Embedded Linux Graphics Quick Reference Guide

http://www.linuxfordevices.com/c/a/Linux-For-Devices-Articles/Embedded-Linux-Graphics-Quick-Reference-Guide/

Embedded Linux Graphics Quick Reference Guide

By Rick Lehrbaum
2002-02-28 

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When you install Linux on a desktop PC, you normally choose from among a few "standard" graphics support components. You'll likely use the X Window system (XFree86 or ) as the display interface foundation (with associated Linux drivers to control the hardware), 

target="_blank">GNOME or KDE as a windowing environment, and one of several full-featured browsers such as Firefox, Konqueror, or Opera. 

But the typical desktop Linux "graphics stack" isn't well suited to embedded Linux applications. Embedded devices frequently have highly constrained resources and can afford neither the program storage space nor the memory footprint of desktop graphics software. For example, embedded devices may easily have as little as 2 to 16 MB of Flash disk from which to load programs, and 4 to 32 MB of RAM memory in which to run them. But the typical desktop graphics components are notorious resource hogs . . .

• X Window System: 5MB RAM, 16MB disk
  
• GNOME: 14MB RAM, 95MB disk
  
• KDE: 11MB RAM, 96MB disk
  
• Mozilla: 12MB RAM, 26MB disk

All that memory costs money, requires board space, and consumes power. Then too, embedded systems frequently have unique needs that can't be met by desktop graphics system components. These include the requirement for a customized look and feel, control over what functions are available to users, speed of loading, unusual display or input device characteristics, etc.

To satisfy the demands of the rapidly emerging embedded Linux marketplace, a growing number of graphics support projects and products have sprung up. Targeted environments run the full gamut -- including fixed, portable, and mobile systems -- and the applications range from hand-held consumer products like PDAs and cell phones, to medical instruments, factory automation, and commercial airlines cockpit displays.

With this in mind, LinuxDevices.com has created The Embedded Linux Graphics Quick Reference Guide. We intend to continually update this guide -- so be sure to check back frequently for the latest info.

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Open source Embedded Linux Graphics System Software

---

Dillo -- Dillo is a very small (less than 300KB), fast, Open Source multi-platform web browser that's written completely in C and built on GTK+ libraries. Dillo's high efficiency and minimal library dependencies make it quite suitable for embedded apps. Dillo can be teamed up with an embedded webserver to completely eliminate the need for a window manager in an embedded device. -- details

DirectFB -- DirectFB is a thin library that provides developers with hardware graphics acceleration, input device handling and abstraction, integrated windowing system with support for translucent windows and multiple display layers on top of the Linux Framebuffer Device. It is a complete hardware abstraction layer with software fallbacks for every graphics operation that is not supported by the underlying hardware. -- details

The Familiar Project -- this open source PDA Linux project, which is an offshoot of the activities at handhelds.org, has collected together all of the key components of a complete Linux-based PDA computing platform. The Familiar distribution currently includes a Blackbox-based window manager, Agenda Computing's Fltk+ based PIM applications, an embedded Python implementation, system configuration and settings backup utilities, OpenSSH client and server, and a Debian-based ARM kernel. -- details

FBUI -- FBUI is a tiny GUI that resides inside the Linux kernel. The key concepts of FBUI are that firstly it is small; secondly that it is spartan, which is good; thirdly that it is just another driver; and fourthly that drivers belong in the kernel, not in userspace. details

GGI project -- the "General Graphics Interface" project is dedicated to development of fast, stable, open-source cross-platform multimedia API systems. Designed from the ground up with environments such as embedded systems in mind, GGI is fast, clean, abstract, dynamically modular and highly optimizeable. -- details

GPE Palmtop Environment -- this project aims to provide a Free Software GUI environment for palmtop/handheld computers running the GNU/Linux operating system. GPE uses the X Window System, and the GTK+ widget toolkit. -- details

GtkFB -- beginning with version 2.0, GTK+ will support rendering directly to the Linux framebuffer instead of using the X Window System. This is good for embedded systems and devices with limited resources, because it eliminates the overhead of an X server, while still taking advantage of the power of GTK+ and the large base of existing programs. -- details

handhelds.org PDA support -- want to create your own unique Linux PDA implementation? handhelds.org is for you! Early this year, Compaq created the Open Handheld Program, an initiative designed to stimulate innovation and research on handheld devices that resulted from the company's "Itsy" pocket computer project. To support this initiative, Compaq created handhelds.org -- a vendor neutral website dedicated to open source handheld development. Not surprisingly, Compaq's iPAQ PDA is used as the base platform for all these activities and, consequently, a iPAQ Linux port is available as freely available open source software. -- details

