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Tobias Preuss johnjohndoe

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public class Article {
String author;
File photo;
johnjohndoe /
Created Jun 11, 2015
Excel: Umrechnung von Uhrzeit in Stunden


=WENN(Uhrzeit_Anfang<>"";(Uhrzeit_Ende - Uhrzeit_Anfang)*24-Pause/60;"")



Hacking in a material world


We will be playing with android's gorgeous new Material Design theme. We will be covering the following material widgets and animations that were introduced in Android 5.0 (API level 21).

johnjohndoe /
Last active Sep 12, 2015
Helper class to get the consumer friendly device name.
* Copyright (C) 2015 Jared Rummler <>
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* Unless required by applicable law or agreed to in writing, software
johnjohndoe / gist:723302
Created Dec 1, 2010
Colored bash prompt showing git branch (.bash_rc)
View gist:723302
# Set git tab completion and PS1 integration
if [ -f /usr/local/git/contrib/completion/git-completion.bash ]; then
. /usr/local/git/contrib/completion/git-completion.bash
if [ -f /opt/local/etc/bash_completion ]; then
. /opt/local/etc/bash_completion
johnjohndoe / gist:1007379
Created Jun 3, 2011
Java introspection for class name and function name
View gist:1007379
// Print name of the current function.
new Throwable().fillInStackTrace().getStackTrace()[0].getMethodName();
// Print simple class name.
// Print full class name.
johnjohndoe / gist:1024839
Created Jun 14, 2011
Convert from NSRect to CGRect
View gist:1024839
// Convert from NSRect to CGRect.
NSRect baz = NSMakeRect(0, 0, 100, 100);
CGRect foo = *(CGRect*)&baz;
// Include this inline function in a header file.
NS_INLINE CGRect CGRectMakeFromNSRect(NSRect rect) {
return *(CGRect*)&rect;
// Doooooh! They already exist.. - I could not find 'em before.
johnjohndoe / gist:3754453
Created Sep 20, 2012 — forked from gnunicorn/gist:3748738
Git for Beginners: Call for Coaches
View gist:3754453

The OpenTechSchool has set up and hosted a few tech workshops and meetups here in Berlin now. Aside from the monthly Beginners Meetup and hosting the Udacity Global Meetup we hosted workshops for program beginners in Python and Javascript on our own and on the premise of CampusParty.

One thing that was extraordinary popular on CampusParty was the Workshop on Git for beginners. And we decided to do it again, this time with a closer focus on version control as a major benefit in code sharing (by using git and github) for beginners - free of charge.

So if you are interested in

johnjohndoe / Host.m
Created Sep 25, 2012
Objective-C: Conversion of NetService addresses into human readable IP addresses.
View Host.m
// Host.m
// Dependencies: NSString+HexValue - Source:
#import "Host.h"
#import "NSString+HexValue.h"
#pragma mark
@interface Host()
View convert.rb
#!/usr/bin/env ruby
require "rubygems"
require "xml/libxml"
require "uri"
require "net/http"
require "time"
URL = ""