From 577a0a65988ba0e980f8a41f5b2d3bf1adb77b84 Mon Sep 17 00:00:00 2001
From: Dani Palou <dani@moodle.com>
Date: Mon, 5 Feb 2018 12:31:48 +0100
Subject: [PATCH] MOBILE-2335 contextmenu: Merge menus in navbuttons component

---
 src/components/context-menu/context-menu.ts   | 67 +++++++++++---
 .../navbar-buttons/navbar-buttons.ts          | 88 +++++++++++++++----
 src/core/course/pages/section/section.html    |  4 +-
 src/providers/utils/dom.ts                    | 52 +++++++++++
 4 files changed, 182 insertions(+), 29 deletions(-)

diff --git a/src/components/context-menu/context-menu.ts b/src/components/context-menu/context-menu.ts
index 7c96cfcd6..6ef697cc4 100644
--- a/src/components/context-menu/context-menu.ts
+++ b/src/components/context-menu/context-menu.ts
@@ -12,9 +12,10 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-import { Component, Input, OnInit } from '@angular/core';
+import { Component, Input, OnInit, OnDestroy, ElementRef } from '@angular/core';
 import { PopoverController } from 'ionic-angular';
 import { TranslateService } from '@ngx-translate/core';
+import { CoreDomUtilsProvider } from '../../providers/utils/dom';
 import { CoreContextMenuItemComponent } from './context-menu-item';
 import { CoreContextMenuPopoverComponent } from './context-menu-popover';
 import { Subject } from 'rxjs';
@@ -26,7 +27,7 @@ import { Subject } from 'rxjs';
     selector: 'core-context-menu',
     templateUrl: 'context-menu.html'
 })
-export class CoreContextMenuComponent implements OnInit {
+export class CoreContextMenuComponent implements OnInit, OnDestroy {
     @Input() icon?: string; // Icon to be shown on the navigation bar. Default: Kebab menu icon.
     @Input() title?: string; // Aria label and text to be shown on the top of the popover.
 
@@ -34,8 +35,11 @@ export class CoreContextMenuComponent implements OnInit {
     ariaLabel: string;
     protected items: CoreContextMenuItemComponent[] = [];
     protected itemsChangedStream: Subject<void>; // Stream to update the hideMenu boolean when items change.
+    protected instanceId: string;
+    protected parentContextMenu: CoreContextMenuComponent;
 
-    constructor(private translate: TranslateService, private popoverCtrl: PopoverController) {
+    constructor(private translate: TranslateService, private popoverCtrl: PopoverController, private elementRef: ElementRef,
+            private domUtils: CoreDomUtilsProvider) {
         // Create the stream and subscribe to it. We ignore successive changes during 250ms.
         this.itemsChangedStream = new Subject<void>();
         this.itemsChangedStream.auditTime(250).subscribe(() => {
@@ -49,6 +53,8 @@ export class CoreContextMenuComponent implements OnInit {
                 return a.priority <= b.priority ? 1 : -1;
             });
         });
+
+        this.instanceId = this.domUtils.storeInstanceByElement(elementRef.nativeElement, this);
     }
 
     /**
@@ -65,15 +71,44 @@ export class CoreContextMenuComponent implements OnInit {
      * @param {CoreContextMenuItemComponent} item The item to add.
      */
     addItem(item: CoreContextMenuItemComponent): void {
-        this.items.push(item);
-        this.itemsChanged();
+        if (this.parentContextMenu) {
+            // All items were moved to the "parent" menu. Add the item in there.
+            this.parentContextMenu.addItem(item);
+        } else {
+            this.items.push(item);
+            this.itemsChanged();
+        }
     }
 
