By PDLCPayday Loan
This seems to be a popular problem in kde’s history, after an update your menus and general look & feel of your desktop is just weird (actually is just without any theme). Trying to set a theme again it won’t work. To fix this you just have to remove one file and regenerate the cache config with another command, just execute:
$ rm ~/.config/Trolltech.conf $ kbuildsycoca4 --noincremental |
Then restart your session (or close your apps and open them again) and there you go, pretty again!
If you have an error like:
...
super(NuclearMissileHandler, self).__init__()
TypeError: must be type, not classobj |
That means you have forgotten to inherit from object in the superclass/es.
Mental note: write something interesting in the fraking blog yo.
You could be an awesome developer or a really bad one, it doesn’t matter, a job interview is something different. It’s like doing a crossword for a writer or a drive license test for a f1 driver, they should do it just ok, but a bit of practice before won’t hurt.
Things I’d recommend:
May the source be with you.
Let’s start with the basic. What are bindings? It’s a way to call low level libraries (normally in C or C++) from another language (high level one, like ruby, java or whatever). This simple step requires two important things: 1) first, to know how we should call the method itself and 2) second, how to map the type from the high level language to C primitives types. To accomplish this, we have what is called foreign function interface which trivialize this task.
In ruby/jruby world we are gonna need ffi gem (jruby also has a compatible ffi gem), besides that the most important part is to have a clear interface in C. You can do bindings for a C++ library if you create a C interface first (because the bindings between C++ and C are free, the compiler knows how to do it by itself). So let’s cut the crap and write some code
First our C++ library which can be this few lines or thousands:
class awesome_object { public: awesome_object(int a, int b) : a_(a), b_(b) {} int awesome_method() { return a_ + b_; } protected: int a_, b_; } |
Now the C bindings which will be our façade for our c++ library:
extern "C" { typedef awesome_object_p void *; awesome_object_p create_awesome_object(int a, int b) { return static_cast<void *>(new awesome_object(a, b)); } void delete_pointer_to_awesome_object(awesome_object_p p) { delete static_cast<awesome_object *>(p); } int awesome_method(awesome_object_p p) { awesome_object o = *static_cast<awesome_object *>(p); return o.awesome_method(); } } |
Now ruby code that use ffi gem to be able to call the methods defined in C:
require 'ffi' module AwesomeObject include FFI extend FFI::Library ffi_lib "libawesome.so" # .dll if you are in windows, it doesn't matter the OS attach_function "delete_pointer_to_awesome_object", "delete_pointer_to_awesome_object", [:pointer], :void attach_function "awesome_method", "awesome_method", [:pointer], :int attach_function "create_awesome_object", "create_awesome_object", [:int, :int], :pointer end |
With this you can use your C++ library from ruby code (I’d recommend package everything as a gem) just like this:
class MyTest include AwesomeObject def test! object = create_awesome_object(11, 31) awesome_method object delete_pointer_to_awesome_object object end end MyTest.new.test! |
So, if you have read until now, probably you just want something working, say no more. Download this tar.gz, and see all this by yourself. In the tar you have the code split into c/h cpp/hpp files as it should be, in the post I’ve put all together to simplify things. Just execute make test and if you have ruby, ffi gem and g++ installed on your system, you’ll see something like:
$ make test g++ -g -Wall -fPIC -c awesome_object.cpp g++ -g -Wall -fPIC -c awesome.c g++ -g -Wall -fPIC -shared -o libawesome.so awesome.o awesome_object.o ruby test.rb 42 |
One of the awesome things about dealing with open software is to be able to access to the source code. When you deal with complex systems (so, every fraking day normally) the worst thing are black boxes that you cannot see, check or change their inside. This black boxes use to be closed/privaty systems/libraries/whatever. Lucky we are, android is open source you can get the source easily with repo but for developing applications in eclipse you can just install Android sources plugin and that’s it, really nice.
http://adt-addons.googlecode.com/svn/trunk/source/com.android.ide.eclipse.source.update/
I honestly don’t know why I still use ubuntu, it pisses me off a lot with so many useless change related to its user interface, very pretty (the first 2 minutes) but totally useless. At least it’s easy to change this stuff. To go back to the typical scrollbar just execute this in a console:
$ gsettings set org.gnome.desktop.interface ubuntu-overlay-scrollbars false