I figured it’d be best to come up with a simple solution, so I started coding something out in bash and it worked:

#!/bin/bash
# css.sh - generate common css and html
# Tyler Mulligan (z@interwebninja.com)
# Last Update: 02/16/2011
# MIT License

create_block_image() {
    feh -lr ${1:-.} | awk '{ print $3" "$4" "$8 }' | sed '1d' | while read l; do N=$((N+1));
        cbi_css $l
    done
    feh -lr ${1:-.} | awk '{ print $3" "$4" "$8 }' | sed '1d' | while read l; do N=$((N+1));
        cbi_html_a $l
    done
    feh -lr ${1:-.} | awk '{ print $3" "$4" "$8 }' | sed '1d' | while read l; do N=$((N+1));
        cbi_html_div $l
    done
}
cbi_css() {
    f=${3##*/}
    echo "#${f%.*} {
    display: block;
    background: url('$3') no-repeat 0 0;
    width: 0;
    height: $2px;
    padding-left: $1px;
    overflow: hidden;
}"
}
cbi_html_a() {
    f=${3##*/}
    echo "<a href=\"#\" id=\"${f%.*}\" alt=\"$f\" title=\"$f\">${f%.*}</a>"
}
cbi_html_div() {
    f=${3##*/}
    echo "
<div id=\"${f%.*}\"></div>

"
}

s=$1; shift; case $s in
  --image-block|--cbi|-i) create_block_image $@;;
  *) help help;;
esac

Which ouputs something like:

z@zygon:~/scripts/css$ ./css.sh -i img/
#dumbtubes-fav {
    display: block;
    background: url('img/dumbtubes-fav.png') no-repeat 0 0;
    width: 0;
    height: 14px;
    padding-left: 16px;
    overflow: hidden;
}
#submit_new {
    display: block;
    background: url('img/submit_new.png') no-repeat 0 0;
    width: 0;
    height: 106px;
    padding-left: 244px;
    overflow: hidden;
}
#dumbtubes-logo {
    display: block;
    background: url('img/dumbtubes-logo.png') no-repeat 0 0;
    width: 0;
    height: 70px;
    padding-left: 274px;
    overflow: hidden;
}
<a href="#" id="dumbtubes-fav" alt="dumbtubes-fav.png" title="dumbtubes-fav.png">dumbtubes-fav</a>
<a href="#" id="submit_new" alt="submit_new.png" title="submit_new.png">submit_new</a>
<a href="#" id="dumbtubes-logo" alt="dumbtubes-logo.png" title="dumbtubes-logo.png">dumbtubes-logo</a>
<div id="dumbtubes-fav"></div>
<div id="submit_new"></div>
<div id="dumbtubes-logo"></div>

To explain the way this CSS works, it uses the padding-left as the actual width, setting the width 0 and then pushes whatever content you have out of view using overflow:hidden to hit it from view. This makes it easy for search engines, keeping your HTML clean and CSS simple.

The bash script relies of “feh” a lightweight image viewer for linux that outputs a list of images and their dimensions. It also generates some sample HTML to quickly drop in and modify.

This is not an elegant solution and I’m not happy with the fact that it relies on feh. I’ve been slowly getting into python and I was amazed at how fast I was able to recreate this script in Python.

#!/usr/bin/python
# css.py - generate common css and html
# Tyler Mulligan (z@interwebninja.com)
# Last Update: 02/17/2011
# MIT License
from PIL import Image
import sys
import os.path

CSS_FORMAT = """#%s {\n\
    display: block;\n\
    background: url('%s') no-repeat 0 0;\n\
    height: %spx;\n\
    width: 0;\n\
    padding: %spx;\n\
    overflow: hidden;\n\
}\n"""

HTML_A_FORMAT = """<a href="#" id="%s" alt="%s" title="%s">%s</a>\n"""
HTML_DIV_FORMAT = """
<div id="%s">%s</div>

\n"""

css=""
html_a=""
html_div=""
for tf in os.listdir(sys.argv[1]):
    f = os.path.join(sys.argv[1],tf)
    if os.path.isfile(f) == True :
        img = Image.open(f)
        fid = os.path.splitext(tf)[0]
        (width, height) = img.size[0:2]
        css += CSS_FORMAT % (fid,f,height,width)
        html_a += HTML_A_FORMAT % (fid,f,fid,fid)
        html_div += HTML_DIV_FORMAT % (fid,fid)

print css
print html_a
print html_div 

This is just the basic idea, I didn’t spend more than 15 minutes on this rewrite, it does what I need it to do so far. It was suggested by friends if I make it any bigger, to look into a templating engine, such as mako. I hope this script can be useful to someone :). PS, HTML_DIV_FORMAT should be on one line, not sure why my syntax highlighter is trying to put it on 3.