Matchbox -- a small foot-print window manager and associated applications, designed specifically for resource-constrained X11-enabled devices such as handheld computers, PDA's, set-top boxes, and consumer devices where display size, storage, CPU bandwidth, and input mechanisms are limited. Matchbox includes a window manager, a panel, a desktop, a shared utility library, and a number of small panel applications. -- details

Microwindows -- an Open Source project aimed at bringing the features of modern graphical windowing environments to smaller devices and platforms. Microwindows applications can be built and tested on the Linux desktop, as well as cross-compiled for the target device. -- details

NxZilla (formerly nanozilla) -- a set of libraries that allow Mozilla to be used with a NanoX server from the Microwindows project. -- details

OpenGL ES -- a light-weight, royalty-free embedded graphics standard that provides graphics API profiles for a broad range of embedded systems and devices, including handheld wireless devices, automotive and avionics displays, and multimedia consumer devices such as advanced digital TVs, set-top boxes, and game consoles. -- details

OpenGUI -- a fast, 32-bit, high-Level C/C++ graphics & windowing library/GUI built upon a fast, low-level x86 asm graphics kernel. It is under LGPL license. OpenGUI provides 2D drawing primitives and an event-driven windowing API for easy application development. -- details

PicoGUI -- small, portable client/server GUI designed to work on many types of hardware including handheld computers. Like the X Window System, it has a flexible client-server architecture. Unlike X, however, fonts, bitmaps, widgets, and anything else the application needs are built directly into the server. This sacrifices a small decrease in flexibility for an increase in speed and a large decrease in size. -- details

Qt/Embedded -- provides a full graphics stack, from the hardware interface to a full GUI tookkit. Although the API is identical to the popular Qt/X11 and Qt/Windows products, Qt/Embedded is not based on X11 and therefore it has substantially reduced memory requirements. Memory demands can be tuned to the range of 800 KB to 3 MB in ROM (Intel x86). Qt/Embedded is available as open source software, under the GNU General Public License (GPL), or can be licensed on other terms from its originator, Trolltech. -- details

Simple DirectMedia Layer -- an open source cross-platform multimedia development API/library designed to provide fast access to the graphics framebuffer and audio device. SDL is currently being applied to a number of Embedded Linux implementations such as Microwindows. details

Tiny-X -- a small footprint X Window server implementation for embedded systems. It was developed by Keith Packard of the XFree86 Core Team, sponsored by SuSE. The goal was to create something that would work well in a small memory footprint and, importantly, be robust in near out-of-memory situations. Typical X servers based on Tiny-X can fit in less than 1MB on x86 CPUs. The project has since forked into several projects, including KDrive, SmallX, and Integrated Tiny-X. 

ViewML -- a freely available, open source web browser targeted specifically at the embedded Linux platform. Currently, ViewML along with it's interface requires 2.1 MB of RAM, with a disk image of only 760K. -- details

WML Browser -- a project, sponsored by 5NINE to develop a browser which will allow any wireless device to have WAP functionality. It must support multiple protocol stacks (WAP 1.2.1, http), in differing environments, using differing input devices. The browser will work with framebuffer graphics. -- details

Xynth Windowing System -- a free software project to build a portable, embedded client-server windowing system. The Xynth Windowing System, released under the GPL, offers a lightweight GUI-capable windowing system usable in Linux-based embedded systems and devices, such as handhelds and set-top boxes. details

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"Commercial" Embedded Linux Graphics System Software

---

Access: Netfront browser -- an embedded browser designed for information appliances with modest memory and CPU performance. It requires less than 1.3MB ROM and 2MB RAM, supports full HTML 3.2 and selected features from HTML 4.0, frames, JavaScript, cookies, Web-printing and multi-languages. Its modular and scalable architecture can be enhanced by application-specific modules and plug-ins. An independent user interface layer and design tool allows device manufacturers to create a unique look and feel for their product. -- details

ANT: Freesco browser -- a small memory footprint, standards-compliant JAVA based browser that enables OEMs to quickly and easily design a branded interface for Internet appliances. It is platform-independent, so it can be used with any hardware or operating system environment (including various implementations of Embedded Linux). -- details

Century Software: PIXIL PDA and Microwindows -- a complete PDA system including an operating environment, PIM applications, email client, web browser, and a set of multimedia applications. The Microwindows graphical windowing system (described above) is at the core of the PIXIL PDA solution. -- details

Espial: Espial Suite -- a complete, 100% Java application layer that sits independently from the operating system and JVM on the upper layer of a device stack and has been used extensively with Linux. Espial Suites include the following applications: Espial DeviceTop graphical OSGi client, Espial Escape web browser, Espial Ebox email client, and Espial Espresso lightweight GUI toolkit.

