Force JScrollPane to scroll in one direction only

Thread view:

Rene Ruppert - 31 Oct 2003 15:04 GMT

Hi,

is there a way to force a JScrollPane to display a vertical scrollbar only
if the amount of components cannot be displayed within the visible area?

Background: I want to create a kind of thumb view where an unknown number of
thumbnails will be inserted. As long as there's space for another item it
will be displayed within the same line; if not it will be wrapped to the
next line. If the number of lines exceeds the available vertical space a
vertical scrollbar will be shown.
If the window is resized the thumbs are supposed to be wrapped according to
the current width.

I tried the following without succes:
- setHorizontalScrollBarPolicy() to never
- use FlowLayout Manager
- use GridLayout

I found lots of articles an Google - but all without a real solution.

Please help! :-(

cu

Rene

Reply to this Message

Thomas Fritsch - 31 Oct 2003 17:54 GMT

>is there a way to force a JScrollPane to display a vertical scrollbar only
>if the amount of components cannot be displayed within the visible area?

Call

yourScrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED);

Thomas

Reply to this Message

Thomas Fritsch - 31 Oct 2003 18:26 GMT

Thomas Fritsch schrieb:

>> is there a way to force a JScrollPane to display a vertical scrollbar
>> only
[quoted text clipped - 5 lines]
>
> Thomas

Sorry, I meant

yourScrollPane.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);

Thomas

Reply to this Message

Babu Kalakrishnan - 01 Nov 2003 07:29 GMT

> Thomas Fritsch schrieb:
>
[quoted text clipped - 11 lines]
>
> yourScrollPane.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);

I think the first suggestion was the correct one. The
HorizontalScrollBarPolicy should be set to NEVER.

Some more points to remember are - a) Use an appropriate LayoutManager
for the panel that is inside the viewport, b) *Not* calling
setPreferredSize on this panel, c) Having the panel implement the
Scrollable interface and return "true" for the
getScrollableTracksViewportWidth method and "false" for
getScrollableTracksViewportHeight method.

Read the documentation of javax.swing.Scrollable and JScrollPane, as
well as the Java Tutorial chapter on How to use JScrollPane.

BK

Reply to this Message

Rene Ruppert - 03 Nov 2003 09:10 GMT

Hi Thomas,

yourScrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_AS_
NEEDED);

yourScrollPane.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR
_AS_NEEDED);

sorry, but both won't work. Setting the scrollbar policies has no effect.
Setting horizontal to NEVER disables the scrolling completely without
leading to a wrapping of the content and setting vertical to AS_NEEDED won't
show a bar at all.

Anyway thanks.

cu

Rene

Reply to this Message

Babu Kalakrishnan - 04 Nov 2003 11:22 GMT

> yourScrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_AS_
> NEEDED);
[quoted text clipped - 8 lines]
>
> Anyway thanks.

Did you try implementing the Scrollable interface ? If not, try doing that.

Are you by any chance setting some hardcoded values to the preferredSize
parameter of the panel ? If you did so, remove that piece of code.

Difficult to guess further without seeing some code. I'm sure a lot of
people have used a JScrollPane in a zillion applications without having
a similar problem - which means you must be doing something wrong in
your code.

BK

Reply to this Message

Force JScrollPane to scroll in one direction only

Free Magazines