FLTK-Tutorial.pdf

FLTK 1.3.0 Tutorial

This a tutorial can be used by the absolute FLTK beginner. In the course of the tutorial

the most common widgets will be explained and you will gain a good overview of the FLTK

toolkit. The examples have been kept as short and simple as possible so it will not take a

lot of time to understand them.

I ported FLTK to DOS and took the screenshots in DOS. The examples will work without

any changes on any platform FLTK can be used for.

Contents

1. Introduction

2. The FLTK structure

3. Installation of the FLTK toolkit

4. The first program

5. The button widget

6. Callback functions

7. Input and Output boxes

8. The editor widget

9. The browser widget

10. The menubar widget

11. Toolbar and drop-down list

12. A dialog window with radio buttons

13. Displaying images

14. Grouping widgets in Tabs

15. Handling mouse events part1

16. Handling mouse events part2

17. Displaying the events generated by FLTK

18. The tree widget

19. References

1. Introduction

FLTK shall stand for Fast Light ToolKit and is a GUI written in C++ for C++ programs. It

can be used on Linux, Windows, Apple Mac and DOS. FLTK has lower memory

requirements than other toolkits and can be linked as a static library with an application. It

can also be compiled as a shared library too.

FLTK has been in development over many years and the currently latest version is 1.3.0.

There had been a version 2.0 before but unfortunately this branch never got out of alpha

and development of that has been canceled now in favor of version 1.3.0. So 1.3.0 is the

version any new development should be based on.

2. The FLTK structure

Being written in C++ FLTK defines a class for every widget. GUI toolkits usually refer to all

sorts of objects, like buttons, input boxes, scrollbars etc as widgets.

The base class for all widgets is the Fl_Widget class. All widgets are subclasses from the

Fl_Widget class or again subclasses from these subclasses.

This are some of the direct subclasses of Fl_Widget: Fl_Box, Fl_Button, Fl_Group,

Fl_Input_, Fl_Menu_, Fl_Progress and Fl_Timer.

A subclass of Fl_Group again is Fl_Window, a class you will be using in every program.

An example of a long tree of subclasses is FL_Radio_Round_Button. As shown below this

button type is a subclass of Fl_Round_Button which is a subclass of Fl_Light_Button

which is again a subclass of Fl_Button.

The FL_Radio_Round_Button class has access to all methods or functions defined in one

of the classes it is a subclass of. You will have to check in the documentation whether any

of these classes has a method which does what you want to achieve.

There is also the FL global (static) class containing state information and global methods

for the current application.

In addition several non-class functions and symbols are provided, they are grouped into

header files with lower-case names.

3. Installation of the FLTK toolkit

a.) Linux

download the latest source, unpack it and then do configure,make,install. Then compile

your program e.g. as:

"fltk-config' --compile example.cxx"

or if you use images:

"fltk-config --use-images --compile example.cxx"

Further details can be found in the FLTK manual here:

http://www.fltk.org/doc-1.3/basics.html There is a section called "Compiling Programs with

Standard Compilers" further below on that page.

You can also read the README.Unix.txt file that is included in the FLTK source code

package. This also covers using FLTK with the Code::Blocks IDE.

b.) Windows

There are a number of alternatives to develop FLTK programs on Windows. The FLTK site

just has the source code so you either compile FLTK on Windows or download binaries

from the net as described below.

b1.) DEV-CPP

This is an IDE which uses MinGW to generate C and C++ programs on Windows. You can

download it here: http://www.bloodshed.net/dev/devcpp.html

Then you can download a "devpak" of FLTK 1.3.0 here:

http://nanox-microwindows-nxlib-fltk-for-dos.googlecode.com/files/fltk-130-1gp.DevPak

After starting DEV-CPP select "Tools" from the menu and "Package Manager". In there

select "Install" and open the downloaded DevPak to install it.

