The FLTK distribution contains over 60 sample applications written in, or ported to, FLTK.
If the FLTK archive you received does not contain either an 'examples' or 'test' directory, you can download the complete FLTK distribution from http://fltk.org/software.php .
Most of the example programs were created while testing a group of widgets. They are not meant to be great achievements in clean C++ programming, but merely a test platform to verify the functionality of the FLTK library.
Note that extra example programs are also available in an additional 'examples' directory, but these are NOT built automatically when you build FLTK, unlike those in the 'test' directory shown below.
Example Applications
adjuster
adjuster shows a nifty little widget for quickly setting values in a great range.
arc
- The
arc demo explains how to derive your own widget to generate some custom drawings. The sample drawings use the matrix based arc drawing for some fun effects.
ask
ask shows some of FLTK's standard dialog boxes. Click the correct answers or you may end up in a loop, or you may end up in a loop, or you... .
bitmap
- This simple test shows the use of a single color bitmap as a label for a box widget. Bitmaps are stored in the X11 '.bmp' file format and can be part of the source code.
blocks
- A wonderful and addictive game that shows the usage of FLTK timers, graphics, and how to implement sound on all platforms.
blocks is also a good example for the Mac OS X specific bundle format.
boxtype
boxtype gives an overview of readily available boxes and frames in FLTK. More types can be added by the application programmer. When using themes, FLTK shuffles boxtypes around to give your program a new look.
browser
browser shows the capabilities of the Fl_Browser widget. Important features tested are loading of files, line formatting, and correct positioning of the browser data window.
button
- The
button test is a simple demo of push-buttons and callbacks.
buttons
buttons shows a sample of FLTK button types.
checkers
- Written by Steve Poulsen in early 1979,
checkers shows how to convert a VT100 text-terminal based program into a neat application with a graphical UI. Check out the code that drags the pieces, and how the pieces are drawn by layering. Then tell me how to beat the computer at Checkers.
clock
- The
clock demo shows two analog clocks. The innards of the Fl_Clock widget are pretty interesting, explaining the use of timeouts and matrix based drawing.
colbrowser
colbrowser runs only on X11 systems. It reads /usr/lib/X11/rgb.txt to show the color representation of every text entry in the file. This is beautiful, but only moderately useful unless your UI is written in Motif.
color_chooser
- The
color_chooser gives a short demo of FLTK's palette based color chooser and of the RGB based color wheel.
cube
- The
cube demo shows the speed of OpenGL. It also tests the ability to render two OpenGL buffers into a single window, and shows OpenGL text.
CubeView
CubeView shows how to create a UI containing OpenGL with Fluid.
cursor
- The
cursor demo shows all mouse cursor shapes that come standard with FLTK. The fgcolor and bgcolor sliders work only on few systems (some version of Irix for example).
curve
curve draws a nice Bezier curve into a custom widget. The points option for splines is not supported on all platforms.
demo
- This tool allows quick access to all programs in the
test directory. demo is based on the visuals of the IrixGL demo program. The menu tree can be changed by editing test/demo.menu.
device
- Exercises the Fl_Image_Surface, Fl_Copy_Surface, and Fl_Printer classes to draw to an Fl_Image object, copy graphical data to the clipboard, and for print support.
- Note
- The clipboard.cxx program of the 'examples' directory is a clipboard watching application that continuously displays the textual or graphical content of the system clipboard (a.k.a pasteboard on Mac OS X) exercising Fl::paste().
doublebuffer
- The
doublebuffer demo shows the difference between a single buffered window, which may flicker during a slow redraw, and a double buffered window, which never flickers, but uses twice the amount of RAM. Some modern OS's double buffer all windows automatically to allow transparency and shadows on the desktop. FLTK is smart enough to not tripple buffer a window in that case.
editor
- FLTK has two very different text input widgets. Fl_Input and derived classes are rather light weight, however Fl_Text_Editor is a complete port of nedit (with permission). The
editor test is almost a full application, showing custom syntax highlighting and dialog creation.
fast_slow
fast_slow shows how an application can use the Fl_Widget::when() setting to receive different kinds of callbacks.
file_chooser
- The standard FLTK
file_chooser is the result of many iterations, trying to find a middle ground between a complex browser and a fast light implementation.
fonts
fonts shows all available text fonts on the host system. If your machine still has some pixmap based fonts, the supported sizes will be shown in bold face. Only the first 256 fonts will be listed.
forms
forms is an XForms program with very few changes. Search for "fltk" to find all changes necessary to port to fltk. This demo shows the different boxtypes. Note that some boxtypes are not appropriate for some objects.
fractals
fractals shows how to mix OpenGL, Glut and FLTK code. FLTK supports a rather large subset of Glut, so that many Glut applications compile just fine.
fullscreen
- This demo shows how to do many of the window manipulations that are popular for games. You can toggle the border on/off, switch between single- and double-buffered rendering, and take over the entire screen. More information in the source code.
gl_overlay
gl_overlay shows OpenGL overlay plane rendering. If no hardware overlay plane is available, FLTK will simulate it for you.
glpuzzle
- The
glpuzzle test shows how most Glut source code compiles easily under FLTK.
hello
hello: Hello, World. Need I say more? Well, maybe. This tiny demo shows how little is needed to get a functioning application running with FLTK. Quite impressive, I'd say.
help
help displays the built-in FLTK help browser. The Fl_Help_Dialog understands a subset of html and renders various image formats. This widget makes it easy to provide help pages to the user without depending on the operating system's html browser.
iconize
iconize demonstrates the effect of the window functions hide(), iconize(), and show().
