I recently knew a latex-editor "gummi", see http://gummi.midnightcoding.org/
, which is written by GTK+ graphical interface toolkit. There are two panels, one in the left which is an editor (using the library gtksourceview) and on in the right which is a viewer (using the library poppler). I am curious that if we can do similary things for every program.
For example, replace the editor with "terminal"、"emacs"、"vim"、"terminator (a multi-windows terminal)"...etc. And replace the viewer with other viewers, which in my mind is Adobe Reader.
With discussion with the author, he mentioned:
The viewer component is also replacable, but doing it with Adobe Reader would not be easy or perhaps even impossible. The reason for this being that Adobe Reader is a complete program instead of a library, and also closed-source
So I have some questions:
a) We can only make "library" embedded as a panel, but we can't do this for a (any) program?
b) Could we replace the editor with emacs? with terminal?
c) Could we replace the viewer with Adobe Reader? If not, why? Because it's a program or it's closed-source?
I know the questions in this thread are not very precise, sorry.
a) You can do it for any program if it has a sufficient API for doing so, but that is rather rare. Libraries them selfes provide functionality beyond the means of the toolkit (here: gtk+). So in the end you would have to replace a class for another (within the source code) which uses another library (or provides cross process functionality).
b) terminal: yes (see anjuta), for emacs, probably yes, but from my point of view with limited knowledge about emacs I'd say it is a lot more work to achieve this
c) It has neither a sufficient cross process API nor do we have the source code to directly use its classes. You could use evince (or similar opensource pdf viewers) instead.
Related
I am fairly new to C++ and this might sound like a very dumb question, but is there any resource or common practice to find the headers that need to be included when using C/C++ libraries?
For example: I am currently doing a project using the OpenSSL library.
How do I find out which headers I need to include for the sample codes on this page:
https://wiki.openssl.org/index.php/EVP_Key_and_Parameter_Generation
I had this issue many times and I am almost always struggling to find the right header files to include if the documentation doesn't provide a full working example.
Am I missing smoething when it comes to finding the required header files or is this lack of documentation the norm for examples?
I am aware that you were hoping to find something like a fancy database or any secret documentation to get the header.
Like for the Qt framework in the Qt Creator would be positioning the cursor on a written class in the code and just pressing alt + enter is adding the necessary header on top of the code.
Sadly that functionality is just for Qt not for c/c++ implemented.
The correct answer to your question might be as simple and maybe basic as so and it is also the fastest way I found and probably most people use:
A search engine of your choice(Google, DuckDuckgo, Startpage.com ...)
library command (f.e. EVP_PKEY)
Programming language name (f.e. c++, Qt, ...)
Proof of concept f.e. for startpage.com:
Maybe https://en.cppreference.com/w/cpp/header is an alternative - I just never found stuff real quick there.
The second best option I found and use regularly to find in addition to the header even good sample codes/examples is a program called Recoll (For Linux, Mac and Windows - or a similar desktop search engine)
Recoll is based on the very capable Xapian search engine library, for
which it provides a powerful text extraction layer and a complete, yet
easy to use, Qt graphical interface.
(https://www.lesbonscomptes.com/recoll/)
It works like that:
I put a selection of the best 50 books to a special topic in a folder (f.e. c++, c, qt - just stay really specific) and let recoll crawl the folder.
Now use keywords like EVP_PKEY to find every topic in all of your most loved and respected pdf c++ books in nano- to milliseconds - depending on how much money you spend on your pdf library. (Sure, you have to get/buy them first)
(But its a freaking fast tool and even prioritized due to the Xapian search engine library)
Is there a library/tool that can be used in C/C++ that would convert the PS (post script) file to .PDF file, on embedded platform (proprietary operating system, no windows, no linux)?
I was looking for some kind of library that could be ported to our OS. I have found basically only Ghostscript, but issue there is with the license, if i understood it correctly, we would have to make our source public, which is not possible for us...
