Author: Johannes Luderschmidt

HP Sprout – Blended Touch and Projection All-in-One PC

Well, that thing looks promising.

Posted in Hardware, Multi-Touch, Natural User Interfaces, Projection, Tangible Interfaces

Find and Delete Empty Files Using a Shell Script on the Command Line

If you – like me – copy image files regularly to an external HD, you might also have come across the problem that sometimes the file references are created but the eventual copying of the file contents failed. Thus, I

Posted in bash, Command Line

Objective-C Category for Location Authorization Request for iOS8 with Xcode 5 Support [Update]

<update date=″17.9.15″> Fixed a bug when checking ‘authorization always’. Added a Swift extension that does the same. </update> When you use the location of the user in your app and want also your iOS8 users to be able to enable

Posted in iOs, iPad, iPhone, Objective-C

Provision iOS IPA App for In-House Enterprise Distribution

EDIT: Please make sure at first that you are using an enterprise account and not a normal account before following any guidelines! Provisioning an iOS app for in-house distributione is damn complicated. As my efforts to do so were eventually

Posted in apple, In-House Provisioning, iOs, iPad, iPhone

Fix Broken WordPress RSS Feed Due to HTML Above the XML Declaration

I had the problem that my RSS feed was broken due to HTML that appeared above the XML declaration.

Posted in PHP, Wordpress

A Gesture-Controlled Car User Interface

[UPDATE] You can now try out the Car UI yourself in Safari on your iPad. Well, the title says it all: »A New Car UI: How touch screen controls in cars should work«. I am not convinced that car user

Posted in Car UI, Gestures, HCI, UI Prototypes Tagged with: Car, Prototype, UI

Bash Script Batch Rename Image Files Employing Parameter Expansion

This one is a classic in the use of shell scripts: batch renaming (image) files. You can find solutions on how to batch rename files on stackoverflow (e.g., here and here).

Posted in bash

Prevent Opening Additional Popover View from Navigation Bar Button Using UIPopoverController

In a recent iOS project for the iPad, I wanted to open a popover view from a bar button in the navigation bar. However, tapping somewhere on the navigation bar would not dismiss the popover view but (depending on where

Posted in Cocoa, iOs, iPad

Creating Animated GIFs from the Command Line in Mac OS X Using Convert

You can easily create animated GIFs from the command line in Mac OS X (or Linux) using ImageMagick. To figure out if ImageMagick is installed open the application Terminal from the Utilities folder in Applications, type ‘convert’ and hit ‘Enter’.

Posted in Command Line Tagged with: animated gif, commandline, imagemagick

SimProj: A Tool for the Calculation of Rear-Projection Mirroring

The SimProj Project provides a Processing-based (and therefore Java-based) application that provides a GUI for the simulated calculation of a video projection setup. SimProj allows to add and manipulate virtual projectors, mirrors and projection planes in order to show how

Posted in DIY, Multi-Touch, Projection, Video Projection