I have a JScrollPane with a JTable in it. In the JTable I have initially 3 rows. Later on rows get added.
The default JTable with my 3 rows is ugly because JScrollPane calls getPreferredScrollableViewportSize from the client (JTable) and the return value is always the same. That's why my JTable/JScrollpane with 3 rows has this free space, JScrollpane andJTable do not have the same size.
My solution is to make a subclass JTable, override getPreferredScrollableViewportSize and return in this function getPreferredSize();. Now the whole JScrollPane has exactly the size of the 3 row `JTable!
When a row gets added I have the command ((JComponent) scrollPane.getParent()).revalidate();
The scrollpane grows with the table.
Everything works fine!
But now I want to set a certain layout for the container of the scrollpane (panel):
myjpanel.setLayout (new BoxLayout(contentPane, BoxLayout.Y_AXIS));
When I add this command my whole solution doesn't work anymore.
The scrollpane hasn't the size of the 3 row table, this free space is there again.
Why is this?
Does anybody have a solution?
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Thank you camickr for pointing me in the right direction. My solution is the following:
scrollPane = new JScrollPane (table) {
public Dimension getMaximumSize () {
double height = 0;
double width = super.getMaximumSize().getWidth();
height += columnHeader.getViewSize().getHeight();
height += viewport.getView().getPreferredSize().getHeight();
height += (getViewportBorderBounds().getHeight() * -1);
Dimension returnValue = new Dimension ((int) width, (int) height);
return returnValue;
}
};
It works now at the beginning.
But when a row is added to the jtable and I call revalidate(); on the jpanel (parent container of the scrollpanel) the jscrollpanel shrinks in height to 1 row + header!
Has anyone got an idea what is to do in this situation.
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Now I know the problem. It is the viewportBorder. In order to get the whole, exact height I have to total the height of the view (Jtable), the height of the column header and the height of the viewportBorder. The first time getViewportBorderBounds().getHeight() returns -3, next time - after a new row is inserted in the table model - the function returns 48. I do not understand why this function returns 48 now.
Another point is that camickr says that changing the size of the jscrollpane defeats the purpose of the scrollpane. I do not understand this. How can anyone be satisfied with a default jscrollpane size of 450 x 400 (http://www.javalobby.org/java/forums/t19559.html) even when the jtable has only 3 lines at the beginning. This unfilled extra space does not look very professional in my eyes. Has anyone got a better solution for this.
Thank you very much for your answers
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Now everything works!
At the beginning I simply set the jscrollpane border to 0 ... sp.setBorder(createEmptyBorder());
In this way I avoid having these strange return values of getViewportBorderBounds().getHeight()
Wolfgang
The BoxLayout allows the component to grow up to the maximum size of the component. I guess you need to override the getMaximumSize() of the scrollpane to return the preferred size.
When a row gets added I have the command "((JComponent) scrollPane.getParent()).revalidate();" The scrollpane grows with the jtable.
That kind of defeats the purpose of the scrollpane. The scrollbar is supposed to stay at a fixed size and then scrollbars will appear if necessary.
I had a similar problem - the basic upshot is that I wanted a JTable in a scroll pane that had a minimum and maximum size: when there was no data in the table, it should have a one-row-height pane background displayed (not a fake row, obviously), and when it was over 10 rows to limit the displayed table size to those 10 rows plus scrollbars. Any size between 1 and 10 should display the table at full height. The situation was a parent-child table, and this was the child table, so I had to trigger the child table resize depending on which parent table row was clicked. A fixed pane size looked ugly in that it took up unnecessary space to push other potentially viewable info under the child table out of view with just blank space.
Using the setPreferredScrollableViewportSize after updating the model with the child rows (and setFillsViewportHeight(true) of course) gave me almost everything I needed. Except that the viewport wouldn't redraw until I clicked on it, or took focus from the window then flicked back, it was most annoying.
The solution was super-simple after reading this post: I just had to call revalidate on the scrollpane's parent, as pointed out in the solution. Fixed it perfectly. Mostly I just wanted to share a use case where you want the scrollpane size to change dynamically up to a maximum size. Swing is so much simpler if everything is created at a fixed size forever... unlike pretty much every real-life use case I've ever encountered :-)
Related
I have a view in my java project that needs to resize a table.
I have n number of Jtables inside a JScrollPane. Some of them doesn't have enough rows to fill the total size of the table. The best solution I think would be to resize the table to fill to the number of rows that were allocated.
1) The table has a dimension of 4x4 but if there is not enough rows (i.e, less than 4) it will have a gap, which I don't want.
Since this table is static and won't be changed how can I resize this table programmatically based on the number of rows that it will have, like having 1, 2 or only 3 rows and not have this gap?
PS: I know how many rows it will have, I just don't know how to resize the table height programmatically during runtime.
