Re: [whatwg] Canvas ScrollBar
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-weba...@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. 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, -- Ian Hickson U+1047E)\._.,--,'``.fL http://ln.hixie.ch/ U+263A/, _.. \ _\ ;`._ ,. Things that are impossible just take longer. `._.-(,_..'--(,_..'`-.;.'
Re: [whatwg] Canvas ScrollBar
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-weba...@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). Brona
[whatwg] Canvas ScrollBar
Hello, 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. Brona Klucka
Re: [whatwg] Canvas ScrollBar
On Thu, 20 Oct 2011 14:14:12 +0200, Bronislav Klučka bronislav.klu...@bauglir.com wrote: Hello, 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. Brona Klucka Which is your use case ? It doesn't make any sense at all to me to have scrollbars in a canvas. However, if you need scrolling, you can wrap the canvas with an element with specified dimensions and overflow:auto.
Re: [whatwg] Canvas ScrollBar
On 20.10.2011 14:35, João Eiras wrote: On Thu, 20 Oct 2011 14:14:12 +0200, Bronislav Klučka bronislav.klu...@bauglir.com wrote: Hello, 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. Brona Klucka Which is your use case ? It doesn't make any sense at all to me to have scrollbars in a canvas. However, if you need scrolling, you can wrap the canvas with an element with specified dimensions and overflow:auto. Hi, 1/ your solution is very wrong solution could you imagine canvas 10x10px? well not possible, only solution is to create smaller canvas, wrap it into overflow auto div with inner div and then compute the dimension of whole image with javascript and transfer it to inner div dimensions (so scrollbars would match) and listen to onScroll event of outer div, and repaint the image with shifted origin 2/ use cases? a) diagram modeller http://www.webnt.cz/demos/033_canvas_diagram/ what if I have some large diagram? 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... Brona Klucka
