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| author | Michael R Sweet <michael.r.sweet@gmail.com> | 1998-12-29 14:21:17 +0000 |
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| committer | Michael R Sweet <michael.r.sweet@gmail.com> | 1998-12-29 14:21:17 +0000 |
| commit | 87dd7f0d23eba5c09e71ec6efeb34c6844f5e95f (patch) | |
| tree | ecd25b3fbecdd2d1c6abf106d0c94ac2b1e9926e /documentation/basics.html | |
| parent | 20adb6834b22523e9d1fecdb7bb8a117f7b6179a (diff) | |
Revised documentation files.
git-svn-id: file:///fltk/svn/fltk/trunk@177 ea41ed52-d2ee-0310-a9c1-e6b18d33e121
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diff --git a/documentation/basics.html b/documentation/basics.html new file mode 100644 index 000000000..62e74d7e0 --- /dev/null +++ b/documentation/basics.html @@ -0,0 +1,211 @@ +<HTML> +<BODY> + +<H1 ALIGN=RIGHT>2 - FLTK Basics</H1> + +This chapter will teach you the basics of compiling programs that use +FLTK. + +<H2>Naming</H2> + +All public symbols in FLTK start with the characters 'F' and 'L': + +<ul> + + <li>Functions are either <tt>Fl::foo()</tt> or <tt>fl_foo()</tt>. + + <li>Class and type names are capitalized: <tt>Fl_Foo</tt>. + + <li><a href=#Enumerations>Constants and enumerations</a> are + uppercase: <tt>FL_FOO</tt>. + + <li>All header files start with <tt><FL/...></tt>. + +</ul> + +<H2>Header Files</H2> + +The proper way to include FLTK header files is: + +<ul><pre> +#include <FL/Fl_xyz.H> +</pre></ul> + +Microsoft Windows developers please note: case *is* significant +under other operating systems, and the C standard uses the forward +slash (/) to separate directories. The following <tt>#include</tt> +directives are *not* recommended for portability reasons: + +<ul><pre> +#include <fl\fl_xyz.h> +#include <fl/fl_xyz.h> +#include <FL\Fl_xyz.H> +</pre></ul> + +<H2>Compiling Programs with Standard Compilers</H2> + +Under UNIX (and under Microsoft Windows when using the GNU development tools) +you will probably need to tell the compiler where to find the header files. +This is usually done using the <tt>-I</tt> option: + +<ul><pre> +CC -I/usr/local/include ... +gcc -I/usr/local/include ... +</pre></ul> + +Similarly, when linking your application you will need to tell the compiler +to use the FLTK library: + +<ul><pre> +CC ... -L/usr/local/lib -lfltk -lXext -lX11 -lm +gcc ... -L/usr/local/lib -lfltk -lXext -lX11 -lm +</pre></ul> + +<H2>Compiling Programs with Microsoft Visual C++</H2> + +In Visual C++ you will need to tell the compiler where to find the FLTK +header files. This can be done by selecting "Settings" from the +"Project" menu and then changing the "Preprocessor" settings under the +"C/C++" tab. Similarly, you will need to add the FLTK library to the +"Link" settings. + +<p>You can build your Microsoft Windows applications as Console or +WIN32 applications. If you want to use the standard C <tt>main()</tt> +function as the entry point, enter the name <tt>mainCRTStartup</tt> in +the "Entry-point symbol" field in the "Output" settings under the +"Link" tab. + +<p><i>Note: The Visual C++ optimizer is known to cause problems with +many programs. We only recommend using the "Favor Small Code" +optimization setting. + +<H2>Writing Your First FLTK Program</H2> + +All programs must include the file <tt><FL/Fl.H></tt>. In +addition the program must include a header file for each FLTK class it +uses. Listing 1 shows a simple "Hello, World!" program that uses +FLTK to display the window. + +<ul> +<i>Listing 1 - "hello.cxx"</i> +<br> +<pre> +#include <FL/Fl.H> +#include <FL/Fl_Window.H> +#include <FL/Fl_Box.H> + +int main(int argc, char **argv) { + Fl_Window *window = new Fl_Window(300,180); + Fl_Box *box = new