Maybe a little bit more background, we are trying to find format that will be easily viewable by user. We already have our output in PS for other reasons (printer). But now we want to provide this output in file by itself, so we are trying to find feasible file format. We are considering the PS itself, but usual user does not have PS viewer, so that's why I am trying to find something to convert this to PDF. So perhaps alternative question could be, is there some another format that can be easily acquired from PS, such that "regular" user can view it?
The main complexity for converting PostScript to something else comes from the fact, that PostScript is a programming language and PostScrip files in fact are programs executed on the printer.
In contrast to PostScript, PDF is not a programming language. When converting PostScript to PDF (or anything else), you actually have to run the PostScript program and record the graphic primitive calls, executed during the execution of the PostScript program.
This general approach is needed, when you want to convert PostScript programs from any source to PDF.
But you wrote, that you are creating the PostScript code yourself. Perhaps your PostScript program is just a linear sequence of calls to drawing primitives and does not use anything like subroutines or control structures.
If not, it might be easy to change your generator to do those computation at creation time,that currently are performed at print time. You would end up in a linear sequence of calls to drawing primitives.
When there are no more computations done at print-time, it should not be too hard to directly create PDF instead of PostScript. This answer mentions an open source PDF generation library, that uses an MIT style license.
The AGPL licence for Ghostscript would require you to make your source open, yes. However Ghostscript is dual licenced, in addition to the AGPL licence you can purchase a commercial licence, which doesn't require you to open source your own code.
Rather than converting to PDF you can, of course, also simply use Ghostscript to render the PostScript to a bitmap, its usually pretty easy to wrap a viewer around that.
I should point out that there are other companies offering commercial licences for PostScript interpreters which are capable of creating PDF files and/or rendering PostScript. Adobe is the obvious one, there's also Global Graphics.
These days there are not many players left in the field, if you want to handle PostScript, and the AGPL or similar licences won't suit you, then you will need to go commercial.
actually i'm thinking of creating a cool interface for my programming assignment , so i go around searching on how to do it so that such an effect can be create , below is the image .
The Question
1.)What is needed in order to create a program that run pseudographic(semigraphic or whatever they called it) that has menu like BIOS wizard did??I always see some program run in console but it could have graphical-like looking , for example blue environment , and user can use keyboard to choose a list of setting in a menu.
Thanks for spending time reading my question.
It's called Text-based user interface. There're several libraries for doing this. I think this is what you're looking for. :)
Cross platform, Interactive text-based interface with command completion
http://www.gnu.org/s/ncurses/
Ncurses(or maybe pdcurses) is probably what you need.
In the days of 16-bit Windows console windows used to support ANSI escape sequences (via the ansi.sys driver), but they no longer do.
For the apparent line graphics you need to use a platform specific solution anyway, so I recommend just writing an abstraction (functions, class) over the Windows APIs console functions.
The line graphics is done by using characters from the original IBM PC character set, codepage 437. At first you can just hardcode the various patterns. In order to make it seem more like line drawing to the code, or from the code's perspective, so to speak, you'll have to abstract things again. As I remember there is some partial but not complete system in the original codepage 437 character codes. But for Windows console you will need to use the Unicode character codes, which probably do not preserve the original system, so perhaps just define a map where these graphics characters are placed more systematically.
Possibly that already exists.
If you don't care about portability, the Windows API for this can be found here. It will supply all the functions you need, without the need to pack additional libraries with your application.
You can also look in to graphics.h, a non-standard Borland extension that a lot of older graphical games used to use. It goes far beyond the normal limits of the console, but is only supported by 16 bit systems, of which Microsoft has all but removed support for from Windows. You'd also need an ancient Borland compiler, or an emulation, though you probably want the original look and feel.
I am currently developing a C++ program that does all the mathematical calculations, prints items to the screen that is scanned in by an RFID Reader, and allows the user to select a payment method. (Basically using RFID tags to replace barcodes)
I have started writing my C++ code for a keyboard entry and have no idea how to take an input from my RFID reader into my program. My RFID Reader is a DLP-RFID1 from it comes with some demo software and drivers. I got it working with windows 7 last week on the demo software(a GUI using Microsoft Visual Studio).
My question is can I take the input from my Demo GUI and some how use that as my input for my C++ program? If I can can some one push me in the right direction by links, pointers, reading material?
