J2ME scrolling canvas?

[Oz Mortimer]

Hi,

Is there any way that I can scroll a canvas - i.e. if there are too many
items on the canvas you can still access by pressing down. I know Form does
this (apparently) but I need to do it using a canvas!. Maybe I can attach my
Canvas to a form?

Ideas?
Oz.

 

[Darryl L. Pierce]

Is there any way that I can scroll a canvas - i.e. if there are too many
items on the canvas you can still access by pressing down. I know Form does
this (apparently) but I need to do it using a canvas!.i

You have to do it programmatically yourself. A Canvas represents the
physical display area of the device on which it's running. If you have
more items than can be displayed on the physical screen, then you have
to draw your own scroll bars and handle determining what items to render
on the physical display.

Maybe I can attach my
Canvas to a form?

No. You can't mixed the hi-level widgets with the low-level widgets in
MIDP 1.0. With MIDP 2.0 you will have the CustomItem, but with MIDP 1.0
you're not able to mix programmer designed widgets with the LCDUI
widgets.

 

[Oz Mortimer]

Wow!... I can't believe that J2ME doesn't cater for that!. Has anyone got
any examples? is there a scrollbar class?

Oz.

 

[Fred L. Kleinschmidt]

Wow!... I can't believe that J2ME doesn't cater for that!. Has anyone got
any examples? is there a scrollbar class?

Oz.

Look at JScrollPane

 

[Tim Tyler]

: Oz Mortimer wrote:

:> Wow!... I can't believe that J2ME doesn't cater for that!. Has anyone got
:> any examples? is there a scrollbar class?

[...]

: Look at JScrollPane

No JScrollPane in J2ME.

There are GUI toolkits for J2ME - e.g. the kAWT: http://www.kawt.de/

That has a ScrollPane class - and a MIDP version.

 

[Darryl L. Pierce]

Wow!... I can't believe that J2ME doesn't cater for that!.

It's a low-level graphic canvas. The MIDP 1.0 spec has it rendering for
the physical display. With MIDP 2.0, there's a new GameCanvas class that
can define a graphical area larger than the physical display and uses
the physical display as a portal.

Has anyone got
any examples?

Check out the Lightweight Windowing Toolkit and OWT.

is there a scrollbar class?

No. But, if there were, you wouldn't be able to use it in the Canvas;
you can't mix high-level and low-level graphic components in the MIDP.

 

[Darryl L. Pierce]

Look at JScrollPane

No such class in the MIDP. He's not talking about J2SE, but J2ME/MIDP.