I'm working on a project that's supposed to work on both Windows and Linux (with an unofficial Mac port as well) that emulates a true colour system console.
My problem is that recently there appeared a request for textfield support (yes, console-based) and it would be cool to add the possibility of copying text to clipboard and pasting from it. Is there a way of achieving this that will:
be done in C (not C++),
work in both Windows and in Linux (preprocessor macros are an option if there's no platform-independent code),
require no extra libraries to link to?
Thanks in advance for your help.
If you're not using a cross platform UI library (like wx or something), then it sounds like you're just going to have to write native clipboard code for each platform you want to support.
Remember, on Macintoshes, you copy with Command-C, not Ctrl+C :)
The clipboard is inherently an operating system defined concept. The C language itself has no knowledge of what a clipboard is or how to operate on it. You must either interface directly with the OS, or use a portability library that does this on your behalf. There is no way around this.
Personally I would define my your own function
getClipboardText();
That is defined in two different header files (linux_clipboard.h, windows_clipboard.h, etc) and then do pre-proccessor stuff to load the appropriate one accordingly. I don't really code in C/C++ so I'm sorry if that didn't make any sense or is bad practice but that's how I'd go about doing this.
#if WIN32
#include windows_clipboard.h
#endif
That sort of thing
Remember:
For linux you have to deal with different window managers (Gnome, KDE) all with different ways of managing the clipboard. Keep this in mind when designing your app.
You may be able to communicate to the clipboard by using xclip. You can use this python script here to do this job via communicating with 'dcop' and 'klipper' here. That is for KDE, I do not know how it would be done under GNOME... You may also be able to do this independantly of either GNOME/KDE by using DBUS, although I cannot say 100% confidently on that either...
Just be aware, that for a truly cross-platform job, you have to take into account of the different GUI's such as under Linux, X is the main window manager interface and either GNOME/KDE sits on top of it..I am not singling out other GUI's such as FluxBox, WindowMaker to name but a few, and that there will be a lot of platform dependant code, and also in conjunction, you will be dealing with Windows clipboard as well..all in all, a big integrated code...
Have you not considered looking at the raw X programming API for clipboard support? Maybe that might be better as I would imagine, GNOME/KDE etc are using the X's API to do the clipboard work...if that is confirmed, then the work would be cut out and be independant of the major GUI interfaces...(I hope that would be the case as it would make life easier for your project!)
Perhaps using compile-time switches, for each platform...WIN, KDE, GNOME, MAC or use the one that is already pre-defined..
Hope this helps,
Best regards,
Tom.
Related
my question is general for all languages, but I'm using only C, so, I would like to get answer in this one.
My question is, How Can I control the behavior of another applications that I didn't write?
For example:
How Can I fill this entry box (in
this site) using C? Do I need to
control the browser? (I'm using
firefox.)
Still in this example, How Can I open
another tab in this browser using C?
(see, I want to control this
application such another one)
How Can I embed a program im my one?
How Can I fill a database program using your gui, doing it by c?
and so on...
Thanks a lot!
There's no concrete or single answer to your (multiple) questions because every program varies. Short of the desired application having an API, you can resort to using low level Win32 commands to identify handles of processes and windows within those processes which you want to change/read. It's by no means a straightforward or scalable process though.
You'd have to interact with that programs API.
Some programs are scriptable and publish APIs that allow other programs to send commands to them. If your "target" app does something like this, then that will typically be your best bet.
If the app doesn't have a C API, then you probably can't control it in C. That doesn't mean it's impossible, only that you might need a different language. If your app is a Windows GUI app, you can use AutoIt to interact with the GUI programmatically.
Typically you use a program's application programming interface (API) to gain access to publicly available functions that let you accomplish tasks within that program. However, not every application has an API that you can use.
You should start by looking at the documentation of the application you're intending to take control of with your program and seeing if they have an API suitable for your needs.
Most of the time application need API to work with each other.
There is another way around to automatise actions done to applications (like an user would). For example on Windows there is an "language" named AutoIt which can interact with your computer.
I'm not really sure if this is what your seeking but it can do almost all the thing you asked for.
question is, How Can I control the behavior of another applications that I didn't write
Answer: that depends on the application and platform (linux, windows, mac, ...). It generally does not depend on your language of choice.
As an example, quite a lot of gtk/ kde programs on linux can be partially controlled via the dbus messaging bus. Those apps are designed to be controlled in that way.
I think firefox has a command line option to open a new website using an already running browser.
Applescript or automator on a mac can be used to control some apps too, I believe.
In short, make a separate question on what you want to do exactly, stating both platform and app you need to control.
I wanted to know if there is any library in C available for calculating the Font Metrics (Basically i wanted to know the width of a string of Particular Font).
QT has QFontMetrics. Is there any way I can get similar data in C.
I wouldn't say just use FreeType, unless you are on a system that uses X as the graphics display. If you are on Windows, use the Windows API to get font metrics information and on Mac use whatever Cocoa provides.
It might also help if you told us what you are trying to do.