Fl_Box(FL_UP_BOX,20,40,260,100,"Hello, World!"); + box->labelsize(36); + box->labelfont(FL_BOLD+FL_ITALIC); + box->labeltype(FL_SHADOW_LABEL); + window->end(); + window->show(argc, argv); + return Fl::run(); +} +</pre></ul> + +After including the required header files, the program then creates a +window: + +<ul><pre> +Fl_Window *window = new <a href="#Fl_Window">Fl_Window</a>(300,180); +</pre></ul> + +and a box with the "Hello, World!" string in it: + +<ul><pre> +Fl_Box *box = new <a href="#Fl_Box">Fl_Box</a>(FL_UP_BOX,20,40,260,100,"Hello, World!"); +</pre></ul> + +Next, we set the size, font, and style of the label: + +<ul><pre> +box-><a href="#Fl_Widget.labelsize">labelsize</a>(36); +box-><a href="#Fl_Widget.labelfont">labelfont</a>(FL_BOLD+FL_ITALIC); +box-><a href="#Fl_Widget.labeltype">labeltype</a>(FL_SHADOW_LABEL); +</pre></ul> + +Finally, we show the window and enter the FLTK event loop: + +<ul><pre> +window-><a href="#Fl_Group.end">end</a>(); +window-><a href="#Fl_Window.show">show</a>(argc, argv); +return <a href="#run">Fl::run</a>(); +</pre></ul> + +The resulting program will display the window below. You can quit +the program by closing the window or pressing the ESCape key. + +<center><img src=hello.C.gif></center> + +<H3>Creating the Widgets</H3> + +The widgets are created using the C++ <tt>new</tt> operator; the arguments +to the constructors are usually one of the following: + +<ul><pre> +Fl_Widget(boxtype, x, y, width, height) +Fl_Widget(x, y, width, height) +Fl_Widget(width, height) +</pre></ul> + +The <tt>boxtype</tt> value is the style of the box that is drawn around +the widget. Usually this is <tt>FL_NO_BOX</tt>, which means that no +box is drawn. In our "Hello, World!" example we use <tt>FL_UP_BOX</tt>, +which means that a raised button border will be drawn around the +widget. You can learn more about boxtypes in <a href="#common">Chapter +3</a>. + +<p>The <tt>x</tt> and <tt>y</tt> parameters determine where the widget +or window is placed on the screen. In FLTK the top left corner of the +window or screen is the origin (i.e. x = 0, y = 0) and the units are in +pixels. + +<p>The <tt>width</tt> and <tt>height</tt> parameters determine the size +of the widget or window in pixels. The maximum widget size is typically +governed by the underlying window system or hardware. + +<H3>Labels</H3> + +All widgets support labels. In the case of window widgets, the label +is used for the label in the title bar. Our example program calls the +<a href="#Fl_Widget.labelfont"><tt>labelfont</tt></a>, +<a href="#Fl_Widget.labelsize"><tt>labelsize</tt></a>, and +<a href="#Fl_Widget.labeltype"><tt>labeltype</tt></a> methods. + +<p>The <tt>labelfont</tt> method sets the typeface and style that is +used for the label, which for this example we are using +<tt>FL_BOLD</tt> and <tt>FL_ITALIC</tt>. You can also specify typefaces +directly. + +<p>The <tt>labelsize</tt> method sets the height of the font in pixels. + +<p>The <tt>labeltype</tt> method sets the type of label. FLTK supports +normal, embossed, shadowed, symbol, and image labels. + +<p>A complete list of all label options can be found in <a href="#common"> +Chapter 3</a>. + +<H3>Showing the Window</H3> + +The <tt>show()</tt> method shows the widget or window. For windows you can +also provide the command-line arguments to allow users to customize the +appearance, size, and position of your windows. + +<H3>The Main Event Loop</H3> + +FLTK provides the <a href="#run"><tt>Fl:run()</tt></a> method to enter +a standard event processing loop. This is equivalent to the following +code: + +<ul><pre> +while (Fl::wait()); +</pre></ul> + +<tt>Fl::run()</tt> does not return until all of the windows under FLTK control +are closed (either by the user or your program). + +</BODY> +</HTML> |