Use cached instances in PadCalculatorSelector and AlignmentMarkerStrategy

Author: darkriszty

src/padCalculation/padCalculatorSelector.ts

@@ -6,29 +6,41 @@ import * as CenterAlignment from "./center";
 import { Alignment } from "../models/alignment";
 
 export class PadCalculatorSelector {
-    public select(table: Table,  column: number) : BasePadCalculator {
+    private static readonly leftFirstColumn = new LeftAlignment.FirstColumnPadCalculator();
+    private static readonly leftMiddleColumn = new LeftAlignment.MiddleColumnPadCalculator();
+    private static readonly leftLastColumn = new LeftAlignment.LastColumnPadCalculator();
+
+    private static readonly centerFirstColumn = new CenterAlignment.FirstColumnPadCalculator();
+    private static readonly centerMiddleColumn = new CenterAlignment.MiddleColumnPadCalculator();
+    private static readonly centerLastColumn = new CenterAlignment.LastColumnPadCalculator();
+
+    private static readonly rightFirstColumn = new RightAlignment.FirstColumnPadCalculator();
+    private static readonly rightMiddleColumn = new RightAlignment.MiddleColumnPadCalculator();
+    private static readonly rightLastColumn = new RightAlignment.LastColumnPadCalculator();
+
+    public select(table: Table, column: number) : BasePadCalculator {
         switch (table.alignments[column]) {
             case Alignment.Center: return this.centerAlignmentPadCalculator(table, column);
             case Alignment.Right: return this.rightAlignmentPadCalculator(table, column);
             default: return this.leftAlignmentPadCalculator(table, column);
         }
     }
 
-    private leftAlignmentPadCalculator(table: Table,  column: number) : BasePadCalculator {
-        if (column == 0) return new LeftAlignment.FirstColumnPadCalculator();
-        if (column == table.columnCount - 1) return new LeftAlignment.LastColumnPadCalculator();
-        return new LeftAlignment.MiddleColumnPadCalculator();
+    private leftAlignmentPadCalculator(table: Table, column: number) : BasePadCalculator {
+        if (column == 0) return PadCalculatorSelector.leftFirstColumn;
+        if (column == table.columnCount - 1) return PadCalculatorSelector.leftLastColumn;
+        return PadCalculatorSelector.leftMiddleColumn;
     }
 
-    private centerAlignmentPadCalculator(table: Table,  column: number) : BasePadCalculator {
-        if (column == 0) return new CenterAlignment.FirstColumnPadCalculator();
-        if (column == table.columnCount - 1) return new CenterAlignment.LastColumnPadCalculator();
-        return new CenterAlignment.MiddleColumnPadCalculator();
+    private centerAlignmentPadCalculator(table: Table, column: number) : BasePadCalculator {
+        if (column == 0) return PadCalculatorSelector.centerFirstColumn;
+        if (column == table.columnCount - 1) return PadCalculatorSelector.centerLastColumn;
+        return PadCalculatorSelector.centerMiddleColumn;
     }
 
-    private rightAlignmentPadCalculator(table: Table,  column: number) : BasePadCalculator {
-        if (column == 0) return new RightAlignment.FirstColumnPadCalculator();
-        if (column == table.columnCount - 1) return new RightAlignment.LastColumnPadCalculator();
-        return new RightAlignment.MiddleColumnPadCalculator();
+    private rightAlignmentPadCalculator(table: Table, column: number) : BasePadCalculator {
+        if (column == 0) return PadCalculatorSelector.rightFirstColumn;
+        if (column == table.columnCount - 1) return PadCalculatorSelector.rightLastColumn;
+        return PadCalculatorSelector.rightMiddleColumn;
     }
 }

src/viewModelFactories/alignmentMarking/alignmentMarkerStrategy.ts

@@ -1,16 +1,25 @@
 import { Alignment } from "../../models/alignment";
 import { IAlignmentMarker, LeftAlignmentMarker, RightAlignmentMarker, CenterAlignmentMarker, NotSetAlignmentMarker } from ".";
 
-
 export class AlignmentMarkerStrategy {
-    constructor(private _markerChar: string) { }
+    private readonly _leftMarker: IAlignmentMarker;
+    private readonly _rightMarker: IAlignmentMarker;
+    private readonly _centerMarker: IAlignmentMarker;
+    private readonly _notSetMarker: IAlignmentMarker;
+
+    constructor(private _markerChar: string) {
+        this._leftMarker = new LeftAlignmentMarker(this._markerChar);
+        this._rightMarker = new RightAlignmentMarker(this._markerChar);
+        this._centerMarker = new CenterAlignmentMarker(this._markerChar);
+        this._notSetMarker = new NotSetAlignmentMarker();
+    }
 
     public markerFor(alignment: Alignment): IAlignmentMarker {
         switch (alignment) {
-            case Alignment.Left: return new LeftAlignmentMarker(this._markerChar);
-            case Alignment.Right: return new RightAlignmentMarker(this._markerChar);
-            case Alignment.Center: return new CenterAlignmentMarker(this._markerChar);
-            default: return new NotSetAlignmentMarker();
+            case Alignment.Left: return this._leftMarker;
+            case Alignment.Right: return this._rightMarker;
+            case Alignment.Center: return this._centerMarker;
+            default: return this._notSetMarker;
         }
     }
 }