Can Components be Rotated Visually?

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larkmore@aol.com - 18 May 2007 21:54 GMT

This has come up a lot recently. Is there a way to apply a rotation
to how a component is displayed? I'm not referring to things covered
by SwingConstants.VERTICAL or SwingConstants.HORIZONTAL. What I want
to do is take a JLabel and rotate the entire thing counterclockwise by
ninety degrees so it reads along the side of the screen, or flip a
JProgressBar so it "grows" from top to bottom instead of bottom to
top. Is there a way to do this with predefined components?
-Will

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Tom Hawtin - 18 May 2007 22:24 GMT

> This has come up a lot recently. Is there a way to apply a rotation
> to how a component is displayed? I'm not referring to things covered
[quoted text clipped - 3 lines]
> JProgressBar so it "grows" from top to bottom instead of bottom to
> top. Is there a way to do this with predefined components?

You can rotate the Graphics object passed through paint. Unfortunately
it becomes more complicated if you include events (like repaint events),
and the whole component tree and co-ordinate thing is exposed and all
incestuous.

Tom Hawtin

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larkmore@aol.com - 21 May 2007 13:17 GMT

Sounds ugly, but how exactly would one do that? I skimmed the API
documentation for the Graphics class and didn't see anything about
rotating.
-Will

> larkm...@aol.com wrote:
> > This has come up a lot recently. Is there a way to apply a rotation
[quoted text clipped - 11 lines]
>
> Tom Hawtin

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Tom Hawtin - 21 May 2007 22:22 GMT

> Sounds ugly, but how exactly would one do that? I skimmed the API
> documentation for the Graphics class and didn't see anything about
> rotating.

It's the Graphics2D features you want.

Tom Hawtin

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larkmore@aol.com - 22 May 2007 14:13 GMT

> It's the Graphics2D features you want.
>
> Tom Hawtin

I'm still confused on how to do this. How do I convert a Graphics
object into a Graphics2D object so I can apply the rotation? If I
wait until the paint(Graphics g) method to be called, the Graphics
object is already instantiated and I see no way to cast it or convert
it into a Graphics2D object.
-Will

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Lew - 22 May 2007 14:38 GMT

>> It's the Graphics2D features you want.
>>
[quoted text clipped - 5 lines]
> object is already instantiated and I see no way to cast it or convert
> it into a Graphics2D object.

Graphics2D g2 = (Graphics2D) g;

You'll be wanting to read
<http://java.sun.com/docs/books/tutorial/2d/index.html>

Signature

Lew

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Tom Hawtin - 22 May 2007 15:21 GMT

> I'm still confused on how to do this. How do I convert a Graphics
> object into a Graphics2D object so I can apply the rotation? If I
> wait until the paint(Graphics g) method to be called, the Graphics
> object is already instantiated and I see no way to cast it or convert
> it into a Graphics2D object.

The Graphics object you get from paint will be a Graphics2D object. You
just need to cast it to get the more specific static type.

Tom Hawtin

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Can Components be Rotated Visually?

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