EDIT: Since the output of your library is intended to be consumed by a particular GUI app, you will probably want to use the same GUI library to get the font metrics information as the app is using. Even better would be to have the app provide metrics information to the library, or a callback method that can provide that information. Then the library doesn't even have to know how the font metrics were derived, reducing an unnecessary dependency. This also means that you can use Qt (C++) in your GUI app, but still write your library in C and not have to figure out a way to call C++ from C, which is very difficult, especially if you are trying to make it cross-platform.
C is (just) a programming language. By design C has no embedded functions at all, not even for File I/O.
So you will have to indicate what Graphics/GUI platform you are using.
You can use freetype2 : http://www.freetype.org/freetype2/docs/reference/ft2-base_interface.html#FT_Glyph_Metrics
Check out FreeType: http://freetype.sourceforge.net/freetype2/docs/tutorial/step2.html
In our Bioinformatics lab we've recently been asked to create a GUI for a program written (and optimized) in C. Any GUI we designed would need to be able to feed input to and receive output from the C program, while also being easily portable to both Windows and Mac. What are ways to go about doing this?
If your looking for a GUI toolkit that works on windows/mac in C, have you considered GTK?
Download QT or wxWidgets.
Why do the hard work when someone already has and will let you use it for free? I prefer QT myself, btw.
Edit: It does mean using C++ but it will work perfectly with C code.
Use a separate program.
It doesn't break the existing code - especially important if the code has bio knowledge that a programmer might not know/understand/test.
Gui's change often, in a couple of years you are going to be rewriting the gui for NewSuperOsToolkit(tm) but the underlying worker code won't change. We have atmospheric modelling code that I'm sure was originally written in latin.
You keep the ability to run the engine code as a batch, in parallel on MPI in the cloud, and a bunch of other ways you haven't thought of.
You could write the front end GUIs in Java, and have them feed input and receive output from your C programs. I've known a couple of groups here at work that do something similar with C# and C code (but they don't have the multi-platform restraint).
This way you don't necessarily have to create your GUIs using a C toolkit.
Depending on the nature of the program, you could create an entirely separate GUI application (in any language you prefer), and fork/execute the existing program from it, redirecting it's stdin and stdout to your GUI program. Depending on how the existing program works, this could work well, or be very cumbersome.
You could also extend the existing program with GUI code in something like GTK (which has a C API), or you could use Qt (which is C++, but there's usually no problems calling C functions from C++ if you define them as 'extern "C"').
There are a number of scripting with languages that can make this easy. I'd go for tcl/tk it works on mac pretty much out of the box, and is cross platform across pretty much any machine you can think of.
Also GTK is great and a number of scripting languages have bindings for it.
You probably don't want to write your gui in c if you don't have to. use a rapid develoment scripting language.
If you want a native GUI, then go with wxWidgets or QT. (I use wxWidgets ...)
The alternative is to have an HTML based interface using Javascript and CSS. You avoid GUI libraries altogether, you get cross-platform support and the outcome is better on some dimensions, worse on others.
If you really want a standalone user interface, you can integrate it into a binary with something like WebKit.
I'm lookin for a portable wiimote library. I want to use the wiimote for the hardware it has (but I don't need to access any data stored on it).
Required features:
access to all the buttons (as an exception, no use of the power button is OK)
make the wiimote play sound
talk to nunchuks and classic controllers
preferably: make the wiimote rumble.
interface with C. Preferably native C. Bonus points for bindings with Haskell or python.
The library should port to Linux, Windows and OS X (in order of importance) and should be agnostic with respect to CPU architecture.
Anyone got a good suggestion?
Haven't use it (I've only read about the managed Wiimote library really), but you may want to check out wiiuse. It seems like the most complete of the native libararies.
Others include:
GlovePIE
WiiYourself
You can use my WiiMouse program to do this (which is based on the wiimotelib open source project), it allows you to connect via named pipes and play PCM sounds and use all the attachments including the MotionPlus, it even calculates the MotionPLus vectors for you, you can get it here:
http://home.exetel.com.au/amurgshere/wiimouse.phtml
See the download for an example on how to connect to a wiimote via named pipes and play sounds and stuff.
I'm new to windows programming and I'm trying to get notified of all changes to the file system (similar to the information that FileMon from SysInternals displays, but via an API). Is a FindFirstChangeNotification for each (non-network, non-substed) drive my best bet or are there other more suitable C/C++ APIs?
FindFirstChangeNotification is fine, but for slightly more ultimate power you should be using ReadDirectoryChangesW. (In fact, it's even recommended in the documentation!)
It doesn't require a function pointer, it does require you to manually decode a raw buffer, it uses Unicode file names, but it is generally better and more flexible.
On the other hand, if you want to do what FileMon does, you should probably do what FileMon does and use IFS to create and install a file system filter.
There are other ways to do it, but most of them involve effort on your part (or take performance from your app, or you have to block a thread to use them, etc). FindFirstChangeNotification is a bit complicated if you're not used to dealing with function pointers, etc, but it has the virtue of getting the OS to do the bulk of the work for you.
Actually FileSystemWatcher works perfectly with shared network drives. I am using it right now in an application which, among other things, monitors the file system for changes. (www.tabbles.net).
You can use FileSystemWatcher class. Very efficient but cannot work with Network shared drives.