I’m still relatively new to Python. I dabble once in a while. Usually when I catch myself writing something overly complicated in bash. I figured doing MySQL from a Python script would be easier and better implemented in Python. Well, I was in for a few surprises I’d like to share with others looking to integrate with MySQL in Python before you encounter the same problems I did.

Getting on with it

As a Python noob, it made sense to me to use the python-mysqldb module. It “works” but not well. Read through the [working] code below and see if you can find the problem and how I circumvented it.

#!/bin/python
# Tyler Mulligan (tyler@doknowevil.net)
# MySQL the WRONG way in Python
import MySQLdb

def connection_settings():
    global DB_ADMIN, DB_ADMIN_PASSWORD, DB_NAME, DB_HOST, DB_USER, DB_PASSWORD
    DB_ADMIN="root"
    DB_ADMIN_PASSWORD="local"
    DB_NAME="foobardb"
    DB_HOST="localhost"
    DB_USER="foobar"
    DB_PASSWORD="local"

def run_admin_sql():
    conn = MySQLdb.Connection(host=DB_HOST, user=DB_ADMIN, passwd=DB_ADMIN_PASSWORD)
    cursor = conn.cursor()

    #cursor.execute("DROP USER %s@%s", (DB_USER, DB_HOST))
    #cursor.execute("DROP DATABASE %s" % DB_NAME)

    cursor.execute("CREATE USER %s@%s IDENTIFIED BY %s", (DB_USER, DB_HOST, DB_PASSWORD))
    cursor.execute("CREATE DATABASE %s" % DB_NAME)
    cursor.execute("GRANT USAGE ON %s.* TO %s@%s IDENTIFIED BY '%s'" % (DB_NAME, DB_USER, DB_HOST, DB_PASSWORD))
    cursor.execute("GRANT ALL PRIVILEGES ON *.* to %s@%s IDENTIFIED BY %s", (DB_USER, DB_HOST, DB_PASSWORD))

    cursor.close()
    conn.close()

    conn = MySQLdb.Connection(db=DB_NAME, host=DB_HOST, user=DB_USER, passwd=DB_PASSWORD)
    cursor = conn.cursor()

    cat_table_sql = """CREATE TABLE cats
    (
    `id` int(3) unsigned NOT NULL AUTO_INCREMENT,
    `name` varchar(50) NOT NULL,
    `age` int(2) NOT NULL,
    `type` int(2) NOT NULL,
    PRIMARY KEY (`id`)
    )"""

    cursor.execute(cat_table_sql)
    cursor.execute("INSERT INTO cats (name, age, type) VALUES (%s, %s, %s)", ("fluffy", 5, 1))
    cursor.execute("INSERT INTO cats (name, age, type) VALUES (%s, %s, %s)", ("meow meow", 6, 1))
    cursor.execute("INSERT INTO cats (name, age, type) VALUES (%s, %s, %s)", ("purrfect", 3, 1))

    cursor.execute("SELECT * FROM cats")

    results = cursor.fetchall()
    cursor.close()
    conn.close()
    return results

connection_settings()
print run_admin_sql()

The problem is parameterization. The python-mysqldb module sucks at it. It’s glaringly obvious when you look at the follow snippet and how I worked around it.

cursor.execute("CREATE USER %s@%s IDENTIFIED BY %s", (DB_USER, DB_HOST, DB_PASSWORD)) # GOOD
cursor.execute("CREATE DATABASE %s" % DB_NAME) # BAD NEWS BEARS
cursor.execute("CREATE DATABASE %s", (DB_NAME)) # but the module won't support this

The difference, is that the first implementation uses the module’s parameterization to escape the variables that are passed to it, making it safe. The second is using Python’s string formatter which means I’d have to do all the escaping and sanitization prior, which is obviously more dangerous and annoying.

The MySQLdb docs bury this little note, “Parameter placeholders can only be used to insert column values. They can not be used for other parts of SQL, such as table names, statements, etc.”

