How can I use content.scrollTo() for ion-scroll in ionic2?

Tobias Bambullis picture Tobias Bambullis · May 21, 2017 · Viewed 13.9k times · Source

I try to scroll to a fixed position, for example scrollTo(500, 20). Let's say that you are on a device, which has got a width of 300 pixel. The scroll target is now out of the screen scope, you have to scroll to the right.

I solved this by doing the following:

<ion-content>
    <ion-scroll scrollX="true" style="width:100%; height:100%; white-space: nowrap; ">
        <div style="width:1000px; ">
            [box1] [box2] [box3] [...]
        </div>
    </ion-scroll>
</ion-content>

Up to here everything is fine. The problem starts if i want to jump 500 pixel to the right by pressing a button for example. Swiping to the right works. I know that there is a function to do this for <ion-content>:

@ViewChild(Content) content: Content;
[...]
this.content.scrollTo(500, 500, 500); 

This unfortunately doesn't work in my case. I think the problem is that the content is related to the device size so the scrollTo() method does not take affect for <ion-scoll>. How can I use the scrollTo() method for <ion-scroll> instead of <ion-content>?

Thanks for any help!

Answer

sebaferreras picture sebaferreras · May 27, 2017

How can I use the scrollTo() method for <ion-scroll> instead of <ion-content>?

I'm still working on how to animate the scroll, but at least this may be considered as a solution for your scenario. Please take a look at this plunker.

Since we can't use theion-content for scrolling, I though about getting the instance of the Scroll, then accessing the inner html scroll element, and then using the element.scrollLeft property to scroll on that element:

The element.scrollLeft property gets or sets the number of pixels that an element's content is scrolled to the left.

So in the component code:

import { Component, ViewChild } from '@angular/core';
import { NavController, Content } from 'ionic-angular';

@Component({...})
export class HomePage {
  @ViewChild('scroll') scroll: any;

    constructor() {}

    public backToStart(): void {
      this.scroll.scrollElement.scrollLeft = 0;
    }

    public scrollToRight(): void {
      this.scroll.scrollElement.scrollLeft = 500;
    }

}

And in the view:

<ion-content padding>
  <ion-scroll #scroll scrollX="true" style="width:100%; height:150px; white-space: nowrap;">
        <div  style="width:1000px;">
            <div style="display:inline-block;height:100px;width:100px;border:1px solid black;"></div>
            <div style="display:inline-block;height:100px;width:100px;border:1px solid red;"></div>
            <div style="display:inline-block;height:100px;width:100px;border:1px solid blue;"></div>
            <div style="display:inline-block;height:100px;width:100px;border:1px solid green;"></div>
            <div style="display:inline-block;height:100px;width:100px;border:1px solid grey;"></div>
            <div style="display:inline-block;height:100px;width:100px;border:1px solid brown;"></div>
            <div style="display:inline-block;height:100px;width:100px;border:1px solid yellow;"></div>
            <div style="display:inline-block;height:100px;width:100px;border:1px solid orange;"></div>
            <div style="display:inline-block;height:100px;width:100px;border:1px solid pink;"></div>
            <div style="display:inline-block;height:100px;width:100px;border:1px solid violet;"></div>
        </div>
    </ion-scroll>

    <button (click)="backToStart()" ion-button text-only>Go to start</button>
    <button (click)="scrollToRight()" ion-button text-only>Scroll to right!</button>
</ion-content>

By doing this.scroll.scrollElement.scrollLeft = 500;, we can scroll the content of the ion-scroll 500px to the right. We can then go back to the start again by doing this.scroll.scrollElement.scrollLeft = 0;.