     /**
      * Function called when the items change.
      */
     itemsChanged(): void {
-        this.itemsChangedStream.next();
+        if (this.parentContextMenu) {
+            // All items were moved to the "parent" menu, call the function in there.
+            this.parentContextMenu.itemsChanged();
+        } else {
+            this.itemsChangedStream.next();
+        }
+    }
+
+    /**
+     * Merge the current context menu with the one passed as parameter. All the items in this menu will be moved to the
+     * one passed as parameter.
+     *
+     * @param {CoreContextMenuComponent} contextMenu The context menu where to move the items.
+     */
+    mergeContextMenus(contextMenu: CoreContextMenuComponent): void {
+        this.parentContextMenu = contextMenu;
+
+        // Add all the items to the other menu.
+        for (let i = 0; i < this.items.length; i++) {
+            contextMenu.addItem(this.items[i]);
+        }
+
+        // Remove all items from the current menu.
+        this.items = [];
+        this.itemsChanged();
     }
 
     /**
@@ -82,11 +117,16 @@ export class CoreContextMenuComponent implements OnInit {
      * @param {CoreContextMenuItemComponent} item The item to remove.
      */
     removeItem(item: CoreContextMenuItemComponent): void {
-        const index = this.items.indexOf(item);
-        if (index >= 0) {
-            this.items.splice(index, 1);
+        if (this.parentContextMenu) {
+            // All items were moved to the "parent" menu. Remove the item from there.
+            this.parentContextMenu.removeItem(item);
+        } else {
+            const index = this.items.indexOf(item);
+            if (index >= 0) {
+                this.items.splice(index, 1);
+            }
+            this.itemsChanged();
         }
-        this.itemsChanged();
     }
 
     /**
@@ -100,4 +140,11 @@ export class CoreContextMenuComponent implements OnInit {
             ev: event
         });
     }
+
+    /**
+     * Component destroyed.
+     */
+    ngOnDestroy(): void {
+        this.domUtils.removeInstanceById(this.instanceId);
+    }
 }
diff --git a/src/components/navbar-buttons/navbar-buttons.ts b/src/components/navbar-buttons/navbar-buttons.ts
index 98edb3421..3bdb50e26 100644
--- a/src/components/navbar-buttons/navbar-buttons.ts
+++ b/src/components/navbar-buttons/navbar-buttons.ts
@@ -14,6 +14,7 @@
 
 import { Component, Input, OnInit, ContentChildren, ElementRef, QueryList } from '@angular/core';
 import { Button } from 'ionic-angular';
+import { CoreLoggerProvider } from '../../providers/logger';
 import { CoreDomUtilsProvider } from '../../providers/utils/dom';
 
 /**
@@ -63,41 +64,80 @@ export class CoreNavBarButtonsComponent implements OnInit {
     protected element: HTMLElement;
     protected _buttons: QueryList<Button>;
     protected _hidden: boolean;
+    protected logger: any;
 
-    constructor(element: ElementRef, private domUtils: CoreDomUtilsProvider) {
+    constructor(element: ElementRef, logger: CoreLoggerProvider, private domUtils: CoreDomUtilsProvider) {
         this.element = element.nativeElement;
+        this.logger = logger.getInstance('CoreNavBarButtonsComponent');
     }
 
     /**
      * Component being initialized.
      */
     ngOnInit(): void {
-        const header = this.searchHeader();
+        this.searchHeader().then((header) => {
+            if (header) {
+                // Search the right buttons container (start, end or any).
+                let selector = 'ion-buttons',
+                    buttonsContainer: HTMLElement;
 
-        if (header) {
-            // Search the right buttons container (start, end or any).
-            let selector = 'ion-buttons',
-                buttonsContainer: HTMLElement;
+                if (this.element.hasAttribute('start')) {
+                    selector += '[start]';
+                } else if (this.element.hasAttribute('end')) {
+                    selector += '[end]';
+                }
 
