Rectangle commands operate on a rectangular area of the text, that is all the characters between two columns in a certain range of lines.
A rectangle is selected using the standard selection mechanism. You can therefore use either the mouse to highlight the proper region, or <shift> and the cursor keys to extend the selection, or the Emacs selection (with the mark and the current cursor location) if you have activated the emacs.py plugin.
Visually, a selected rectangle is exactly the same as the standard selection. In particular, the characters after the last column, on each line, will also be highlighted. The way the selection is interpreted (either as a full text or as a rectangle) depends on the command you then chose to manipulate the selection.
If you chose one of the commands from the /Edit/Rectangles menu,
the actual rectangle will extend from the top-left corner down to the
bottom-right corner. All characters to the right of the right-most column,
although they are highlighted, are not part of the rectangle.
Consider for instance the following initial text:
package A is
procedure P;
procedure Q;
end A;
and assume we have selected from the character "p" in "procedure P", down to the character "c" in "procedure Q".
The following commands can then be used (either from the menu, or you
can assign key shortcuts to them via the usual /Edit/Key shortcuts
menu.
Cut or Delete
These commands will remove the selected text (and have no effect on empty
lines within the rectangle). The former will in addition copy the rectangle
to the clipboard, so that you can paste it later. In our example, we end up
with
package A is
edure P;
edure Q;
end A;
Copy
This command has no visual effect, but copies the contents of the rectangle
into the clipboard.
Paste
Pastes the contents of the clipboard as a rectangle: each line from the
clipboard is treated independently, and inserted on successive lines in the
current editor. They all start in the same column (the one where the cursor
is initially in), and existing text in the editor lines is shifted to the
right). If for instance you now place the cursor in the second line, first
column, and paste, we end up with:
package A is
proc edure P;
proc edure Q;
end A;
Clear
Replaces the contents of the selected rectangle with spaces. If we start
from our initial exmaple, we end up with the following. Note the difference
with Delete.
package A is
edure P;
edure Q;
end A;
Open
Replaces the contents of the selected rectangle with spaces, but shifts the
lines to the right to do so. Note the difference with Clear.
package A is
procedure P;
procedure Q;
end A;
Replace With Text
This is similar to Clear, but the rectangle is replaced with
user-defined text. The lines will be shifted left or right if the text you
insert is shorter (resp. longer) than the width of the rectangle. If for
instance we replace our initial rectangle with the text TMP, we end up with
the following. Note that the character "c" has disappeared, since TMP is
shorter than our rectangle width (4 characters). This command will impact
lines that are empty in the initial rectangle.
package A is
TMPedure P;
TMP
TMPedure Q;
end A;
Insert Text
This inserts a text to the left of the rectangle on each line. The following
example inserts TMP. Note the difference with Replace With Text. This
command will also insert the text on lines that are empty in the initial
rectangle.
package A is
TMPprocedure P;
TMP
TMPprocedure Q;
end A;
Sort
This sorts the selected lines according to the key which starts and ends on
the corresponding rectangle's columns.
aaa 15 aa
bbb 02 bb
ccc 09 cc
With a selection starting from the 1 on the first line and ending on the 9 on the last one, sorting will result with the following content:
bbb 02 bb
ccc 09 cc
aaa 15 aa
Sort reverse
As above but in the reverse order.