChange}) : super(key: key);
+
+  final void Function(Pen pen) onPenChange;
+
+  @override
+  State<ToolBar> createState() => _ToolBarState();
+}
+
+class _ToolBarState extends State<ToolBar> {
+  Pen activepen = Pen.pen;
+
+  @override
+  Widget build(BuildContext context) {
+    return Container(
+      color: const Color(0xff3f3f3f),
+      width: 45,
+      child: Column(
+        children: [
+          const SizedBox(
+            height: 10,
+          ),
+          IconMaterialButton(
+            icon: const Iconify(
+              EmojioneMonotone.fountain_pen,
+              color: Color.fromRGBO(255, 255, 255, .85),
+            ),
+            color: const Color.fromRGBO(255, 255, 255, .85),
+            onPressed: () {
+              setState(() => activepen = Pen.pen);
+              widget.onPenChange(Pen.pen);
+            },
+            selected: activepen == Pen.pen,
+            iconSize: 24,
+          ),
+          IconMaterialButton(
+            icon: const Iconify(
+              Jam.highlighter,
+              color: Color.fromRGBO(255, 255, 255, .85),
+            ),
+            color: const Color.fromRGBO(255, 255, 255, .85),
+            onPressed: () {
+              setState(() => activepen = Pen.highlighter);
+              widget.onPenChange(Pen.highlighter);
+            },
+            selected: activepen == Pen.highlighter,
+            iconSize: 24,
+          ),
+          IconMaterialButton(
+            icon: Transform.translate(
+              offset: const Offset(-2.0, .0),
+              child: const AdwaitaIcon(AdwaitaIcons.eraser2),
+            ),
+            color: const Color.fromRGBO(255, 255, 255, .85),
+            onPressed: () {
+              setState(() => activepen = Pen.eraser);
+              widget.onPenChange(Pen.eraser);
+            },
+            iconSize: 24,
+            selected: activepen == Pen.eraser,
+          ),
+          IconMaterialButton(
+            icon: const Icon(FluentIcons.select_object_24_regular),
+            color: const Color.fromRGBO(255, 255, 255, .85),
+            onPressed: () {
+              setState(() => activepen = Pen.selector);
+              widget.onPenChange(Pen.selector);
+            },
+            selected: activepen == Pen.selector,
+            iconSize: 24,
+          ),
+        ],
+      ),
+    );
+  }
+}