added button to scroll back to top of feed issue #24

src/pages/stream/stream.html

@@ -96,4 +96,10 @@
     </button>
   </ion-fab>
 
+  <ion-fab *ngIf="showScrollBtn" left bottom>
+    <button ion-fab color="light" (click)="scrollToTop()">
+      <ion-icon name="arrow-dropup"></ion-icon>
+    </button>
+  </ion-fab>
+
 </ion-content>

src/pages/stream/stream.ts

@@ -1,5 +1,5 @@
-import { Component } from '@angular/core';
-import { ViewController, NavController, NavParams, ModalController } from 'ionic-angular';
+import { Component, ViewChild, ChangeDetectorRef } from '@angular/core';
+import { ViewController, NavController, NavParams, ModalController, Content  } from 'ionic-angular';
 import { ThreadPage } from '../thread/thread';
 
 import * as pnut from 'pnut-butter';
@@ -16,6 +16,8 @@ import * as pnut from 'pnut-butter';
 })
 export class StreamPage {
 
+  @ViewChild(Content) content: Content;
+
   title: string;
   posts: Array<Object> = [];
   since_id: string;
@@ -23,9 +25,12 @@ export class StreamPage {
   fetcher: any;
   fcaller: any;
   myUsername: string;
+  showScrollBtn: boolean = false;
 
-  constructor(public navCtrl: NavController, public navParams: NavParams, public modalCtrl: ModalController) {
+  constructor(public navCtrl: NavController, public navParams: NavParams, public modalCtrl: ModalController,
+    private changeDetectorRef: ChangeDetectorRef) {
     // console.log(JSON.stringify(navParams));
+
     switch (navParams.data.stream) {
       case 'global':
         this.title = 'Global';
@@ -55,6 +60,18 @@ export class StreamPage {
     });
   }
 
+  ngAfterViewInit() {
+    this.content.ionScroll.subscribe((event) => {
+      // console.log('scrolling ', event);
+      if (event.scrollTop > 0) {
+        this.showScrollBtn = true;
+      } else {
+        this.showScrollBtn = false;
+      }
+      this.changeDetectorRef.detectChanges();
+    });
+  }
+
   fetchOlderPosts(infiniteScroll) {
     let params = {include_raw: 1, include_reposted_by:1, before_id: this.before_id, count: 40};
     if (this.title === 'Mentions') {
@@ -231,6 +248,10 @@ export class StreamPage {
     newPostModal.present();
   }
 
+  scrollToTop() {
+    this.content.scrollToTop();
+  }
+
 }
 
 @Component({