-            if (this.element.hasAttribute('start')) {
-                selector += '[start]';
-            } else if (this.element.hasAttribute('end')) {
-                selector += '[end]';
+                buttonsContainer = <HTMLElement> header.querySelector(selector);
+                if (buttonsContainer) {
+                    this.mergeContextMenus(buttonsContainer);
+
+                    this.domUtils.moveChildren(this.element, buttonsContainer);
+                } else {
+                    this.logger.warn('The header was found, but it didn\'t have the right ion-buttons.', selector);
+                }
             }
+        }).catch(() => {
+            // Header not found.
+            this.logger.warn('Header not found.');
+        });
+    }
 
-            buttonsContainer = <HTMLElement> header.querySelector(selector);
-            if (buttonsContainer) {
-                this.domUtils.moveChildren(this.element, buttonsContainer);
-            }
+    /**
+     * If both button containers have a context menu, merge them into a single one.
+     *
+     * @param {HTMLElement} buttonsContainer The container where the buttons will be moved.
+     */
+    protected mergeContextMenus(buttonsContainer: HTMLElement): void {
+        // Check if both button containers have a context menu.
+        const mainContextMenu = buttonsContainer.querySelector('core-context-menu');
+        if (!mainContextMenu) {
+            return;
+        }
+
+        const secondaryContextMenu = this.element.querySelector('core-context-menu');
+        if (!secondaryContextMenu) {
+            return;
+        }
+
+        // Both containers have a context menu. Merge them to prevent having 2 menus at the same time.
+        const mainContextMenuInstance = this.domUtils.getInstanceByElement(mainContextMenu),
+            secondaryContextMenuInstance = this.domUtils.getInstanceByElement(secondaryContextMenu);
+
+        if (mainContextMenuInstance && secondaryContextMenuInstance) {
+            secondaryContextMenuInstance.mergeContextMenus(mainContextMenuInstance);
+
+            // Remove the empty context menu from the DOM.
+            secondaryContextMenu.parentElement.removeChild(secondaryContextMenu);
         }
     }
 
     /**
      * Search the ion-header where the buttons should be added.
      *
-     * @return {HTMLElement} Header element.
+     * @param {number} [retries] Number of retries so far.
+     * @return {Promise<HTMLElement>} Promise resolved with the header element.
      */
-    protected searchHeader(): HTMLElement {
+    protected searchHeader(retries: number = 0): Promise<HTMLElement> {
         let parentPage: HTMLElement = this.element;
 
         while (parentPage) {
@@ -112,10 +152,24 @@ export class CoreNavBarButtonsComponent implements OnInit {
                 // Check if the page has a header. If it doesn't, search the next parent page.
                 const header = this.searchHeaderInPage(parentPage);
                 if (header) {
-                    return header;
+                    return Promise.resolve(header);
                 }
             }
         }
+
+        // Header not found.
+        if (retries < 5) {
+            // If the component or any of its parent is inside a ng-content or similar it can be detached when it's initialized.
+            // Try again after a while.
+            return new Promise((resolve, reject): void => {
+                setTimeout(() => {
+                    this.searchHeader(retries + 1).then(resolve, reject);
+                }, 200);
+            });
+        }
+
+        // We've waited enough time, reject.
+        return Promise.reject(null);
     }
 
     /**
diff --git a/src/core/course/pages/section/section.html b/src/core/course/pages/section/section.html
index 2360f470f..dfefb39d7 100644
--- a/src/core/course/pages/section/section.html
+++ b/src/core/course/pages/section/section.html
@@ -4,8 +4,8 @@
 
