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An example JTable
Many of the windows, including the
Data Window,
display their data in a visual component called a JTable.
This displays a grid of values, with headings for each column, in
a window which you can scroll around. Although JTables are used for
a number of different things (for instance, showing the table data themselves
in the Data Window
and showing the column metadata in the
Columns Window),
the fact that the same widget is
used provides a common look and feel.
Here are some of the things you can do with a JTable:
- Scroll around
- Using the scrollbars which may appear to the right and below the
table you can scroll around it to see parts which are not initially
visible.
You can grab the sliders and drag them around by holding the mouse
button down while you move it, or click in the slider "trough" one side
or other of the current slider position to move a screenful.
Under some circumstances the cursor arrow keys and PageUp/PageDown
keys may move the table too.
If the JTable is small enough to fit within the window the scrollbars
may not appear.
- Move columns
- By clicking on the header (grey title bit at the top) of a column
and dragging it left or right, you can change the order of columns
as displayed. In some cases
(the Data Window)
this actually has the effect of changing the order of the columns
in the table; in other cases it is just cosmetic.
- Resize columns
- By dragging on the line between row headers you can change the width
of the columns in the table.
- Edit cells
- In some cases, cells are editable. If they are, then double-clicking
in the cell will begin an edit session for that cell, and pressing
Return will confirm that the edit has been made.
- Select rows
- Sometimes rows can be highlighted; you can select one row by clicking
on it or a number of contiguous rows by clicking and dragging from the
first to the last.
To add further rows to a set already selected without deselecting
the first lot, hold the "Control" key down while you do it.
- Sort rows
- In some, but not all cases, you may see a little up or down arrow
in one of the column headers. This indicates that the rows of the
table have been sorted according to the values in that column.
If you click on another column header, the rows will be re-sorted
according to the values in that column. Clicking again on the same
column reverses the sort order.
This feature is only available for certain displayed JTables.
In some cases where a JTable is displayed, there will be a menu
on the menu bar named Display.
This permits you to select which columns are visible and which are hidden.
Clicking on the menu will give you a list of all the available columns
in the table, each with a checkbox by it; click the box to toggle
whether the column is displayed or not.
Next Previous Up Contents
Next: Column Selector
Up: Common Window Features
Previous: Menus
TOPCAT - Tool for OPerations on Catalogues And Tables
Starlink User Note253
TOPCAT web page:
http://www.starlink.ac.uk/topcat/
Author email:
m.b.taylor@bristol.ac.uk
Mailing list:
topcat-user@jiscmail.ac.uk