#! /usr/bin/env python
# A minimal single-window text editor using STDWIN's text objects.
#
# Usage: microedit file
#
# This is not intended as a real application but as an introduction
# to STDWIN programming in Python, especially text objects.
# Once you understand microedit.py, study miniedit.py to learn
# about multiple windows and menus, cut and paste, etc.
import sys
import stdwin
from stdwinevents import *
# Main program
#
def main():
#
# Get the filename argument and read its contents as one very
# large string.
# An exception will terminate the program if there is no argument
# or if the file could not be read...
#
filename = sys.argv[1]
fp = open(filename, 'r')
contents = fp.read()
del fp # Close the file
#
# Create the window, using the filename as window title
#
window = stdwin.open(filename)
#
# Add a simple File menu to the window with two items
#
filemenu = window.menucreate('File')
filemenu.additem('Save', 'S') # Item 0 (shortcut Meta-S)
filemenu.additem('Save As...') # Item 1
#
# Create a text object occupying the entire window
# and fill it with the file's contents
#
corner = window.getwinsize() # (width, height)
area = (0, 0), corner # Rectangle as large as the window
text = window.textcreate(area)
text.settext(contents)
del contents # Get rid of contents object
fix_textsize(window, text) # Set document size accordingly
#
# Main event loop -- stop if a close request comes in.
#
# STDWIN applications should regularly call stdwin.getevent()
# otherwise the windows won't function as expected.
#
while 1:
#
# Get the next event
#
type, w, detail = e = stdwin.getevent()
#
# Event decoding switch
#
if type == WE_CLOSE:
break # Stop (no check for saved file!)
elif type == WE_SIZE:
#
# The window was resized --
# let the text object recompute the line breaks
# and change the document size accordingly,
# so scroll bars will work
#
fix_textsize(window, text)
elif type == WE_MENU:
#
# Execute a file menu request (our only menu)
#
menu, item = detail
if item == 0:
#
# "Save": save to the current filename
#
dummy = save_file(window, text, filename)
elif item == 1:
#
# "Save As": ask a new filename, save to it,
# and make it the current filename
#
# NB: askfile raises KeyboardInterrupt
# if the user cancels the dialog, hence
# the try statement
#
try:
newfile = stdwin.askfile( \
'Save as:', filename, 1)
except KeyboardInterrupt:
newfile = ''
if newfile:
if save_file(window, text, newfile):
filename = newfile
window.settitle(filename)
elif text.event(e):
#
# The text object has handled the event.
# Fix the document size if necessary.
# Note: this sometimes fixes the size
# unnecessarily, e.g., for arrow keys.
#
if type in (WE_CHAR, WE_COMMAND):
fix_docsize(window, text)
# Save the window's contents to the filename.
# If the open() fails, put up a warning message and return 0;
# if the save succeeds, return 1.
#
def save_file(window, text, filename):
#
# Open the file for writing, handling exceptions
#
try:
fp = open(filename, 'w')
except RuntimeError:
stdwin.message('Cannot create ' + filename)
return 0
#
# Get the contents of the text object as one very long string
#
contents = text.gettext()
#
# Write the contents to the file
#
fp.write(contents)
#
# The file is automatically closed when this routine returns
#
return 1
# Change the size of the text object to fit in the window,
# and then fix the window's document size to fit around the text object.
#
def fix_textsize(window, text):
#
# Compute a rectangle as large as the window
#
corner = window.getwinsize() # (width, height)
area = (0, 0), (corner)
#
# Move the text object to this rectangle.
# Note: text.move() ignores the bottom coordinate!
#
text.move(area)
#
# Now fix the document size accordingly
#
fix_docsize(window, text)
# Fix the document size, after the text has changed
#
def fix_docsize(window, text):
#
# Get the actual rectangle occupied by the text object.
# This has the same left, top and right, but a different bottom.
#
area = text.getrect()
#
# Compute the true height of the text object
#
origin, corner = area
width, height = corner
#
# Set the document height to the text object's height.
# The width is zero since we don't want a horizontal scroll bar.
#
window.setdocsize(0, height)
# Once all functions are defined, call main()
#
main()
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