move window.__config to an Angular constant; refactor AngularViewArray -> ViewArray + ViewArrayFactory

static/js/services/view-array/view-array.impl.ts

@@ -0,0 +1,89 @@
+import { ViewArray } from './view-array';
+
+
+export class ViewArrayImpl implements ViewArray {
+
+  public entries: any[];
+  public isVisible: boolean;
+  public visibleEntries: any[];
+  public hasEntries: boolean;
+  public hasHiddenEntries: boolean;
+  private timerRef: any;
+  private currentIndex: number;
+
+  constructor(private interval: any, private additionalCount: number) {
+    this.isVisible = false;
+    this.visibleEntries = null;
+    this.hasEntries = false;
+    this.entries = [];
+    this.hasHiddenEntries = false;
+    this.timerRef = null;
+    this.currentIndex = 0;
+  }
+
+  public length(): number {
+    return this.entries.length;
+  }
+
+  public get(index: number): any {
+    return this.entries[index];
+  }
+
+  public push(elem: any): void {
+    this.entries.push(elem);
+    this.hasEntries = true;
+
+    if (this.isVisible) {
+      this.startTimer();
+    }
+  }
+
+  public toggle(): void {
+    this.setVisible(!this.isVisible);
+  }
+
+  public setVisible(newState: boolean): void {
+    this.isVisible = newState;
+
+    this.visibleEntries = [];
+    this.currentIndex = 0;
+
+    if (newState) {
+      this.showAdditionalEntries();
+      this.startTimer();
+    }
+    else {
+      this.stopTimer();
+    }
+  }
+
+  private showAdditionalEntries(): void {
+    var i: number = 0;
+    for (i = this.currentIndex; i < (this.currentIndex + this.additionalCount) && i < this.entries.length; ++i) {
+      this.visibleEntries.push(this.entries[i]);
+    }
+
+    this.currentIndex = i;
+    this.hasHiddenEntries = this.currentIndex < this.entries.length;
+    if (this.currentIndex >= this.entries.length) {
+      this.stopTimer();
+    }
+  }
+
+  private startTimer(): void {
+    if (this.timerRef) {
+      return;
+    }
+
+    this.timerRef = this.interval(() => {
+      this.showAdditionalEntries();
+    }, 10);
+  }
+
+  private stopTimer(): void {
+    if (this.timerRef) {
+      this.interval.cancel(this.timerRef);
+      this.timerRef = null;
+    }
+  }
+}