You can implement it this way but you’ll be wasting your time. There are better modules out there to make up for this one’s shortcomings. OurSQL and SQLAlchemy were the two libraries recommended to me in #python on irc.freenode.org. I will make another post when I develop the same example above using one of these libraries.

The following development notes were written after researching the underlying handling of dual monitors in the X window system on Linux. I’ve included a code snippet that I built to help demonstrate behavior and create a proof of concept to show I can determine which monitor a window is on using only python and no statically set coordinates.

Introduction

I mentioned in my previous post that I’m using an nVidia video card with “TwinView” software that outputs my video as if it were one screen, which it technically is, one X screen. This means that the distinction between monitors is not mapped in the X tree, it’s handled by the window manager. Unlike Xinerama, which has an x session per monitor and stitches them together. Xinerama, however, has is being deprecated in favor of RandR but regardless, TwinView is my choice and is not an option for me to change to.

With all of that said, the decision to bridge python to c that interfaces with compiz is a deadend and would be better implemented based on the new 0.9.0 C++ api. It would be nice to be able to return a list of windows from a “monitor” object. However, that’s beyond my current scope. I was able to whip up some python that to show that implementing the monitor management in python using the gtk module isn’t /that/ hacky. I emphasize because I read some posts that claimed window decorations could be an issue in accurate calculations.

Some Code

Read the comment on line 2. Learn more about pygtk here

#!/usr/bin/python
# Print some information about the X environment, the monitor setup, currently active window and cursor position
import gtk.gdk

screen = gtk.gdk.screen_get_default()
print "X default screen size: %d x %d" % (screen.get_width(), screen.get_height())
print "xid of root window: %d" % screen.get_root_window().xid

monitors = int(screen.get_n_monitors())
print "== %d monitors ==" % monitors
for m in range(0, monitors):
    print " - geometry of monitor %d: %s" % (m, screen.get_monitor_geometry(m))

window = screen.get_active_window()
win_x, win_y, win_w, win_h, win_bit_depth = window.get_geometry()
print "active window on monitor: %d" % screen.get_monitor_at_point((win_x+(win_w/2)),(win_y+(win_h/2)))
print "window geometry (x,y,w,h): %d, %d, %d, %d" % (win_x,win_y,win_w,win_h)

display = gtk.gdk.display_get_default()
pointer = display.get_pointer()
print "cursor position (x, y): %d, %d" % (pointer[1], pointer[2])
print "cursor on monitor: %d" % screen.get_monitor_at_point(pointer[1],pointer[2])

thanks to those in #compiz-dev and #python on freenode who helped me come around to create this snippet. I hope it will help others looking to develop for multi-head setups in Linux. Please let me know if I missed anything or did something incorrectly, this is new territory for me.

I’m releasing this early on my blog just in case I caught any people yesterday who’ve been experimenting with my research / code so far. I’ll share it on github when I evolve it just a bit more.

Video of it in Action

#!/usr/bin/env python
#
# Title: scp-notifications
# Author: Tyler Mulligan (tyler@detrition.net)
# Date: 06/26/2010
# Version: 0.6
# Description:
# Used in combination with an event, such as an action or cronjob, this script
# will scp the latest file from a folder to your server.
#
# Optionally, it can copy the url to your clipboard and/or show a popup with a
# link to the file after succesfully uploading
#
# Orginally developed to be piped to from compiz screenshot tool
# http://interwebninja.com/videos/compiz-screenshot-piped-to-notification-daemon-for-upload.ogv
#
# The MIT License
#
# Copyright (c) 2010 Tyler Mulligan
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE
#

import pygtk
pygtk.require('2.0')
import pynotify
import gtk
import sys
import os
import subprocess

# Set Variables
#####################################
user = "user"
host = "server.com"
# All should have trailing slashes
lfolder = "/home/user/screenshots/"
hfolder = "/home/remote_user/screenshots/"
httplink = "http://"+host+"/screenshots/"

# Display
#####################################
t1 = 5000 # timeout for screenshot upload dialog
t2 = 3000 # timeout for screenshot preview
t3 = 7000 # timeout for link dialog

screenshot_preview = 1 # If using with the compiz screenshot plugin, you may want this
popup_link = 1 # another popup
copy_to_clipboard = 0 # automatically copy text to keyboard