         <ion-buttons end>
             <core-context-menu>
-                <core-context-menu-item [priority]="900" [content]="'core.settings.enabledownloadsection' | translate" (action)="toggleDownload()" [iconAction]="downloadEnabledIcon"></core-context-menu-item>
-                <core-context-menu-item [priority]="850" [content]="'core.course.downloadcourse' | translate" (action)="prefetchCourse()" [iconAction]="prefetchCourseData.prefetchCourseIcon" [closeOnClick]="false"></core-context-menu-item>
+                <core-context-menu-item [priority]="2000" [content]="'core.settings.enabledownloadsection' | translate" (action)="toggleDownload()" [iconAction]="downloadEnabledIcon"></core-context-menu-item>
+                <core-context-menu-item [priority]="1900" [content]="'core.course.downloadcourse' | translate" (action)="prefetchCourse()" [iconAction]="prefetchCourseData.prefetchCourseIcon" [closeOnClick]="false"></core-context-menu-item>
             </core-context-menu>
         </ion-buttons>
     </ion-navbar>
diff --git a/src/providers/utils/dom.ts b/src/providers/utils/dom.ts
index 41e3dc049..d9dbd7909 100644
--- a/src/providers/utils/dom.ts
+++ b/src/providers/utils/dom.ts
@@ -32,9 +32,12 @@ export class CoreDomUtilsProvider {
     // List of input types that support keyboard.
     protected INPUT_SUPPORT_KEYBOARD = ['date', 'datetime', 'datetime-local', 'email', 'month', 'number', 'password',
         'search', 'tel', 'text', 'time', 'url', 'week'];
+    protected INSTANCE_ID_ATTR_NAME = 'core-instance-id';
 
     protected element = document.createElement('div'); // Fake element to use in some functions, to prevent creating it each time.
     protected matchesFn: string; // Name of the "matches" function to use when simulating a closest call.
+    protected instances: {[id: string]: any} = {}; // Store component/directive instances by id.
+    protected lastInstanceId = 0;
 
     constructor(private translate: TranslateService, private loadingCtrl: LoadingController, private toastCtrl: ToastController,
             private alertCtrl: AlertController, private textUtils: CoreTextUtilsProvider, private appProvider: CoreAppProvider,
@@ -410,6 +413,20 @@ export class CoreDomUtilsProvider {
         return this.textUtils.decodeHTML(this.translate.instant('core.error'));
     }
 
+    /**
+     * Retrieve component/directive instance.
+     * Please use this function only if you cannot retrieve the instance using parent/child methods: ViewChild (or similar)
+     * or Angular's injection.
+     *
+     * @param {Element} element The root element of the component/directive.
+     * @return {any} The instance, undefined if not found.
+     */
+    getInstanceByElement(element: Element): any {
+        const id = element.getAttribute(this.INSTANCE_ID_ATTR_NAME);
+
+        return this.instances[id];
+    }
+
     /**
      * Check if an element is outside of screen (viewport).
      *
@@ -513,6 +530,25 @@ export class CoreDomUtilsProvider {
         return this.element.innerHTML;
     }
 
+    /**
+     * Remove a component/directive instance using the DOM Element.
+     *
+     * @param {Element} element The root element of the component/directive.
+     */
+    removeInstanceByElement(element: Element): void {
+        const id = element.getAttribute(this.INSTANCE_ID_ATTR_NAME);
+        delete this.instances[id];
+    }
+
+    /**
+     * Remove a component/directive instance using the ID.
+     *
+     * @param {string} id The ID to remove.
+     */
+    removeInstanceById(id: string): void {
+        delete this.instances[id];
+    }
+
     /**
      * Search for certain classes in an element contents and replace them with the specified new values.
      *
@@ -883,6 +919,22 @@ export class CoreDomUtilsProvider {
         return loader;
     }
 
+    /**
+     * Stores a component/directive instance.
+     *
+     * @param {Element} element The root element of the component/directive.
+     * @param {any} instance The instance to store.
+     * @return {string} ID to identify the instance.
+     */
+    storeInstanceByElement(element: Element, instance: any): string {
+        const id = String(this.lastInstanceId++);
+
+        element.setAttribute(this.INSTANCE_ID_ATTR_NAME, id);
+        this.instances[id] = instance;
+
+        return id;
+    }
+
     /**
      * Check if an element supports input via keyboard.
      *