We are developing a software on Hi3536 processor based board. The SDK provided by HiSilicon comes with samples for developing user interface using frame buffer API - which is too low level. i.e., to design Combo Box, Text box, we have to write code from Scratch.
We are now trying to use QT. Not sure what other vendors do use for developing software on Hi3535 or Hi3536.
Can somebody suggest which SDK is most suitable for developing user Interface on HiSilicon processor based boards ?
We referred the sample code given in the following link and we would bring up the GUI successfully in Hi3536 using QT 5.6 - http://bbs.ebaina.com/thread-8217-1-1.html.
Please note that you need to use Google translator to translate the text in chinese.
In a past job, a few years ago, I worked on a GUI for an older Hisilicon chip based board.
I greatly enjoyed using Qt for Embedded Linux, version 4.8 on Linux framebuffer.
As far as I remember, be sure to study the Hisilicon documentation on how the framebuffers can/must be initialized and used. Hisilicon SDK used to contain also some sample programs with source code, there should be one that deals with framebuffers too.
My knowledge of Qt for Embedded is stuck at 4.8, I know version 5.x has radically re-designed that part, but I can't help you on details related to Qt5.
I try to developing simple scada system with C++ in Qt. I want to control hardware or get status(or something) of hardware and send to server or router.(actually my application control softwares too)
And in finish: Qt have a good tools for scada systems?
As of QT 5.7 there is a new Serial Bus library for use with protocols such as CAN BUS and MODBUS, you can read more about it here:
http://doc.qt.io/qt-5/qtserialbus-index.html
For your scenario, QT has plenty of Network support that you could use for your interface, depending on what your hardware specification is. QT does not compare to 'out of the box' SCADA solutions such as a Siemens SCADA system, however developing one based on QT could give you much more flexibility. Depending on what you are trying to achieve, this becomes a trade-off between productivity/time to market and flexibility/value add.
Also there is an opensource qt scada toolkit https://github.com/IndeemaSoftware/QSimpleScada, for visualization.
Both Windows (Win32 API) and OS X (Cocoa) have their own APIs to handle windows, events and other OS stuff. I have never really got a clear answer as to what Linux’s equivalent is?
I have heard some people say GTK+, but GTK+ being cross platform. How can it be native?
In Linux the graphical user interface is not a part of the operating system. The graphical user interface found on most Linux desktops is provided by software called the X Window System, which defines a device independent way of dealing with screens, keyboards and pointer devices.
X Window defines a network protocol for communication, and any program that knows how to "speak" this protocol can use it. There is a C library called Xlib that makes it easier to use this protocol, so Xlib is kind of the native GUI API. Xlib is not the only way to access an X Window server; there is also XCB.
Toolkit libraries such as GTK+ (used by GNOME) and Qt (used by KDE), built on top of Xlib, are used because they are easier to program with. For example they give you a consistent look and feel across applications, make it easier to use drag-and-drop, provide components standard to a modern desktop environment, and so on.
How X draws on the screen internally depends on the implementation. X.org has a device independent part and a device dependent part. The former manages screen resources such as windows, while the latter communicates with the graphics card driver, usually a kernel module. The communication may happen over direct memory access or through system calls to the kernel. The driver translates the commands into a form that the hardware on the card understands.
As of 2013, a new window system called Wayland is starting to become usable, and many distributions have said they will at some point migrate to it, though there is still no clear schedule. This system is based on OpenGL/ES API, which means that in the future OpenGL will be the "native GUI API" in Linux. Work is being done to port GTK+ and QT to Wayland, so that current popular applications and desktop systems would need minimal changes. The applications that cannot be ported will be supported through an X11 server, much like OS X supports X11 apps through Xquartz. The GTK+ port is expected to be finished within a year, while Qt 5 already has complete Wayland support.
To further complicate matters, Ubuntu has announced they are developing a new system called Mir because of problems they perceive with Wayland. This window system is also based on the OpenGL/ES API.
Linux is a kernel, not a full operating system. There are different windowing systems and gui's that run on top of Linux to provide windowing. Typically X11 is the windowing system used by Linux distros.
Wayland is also worth mentioning as it is mostly referred as a "future X11 killer".
Also note that Android and some other mobile operating systems don't include X11 although they have a Linux kernel, so in that sense X11 is not native to all Linux systems.
Being cross-platform has nothing to do with being native. Cocoa has also been ported to other platforms via GNUStep but it is still native to OS X / macOS.
