TiddlyWiki5/editions/tw5.com/tiddlers/widgets/ScrollableWidget.tid

caption: scrollable
created: 20140324223413403
modified: 20230731100903977
tags: Widgets
title: ScrollableWidget
type: text/vnd.tiddlywiki

! Introduction

The scrollable widget wraps its content in a scrollable frame. The user can scroll the contents with the mouse or with touch gestures. Code can use the [[WidgetMessage: tm-scroll]] to programmatically scroll specific DOM nodes into view.

! Content and Attributes

The content of the `<$scrollable>` widget is displayed within a pair of wrapper DIVs. If the inner DIV is larger then it scrolls within the outer one. CSS is used to specify the size of the outer wrapper.

|!Attribute |!Description |
|class |The CSS class(es) to be applied to the outer DIV |
|fallthrough |See below |
|bind |<<.from-version "5.3.2">> Optional title of tiddler to which the scroll position should be bound |

Binding the scroll position to a tiddler automatically copies the scroll coordinates into the `scroll-left` and `scroll-top` fields after scrolling occurs. Conversely, setting those field values will automatically cause the scrollable to scroll if it can.

<$macrocall $name=".note" _="""If a scrollable widget can't handle the `tm-scroll` message because the inner DIV fits within the outer DIV, then by default the message falls through to the parent widget. Setting the ''fallthrough'' attribute to `no` prevents this behaviour."""/> 

! Examples

These examples require the following CSS definitions from [[$:/_tw5.com-styles]]:

```
.tc-scrollable-demo {
	border: 1px solid <<colour message-border>>;
	background-color: <<colour message-background>>;
	padding: 1em;
	height: 400px;
	position: relative;
}
```

!! Simple Usage

This wiki text shows how to display a list within the scrollable widget:

<<wikitext-example-without-html "<$scrollable class='tc-scrollable-demo'>
<$list filter='[tag[Reference]]'>

<$view field='title'/>: <$list filter='[all[current]links[]sort[title]]' storyview='pop'>
<$link><$view field='title'/></$link>
</$list>

</$list>
</$scrollable>
">>

!! Binding scroll position to a tiddler

[[Current scroll position|$:/my-scroll-position]]: {{$:/my-scroll-position!!scroll-left}}, {{$:/my-scroll-position!!scroll-top}}

<$button>
<$action-setfield $tiddler="$:/my-scroll-position" scroll-left="100" scroll-top="100"/>
Set current scroll position to 100,100
</$button>

<$button>
<$action-setfield $tiddler="$:/my-scroll-position" scroll-top={{{ [{$:/my-scroll-position!!scroll-top}subtract[10]] }}}/>
Scroll up by 10 pixels
</$button>

<$button>
<$action-setfield $tiddler="$:/my-scroll-position" scroll-top={{{ [{$:/my-scroll-position!!scroll-top}add[10]] }}}/>
Scroll down by 10 pixels
</$button>

<<wikitext-example-without-html "<$scrollable class='tc-scrollable-demo' bind='$:/my-scroll-position'>
<$list filter='[tag[Reference]]'>

<$view field='title'/>: <$list filter='[all[current]links[]sort[title]]' storyview='pop'>
<$link><$view field='title'/></$link>
</$list>

</$list>
</$scrollable>
">>