How can I use COM ATL project in Linux? - c++

I've got a small C++ library which is made as ATL Project in Visual Studio. I want to make it crossplatfrom. It will be used in Windows and Linux. It will be included in my project, which uses Qt 4.x. How can I easily convert the library?

Short answer: Not easily.
Long answer: The COM technology is an exclusively Windows technology and ATL is built on top of it. That means you can not compile/run it under linux, except if you use Wine or something similar.
Here's what you can do: You can switch to XPCOM - a cross platform implementation of COM technology, implemented by the Mozilla platform. COM and XPCOM are binary compatible under Windows (but only if used from XPCOM - MS Windows COM is agnostic of Mozilla's XPCOM).
I am unsure if you would be able to compile any ATL code using XPCOM instead of COM as a base though (but I doubt it), and if you go with XPCOM, you're better off using an XPCOM GUI (using the same code that Mozilla/Firefox does), instead of Qt.
This would mean implementing your GUI using Javascript and XUL.

Related

c++ gui window cross platform

I would like to make c++ that will work both on Linux and windows as I understand if I use the win32 template in visual studio then it will only work on windows is there something built into c++ like java's jframe that I can use. Also I would like to use any external library at this time.
Here are some cross platform alternatives QT, wxWidgets, Ultimate++. I have used QT, it is intuitive with a huge collection of tools to use in your code. The others are also popular but I have never used them.
I make used of wxWidgets due to it's cross platform and even cross architecture, native look on the OS where it appear. Binary application yields by wxWidgets is small enough thus make it possible to linking statically as portable application. Qt produce huge binary if linked statically (and may be violate qt licensing scheme).
Another reason are licensing flexibly, well documentation and supported by huge community arround the world. wx is considered as mature framework since it first release about 20yrs ago. It's use standard C++ syntax and preprocessor that will make you easily switch from plain C or C++. Complete library are available ranging from appeal window GUI, string, network, stream, webview, xml, and wx is playing very well with 3rd party library as such database SOCI, Asio, etc ....
You may try start to code with wxWidgets easily using Eclipse-IDE and wxFormBuilder as GUI designer. Plese check my experience for ease setup it's IDE+Toolchain. This wx installer can be used do develop, test and run wx application on Linux desktop, and then deploy the binary on Raspberry Pi is available for another board target beside Linux x86_64.
http://yasriady.blogspot.co.id/2016/01/raspberry-pi-toolchain.html
There is a cross-platform application & UI development framework called Qt. I think it meets your requirements. Click here for more info.
There is a long list of both active and dead cross-platform C++ UI libraries here: https://philippegroarke.com/posts/2018/c++_ui_solutions/

Is it possible to create a C++ GUI with Visual Studio?

Can we create C++ GUI applications with Visual Studio or do we need QT like cross platform softwares?
(By the way, I am assuming if I create a GUI with C++ it would be a cross platform application because as far as I know C++ is a cross platform language)
For some of you maybe this is a very obvious question but I couldn't figure out.
The C++ language is cross-platform, but its standard libraries don't provide anything specifically for any GUI development. For that, you need a C++ GUI framework/library. Qt happens to provide just that and it's also cross-platform.
So no, without the use of some cross-platform GUI framework, your application not only won't be cross platform, it simply won't have a GUI at all, since C++ standard libraries don't provide this functionality.
If you use one of the GUI frameworks available only for Windows, like MFC or Windows Runtime, you're not cross-platform.
There are no GUI libraries built directly into c++. Therefore, any GUI you built using c++ would not be cross-platform. There are a couple GUI libraries that come with Visual Studio - MFC and ATL are both fairly common. Neither are cross-platform, however. That doesn't stop you from using some other GUI framework, of course, if you include it. There are plenty to choose from, including ones that are cross-platform.
Just because a language is system-independent, doesn't mean people haven't written frameworks for it that aren't system-independent.
C++ has no standard, built-in GUI library. If you want to make cross-platform GUIs you must use an add-on library like C++, GTKmm, wx, etc.
If you're OK with targeting Windows only, MFC exists and is included with Visual C++.
If You want multi platform application, You should concern using Qt. It makes multi platform development easier by providing API for handling both Windows and Linux (and others). You can use Qt in Visual Studio easily. And is really easy to learn. Check official Qt docs for integration tips.
OK, the point is that qt claims (and prooves) to be platform independent. It shouldn't matter at least if you compile it on a windows platform using either the MinGw GCC or MSVC toolchain.
The difference is, if you use Visual Studio's integrated GUI support, you'll end up with their proprietary, non portable CLR/CLI implementations, and the code won't be portable for other platforms.

MFC app to Linux dll

Currently we have a legacy client/server system written in MFC(server) and Java(client). This system cant not run on Internet because of various reason. So, we are developing a small system (very few functionalities of this legacy system) in cake php etc to fullfill customer requirement.
Now, one functionality in legacy system needs in this new system. We are thinking of making a DLL of that code and then integrate it with cake php (to save time) but this DLL will not work on Linux where this new system will sit.
So, is there any way to generate a dll so that it works with php in Linux system using QT etc?
OR
we have to rewrite the whole thing? In this case, what would be the most appropriate framework to develop cross platform dll. I would prefer to use Windows to write it.
Also, can we run dll with cake php?
Thanks
So, is there any way to generate a dll so that it works with php in Linux system using QT etc?
No, Linux doesn't support the DLL file format. You may want to compile a shared object file in the ELF format from your source code.
I think, the two most prominent cross platform GUI libraries are wxWidgets and Qt.
You cannot use a Windows DLL as a part of a Linux application. That is simply not possible, because of the different object formats.
So, the only option is to rewrite or port it in some form.
A guide for porting your application might be Porting MFC applications to Linux, which uses wxWidgets.
Another one using Qt, could be MFC to Qt Migration - Walkthrough.