Strictly speaking, the API of Linux consists of its system calls. These are all of the kernel functions that can be called by a user-mode (non-kernel) program. This is a very low-level interface that allows programs to do things like open and read files. See http://en.wikipedia.org/wiki/System_call for a general introduction.
A real Linux system will also have an entire "stack" of other software running on it, in order to provide a graphical user interface and other features. Each element of this stack will offer its own API.
To aid in what has already been mentioned there is a very good overview of the Linux graphics stack at this blog: http://blog.mecheye.net/2012/06/the-linux-graphics-stack/
This explains X11/Wayland etc and how it all fits together. In addition to what has already been mentioned I think it's worth adding a bit about the following API's you can use for graphics in Linux:
Mesa - "Mesa is many things, but one of the major things it provides that it is most famous for is its OpenGL implementation. It is an open-source implementation of the OpenGL API."
Cairo - "cairo is a drawing library used either by applications like Firefox directly, or through libraries like GTK+, to draw vector shapes."
DRM (Direct Rendering Manager) - I understand this the least but its basically the kernel drivers that let you write graphics directly to framebuffer without going through X
I suppose the question is more like "What is linux's native GUI API".
In most cases X (aka X11) will be used for that: http://en.wikipedia.org/wiki/X_Window_System.
You can find the API documentation here
XWindows is probably the closest to what could be called 'native' :)
The linux kernel graphical operations are in /include/linux/fb.h as struct fb_ops. Eventually this is what add-ons like X11, Wayland, or DRM appear to reference. As these operations are only for video cards, not vector or raster hardcopy or tty oriented terminal devices, their usefulness as a GUI is limited; it's just not entirely true you need those add-ons to get graphical output if you don't mind using some assembler to bypass syscall as necessary.
Wayland
As you might hear, wayland is the featured choice of many distros these days, because of its protocol is simpler than the X.
Toolkits of wayland
Toolkits or gui libraries that wayland suggests are:
QT 5
GTK+
LSD
Clutter
EFL
The closest thing to Win32 in linux would be the libc, as you mention not only the UI but events and "other os stuff"
GUI is a high level abstraction of capability, so almost everything from XOrg server to OpenGL is ported cross-platform, including for Windows platform. But if by GUI API you mean *nix graphics API then you might be wandering around "Direct Rendering Infrastructure".
I want to know what operating system NOKIA smart-phones use? Which programming language is used to write it and is it possible to do kernel level programming for these systems? Can we use C codes to change the system software? Libraries are available or not? I have never coded for mobile phones. So if possible give me a link to the pages where these topics are discussed in detail. Thanks in advance.
EDIT: I want the details for NOKIA s60 v3 and v5.
From http://en.wikipedia.org/wiki/Nokia_S60:
The S60 Platform (formerly Series 60 User Interface) is a software platform for
mobile phones that runs on Symbian OS.
The S60 software is a multivendor standard for smartphones that supports
application development in Java MIDP, C++, Python and Adobe Flash.
Note that you'll have to register as a developer or jailbreak the phone:
(S60v3) uses a hardened version of Symbian OS (v9.1), which has mandatory
code signing. In S60v3, a user may install only programs that have a
certificate from a registered developer, unless the user disables that
feature or modify the phone's firmware through third-party hacks that
circumvent the mandatory signing restrictions.
Nokia has Symbian kernel (i don't know about them much) and LINUX kernel like the one in N900 (using maemo and meego) though N900 is considered as a tablet-pc more than a smartphone and it has lots of modified kernels .
I want to start learning drivers programming under windows .
I never programed drivers , and i am looking for information how to get started .
Any tutorials ,links ,book recommendations , and what development tool kit i should start with ? (WDF will be good one ?)
I really want to program following clock link text
Thanks for your help .
I would start by downloading the windows driver kit (WDK).
Afterwards, you decide which kind of driver you want. FileSystem driver? (probably not), RS-232 driver? usb driver? They all follow different rules and quirks.
The WDK comes with examples drivers for most kinds of drivers and should get you on track fast.
To interact with USB hardware you would be best served by looking at WinUSB or the Usermode Driver Framework. Usermode drivers are orders of magnitude easier, being able to use a C++/COM(kind of) framework and a normal debugging environment.
Writing kernelmode drivers should be reserved for stuff like video card, disk, and other latency/throughput sensitive drivers.
An even easier method would be to use libusb-win32 which is a C library that makes talking to a USB endpoint almost as easy as writing data to a file.
Must see resource for windows driver development, of course as addition to the WDK mentioned by Eric.