3 files changed, 107 insertions, 0 deletions

diff --git a/client/src/app/shared/menu/top-menu-dropdown.component.html b/client/src/app/shared/menu/top-menu-dropdown.component.html
new file mode 100644
index 000000000..2d6d1c4bf
--- /dev/null
+++ b/client/src/app/shared/menu/top-menu-dropdown.component.html
@@ -0,0 +1,18 @@
+<div class="sub-menu">
+  <ng-container *ngFor="let menuEntry of menuEntries">
+
+    <a *ngIf="menuEntry.routerLink" [routerLink]="menuEntry.routerLink" routerLinkActive="active" class="title-page">{{ menuEntry.label }}</a>
+
+    <div *ngIf="!menuEntry.routerLink" ngbDropdown class="parent-entry" #dropdown="ngbDropdown" (mouseleave)="closeDropdownIfHovered(dropdown)">
+      <span (mouseenter)="openDropdownOnHover(dropdown)" role="button" class="title-page" [ngClass]="{ active: !!suffixLabels[menuEntry.label] }" ngbDropdownToggle>
+        <ng-container i18n>{{ menuEntry.label }}</ng-container>
+        <ng-container *ngIf="!!suffixLabels[menuEntry.label]"> - {{ suffixLabels[menuEntry.label] }}</ng-container>
+      </span>
+
+      <div ngbDropdownMenu>
+        <a *ngFor="let menuChild of menuEntry.children" class="dropdown-item" [routerLink]="menuChild.routerLink">{{ menuChild.label }}</a>
+      </div>
+    </div>
+
+  </ng-container>
+</div>
diff --git a/client/src/app/shared/menu/top-menu-dropdown.component.scss b/client/src/app/shared/menu/top-menu-dropdown.component.scss
new file mode 100644
index 000000000..f3ef8f814
--- /dev/null
+++ b/client/src/app/shared/menu/top-menu-dropdown.component.scss
@@ -0,0 +1,14 @@
+.parent-entry {
+  span[role=button] {
+    cursor: pointer;
+  }
+
+  a {
+    display: block;
+  }
+}
+
+/deep/ .dropdown-toggle::after {
+  position: relative;
+  top: 2px;
+}
diff --git a/client/src/app/shared/menu/top-menu-dropdown.component.ts b/client/src/app/shared/menu/top-menu-dropdown.component.ts
new file mode 100644
index 000000000..272b721b2
--- /dev/null
+++ b/client/src/app/shared/menu/top-menu-dropdown.component.ts
@@ -0,0 +1,75 @@
+import { Component, Input, OnDestroy, OnInit } from '@angular/core'
+import { filter, take } from 'rxjs/operators'
+import { NavigationStart, Router } from '@angular/router'
+import { Subscription } from 'rxjs'
+import { NgbDropdown } from '@ng-bootstrap/ng-bootstrap'
+import { drop } from 'lodash-es'
+
+export type TopMenuDropdownParam = {
+  label: string
+  routerLink?: string
+
+  children?: {
+    label: string
+    routerLink: string
+  }[]
+}
+
+@Component({
+  selector: 'my-top-menu-dropdown',
+  templateUrl: './top-menu-dropdown.component.html',
+  styleUrls: [ './top-menu-dropdown.component.scss' ]
+})
+export class TopMenuDropdownComponent implements OnInit, OnDestroy {
+  @Input() menuEntries: TopMenuDropdownParam[] = []
+
+  suffixLabels: { [ parentLabel: string ]: string }
+
+  private openedOnHover = false
+  private routeSub: Subscription
+
+  constructor (private router: Router) {}
+
+  ngOnInit () {
+    this.updateChildLabels(window.location.pathname)
+
+    this.routeSub = this.router.events
+                        .pipe(filter(event => event instanceof NavigationStart))
+                        .subscribe(() => this.updateChildLabels(window.location.pathname))
+  }
+
+  ngOnDestroy () {
+    if (this.routeSub) this.routeSub.unsubscribe()
+  }
+
+  openDropdownOnHover (dropdown: NgbDropdown) {
+    this.openedOnHover = true
+    dropdown.open()
+
+    // Menu was closed
+    dropdown.openChange
+            .pipe(take(1))
+            .subscribe(e => this.openedOnHover = false)
+  }
+
+  closeDropdownIfHovered (dropdown: NgbDropdown) {
+    if (this.openedOnHover === false) return
+
+    dropdown.close()
+    this.openedOnHover = false
+  }
+
+  private updateChildLabels (path: string) {
+    this.suffixLabels = {}
+
+    for (const entry of this.menuEntries) {
+      if (!entry.children) continue
+
+      for (const child of entry.children) {
+        if (path.startsWith(child.routerLink)) {
+          this.suffixLabels[entry.label] = child.label
+        }
+      }
+    }
+  }
+}