Feynman Software: MiniGUI -- [Oct. 26, 2005] -- a dual-licensed (GPL or commercially licensable) project to create a small windowing system support library for embedded systems and devices, which offers the equivalent window management functions of Win32 APIs. -- Details here (article), here(link), and here (news).

Fluffy Spider: FancyPants -- [Oct. 26, 2005] -- This commercial graphics framework from Australian ISV Fluffy Spider is a set of lightweight special effects software for user interfaces (UIs). FancyPants supports skinning, overlays, and fancy effects, and targets media-centric consumer and mobile devices, such as POS (point-of-sales/service) systems, set-top boxes, and mobile phones. Details here, here, and here. 

NetClue: Clue WBC browser -- a compact, modular, and platform independent 100% Java browser. Clue WBC supports Unicode for international characters, smooth scrolling, streamline parsing and display, web printing, customizable user-interface, and is WAP compliant. Other features include support for HTML 4.0, XML, HTTP 1.0 and 1.1, CSS, DOM, cookies, JavaScript, Java Applets. -- details

Swell Software: LinuxPEG -- LinuxPEG is an embedded GUI library and development toolkit designed specifically for embedded systems. The LinuxPEG library is designed to run on any Linux distribution and its development tools run in the X11 development environment. LinuxPEG, which is available under license, is small footprint, completely ROMable, includes full C++ source code, and is royalty fee. -- details

Trolltech: Qtopia and Qt/Embedded -- Qtopia is a mobile device window environment and application suite for PDAs, palmtop computers, Internet appliances, and similar devices. Qtopia is based on Qt/Embedded (described above), and includes PIM applications, Internet clients, entertainment and games, utilities, and more. Qtopia/PDA is available in commercial or open source licenses, while Qtopia Phone Edition is commercial-only. -- details

Linux RAD/GUI Development

Kylix 

Rapid Application Development (RAD), GUI Development for Linux from Borland

Linux GUI Development

Presentation Outline

Background on GUI Development

Overview of Kylix

Demo GUI Tools

Demo Delphi

Demo Kylix

Linux GUI Development

Kylix

RAD/GUI tool for Linux

Port of Delphi for Windows 

Runs on Linux

Builds, compiles native Linux applications

Cross platform – Windows/Linux

GUI Dev Background

Windows 3.0 – 1990

Generates Messages

Basic, COBOL, C

All Text

Visual Basic – 1991

First GUI Dev Tool

Event Handlers – code that runs before or after an Event

Draw window instead of code it

Most widely used language

GUI Dev Background

Other GUI Dev Tools

PowerBuilder

Visual Age

Digitalk, ParcPlace Smalltalk

Forte  ( now at Sun)

Visual C++

Borland C++

Borland Delphi

Borland C++Builder

--------------------------

Visual Café  - Java

JBuilder  - Java

Linux Developement

GNU Linux Toolkit

GCC

Compiles C, C++, Objective C, Fortran

Handles Front-ends for Pascal, Modula-3, Ada

Distributed with Linux

Perl, Shell scripting

Linux Developement

Qt Class Library

C++

Cross Platform 

Qt/Windows

Qt/X11 (Linux, Solaris, HPUX, AIX, etc)

Qt/Mac

GPL – Free for non-commercial apps

Qt was used to build KDE

from Trolltech in Norway

www.trolltech.com

Linux Development

Qt Class Libray

Qwidget base class

Event Handlers

  mousePressEvent (QMouseEvent &);

  mouseMove Event (…

  mousePressEvent (…

  enterEvent (…

Class QMouseEvent : public Qevent {

 public:

   int x();

   int y();

   int button();

   int state();

Linux Development

Open Source IDE’s

KDevelop – www.kdevelop.org

KDE Studio – www.thekompany.com/projects/kdestudio

Code Crusader – www.newplanetsoftware.com

VDK Builder – vdkbuilder.sourceforge.net

Source-Navigator – sources.redhat.com/sourcenav

Delphi Background

Borland’s Delphi =

Pascal, plus

Borland’s implementation of OO in Pascal, plus

GUI  IDE, plus

Visual Component Library (VCL)

              - encapsulates Windows controls

Delphi

Pascal

Pascal dev by Niklas Wirth (Swiss, 1970)

Versions: U of C San Diego, Borland

Borland’s Turbo Pascal 1.0 - ?