# Position
#####################################

# Get screensize < < used for relative positioning
display = gtk.gdk.display_get_default()
screen = display.get_default_screen()
x = screen.get_width() - 1
y = screen.get_height() - 1

# 0 for Automatic Placement
"""
x1 = 0
y1 = 0
x2 = 0
y2 = 0
x3 = 0
y3 = 0
"""
# Define Relative Position (assuming top-right)
x1 = x-1
y1 = 12
x2 = x1
y2 = y1 + 100
x3 = x-1
y3 = 12
# Define Static (1920 puts it on my second monitor)
"""
x1 = 1919
y1 = 12
x2 = x1
y2 = y1 + 100
x3 = 1920
y3 = 12
"""
#####################################

def upload_cb(n, action):
    assert action == "upload"

    subprocess.call(["scp", os.path.join(lfolder, f), '%s@%s:%s' % (user, host, hfolder)])

    # setup URL in
    if copy_to_clipboard:
        clipboard = gtk.clipboard_get()
        clipboard.set_text(httplink + f)
        # make our data available to other applications
        clipboard.store()

    # Notification: Link for the clicking
    if popup_link:
        n3 = pynotify.Notification("Here is your link","<a href='" + httplink + f + "'>" + httplink + f + "")

        helper = gtk.Button()
        icon = helper.render_icon(gtk.STOCK_DIALOG_INFO, gtk.ICON_SIZE_DIALOG)
        n3.set_icon_from_pixbuf(icon)

        n3.set_urgency(pynotify.URGENCY_NORMAL)
        if x3:
            n3.set_hint("x", x3)
        if y3:
            n3.set_hint("y", y3)
        n3.set_timeout(t3)
        n3.connect("closed",closen3_cb)

        if not n3.show():
            print "Failed to send notification"
            sys.exit(1)

        closen1_cb(n1)
        closen2_cb(n2)

    gtk.main_quit()
    sys.exit(1)

# Notification 1 was closed
def closen1_cb(n):
    n1.close()
    if screenshot_preview:
        n2.close()
    gtk.main_quit()

# Notification 2 was closed
def closen2_cb(n):
    n2.close()
    gtk.main_quit()

# Notification 2 was closed
def closen3_cb(n):
    n3.close()
    gtk.main_quit()

# The Ignore button was clicked
def ignore_cb(n, action):
    assert action == "ignore"

    closen1_cb(n1)
    closen2_cb(n2)
    gtk.main_quit()

# Main
def main():
    gtk.main()

# Init
if __name__ == '__main__':
    if not pynotify.init("Notifier 'scp' Option"):
        sys.exit(1)

    # Get latest file and build uri
    start = os.path.abspath(lfolder)
    f = max([(os.path.getmtime(os.path.join(start,p)),p)
         for p in os.listdir(start)])[1]
    uri = lfolder + f

    # Notification: Upload to Server
    n1 = pynotify.Notification("Upload to Server?","Copy the file '" + f + "' to the server?")

    helper = gtk.Button()
    icon = helper.render_icon(gtk.STOCK_DIALOG_QUESTION, gtk.ICON_SIZE_DIALOG)
    n1.set_icon_from_pixbuf(icon)

    n1.set_urgency(pynotify.URGENCY_NORMAL)
    if x1:
        n1.set_hint("x", x1)
    if y1:
        n1.set_hint("y", y1)
    n1.set_timeout(t1)
    n1.add_action("upload", "Yes, Upload", upload_cb)
    n1.add_action("ignore", "Ignore", ignore_cb)
    n1.connect("closed",closen1_cb)

    if not n1.show():
        print "Failed to send notification"
        sys.exit(1)

    # Notification: Screenshot Preview
    if screenshot_preview:
        n2 = pynotify.Notification("Screenshot Preview", "", uri)
        n2.set_urgency(pynotify.URGENCY_LOW)
        if x2:
            n2.set_hint("x", x2)
        if y2:
            n2.set_hint("y", y2)
        n2.set_timeout(t2)
        n2.connect("closed",closen2_cb)

        if not n2.show():
            print "Failed to send notification"
            sys.exit(1)

    main()

.

The long name for this blog used to be “Tyler Mulligan’s Tips and Tricks for Increasing your Efficiency“. I love finding ways to increase my efficiency and let computers do the work while I focus on more interests aspects of what the computer is providing me with. When I recognize an issue, I find a way to cut out time by streamlining the process for the most accurate repetition, like any programmer would/should/could.

