Thursday, October 30, 2014

Mono gtk-sharp IronPython CalendarView

A number of years ago I did a post on the IronPython Cookbook site about the Windows.Forms Calendar control.  I could never get the thing to render nicely on *nix operating systems (BSD family).  It sounds as though Windows.Forms development for mono (and in general) is kind of dead, so there is not much hope that solution/example will ever render nicely on *nix.  Recently I've been playing with mono and decided to give gtk-sharp a shot with IronPython.

Quick disclaimers:

1) I suspect from the examples I've seen on the internet that PyGtk is a little easier to deal with than gtk-sharp.  That's OK; I wanted to use IronPython and have the rest of the mono/dotNet framework available, so I went through the extra trouble to forego CPython and PyGtk and go with IronPython and gtk-sharp instead.

2) The desktop is not the most cutting edge or sexy platform in 2014.  Nonetheless, where I work it is alive and well.  When I no longer see engineers hacking solutions in Excel and VBA, I'll consider the possibility of outliving the desktop.  Right now I'm not hopeful :-\

The results aren't bad, at least as far as rendering goes.  I couldn't get the Courier font to take on OpenBSD, but the Gtk Calendar control looks acceptable.  All in all, I was OK with the results on both Windows and OpenBSD.  I've heard Gtk doesn't do quite as well on Apple products, but I don't own a Mac to test with.  Here are a couple screenshots:

I run the cwm window manager on OpenBSD and have it set up to cut out borders on windows, hence the more minimalist look to the control there.

IronPython output on *nix has always come out in yellow or white - it doesn't show up on a white background, which I prefer.  In order to get around this, I run an xterm with a black background:

xterm -bg black -fg white

Here is the code for the gtk-sharp Gtk.Calendar control:

#!/usr/local/bin/mono /home/carl/IronPython-2.7.4/ipy64.exe

import clr

GTKSHARP = 'gtk-sharp'
PANGO = 'pango-sharp'


import Gtk
import Pango

import datetime

TITLE = 'Gtk.Calendar Demo'
MARKUP = '<span font="Courier New" size="14" weight="bold">{:s}</span>'

INFOMSG = '<span font="Courier New 12">\n\n Program set to run for:\n\n '
INFOMSG += '{:%Y-%m-%d}\n\n</span>'

DATEDIFFMSG = '<span font="Courier New 12">\n\n '
DATEDIFFMSG += 'There are {0:d} days between the\n'
DATEDIFFMSG += ' beginning of the epoch and\n'
DATEDIFFMSG += ' {1:%Y-%m-%d}.\n\n</span>'

ALIGNMENTPARAMS = (0.0, 0.5, 0.0, 0.0)


CALENDARFONT = 'Courier New Bold 12'

class CalendarTest(object):
    inthebeginning = datetime.datetime.fromtimestamp(0)
    # Debug info - make sure beginning of epoch really
    #              is +midnight, Jan 1, 1970 GMT.
    def __init__(self):
        self.window = Gtk.Window(TITLE)
        # DeleteEvent - copied from Gtk demo on internet.
        self.window.DeleteEvent += self.DeleteEvent
        # Frame property provides a frame and title.
        self.frame = Gtk.Frame(MARKEDUPTITLE)
        self.calendar = Gtk.Calendar()
        # Handles date selection event.
        self.calendar.DaySelected += self.dateselect
        # Sets up text for labels.
        # Puts little box around text.
        self.datelabelframe = Gtk.Frame()
        # Try to get datelabel to align with other label.
        self.datelabelalignment = Gtk.Alignment(*ALIGNMENTPARAMS)
        self.datelabel = Gtk.Label(self.caltext)
        # Puts little box around text.
        self.datedifflabelframe = Gtk.Frame()
        self.datedifflabelalignment = Gtk.Alignment(*ALIGNMENTPARAMS)
        self.datedifflabel = Gtk.Label(self.timedifftext)
        self.vbox = Gtk.VBox()
        # Keep text viewable - size no smaller than intended.
        self.window.AllowShrink = False

    def getcaltext(self):
        Get messages for run date.
        # Calendar month is 0 based.
        yearmonthday = self.calendar.Year, self.calendar.Month + 1, self.calendar.Day
        chosendate = datetime.datetime(*yearmonthday)
        self.caltext = INFOMSG.format(chosendate)
        # For reporting of number of days since beginning of epoch.
        timediff = chosendate - CalendarTest.inthebeginning
        self.timedifftext = DATEDIFFMSG.format(timediff.days, chosendate)

    def usemarkup(self):
        Refreshes UseMarkup property on widgets (labels)
        so that they display properly and without
        markup text.
        # Have to refresh this property each time.
        self.frame.LabelWidget.UseMarkup = True
        self.datelabel.UseMarkup = True
        self.datedifflabel.UseMarkup = True

    def prettyup(self):
        Get Gtk objects looking the way we
        # Try to make frame wider.
        # XXX
        # Works nicely on Windows - try on Unix.
        # Allows bold, etc.
        self.frame.SetSizeRequest(WINDOWWIDTH, -1)
        # Get rid of line in middle of text on title.
        self.frame.Shadow = Gtk.ShadowType.None
        # Try to get Courier New on calendar.
        fd = Pango.FontDescription.FromString(CALENDARFONT)
        self.datelabel.Justify = Gtk.Justification.Left
        self.datedifflabel.Justify = Gtk.Justification.Left
        self.window.Title = ''

    def dateselect(self, widget, event):
        self.datelabel.Text = self.caltext
        self.datedifflabel.Text = self.timedifftext

    def DeleteEvent(self, widget, event):

if __name__ == '__main__':

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