Turbo Pascal 3.0 for DOS - 1985

Object Extensions to Pascal 5.5 - ?

Turbo Pascal for Windows - 1991

Delphi - OO Pascal – 1995

polymorphism, inheritance, encapsulation

http://www.engin.umd.umich.edu/CIS/course.des/cis400/index.html

http://www.emsps.com/oldtools/borpasv.htm

Delphi

GUI Integrated Development Environment

Based on Visual Basic model

Delphi

IDE

project manager

keeps track of all source files for a project

code editor

code completion

GUI form designer

integrated debugger

watch variables

change variables

breakpoints

step through code

Kylix

Port of Delphi to Linux

OO Pascal

Delphi IDE

native Linux compiler

Class Library - CLX

Object wrappers for Qt widgets

Borland chose Qt over GTK+

Delphi’s VCL re-engineered to CLX

Kylix

Class Libraries

CLX is to Kylix

VCL is to Delphi, C++Builder

MFC is to Visual C++

Qt is to KDE

GTK is to GNOME

CLX runs on Linux and Windows

Delphi

VCL Class Library

Object wrappers for Windows Controls

TObject

  |

TControl  __

  |                 |

TForm       TButton

Kylix

CLX Class Library

Object wrappers for Qt Widgets

TObject

  |

TControl  __

  |                 |

TForm       Tbutton

CLX also in Delphi 6, and C++Bldr for cross platform

Kylix

Pascal Language

Source File = Unit

Units -> compile, link -> executable

code - .pas file

form - .dfm file

     ( each form has a .pas file )

Kylix

Pascal Language

Data types

Integer – 2147483648 to 2147483647

Cardinal  0 to 4,294,967,785

Byte         0 to 255

Double     floating point

Currency  

Arrays –

MyArray : array[0..10] of Integer; // fixed

MyArray : array of Integer;     // dynamic

SetLength(MyArray, length);  // allocates memory for dynamic array

MyArray[length-1] := 1,024   // assignment

Kylix

Pascal Language

String – dynamic

Concat, Copy, Delete, Insert, Length, Pos, SetLength

Pointers

Exceptions

Try-except (same as try-catch in java, c++)

File IO

function – returns value

procedure – no return value

Kylix

Pascal Language - function

function Factorial(Number : Cardinal):  Int64;

var

  N : Cardinal;

begin

  Result := 1;

  for N := 2 to Number do

    Result := Result * N;

end;

Kylix

Pascal Language – class definition

type

 TAccount = class

  private

   fNumber : Cardinal;

   fBalance : Currency;

  public

   procedure WithDraw(Amount : Currency);

  end;

TSavingsAccount = class (TAccount)

  private

   fReturnCheck : Boolean

  end;

TCertificateof Deposit = class(TSavingsAccount)

  private 

   fTerm : Cardinal;

  end;

Kylix

Pascal Language – use classes

var

  CD1, CD2 : TAccount;

begin

  CD1 := TCertificateofDeposit.Create;

  CD2 := TCertificateofDeposit.Create;

  …

  CD1.WithDraw(100.00);

  …

  …

  CD1.Free;

  CD2.Free;

end;

Kylix

Pascal Language – Records and Arrays

type

  PersonType = record

    LastName  : String[10];

    FirstName  : String[10]; 

    EmployeeNumber  : Integer;

  end;  { Persontype }

MyArrayType = array [1..5]  of PersonType;

var

  PersonArray  :  MyArrayType;

begin

  PersonArray[1].FirstName := ‘Donald’;

  PersonArray[1].LastName := ‘Duck’;

  …

Kylix

Pascal Language – Components and Arrays

var

  ButtonArray : array of TButton;

  i, Num : integer;

begin 

  Num :=0;

  for i := 0 to Self.ComponentCount –1 do       // ‘Self’ same as ‘this’ in C++

  if Self.Components[i] is TButton then 

    begin

      Inc(Num);

      SetLength(ButtonArray, Num);

      ButtonArray[Num-1] := TButton(Components[i]);

    end;

end;

Kylix

Pascal Language – Comparison

Pascal…

var

  i :  Integer;

begin

  i := 1;

C++…

 int  i;

 i = 1;

Perl…

my $i;

$i = 1;

