add auto-highlighting of selected/updated code

src/application/State/Code/ApplicationCode.ts

@@ -1,30 +1,38 @@
+import { CodeChangedEvent } from './Event/CodeChangedEvent';
+import { CodePosition } from './Position/CodePosition';
+import { ICodeChangedEvent } from './Event/ICodeChangedEvent';
 import { SelectedScript } from '@/application/State/Selection/SelectedScript';
 import { IUserSelection } from '@/application/State/Selection/IUserSelection';
-import { UserScriptGenerator } from './UserScriptGenerator';
+import { UserScriptGenerator } from './Generation/UserScriptGenerator';
 import { Signal } from '@/infrastructure/Events/Signal';
 import { IApplicationCode } from './IApplicationCode';
-import { IUserScriptGenerator } from './IUserScriptGenerator';
+import { IUserScriptGenerator } from './Generation/IUserScriptGenerator';
 
 export class ApplicationCode implements IApplicationCode {
-    public readonly changed = new Signal<string>();
+    public readonly changed = new Signal<ICodeChangedEvent>();
     public current: string;
 
-    private readonly generator: IUserScriptGenerator = new UserScriptGenerator();
+    private scriptPositions = new Map<SelectedScript, CodePosition>();
 
     constructor(
         userSelection: IUserSelection,
-        private readonly version: string) {
+        private readonly version: string,
+        private readonly generator: IUserScriptGenerator = new UserScriptGenerator()) {
         if (!userSelection) { throw new Error('userSelection is null or undefined'); }
         if (!version) { throw new Error('version is null or undefined'); }
-        this.generator = new UserScriptGenerator();
+        if (!generator) { throw new Error('generator is null or undefined'); }
         this.setCode(userSelection.selectedScripts);
         userSelection.changed.on((scripts) => {
             this.setCode(scripts);
         });
     }
 
-    private setCode(scripts: ReadonlyArray<SelectedScript>) {
-        this.current = scripts.length === 0 ? '' : this.generator.buildCode(scripts, this.version);
-        this.changed.notify(this.current);
+    private setCode(scripts: ReadonlyArray<SelectedScript>): void {
+        const oldScripts = Array.from(this.scriptPositions.keys());
+        const code = this.generator.buildCode(scripts, this.version);
+        this.current = code.code;
+        this.scriptPositions = code.scriptPositions;
+        const event = new CodeChangedEvent(code.code, oldScripts, code.scriptPositions);
+        this.changed.notify(event);
     }
 }