[whatwg] Canvas ScrollBar

Bronislav Klučka Bronislav.Klucka at bauglir.com
Fri Jan 27 17:28:26 PST 2012

On 27.1.2012 20:02, Ian Hickson wrote:
> On Thu, 20 Oct 2011, Bronislav Klu�~Mka wrote:
>> Would it be possible to extend canvas specification to include scroll
>> bar functionality? To add scroll bar, to manage scroll bar (total size,
>> page size). Creating control based on canvas that needs scrollbar at
>> this point is unnecessarily difficult at this point.
> It is expected that the component model feature being discussed in the
> public-webapps at w3.org mailing list will be how you make widgets on the
> platform.
> You wouldn't want to put the scrollbar in the canvas itself, since then it
> wouldn't follow platform native conventions, for example. Instead, you
> would create a widget which uses overflow:scroll with an element of the
> right height or width to create scrollbars, and then you would react to
> scroll events to repaint the canvas.
How does scrollbar on div, p, textarea etc. follow platform native 
conventions but scroll bar on canvas would not?
> On Thu, 20 Oct 2011, Bronislav Klu�~Mka wrote:
>> b) how about creating user controls using canvas? (rich controls are
>> better doing this way, one has pixel perfect control, full browser
>> compatibility) like document viewer, rich listview/treeview control...
> Generally speaking, canvas isn't intended for anything but the simplest of
> interactive controls.
> HTH,
Generally speaking, widgets are intended to be HTML container, which 
makes them far inferior to possibilities of canvas... simpler, but 
inferior (as is any HTML container at this point).


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