MOBILE-2903 menu: Show menu items depending on device width

src/components/ion-tabs/ion-tabs.ts

@@ -223,6 +223,10 @@ export class CoreIonTabsComponent extends Tabs implements OnDestroy {
      * @param {CoreIonTabComponent} tab The tab to remove.
      */
     remove(tab: CoreIonTabComponent): void {
+        if (tab.isSelected) {
+            // TODO: If selected we should move this navigation to the phantom tab.
+        }
+
         // First search in the list of initialized tabs.
         let index = this._tabs.indexOf(tab);
 

src/core/mainmenu/pages/menu/menu.ts

@@ -30,6 +30,7 @@ import { CoreMainMenuDelegate, CoreMainMenuHandlerToDisplay } from '../../provid
 })
 export class CoreMainMenuPage implements OnDestroy {
     tabs: CoreMainMenuHandlerToDisplay[] = [];
+    allHandlers: CoreMainMenuHandlerToDisplay[];
     loaded = false;
     redirectPage: string;
     redirectParams: any;
@@ -42,7 +43,8 @@ export class CoreMainMenuPage implements OnDestroy {
     @ViewChild('mainTabs') mainTabs: CoreIonTabsComponent;
 
     constructor(private menuDelegate: CoreMainMenuDelegate, private sitesProvider: CoreSitesProvider, navParams: NavParams,
-            private navCtrl: NavController, private eventsProvider: CoreEventsProvider, private cdr: ChangeDetectorRef) {
+            private navCtrl: NavController, private eventsProvider: CoreEventsProvider, private cdr: ChangeDetectorRef,
+            private mainMenuProvider: CoreMainMenuProvider) {
 
         // Check if the menu was loaded with a redirect.
         const redirectPage = navParams.get('redirectPage');
@@ -78,10 +80,32 @@ export class CoreMainMenuPage implements OnDestroy {
 
         this.subscription = this.menuDelegate.getHandlers().subscribe((handlers) => {
             // Remove the handlers that should only appear in the More menu.
-            handlers = handlers.filter((handler) => {
+            this.allHandlers = handlers.filter((handler) => {
                 return !handler.onlyInMore;
             });
-            handlers = handlers.slice(0, CoreMainMenuProvider.NUM_MAIN_HANDLERS); // Get main handlers.
+
+            this.initHandlers();
+
+            if (this.loaded && this.pendingRedirect) {
+                // Wait for tabs to be initialized and then handle the redirect.
+                setTimeout(() => {
+                    if (this.pendingRedirect) {
+                        this.handleRedirect(this.pendingRedirect);
+                        delete this.pendingRedirect;
+                    }
+                });
+            }
+        });
+
+        window.addEventListener('resize', this.initHandlers.bind(this));
+    }
+
+    /**
+     * Init handlers on change (size or handlers).
+     */
+    initHandlers(): void {
+        if (this.allHandlers) {
+            const handlers = this.allHandlers.slice(0, this.mainMenuProvider.getNumItems()); // Get main handlers.
 
             // Re-build the list of tabs. If a handler is already in the list, use existing object to prevent re-creating the tab.
             const newTabs = [];
@@ -105,17 +129,7 @@ export class CoreMainMenuPage implements OnDestroy {
             });
 
             this.loaded = this.menuDelegate.areHandlersLoaded();
-
+        }
-            if (this.loaded && this.pendingRedirect) {
-                // Wait for tabs to be initialized and then handle the redirect.
-                setTimeout(() => {
-                    if (this.pendingRedirect) {
-                        this.handleRedirect(this.pendingRedirect);
-                        delete this.pendingRedirect;
-                    }
-                });
-            }
-        });
     }
 
     /**
@@ -153,5 +167,6 @@ export class CoreMainMenuPage implements OnDestroy {
     ngOnDestroy(): void {
         this.subscription && this.subscription.unsubscribe();
         this.redirectObs && this.redirectObs.off();
+        window.removeEventListener('resize', this.initHandlers.bind(this));
     }
 }

src/core/mainmenu/pages/more/more.ts

@@ -29,6 +29,7 @@ import { CoreMainMenuProvider, CoreMainMenuCustomItem } from '../../providers/ma
 })
 export class CoreMainMenuMorePage implements OnDestroy {
     handlers: CoreMainMenuHandlerData[];
+    allHandlers: CoreMainMenuHandlerData[];
     handlersLoaded: boolean;
     siteInfo: any;
     siteName: string;
@@ -58,32 +59,44 @@ export class CoreMainMenuMorePage implements OnDestroy {
     ionViewDidLoad(): void {
         // Load the handlers.
         this.subscription = this.menuDelegate.getHandlers().subscribe((handlers) => {
-            // Calculate the main handlers to not display them in this view.
+            this.allHandlers = handlers;
-            const mainHandlers = handlers.filter((handler) => {
-                return !handler.onlyInMore;
-            }).slice(0, CoreMainMenuProvider.NUM_MAIN_HANDLERS);
 
-            // Get only the handlers that don't appear in the main view.
+            this.initHandlers();
-            this.handlers = [];
-            handlers.forEach((handler) => {
-                if (mainHandlers.indexOf(handler) == -1) {
-                    this.handlers.push(handler);
-                }
-            });
-
-            this.handlersLoaded = this.menuDelegate.areHandlersLoaded();
         });
+
+        window.addEventListener('resize', this.initHandlers.bind(this));
     }
 
     /**
      * Page destroyed.
      */
     ngOnDestroy(): void {
+        window.removeEventListener('resize', this.initHandlers.bind(this));
+
         if (this.subscription) {
             this.subscription.unsubscribe();
         }
     }
 
+    /**
+     * Init handlers on change (size or handlers).
+     */
+    initHandlers(): void {
+        if (this.allHandlers) {
+            // Calculate the main handlers not to display them in this view.
+            const mainHandlers = this.allHandlers.filter((handler) => {
+                return !handler.onlyInMore;
+            }).slice(0, this.mainMenuProvider.getNumItems());
+
+            // Get only the handlers that don't appear in the main view.
+            this.handlers = this.allHandlers.filter((handler) => {
+                return mainHandlers.indexOf(handler) == -1;
+            });
+
+            this.handlersLoaded = this.menuDelegate.areHandlersLoaded();
+        }
+    }
+
     /**
      * Load the site info required by the view.
      */

src/core/mainmenu/providers/mainmenu.ts

@@ -52,6 +52,7 @@ export interface CoreMainMenuCustomItem {
 @Injectable()
 export class CoreMainMenuProvider {
     static NUM_MAIN_HANDLERS = 4;
+    static ITEM_MIN_WIDTH = 72; // Min with of every item, based on 5 items on a 360 pixel wide screen.
 
     constructor(private langProvider: CoreLangProvider, private sitesProvider: CoreSitesProvider) { }
 
@@ -158,4 +159,22 @@ export class CoreMainMenuProvider {
             });
         });
     }
+
+    /**
+     * Get the number of items to be shown on the main menu bar.
+     *
+     * @return {number} Number of items depending on the device width.
+     */
+    getNumItems(): number {
+        if (window && window.innerWidth) {
+            let numElements;
+
+            numElements = Math.floor(window.innerWidth / CoreMainMenuProvider.ITEM_MIN_WIDTH);
+
+            // Set a mínimum elements to show and skip more button.
+            return numElements > 1 ? numElements - 1 : 1;
+        }
+
+        return CoreMainMenuProvider.NUM_MAIN_HANDLERS;
+    }
 }