Displaying background color for treenodes of JTree

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chandu - 09 Jun 2006 20:43 GMT

Hi,
As part of tree, i wanted to display a alternative background row
color for each node of JTree.
Could you please let me know how can i do it. Please send me some
example programs.

Thanks.

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steve - 09 Jun 2006 22:45 GMT

> Hi,
> As part of tree, i wanted to display a alternative background row
[quoted text clipped - 3 lines]
>
> Thanks.

you need to override :

CustomCellRenderer extends JLabel implements TreeCellRenderer

then inside the paint

public void paint(Graphics g) {
Color bColor;

// Set the correct background color
bColor = bSelected
? SystemColor.LIGHT_GRAY
: otree.getBackground(); // ensure background is same

g.setColor(bColor);
this.setOpaque(false);
this.setBackground(null);

// Draw a rectangle in the background of the cell
g.fillRect(0, 0, getWidth() - 1, getHeight() - 1);
super.paint(g);
}

but you better make sure the colours you choose work on all platforms
I know for a fact that some "blues" work on windows & osx, but under linux
kde are drawn as solid black, and hide the text.

using the above and a little imagination will solve both your questions in
your posts.

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chandu - 11 Jun 2006 01:28 GMT

> > Hi,
> > As part of tree, i wanted to display a alternative background row
[quoted text clipped - 33 lines]
> using the above and a little imagination will solve both your questions in
> your posts

I tried this solution. But i am not getting the alternative colors for
full rows.

Thanks

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steve - 11 Jun 2006 22:58 GMT

>>> Hi,
>>> As part of tree, i wanted to display a alternative background row
[quoted text clipped - 38 lines]
>
> Thanks

that is because it is code to show you how to set the colour , it is NOT code
to completely do the job for you. you need extra SIMPLE logic , to change
the colours.
I.E you need to write about 5 more lines of code yourself.

Steve

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chandu - 12 Jun 2006 16:37 GMT

I have added couple of logic to it. Still i am not getting full row.

public void paint(Graphics g) {
if(rowNo%2 == 0)
{
g.setColor(Color.gray);
}
else
{
g.setColor(Color.white);
}
this.setOpaque(false);
this.setBackground(null);

Rectangle r = tree.getBounds();
System.out.println("X value "+r.x);

//Draw a rectangle in the background of the cell
g.fillRect(r.x, 0, 400, getHeight()-1);

super.paint(g);
}

> >>> Hi,
> >>> As part of tree, i wanted to display a alternative background row
[quoted text clipped - 45 lines]
>
> Steve

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steve - 12 Jun 2006 22:40 GMT

> I have added couple of logic to it. Still i am not getting full row.
>
[quoted text clipped - 70 lines]
>>
>> Steve

what do you mean not getting a full row?
this is a jtree, not a jtable
also where did you set rowNo, and how did you calculate it?
The only way I can see this working is some sort of complex logic, starting
at the root.

I can assure you that the paint method IS called for each node, therefore it
is just a matter of you logic to flip the colours.

but i still do not understand why you are trying to apply a method ,that is
normally used for JTables to a JTree

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steve - 12 Jun 2006 22:47 GMT

> I have added couple of logic to it. Still i am not getting full row.
>
[quoted text clipped - 70 lines]
>>
>> Steve

Ahh , when you say the full row, you mean including the ICON!!

Well i can tell you that it will get a lot more complex, if you want to try
and repaint the icons background on the fly.
basically the above code will only paint the label of the node.

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Displaying background color for treenodes of JTree

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