Visual C++ 2010 and Native executable file

Native exe!
that means my program can run easily without any requirement?
even if I use .net classes?
You know I want to write a program that is so light and I don't like to use C# or any other .net programing language because all of them need .net-framework 4.5.
Just think a 2.5 MB programm needs a +250 MB .netframework.
New Update - 12/01/2016:
It's almost 4 years ago when I asked this question. As you know Dotnet Native is announced. It's an interesting feature which compile IL into native code.
Compiling Apps with .NET Native
.NET Native is a precompilation technology for building and deploying
Windows apps that is included with Visual Studio 2015. It
automatically compiles the release version of apps that are written in
managed code (C# or Visual Basic) and that target the .NET Framework
and Windows 10 to native code. Typically, apps that target the .NET
Framework are compiled to intermediate language (IL). At run time, the
just-in-time (JIT) compiler translates the IL to native code. In
contrast, .NET Native compiles Windows apps directly to native code.
For developers, this means:
Your apps will provide the superior performance of native code.
You can continue to program in C# or Visual Basic.
You can continue to take advantage of the resources provided by the .NET Framework, including its class library, automatic memory
management and garbage collection, and exception handling.
Last I checked none of the .NET frameworks were 250+ MB! Yes, the offline installer for .NET Framework 3.5 SP1 is 231MB but it contains x86 and x64 versions of .NET 2, 3 and 3.5 sp1.
You should read this http://www.smallestdotnet.com for details on sizes of various versions of the installers.
Now on to your question:
Yes, It is a little annoying to have your clients install a big framework, even 20-40MB does get annoying. With .NET, the advantage is the ease of programming (In my opionion) compared to other Native options.
Your native options are:
MFC - You need only the VS runtimes installed, which is 1-2MB and is usually installed on newer pcs. Also, you can ship your application with the MFC libraries packaged into a dll which is again <2MB
The trade of here is you need to program in C++, the libraries overall are a very thin layer over the native libraries. and people have had harsh opinions about MFC. I've barely just tried it.
Win32 API - This is going all bare bones, and quite difficult, you could use C or C++ but you'd really have to know a lot about the Win32 API and how windows itself works (Stuff like windows messages, hwnds etc) Its not fun, believe me. But during deployment you would not need any external libraries.
There are tons more options, see here:
Native Windows Application Development Options
https://stackoverflow.com/questions/2711599/what-programming-language-should-i-use-to-create-small-native-windows-applicatio
Here are some links on MFC that might help:
Want to learn Windows Programming,some suggestions?
How do I decide whether to use ATL, MFC, Win32 or CLR for a new C++ project?
C++ MFC vs .NET?
https://stackoverflow.com/questions/557114/stick-with-mfc-or-go-to-net
you are able to create native exe by using c++ Win 32 projects.
Alas, nearly everything requires a download runtime library and even if you have one installed, you'll need to download updates for them almost continually. Even Microsoft C++ apps nowadays come with security updates that have to be installed if you've compiled your app with them.
But.. there is a solution of sorts. If you use C++, it has a feature where only the things you use are compiled into the final app. Normally, this would require linking with all the library dlls, but if you statically link with the library, you will end up with a single .exe that is as small as can be, and you will not need any dlls (as all the code contained in the library will be compiled into the .exe).
The benefits are debatable compared to dlls, but as MS has pretty much broken the idea of shared dlls in .NET (ie, you practically have to put all the shared dlls in the same directory as your running app, giving you a nightmare in maintenance if you have these shared dlls spread around all your apps) then there's not much of a difference anymore. Static linking is getting a little bit of a comeback and sounds like its what you want.
For modern C++ development, you'll probably want to take a look at Qt instead of MFC. Its a lot nicer to use and is cross-platform so you can run Qt apps on your Android or Linux platforms as well as Windows.

C++ and graphics

I have searched the web for information on creating GUIs(Games, Forms etc) in c++, I have found that OpenGL, Direct X and .Net framework can do this. The question I ask is which one is better to learn, what library for GUI in c++ is the most popular in industry. I know this is a newbie question, but if some on could lead me to the correct path it would be greatly appreciated.
OpenGL and DirectX are different to .Net framework. OpenGL and DirectX are for game development (Graphic acceleration) but .Net framework is for .Net development. If you use .Net framework then your program is not compiled to native code, it will be compiled to MSIL (Microsoft Intermediate Language) then .Net translate it to Native code at run-time (for the first time).
If you want a GUI toolkit for your C++ program, Qt, MFC and wxWidgets are a good choice. Qt and wxWidgets are cross-platform libraries thus your program will be compiled on all platforms (Windows/Linux/Mac OS). But MFC is only available for Windows. Qt is more feature-rich than wxWidgets and maybe is a better choice.
I like QT myself.
Because you mentioned DirectX I'll assume your using windows, for that I would reccomend the basic Win32 API. If you want cross platform capabilities however, I would suggest Qt.
I have searched the web for information on creating GUIs(Games, Forms etc) in c++...
What would work fine for creating traditional form-based applications won't work so well for creating games, and vice versa.
You would be better off using C# with the .NET libraries as the C++ managed extensions can be a little cumbersome. If you must go with C++, then Qt and wxWidgets are both decent options, although you're more likely to find more help and online resources for QT.
If you need to do graphics like games, then you'd better off using a higher level library than directly using DirectX or OpenGL. Ogre3d is one option on the open source side, the C4 engine is an affordable option on the commercial side. If C# is an option, then might want to look at XNA and Unity3d.