I noticed myself taking a lot of screenshots with compiz’ built in screenshot tool (I can hold a hotkey and drag a box to take newspaper style clippings). This is very fast and simple, I highly recommend enabling this option and getting used to it. However, I don’t care much for clicking around on clunky websites to upload images.

This is where my adventure starts… when I find out a very useful feature was deprecated and not replaced in Ubuntu. I don’t use the new notification area, it has too much I don’t need, I never liked the behavior of these new osd-notify notifications which I found out now are even more worthless (sorry team).

Using Sane Notifications in Ubuntu

After reinstalling the GNOME default notifications system in Ubuntu I was able to use SANE notifications that actually… KICK ASS! I don’t understand how osd-notify is better than these which even comes with it’s own notification properties panel. Maybe it’s an under the hood thing…

Regardless, there is no doubt in my mind that notifications that you hover, can still slightly see but click through but cannot perform any actions, even a close, are just plan stupid and annoying..

Screenshot of the script I ended up writing using the “better” notification system to ask me if I want to upload the screenshot I just took to the server.

Linking the notifications

I linked the notifications the following way:

Python Script for Notification that Prompts for File Upload to Server

Knowing diddly squat about Python, I chugged forward with my classic notification popups that allow for interaction as it had the most activity around it and some examples available in /usr/share/doc/python-notify/examples/

I ended coming up with the following script thanks to some help from a few people in #python on irc.freenode.org

This is outside of the scope of this blogpost but this script assumes you have setup passwordless ssh to your server.

#!/usr/bin/env python
#
# Title: Notification 'scp' Option
# Author: Tyler Mulligan (tyler@detrition.net)
# Date: 06/25/2010
# Description:
# Used in combination with an event, such as an action or cron
# the latest file from a folder will be scped to your server and will copy
# the http location of the that file to your clipboard
#
# Orginally developed to be piped to from compiz screenshot tool
#
#
# The MIT License
#
# Copyright (c) 2010 Tyler Mulligan
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE
#

import pygtk
pygtk.require('2.0')
import gtk
import pynotify
import sys
import os
import subprocess

user = "user"
host = "server.com"
lfolder = "/home/user/screenshots/"
hfolder = "/home/remote_user/screenshots/"
httplink = "http://"+host+"/screenshots/"
timeout = 5000

# Set position
display = gtk.gdk.display_get_default()
screen = display.get_default_screen()
x = screen.get_width() - 1
y = screen.get_height() - 1
#x = 1919
#y = 12

def upload_cb(n, action):
    assert action == "upload"

    start = os.path.abspath(lfolder)
    f = max([(os.path.getmtime(os.path.join(start,x)),x)
          for x in os.listdir(start)])[1]

	# setup URL in clipboard
    clipboard = gtk.clipboard_get()
    clipboard.set_text(httplink + f)
    # make our data available to other applications
    clipboard.store()

    os.system('scp "%s" "%s@%s:%s"' % (lfolder + f, user, host, hfolder) ).wait()

    n.close()
    gtk.main_quit()

def ignore_cb(n, action):
    assert action == "ignore"
    n.close()
    gtk.main_quit()

if __name__ == '__main__':
    if not pynotify.init("Notifier 'scp' Option"):
        sys.exit(1)

	# Setup Popup
    n = pynotify.Notification("Upload to Server?")
    n.set_urgency(pynotify.URGENCY_NORMAL)
    n.set_timeout(timeout)
    n.set_category("device")
    n.add_action("upload", "Yes, Upload", upload_cb)
    n.add_action("ignore", "Ignore", ignore_cb)

    # Set position
    n.set_hint("x", x)
    n.set_hint("y", y)

    if not n.show():
        print "Failed to send notification"
        sys.exit(1)

    gtk.main()

edit: I updated the script with some position information — I love that I can put the notifications ANYWHERE on my screen. I also variablized the timeout.

edit 2: Here is a video of my improved script in action — I’ll post the source later

http://interwebninja.com/videos/compiz-screenshot-piped-to-notification-daemon-for-upload.ogv

Going Beyond

The Compiz example is just something that server my immediate needs. The possibilities are however endless. You can for example, link this script to a cron job asking you if you want to sync some other sort of file. Or perhaps you’d like to add multiple buttons to give yourself a folder / server choice.

Happy hacking