PATH
PATH
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pft is a simple shell-based utility for communicating with the NEXTSTEP Window Server. You start up the pft program by typing the program name in a shell window. pft first forms a connection to the Window Server. pft then sends the Window Server PostScript code that you type in the shell window, and prints out data received from the Window Server. ( pft displays both error messages and values returned by the Window Server on the standard output, in the same window where you type.) Use Control-D to quit pft .
The following command-line options are available:
pft sends one line of PostScript to the Window Server at a time, and each line is interpreted by the Window Server immediately after you press Return.
To run the pft program, enter its name in a shell window:
pft
When pft responds with "Connection to PostScript established," it's ready to accept PostScript code. If you're running pft in a Terminal window, you can cut and paste PostScript code from another application.
When you're finished, quit by typing Control-D (or Control-C) in the shell window that pft is running in.
To execute PostScript commands that are contained in a file, you can start pft using the -f option:
pft -f
file
The file argument must be an absolute pathname (that is, starting with either / or ~ ), as shown in these two examples:
pft -f /me/myProgram.ps
pft -f ~/myProgram.ps
Alternatively, once you've started running pft the contents of a PostScript file can be executed using the PostScript run operator:
(
file
) run
In this case, the file name must be an absolute pathname that doesn't start with ~ :
(/me/myProgram.ps) run
The first thing you'll probably want to do in pft , once it has established a connection to the Window Server, is set up a window to draw in. There are two ways to do this:
Obtain the window number of a window the Server has already set up for some other application (usually one you are using pft to debug), and do your drawing in that window.
Set up a new window using the PostScript window operator.
To create a window with the window operator, pass it arguments for its origin, size, and type:
x
y
width
height
type
window
window
where type is one of Retained , Nonretained , or Buffered :
Type |
Value |
|---|---|
The window operator returns a unique ID number for the window, and places this number on the operand stack. You'll need this number in order to refer to the window; for ease of reference you can assign the returned window number to a variable, as follows:
/myWindow
100 100 500 500 Buffered window
def
The new window isn't in the screen list yet, and therefore doesn't appear on the screen and doesn't receive user events. You can add the window to the screen list with the orderwindow operator:
place
otherwindow
window
orderwindow -
The location of the window in the screen list is specified by place , which can be one of Below , Out , or Above :
Place |
Value |
|---|---|
otherwindow should be another window number, or 0 if you want to place the new window above or below all windows currently in the window list.
Once the window is in the screen list it appears on the screen, but before you can draw in the window you need to use the windowdeviceround operator to make the window the current window:
window
windowdeviceround -
Once the window is the current window, the results of any drawing code you enter will be displayed:
newpath
20 20 moveto
40 40 lineto
stroke
flushgraphics % necessary if window is buffered
The connection between pft and the Window Server is buffered in both directions. pft flushes its input buffer, so none of the PostScript you send to the Window Server is ever caught in the buffer. However, you must flush the Window Server's output buffer yourself using the PostScript flush operator.
Here's a one-line example showing how to create a 500-pixel by 500-pixel window whose lower left corner is at the lower left corner of the screen. This example removes the window number from the stack and flushes the Window Server's output buffer:
0 0 500 500 Buffered window = flush
In summary, this simple series of PostScript commands demonstrates how to create a window, draw in the window, and then remove the window:
/myWindow % Create a variable called myWindow
100 100 50 50 Buffered window % Create a window, and assign the returned
def % window number to the myWindow variable
Above 0 myWindow orderwindow % Order myWindow at front of screen list
myWindow windowdeviceround % Make myWindow the current window
newpath % Now draw something to myWindow
25 25 15 0 360 arc
fill
flushgraphics % Flushing is required for buffered windows
myWindow termwindow % Mark myWindow for destruction
nulldevice % Remove references to myWindow