Linux RAD/GUI Development

Kylix – Rapid Application Development (RAD),

GUI Development for Linux from Borland

by Leland Brode

ELB Software

elbrode2@attbi.com

Linux GUI Development

Presentation Outline

– Background on GUI Development– Overview of Kylix– Demo GUI Tools– Demo Delphi– Demo Kylix

by Leland Brode

ELB Software

elbrode2@attbi.com

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

“Visual Basic 6 Bible” - Smith Whistler, & Marquis

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 Programming Unleashed” – Kurt Wall - SAMS

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

“C/C++ Users Journal”, March 2001 – www.cuj.com

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, encapsulationhttp://www.engin.umd.umich.edu/CIS/course.des/cis400/index.htmlhttp://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 definitiontype 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 Arraystype 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 – ComparisonPascal…var i : Integer;begin i := 1;

C++… int i; i = 1;

Perl…my $i;$i = 1;

Kylix

Pascal Language – Comparison

Pascal…

var

i : Integer;

name String[20];

begin

if i = 1 then

begin

name := ‘Leland’;

i := i + 1;

end;

end;

C++…

int i;

char name[20];

if(i == 1) {

strcpy(name, “Leland”);

i = i + 1;

}

Perl…

my $i;

my $name;

if($i == 1) { $name = ‘Leland’; $i = $i + 1; }

Kylix

Pascal Language – Comparison

Pascal…

while i < 100 do Inc(i);

C++…

while (i < 100) i++;

Perl…

while ($i < 100) { $i++;}

Kylix

Pascal Language – ComparisonPascal…

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/download

s/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…