image
- The
image demo shows how an image can be created on the fly. This generated image contains an alpha (transparency) channel which lets previous renderings 'shine through', either via true transparency or by using screen door transparency (pixelation).
inactive
inactive tests the correct rendering of inactive widgets. To see the inactive version of images, you can check out the pixmap or image test.
input
- This tool shows and tests different types of text input fields based on Fl_Input_. The
input program also tests various settings of Fl_Input::when().
input_choice
input_choice tests the latest addition to FLTK1, a text input field with an attached pulldown menu. Windows users will recognize similarities to the 'ComboBox'. input_choice starts up in 'plastic' scheme, but the traditional scheme is also supported.
keyboard
- FLTK unifies keyboard events for all platforms. The
keyboard test can be used to check the return values of Fl::event_key() and Fl::event_text(). It is also great to see the modifier buttons and the scroll wheel at work. Quit this application by closing the window. The ESC key will not work.
label
- Every FLTK widget can have a label attached to it. The
label demo shows alignment, clipping, and wrapping of text labels. Labels can contain symbols at the start and end of the text, like @FLTK or @circle uh-huh @square.
line_style
- Advanced line drawing can be tested with
line_style. Not all platforms support all line styles.
list_visuals
- This little app finds all available pixel formats for the current X11 screen. But since you are now an FLTK user, you don't have to worry about any of this.
mandelbrot
mandelbrot shows two advanced topics in one test. It creates grayscale images on the fly, updating them via the idle callback system. This is one of the few occasions where the idle callback is very useful by giving all available processor time to the application without blocking the UI or other apps.
menubar
- The
menubar tests many aspects of FLTK's popup menu system. Among the features are radio buttons, menus taller than the screen, arbitrary sub menu depth, and global shortcuts.
message
message pops up a few of FLTK's standard message boxes.
minimum
- The
minimum test program verifies that the update regions are set correctly. In a real life application, the trail would be avoided by choosing a smaller label or by setting label clipping differently.
navigation
navigation demonstrates how the text cursor moves from text field to text field when using the arrow keys, tab, and shift-tab.
output
output shows the difference between the single line and multi line mode of the Fl_Output widget. Fonts can be selected from the FLTK standard list of fonts.
overlay
- The
overlay test app shows how easy an FLTK window can be layered to display cursor and manipulator style elements. This example derives a new class from Fl_Overlay_Window and provides a new function to draw custom overlays.
pack
- The
pack test program demonstrates the resizing and repositioning of children of the Fl_Pack group. Putting an Fl_Pack into an Fl_Scroll is a useful way to create a browser for large sets of data.
pixmap_browser
pixmap_browser tests the shared-image interface. When using the same image multiple times, Fl_Shared_Image will keep it only once in memory.
pixmap
- This simple test shows the use of a LUT based pixmap as a label for a box widget. Pixmaps are stored in the X11 '.xpm' file format and can be part of the source code. Pixmaps support one transparent color.
preferences
- I do have my
preferences in the morning, but sometimes I just can't remember a thing. This is where the Fl_Preferences come in handy. They remember any kind of data between program launches.
radio
- The
radio tool was created entirely with fluid. It shows some of the available button types and tests radio button behavior.
resizebox
resizebox shows some possible ways of FLTK's automatic resize behavior.
resize
- The
resize demo tests size and position functions with the given window manager.
scroll
scroll shows how to scroll an area of widgets, one of them being a slow custom drawing. Fl_Scroll uses clipping and smart window area copying to improve redraw speed. The buttons at the bottom of the window control decoration rendering and updates.
shape
shape is a very minimal demo that shows how to create your own OpenGL rendering widget. Now that you know that, go ahead and write that flight simulator you always dreamt of.
subwindow
- The
subwindow demo tests messaging and drawing between the main window and 'true' sub windows. A sub window is different to a group by resetting the FLTK coordinate system to 0, 0 in the top left corner. On Win32 and X11, subwindows have their own operating system specific handle.
sudoku
- Another highly addictive game - don't play it, I warned you. The implementation shows how to create application icons, how to deal with OS specifics, and how to generate sound.
symbols
symbols are a speciality of FLTK. These little vector drawings can be integrated into labels. They scale and rotate, and with a little patience, you can define your own. The rotation number refers to 45 degree rotations if you were looking at a numeric keypad (2 is down, 6 is right, etc.).
tabs
- The
tabs tool was created with fluid. It tests correct hiding and redisplaying of tabs, navigation across tabs, resize behavior, and no unneeded redrawing of invisible widgets.
- The
tabs application shows the Fl_Tabs widget on the left and the Fl_Wizard widget on the right side for direct comparison of these two panel management widgets.
threads
- FLTK can be used in a multithreading environment. There are some limitations, mostly due to the underlying operating system.
threads shows how to use Fl::lock(), Fl::unlock(), and Fl::awake() in secondary threads to keep FLTK happy. Although locking works on all platforms, this demo is not available on every machine.
tile
- The
tile tool shows a nice way of using Fl_Tile. To test correct resizing of subwindows, the widget for region 1 is created from an Fl_Window class.
tiled_image
- The
tiled_image demo uses an image as the background for a window by repeating it over the full size of the widget. The window is resizable and shows how the image gets repeated.
unittests
unittests exercises all of FLTK's drawing features (e.g., text, lines, circles, images), as well as scrollbars and schemes.
utf8
utf8 shows all fonts available to the platform that runs it, and how each font draws each of the Unicode code points ranging between U+0020 and U+FFFF.
valuators
valuators shows all of FLTK's nifty widgets to change numeric values.
fluid
fluid is not only a big test program, but also a very useful visual UI designer. Many parts of fluid were created using fluid. See the Fluid Tutorial for more details.
