perf: Cache SvgModules

It will prevent them to be parsed multiple times.

shared/src/services/svg-module-provider.service.ts

@@ -0,0 +1,36 @@
+import { Injectable } from '@angular/core';
+
+import { SvgModule } from '../components/svg/module';
+import { KeyboardLayout } from '../keyboard/keyboard-layout.enum';
+
+@Injectable()
+export class SvgModuleProviderService {
+
+    private ansiLeft: SvgModule;
+    private isoLeft: SvgModule;
+    private right: SvgModule;
+
+    getSvgModules(layout = KeyboardLayout.ANSI): SvgModule[] {
+        return [this.getRightModule(), this.getLeftModule(layout)];
+    }
+
+    private getLeftModule(layout = KeyboardLayout.ANSI): SvgModule {
+        if (layout === KeyboardLayout.ISO) {
+            if (!this.isoLeft) {
+                this.isoLeft = new SvgModule(require('xml-loader!../../../modules/uhk60-left-half/layout-iso.svg').svg);
+            }
+            return this.isoLeft;
+        }
+        if (!this.ansiLeft) {
+            this.ansiLeft = new SvgModule(require('xml-loader!../../../modules/uhk60-left-half/layout-ansi.svg').svg);
+        }
+        return this.ansiLeft;
+    }
+
+    private getRightModule(): SvgModule {
+        if (!this.right) {
+            this.right = new SvgModule(require('xml-loader!../../../modules/uhk60-right-half/layout.svg').svg);
+        }
+        return this.right;
+    }
+}