Since this table is static and won't be changed how can I resize this table programmatically based on the number of rows that it will have,
After adding all the data to the table you can use:
table.setPreferredScrollableViewportSize(table.getPreferredSize());
Then when the table is added to the scroll pane the size of the scroll pane will be the preferred size of the table.
To make the JTable stretch to fit the height of the view, you can call:
table.setFillsViewportHeight(true);
from the javadoc:
Sets whether or not this table is always made large enough to fill the height of an enclosing viewport.
Since a picture is worth a thousand words:
I have JTable inside a JScrollPane, and currently the table has 10 columns. Each column is given a minimum width (given by setMinWidth(...)).
First picture: When the JFrame is stretched beyond the sum of all of the minimum widths of all columns then the columns are stretched to fill the window: this is the desired effect (do not want empty space at far right of frame).
Second picture: However when the JFrame is set to a size smaller than this combined minimum size, the horizontal bar does not show up properly and it becomes impossible to view the far right columns. Currently I have JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS as the horizontal bar option hince why for both pictures the horizontal bar container (appropriate name?) is there, but the actual bar itself never shows up. If I have JScrollPane.HORIZONTAL_SCROLLBAR_OFF, the horizontal bar container never shows.
Vertical works fine btw.
I have tried many things, including disabling auto resizing and trying to set the column widths myself when the JScrollPane width exceeds the min width sum of the columns. It doesn't seem right that I would have to do that manually myself. I can provide my code if necessary, but I don't think that it is necessary because it's just a JScrollPane hosting a JTable.
The solution was to overwrite the getScrollableTracksViewportWidth() method:
#Override
public boolean getScrollableTracksViewportWidth() {
return (getPreferredSize().width < getParent().getWidth());
}
When I make a JTable; I have the columns, and a single row, and then beneath that I have space for ~20 more rows, more if I increase the window size. I cannot have less as if I reduce the window size I just get a vertical scroll bar.
What I would like to do is make it so that the JTable size only goes to the last row.
I thought something like this:
newTable.setMaximumSize(new Dimension(Integer.MAX_VALUE, (newTable.getRowCount() + 1) * newTable.getRowHeight()));
But this does absolutely nothing. Using setPreferred size instead makes a white background about one row bigger, but the actual table is still the same size.
http://i.imgur.com/ClpD1Y3.png
I also tried the same things on the scrollpane that the JTable is in, setting the max / min sizes did nothing, setting the preferred size allowed me to make the table smaller by resizing the window, so I'm guessing that I may be able to do what I want using this and a layout perhaps? But I get class cast exceptions when trying to give a layout to the scrollpane. So I'm unsure what to do.
Set the preferredSize of the container that the JTable is in, ie. the scrollpane
I want to make the table width at least fitting the enclosing scroll pane's width, and if it's getting larger, the horizontal scroll bar is used.
None of JTable's auto resize modes suits my need: AUTO_RESIZE_OFF does allow the table to be resized larger than the scroll pane's width, but it can't limit the table's minimal width; the other modes don't allow the table width to be larger than the scroll pane's width at all.
I have tried to set the minimal size as below but it didn't work:
JTable table = new JTable(myModel);
JScrollPane scrollPane = new JScrollPane(table);
table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
// After the table is displayed.
table.setMinimalSize(scrollPane.getSize());
Any idea to achieve that?
I have tried to set the minimal size as below but it didn't work:
table.setMinimalSize(scrollPane.getSize());
JTable and JScrollPane can't returns reasonable Min, Max and PreferredSize
you can to fit (on applications startup) JScrollPanes dimension to JTable by using table.setPreferredScrollableViewportSize(table.getPreferredSize()); (carefully with number of row, otherwise you have to calculating a Dimension instead of JTable.getP...) for JFrame.pack(), on runtime must be validated by revalidate() and repaint() for container nested JScrollPane, don't do that
don't reinvent the wheel, to use Fixed Column Table of Table Column Adjuster by #camickr, which one isn't clear from your description, depends of your ...
a JTable's width >= the enclosing scroll pane's width?
couldn't be reversed this idea
I have the following problem: I have a JTable inside a JScrollPane, and the table has 20 rows. However I want the JScrollPane to only display 10 row at a time (thus one has to scroll down to see the rest of the rows). I am using GridBagLayout to position the JScrollPane.
Any suggestion? Thanks.
table.setPreferredScrollableViewportSize(...);
You can get the preferred width by using the getPreferredSize() method of the table.
You will need to caclulate the height to be the height of the table header plus the height of the rows which can be determine by using table.getRowHeight().
If you know the height of the rows then you can put the JScrollPane in panel with an explicit height - getting the explicit height on the panel WRT the layout manager might be the hard part.