Also I have basic C++ experience. I am teaching myself how to program in C++ and right now only know print statements, while loops, switch/case, math functions, and etc.
That is a very specific question about hardware and software of that vendor an not really general knowledge. However, those types of devices, in my past experience with bar code readers and such, usually have a driver that comes with them which allows you to set them up as an actual keyboard (for example, you could even go into a text editor and capture the codes). If you can set them up like that, then reading them is nothing more than reading stdin. For example, cin >> stringVariable;
Assuming that you have demo software in C++:
The demo software should link against one or more libraries that comes with the demo, and include a header that declares the functions in the library. You have to (at minimum) include this header and link against that same library, and use those libraries. The demo will help you understand which functions you need to call and how.
As already said it is very dependent on how they want you to use it but some general guide lines.
Look for header file that came with their demo ( ends in ".h" or ".hpp")
you will need to #include that in your project at the very minimum
Look for a .lib file. you will need to link that to your file. With gcc you would type something like G++ -l[libname].
With MSVS there are two ways i know of. You will need to right click the project in the sidebar. Click something like options or preferences. Expand linker options. Add the library.
or you can type #pragma comment(lib, "filename.lib") in your file near your includes
If there is a .dll (windows) or .so(Linux) file you can dynamically link it. There are many ways to do this. Google search for C++ Dynamic link libraries should be some help. As a newbie try to stick with Static Linking first. that would be another good keyword to search for. The best tutorial on dynamic linking for windows i have found is actually in assembly. but its all Win32 function calls anyways so its not hard to understand. Icz DLL tutorial
I like to print a document. The content of the document are tables and text with different colors. Does a lightwight printer-file-format exist, which can be used like a template?
PS, PDF, DOC files in my opinion are to heavy to parse. May there exist some XML or YAML file format which supports:
Easy creation (maybe with a WYSIWYG-Editor)
Parsing and manipulation with Library-Support
Easy sending to the printer (maybe with Library-Support)
Or do I have to do it the usual way and paint within a CDC?
I noticed you’re using MFC (so, Windows). In that case the answer is a qualified yes. In recent versions of Windows, Microsoft offers the XPS Document API which lets you create and manipulate a PDF-like document using XML, which can then be printed using the XPS Print API.
(For earlier versions of Windows that don’t support this API, you could try to deal with the XPS file format directly, but that is probably a lot harder than using CDC. Even with the API you will be working at a fairly low level.)
End users can generate XPS documents using the XPS print driver that is available for free from Microsoft (and bundled with certain MS products—they probably already have it on their system).
There is no universal language that is supported across all (or even many) printers. While PCL and PS are the most used, there are also printers which only work with specific printer drivers because they only support a proprietary data format (often pre-rendered on the client).
However, you could use XSL-FO to create documents which can then be rendered to a printer driver using library support.
I think something like TeX or LaTeX (or even troff or groff) may meet your needs. Google them and see.
There are also libraries to render documents for print from HTML source. Look at http://libharu.sourceforge.net/ for example. This outputs a printer-ready .PDF
A think that Post Script is a really good choice for that.
It is actually a very simple language, and it must be very easy to parse becuse it is stack-oriented. Then -- most printers supprort it, and even if you have no support you can use GhostScript to convert for many different formats (Consider GS as a "virtual PS supporting printer").
Finally there are a lot of books and tutorials for the language.
About the parsing -- you can actually define new variables and functions in PS. So, maybe, your problem can be solved (almost) entirely using PS.
HTML + CSS can be printed -- properly. CSS was designed to support this with the media attribute to specify that your CSS is for printer layout, not for screen layout. Tools like PRINCE (free + commercial versions) exist to render this for printing.
I think postscript is the markup language used by printers. I read this somewhere, so correct me if postscript is now outdated.
http://en.wikipedia.org/wiki/PostScript
For more powerful suite you can use Latex. It will give options of creating templates where you can just copy the text.
On a more GUI friendly note, MS-Word and other word processors have templates. The issue is they are not of a common standard or markup.
You can also use HTML to render stuff in a common markup but it will not be very printer friendly.