fix type declaration of private fields in cvat-canvas which are possibly null (#4932)

* fix type declaration of private fields in cvat-canvas which are possibly null

* v2.15.3

cvat-canvas/package.json

@@ -1,6 +1,6 @@
 {
   "name": "cvat-canvas",
-  "version": "2.15.2",
+  "version": "2.15.3",
   "description": "Part of Computer Vision Annotation Tool which presents its canvas library",
   "main": "src/canvas.ts",
   "scripts": {

cvat-canvas/src/typescript/drawHandler.ts

@@ -86,7 +86,7 @@ export class DrawHandlerImpl implements DrawHandler {
         y: number;
     };
     private crosshair: Crosshair;
-    private drawData: DrawData;
+    private drawData: DrawData | null;
     private geometry: Geometry;
     private autoborderHandler: AutoborderHandler;
     private autobordersEnabled: boolean;
@@ -100,7 +100,7 @@ export class DrawHandlerImpl implements DrawHandler {
     private initialized: boolean;
     private canceled: boolean;
     private pointsGroup: SVG.G | null;
-    private shapeSizeElement: ShapeSizeElement;
+    private shapeSizeElement: ShapeSizeElement | null;
 
     private getFinalEllipseCoordinates(points: number[], fitIntoFrame: boolean): number[] {
         const { offset } = this.geometry;

cvat-canvas/src/typescript/editHandler.ts

@@ -20,11 +20,11 @@ export interface EditHandler {
 export class EditHandlerImpl implements EditHandler {
     private onEditDone: (state: any, points: number[]) => void;
     private autoborderHandler: AutoborderHandler;
-    private geometry: Geometry;
+    private geometry: Geometry | null;
     private canvas: SVG.Container;
-    private editData: EditData;
-    private editedShape: SVG.Shape;
-    private editLine: SVG.PolyLine;
+    private editData: EditData | null;
+    private editedShape: SVG.Shape | null;
+    private editLine: SVG.PolyLine | null;
     private clones: SVG.Polygon[];
     private controlPointsSize: number;
     private autobordersEnabled: boolean;

cvat-canvas/src/typescript/groupHandler.ts

@@ -22,7 +22,7 @@ export class GroupHandlerImpl implements GroupHandler {
     private bindedOnSelectStart: (event: MouseEvent) => void;
     private bindedOnSelectUpdate: (event: MouseEvent) => void;
     private bindedOnSelectStop: (event: MouseEvent) => void;
-    private selectionRect: SVG.Rect;
+    private selectionRect: SVG.Rect | null;
     private startSelectionPoint: {
         x: number;
         y: number;

cvat-canvas/src/typescript/mergeHandler.ts

@@ -24,7 +24,7 @@ export class MergeHandlerImpl implements MergeHandler {
     private constraints: {
         labelID: number;
         shapeType: string;
-    };
+    } | null;
 
     private addConstraints(): void {
         const shape = this.statesToBeMerged[0];

cvat-canvas/src/typescript/splitHandler.ts

@@ -16,7 +16,7 @@ export class SplitHandlerImpl implements SplitHandler {
     private onSplitDone: (object: any) => void;
     private onFindObject: (event: MouseEvent) => void;
     private canvas: SVG.Container;
-    private highlightedShape: SVG.Shape;
+    private highlightedShape: SVG.Shape | null;
     private initialized: boolean;
     private splitDone: boolean;