Kylix

Pascal Language – Comparison

Kylix

Pascal Language – Comparison

Pascal…

 while i < 100 do  Inc(i);

C++…

 while (i < 100)   i++;

 

Perl…

 while ($i < 100) { $i++;}

Kylix

Pascal Language – Comparison

Pascal…

 for i := 0 to 100 do  begin

   if  i = 50 then Break;

   end;

C++…

 for( i = 0; i <= 100; i++)

   if( i == 50) break;

 

Perl…

 for( $i = 0; $ i <= 100; $i++)  {

  if( $i == 50) last;  

  }

Kylix

Qt

access to all Qt Widget public Events and Properties

Libc

access to all ‘libc’ functions

Kylix

GUI Applications

Database Applications

Console Applications

Web Server Applications

Kylix

Linux Multiprocessing apps

separate memory, communicate via file system

Linux Multithreading apps

same memory, share resources

TThread base class

Kylix

GUI Applications - (CLX TForm class)

Form1.Canvas.Brush.Color := clRed;

or                          := RGB(255, 0, 0);

Form1.Canvas.Rectangle(10, 10, 100, 100);

Form1.Canvas.Pen.color := clBlack;

Form1.Canvas.Pen.Width := 2;

Form1.Canvas.MoveTo(0, 20);   // draw line

Form1.Canvas.LineTo(60, 20);   // draw line

Form1.Canvas.Font.Name := ‘Arial’;

Form1.Canvas.Font.Size := 24;

Form1.Canvas.TextOut(30,1, ‘Hello World’);  // write text

Kylix

Database Applications

db : TClientDataSet

db.FileName := ‘/xxx/nnn/yyy’;

db.Open;

db.Locate(‘EmpNum’, ‘124433’, []);

mystring := db.FieldValues[‘LastName’];

Kylix

Database Applications

db : TSQLDataSet

db.CommandText := ‘select * from ….’;

db.Open;

Kylix

Database Applications

data aware controls

automatically fill in data value from database

automatically update data value to database

controls can be ‘Active’ while building form

Kylix

Web Applications

-  raw CGI

     or

- TWebApplication

       |

  TCGIApplication

Kylix

Kylix Versions

Kylix 1, 2, 3  (I am using 2)

Kylix 1, 2 – Delphi (Pascal)

Kylix 3 – add C++ Builder (C++)

Kylix Enterprise -  Web, Middleware objects, Database objects

Kylix Professional -  Database objects

Kylix Open Edition – Build open source apps licensed under GNU General Public License

Kylix

Technical Requirements – Kylix 2

Pentium 400 Mhz ( I am using 366 Mhz)

128MB RAM ( I am using 192MB)

175MB disk space

Red Hat 6.2 or higher (I am using 7.2, Kernel 2.4.7)

SuSE 7.0 or higher

Kylix

Kylix Download

http://www.borland.com/products/downloads/download_kylix.html#

Kylix 3 currently available

Kylix 2  ??

Kylix

FreeCLX Project

Open Source CLX Class Library

available at SourceForge.net

includes BaseCLX, VisualCLX, and DataCLX classes (brings full functionality to  Kylix Open Edition ?)

lack of detailed information on FreeCLX

Kylix

Bibliography

“Visual Basic Bible”, Smith, Whistler, & Marquis

“Delphi in a Nutshell”, Ray Lischer, O’Reilly

“Linux Programming Unleashed”, Kurt Wall, SAMS

“Object Pascal Language Guide”, Borland Delphi 3 Documentation

“Teach Yourself Delphi in 21 Days”, Osier, Grobman, & Batson, SAMS

“Kylix: The Professional Developer’s Guide and Reference”, Jon Shemitz, Apress

“Mastering Kylix 2”, Cantu & Barbini, SYBEX

“Borland Kylix Developer’s Guide”, Calvert, Calvert, Kaster, & Swart, SAMS

“In the Trenches”, by Dale Fuller, LINUX Magazine, January 2002

Product Review of Kylix 2, LINUX Magazine, May 2002

“Kylix vs. gcc Development” http://community.borland.com/article/0,1410,28555,00.html

“Technical Overview of the Kylix Compiler” http://community.borland.com/article/0,1410,28561,00.html

“Apache Development with Kylix” http://community.borland.com/article/0,1410,28556,00.html 

Kylix and Qt, excerpts form Kylix newsgroup http://community.borland.com/article/0,1410,21850,00.html

Kylix newsgroup – “borland.public.kylix,non-technical”

Kylix

product demo…