Then open a new project (File->New->Project), select the "GUI" tab and in there select

"FLTK". After a few questions how to name the project and the program file this will come

up with the default FLTK program which you can build and run by entering "F9".

b2.) Code::Blocks

This is another good IDE using MinGW. If you open a new project, you can select the

FLTK icon in there. After that you will have enter the location of the FLTK files. You can

download the binaries here: http://code.google.com/p/fltkwinbin/downloads/list

and then put them into a directory of your choice. Then enter that path into the

Code::Blocks' input box. Code::Blocks just needs the path to the root FLTK directory where

bin, include, lib, share and test are in.

You can then select file->new->empty file and save that as main. Then cut and past one of

the examples in this tutorial into the edit window and save the file.

Then right-click on the project, select "Build options" and add the following libraries to the

linker settings:

libcomctl32.a, libcomdlg32.a, libole32.a,libgdi32.a and libuuid.a. You find these libraries in

the "CodeBlocks\MinGW\lib\" directory.

After this select Build->Run or CTRL-F10 that should build the project and run it.

b3.) Compile FLTK on Windows with MinGW.

Both DEV-CPP and Code::Blocks install MinGW on your PC. If you install MinGW after

you already have installed one of these IDEs Windows will point to the new MinGW

directory and and that causes problems with DEV-CPP.

Details how to compile FLTK with MinGW are in the file README.MSWindows.txt which is

included in the FLTK source code package.

It also described in there how to use FLTK with Cygwin.

You can also compile FLTK on Windows with Code::Blocks if you follow this tutorial:

http://gintasdx.althirius-studios.com/2011/08/tutorial-codeblocks-with-fltk.html

b4.) Microsoft Visual C++

This is covered in the file README.MSWindows.txt.

Further details can also be found here:

http://research.cs.wisc.edu/graphics/Courses/559-f2009/Main/Tutorial1

c.) Apple OS X

Please read the file README.OSX.txt which is included in the FLTK source code package.

d.) DOS

Download the DJGPP package from

http://code.google.com/p/nanox-microwindows-nxlib-fltk-for-dos/downloads/list ,

edit the start.bat file in there to your paths. The required FLTK libraries are already

included in the DJGPP package but can be downloaded from that site separately as well.

You can compile the examples either with this line (observe the line wrap here):

gpp -g -I/djgpp/include -o example.exe example.cxx -L/djgpp/lib -lfltk -lNX11 -lnano-X

-lfreetype

For the examples which load an image you have to add additional parameters to this line:

gpp -g -I/djgpp/include -o ex13.exe ex13.cxx -L/djgpp/lib -lfltk_images -lfltk -lNX11 -lnano-X

-lfreetype -ljpeg -lpng -lz

Or you enter a shell with "sh" and use the "fltk-config" script:

sh-2.04$ 'fltk-config' --compile example.cxx

sh-2.04$ 'fltk-config' --use-images --compile example.cxx

4. The first program

This tutorial starts with very simple examples. Some readers may consider them too

simple but those may read these parts more quickly.

Our first program just opens a window with a title. You can terminate the program by

closing the window with your mouse or pressing the ESC key.

To run this or any other example please copy the lines below and paste them into the

editor that you will use for compiling the code.

#include <FL/Fl.H>

#include <FL/Fl_Window.H>

int main()

{

// Create a window - width, height, label (=title)

Fl_Window win(400, 400, "FLTK Tutorial - Example 1" );

// Display the window

win.show();

// Run and return

return Fl::run();

}

All programs must include the file <FL/FL.H> to include the FLTK global class FL. In

addition the program must include a header file for each FLTK class it uses, in our case it

is just Fl_Window, a subclass of Fl_Group.

The statement:

Fl_Window win(400, 400, "FLTK Tutorial - Example 1" );

creates a new object of the Fl_Window class called "win". The call also defines the size of

the window to be created and the title string.

Then there is a call the "show" method of the Fl_Window class to display the window:

win.show();

Finally every FLTK program has to have the Fl::run() statement:

return Fl::run();

This enters the FLTK event loop. The program now waits for events, like mouse clicks or

keystrokes to happen and act upon them. When the window is closed or the ESC key

pressed, this function will return.

Plik z chomika:

Inne pliki z tego folderu:

Inne foldery tego chomika: