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-rw-r--r--documentation/basics.dox249
-rw-r--r--documentation/common.dox498
2 files changed, 355 insertions, 392 deletions
diff --git a/documentation/basics.dox b/documentation/basics.dox
index 3fb1366f7..d9bfc4aad 100644
--- a/documentation/basics.dox
+++ b/documentation/basics.dox
@@ -2,17 +2,17 @@
\page basics 2 - FLTK Basics
- <P>This chapter teaches you the basics of compiling programs
-that use FLTK.</P>
+This chapter teaches you the basics of compiling programs
+that use FLTK.
-<H2>Writing Your First FLTK Program</H2>
+\section basics_writing Writing Your First FLTK Program
-<P>All programs must include the file <TT><FL/Fl.H></TT>.
+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.</P>
+World!" program that uses FLTK to display the window.
-<P><I>Listing 1 - "hello.cxx"</I>
+\par Listing 1 - "hello.cxx"
\code
#include <FL/Fl.H>
#include <FL/Fl_Window.H>
@@ -33,21 +33,21 @@ int main(int argc, char **argv) {
<!-- NEED 2in -->
-<P>After including the required header files, the program then creates a
-window. All following widgets will automatically be children of this window.</P>
+After including the required header files, the program then creates a
+window. All following widgets will automatically be children of this window.
\code
Fl_Window *window = new Fl_Window(300,180);
\endcode
-<P>Then we create a box with the "Hello, World!" string in it. FLTK automatically adds
-the new box to <tt>window</tt>, the current grouping widget.</P>
+Then we create a box with the "Hello, World!" string in it. FLTK automatically
+adds the new box to <tt>window</tt>, the current grouping widget.
\code
Fl_Box *box = new Fl_Box(20,40,260,100,"Hello, World!");
\endcode
-<P>Next, we set the type of box and the size, font, and style of the label:</P>
+Next, we set the type of box and the size, font, and style of the label:
\code
box->box(FL_UP_BOX);
@@ -56,205 +56,209 @@ box->labelfont(FL_BOLD+FL_ITALIC);
box->labeltype(FL_SHADOW_LABEL);
\endcode
-<P>We tell FLTK that we will not add any more widgets to <tt>window</tt>.</P>
+We tell FLTK that we will not add any more widgets to <tt>window</tt>.
\code
window->end();
\endcode
-<P>Finally, we show the window and enter the FLTK event loop:</P>
+Finally, we show the window and enter the FLTK event loop:
\code
window->show(argc, argv);
return Fl::run();
\endcode
-<P>The resulting program will display the window in Figure 2-1.
+The resulting program will display the window in Figure 2-1.
You can quit the program by closing the window or pressing the
-<KBD>ESC</KBD>ape key.</P>
+<KBD>ESC</KBD>ape key.
\image html hello.C.gif "Figure 2-1: The Hello, World! Window"
-<H3>Creating the Widgets</H3>
+\subsection basics_creating Creating the Widgets
-<P>The widgets are created using the C++ <TT>new</TT> operator. For
-most widgets the arguments to the constructor are:</P>
+The widgets are created using the C++ <tt>new</tt> operator. For
+most widgets the arguments to the constructor are:
\code
Fl_Widget(x, y, width, height, label)
\endcode
-<P>The <TT>x</TT> and <TT>y</TT> parameters determine where the
+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>
+0) and the units are in pixels.
-<P>The <TT>width</TT> and <TT>height</TT> parameters determine
+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.</P>
+hardware.
-<P><tt>label</tt> is a pointer to a character string to label
+<tt>label</tt> is a pointer to a character string to label
the widget with or <tt>NULL</tt>. If not specified the label
defaults to <tt>NULL</tt>. The label string must be in static
storage such as a string constant because FLTK does not make a
-copy of it - it just uses the pointer.</P>
+copy of it - it just uses the pointer.
-<H3>Creating Widget hierarchies</H3>
+\subsection basics_hierarchies Creating Widget hierarchies
-<P>Widgets are commonly ordered into functional groups, which
+Widgets are commonly ordered into functional groups, which
in turn may be grouped again, creating a hierarchy of widgets.
FLTK makes it easy to fill groups by automatically adding all widgets
that are created between a <tt>myGroup->begin()</tt> and
<tt>myGroup->end()</tt>. In this example, <tt>myGroup</tt>
-would be the <i>current</i> group.</P>
+would be the <i>current</i> group.
-<P>Newly created groups and their derived widgets implicitly call
+Newly created groups and their derived widgets implicitly call
<tt>begin()</tt> in the constructor, effectively adding all
subsequently created widgets to itself until <tt>end()</tt>
-is called.</P>
+is called.
-<P>Setting the current group to <tt>NULL</tt> will stop automatic
+Setting the current group to <tt>NULL</tt> will stop automatic
hierarchies. New widgets can now be added manually using
-<tt>Fl_Group::add(...)</tt> and <tt>Fl_Group::insert(...)</tt>.</P>
+<tt>Fl_Group::add(...)</tt> and <tt>Fl_Group::insert(...)</tt>.
-<H3>Get/Set Methods</H3>
+\subsection basics_getset Get/Set Methods
-<P><tt>box->box(FL_UP_BOX)</tt> sets the type of box the
+<tt>box->box(FL_UP_BOX)</tt> sets the type of box the
Fl_Box draws, changing it from the default of
<tt>FL_NO_BOX</tt>, which means that no box is drawn. In our
-"Hello, World!" example we use <TT>FL_UP_BOX</TT>,
+"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.html#boxtypes">Chapter 3</A>.</P>
+<A href="common.html#boxtypes">Chapter 3</A>.
-<P>You could examine the boxtype in by doing
+You could examine the boxtype in by doing
<tt>box->box()</tt>. FLTK uses method name overloading to make
short names for get/set methods. A "set" method is always of
the form "void name(type)", and a "get" method is always
-of the form "type name() const".</P>
+of the form "type name() const".
-<H3>Redrawing After Changing Attributes</H3>
+\subsection basics_redrawing Redrawing After Changing Attributes
-<P>Almost all of the set/get pairs are very fast, short inline
+Almost all of the set/get pairs are very fast, short inline
functions and thus very efficient. However, <i>the "set" methods
-do not call <TT>redraw()</TT></i> - you have to call it
+do not call <tt>redraw()</tt></i> - you have to call it
yourself. This greatly reduces code size and execution time. The
only common exceptions are <tt>value()</tt> which calls
-<TT>redraw()</TT> and <tt>label()</tt> which calls
-<TT>redraw_label()</TT> if necessary.</P>
+<tt>redraw()</tt> and <tt>label()</tt> which calls
+<tt>redraw_label()</tt> if necessary.
-<H3>Labels</H3>
+\subsection basics_labels Labels
-<P>All widgets support labels. In the case of window widgets,
+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 <TT>labelfont()</TT>,<TT> labelsize</TT>,
-and <TT>labeltype()</TT> methods.</P>
+program calls the <tt>labelfont()</tt>,<tt> labelsize</tt>,
+and <tt>labeltype()</tt> methods.
-<P>All widgets support labels. In the case of window widgets,
+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.html#Fl_Widget.labelfont>
-<TT>labelfont</TT></A>,
-<A href=Fl_Widget.html#Fl_Widget.labelsize><TT> labelsize</TT></A>,
-and <A href=Fl_Widget.html#Fl_Widget.labeltype><TT>labeltype</TT></A>
-methods.</P>
-
-<P>The <TT>labelfont</TT> method sets the typeface and style
+program calls the
+<A href=Fl_Widget.html#Fl_Widget.labelfont><tt>labelfont</tt></A>,
+<A href=Fl_Widget.html#Fl_Widget.labelsize><tt> labelsize</tt></A>,
+and
+<A href=Fl_Widget.html#Fl_Widget.labeltype><tt>labeltype</tt></A>
+methods.
+
+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> <P>The <TT>labelsize</TT> method sets
-the height of the font in pixels. </P> <P>The <TT>labeltype</TT>
+<tt>FL_BOLD</tt> and <tt>FL_ITALIC</tt>. You can also specify
+typefaces directly.
+
+The <tt>labelsize</tt> method sets the height of the font in pixels.
+
+The <tt>labeltype</tt>
method sets the type of label. FLTK supports normal, embossed,
and shadowed labels internally, and more types can be added as
-desired.</P>
+desired.
-<P>A complete list of all label options can be found in
-<A href="common.html#labels">Chapter 3</A>.</P>
+A complete list of all label options can be found in
+<A href="common.html#labels">Chapter 3</A>.
-<H3>Showing the Window</H3>
+\subsection basics_showing Showing the Window
-<P>The <TT>show()</TT> method shows the widget or window. For windows
+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.</P>
+customize the appearance, size, and position of your windows.
-<H3>The Main Event Loop</H3>
+\subsection basics_eventloop The Main Event Loop
-<P>All FLTK applications (and most GUI applications in general)
+All FLTK applications (and most GUI applications in general)
are based on a simple event processing model. User actions such
as mouse movement, button clicks, and keyboard activity generate
events that are sent to an application. The application may then
ignore the events or respond to the user, typically by redrawing
a button in the "down" position, adding the text to an input
-field, and so forth.</P>
+field, and so forth.
-<P>FLTK also supports idle, timer, and file pseudo-events that
+FLTK also supports idle, timer, and file pseudo-events that
cause a function to be called when they occur. Idle functions
are called when no user input is present and no timers or files
need to be handled - in short, when the application is not doing
anything. Idle callbacks are often used to update a 3D display
-or do other background processing.</P>
+or do other background processing.
-<P>Timer functions are called after a specific amount of time
+Timer functions are called after a specific amount of time
has expired. They can be used to pop up a progress dialog after
a certain amount of time or do other things that need to happen
at more-or-less regular intervals. FLTK timers are not 100%
accurate, so they should not be used to measure time intervals,
-for example.</P>
+for example.
-<P>File functions are called when data is ready to read or
+File functions are called when data is ready to read or
write, or when an error condition occurs on a file. They are
most often used to monitor network connections (sockets) for
-data-driven displays.</P>
+data-driven displays.
-<P>FLTK applications must periodically check (Fl::check())
+FLTK applications must periodically check (Fl::check())
or wait (Fl::wait()) for events or use the Fl::run()
method to enter a standard event processing loop. Calling
-Fl::run() is equivalent to the following code:</P>
+Fl::run() is equivalent to the following code:
\code
while (Fl::wait());
\endcode
-<P>Fl::run() does not return until all of the windows
-under FLTK control are closed by the user or your program.</P>
+Fl::run() does not return until all of the windows
+under FLTK control are closed by the user or your program.
-<H2>Compiling Programs with Standard Compilers</H2>
+\section basics_standard_compiler Compiling Programs with Standard Compilers
-<P>Under UNIX (and under Microsoft Windows when using the GNU development
+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:</P>
+header files. This is usually done using the <tt>-I</tt> option:
\code
CC -I/usr/local/include ...
gcc -I/usr/local/include ...
\endcode
-<P>The <TT>fltk-config</TT> script included with FLTK can be
-used to get the options that are required by your compiler:</P>
+The <tt>fltk-config</tt> script included with FLTK can be
+used to get the options that are required by your compiler:
\code
CC `fltk-config --cxxflags` ...
\endcode
-<P>Similarly, when linking your application you will need to tell the
-compiler to use the FLTK library:</P>
+Similarly, when linking your application you will need to tell the
+compiler to use the FLTK library:
\code
CC ... -L/usr/local/lib -lfltk -lXext -lX11 -lm
gcc ... -L/usr/local/lib -lfltk -lXext -lX11 -lm
\endcode
-<P>Aside from the "fltk" library, there is also a "fltk_forms"
+Aside from the "fltk" library, there is also a "fltk_forms"
library for the XForms compatibility classes, "fltk_gl" for the
OpenGL and GLUT classes, and "fltk_images" for the image file
classes, Fl_Help_Dialog widget, and system icon support.
\note
- The libraries are named "fltk.lib", "fltkgl.lib", "fltkforms.lib",
- and "fltkimages.lib", respectively under Windows.
+The libraries are named "fltk.lib", "fltkgl.lib", "fltkforms.lib",
+and "fltkimages.lib", respectively under Windows.
-<P>As before, the <TT>fltk-config</TT> script included with FLTK can be
-used to get the options that are required by your linker:</P>
+As before, the <tt>fltk-config</tt> script included with FLTK can be
+used to get the options that are required by your linker:
\code
CC ... `fltk-config --ldflags`
@@ -262,7 +266,7 @@ CC ... `fltk-config --ldflags`
<!-- NEED 2in -->
-<P>The forms, GL, and images libraries are included with the "--use-foo"
+The forms, GL, and images libraries are included with the "--use-foo"
options, as follows:
\code
@@ -272,7 +276,7 @@ CC ... `fltk-config --use-images --ldflags`
CC ... `fltk-config --use-forms --use-gl --use-images --ldflags`
\endcode
-<P>Finally, you can use the <TT>fltk-config</TT> script to
+Finally, you can use the <tt>fltk-config</tt> script to
compile a single source file as a FLTK program:
\code
@@ -283,68 +287,61 @@ fltk-config --use-images --compile filename.cpp
fltk-config --use-forms --use-gl --use-images --compile filename.cpp
\endcode
-<P>Any of these will create an executable named <TT>filename</TT>.
+Any of these will create an executable named <tt>filename</tt>.
-<H2>Compiling Programs with Microsoft Visual C++</H2>
+\section basics_visual_cpp Compiling Programs with Microsoft Visual C++
-<P>In Visual C++ you will need to tell the compiler where to
+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. You will also
need to add the FLTK and WinSock2 (WS2_32.LIB) libraries to
-the "Link" settings.</P>
+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, FLTK includes a <TT>WinMain()</TT>
-function that will call your <TT>main()</TT> function for you.</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, FLTK includes a <tt>WinMain()</tt>
+function that will call your <tt>main()</tt> function for you.
-<P><I>Note: The Visual C++ 5.0 optimizer is known to cause problems with
+<I>Note: The Visual C++ 5.0 optimizer is known to cause problems with
many programs. We only recommend using the "Favor Small Code"
optimization setting.</I> The Visual C++ 6.0 optimizer seems to be much
-better and can be used with the "optimized for speed" setting.</P>
-
-<H2>Naming</H2>
+better and can be used with the "optimized for speed" setting.
-<P>All public symbols in FLTK start with the characters 'F' and 'L':</P>
+\section basics_naming Naming
-<UL>
+All public symbols in FLTK start with the characters 'F' and 'L':
- <LI>Functions are either <TT>Fl::foo()</TT> or
- <TT>fl_foo()</TT>.</LI>
+\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>
+\li Class and type names are capitalized: <tt>Fl_Foo</tt>.
- <LI><A href="enumerations.html">Constants and
- enumerations</A> are uppercase: <TT>FL_FOO</TT>.</LI>
+\li <A href="enumerations.html">Constants and enumerations</A>
+ are uppercase: <tt>FL_FOO</tt>.
- <LI>All header files start with <TT><FL/...></TT>.
- </LI>
-
-</UL>
+\li All header files start with <tt><FL/...></tt>.
<!-- NEED 5in -->
-<H2>Header Files</H2>
+\section basics_headerfiles Header Files
-<P>The proper way to include FLTK header files is:</P>
+The proper way to include FLTK header files is:
\code
#include <FL/Fl_xyz.H>
\endcode
\note
- Case <I>is</I> significant on many operating systems,
- and the C standard uses the forward slash (/) to
- separate directories. <i>Do not use any of the following
- include lines:</i>
-
- \code
- #include <FL\Fl_xyz.H>
- #include <fl/fl_xyz.h>
- #include <Fl/fl_xyz.h>
- \endcode
+Case <I>is</I> significant on many operating systems,
+and the C standard uses the forward slash (/) to
+separate directories. <i>Do not use any of the following
+include lines:</i>
+
+\code
+#include <FL\Fl_xyz.H>
+#include <fl/fl_xyz.h>
+#include <Fl/fl_xyz.h>
+\endcode
<hr>
<a class="el" href="index.html">[Index]</a> &nbsp;&nbsp;
diff --git a/documentation/common.dox b/documentation/common.dox
index 62dbebe73..eeceae4cf 100644
--- a/documentation/common.dox
+++ b/documentation/common.dox
@@ -2,37 +2,33 @@
\page common 3 - Common Widgets and Attributes
-<P>This chapter describes many of the widgets that are provided
+This chapter describes many of the widgets that are provided
with FLTK and covers how to query and set the standard
-attributes.</P>
+attributes.
-<H2>Buttons</H2>
+\section common_buttons Buttons
-<P>FLTK provides many types of buttons:</P>
+FLTK provides many types of buttons:
-<UL>
- <LI>Fl_Button - A standard push button.</LI>
+\li Fl_Button - A standard push button.
- <LI>Fl_Check_Button - A button with a check box.</LI>
+\li Fl_Check_Button - A button with a check box.
- <LI>Fl_Light_Button - A push button with a light.</LI>
+\li Fl_Light_Button - A push button with a light.
- <LI>Fl_Repeat_Button - A push button that repeats
- when held.</LI>
+\li Fl_Repeat_Button - A push button that repeats when held.
- <LI>Fl_Return_Button - A push button that is activated
- by the <KBD>Enter</KBD> key.</LI>
+\li Fl_Return_Button - A push button that is activated by the
+ <KBD>Enter</KBD> key.
- <LI>Fl_Round_Button - A button with a radio circle.</LI>
-
-</UL>
+\li Fl_Round_Button - A button with a radio circle.
\image html buttons.gif "Figure 3-1: FLTK Button Widgets"
-<P>All of these buttons just need the corresponding
-<TT><FL/Fl_xyz_Button.H></TT> header file. The constructor
+All of these buttons just need the corresponding
+<tt><FL/Fl_xyz_Button.H></tt> header file. The constructor
takes the bounding box of the button and optionally a label
-string:</P>
+string:
\code
Fl_Button *button = new Fl_Button(x, y, width, height, "label");
@@ -40,8 +36,8 @@ Fl_Light_Button *lbutton = new Fl_Light_Button(x, y, width, height);
Fl_Round_Button *rbutton = new Fl_Round_Button(x, y, width, height, "label");
\endcode
-<P>Each button has an associated <TT>type()</TT> which allows
-it to behave as a push button, toggle button, or radio button:</P>
+Each button has an associated <tt>type()</tt> which allows
+it to behave as a push button, toggle button, or radio button:
\code
button->type(FL_NORMAL_BUTTON);
@@ -49,126 +45,115 @@ lbutton->type(FL_TOGGLE_BUTTON);
rbutton->type(FL_RADIO_BUTTON);
\endcode
-<P>For toggle and radio buttons, the value() method returns
+For toggle and radio buttons, the value() method returns
the current button state (0 = off, 1 = on). The set() and
clear() methods can be used on toggle buttons to turn a
toggle button on or off, respectively.
Radio buttons can be turned on with the setonly()
method; this will also turn off other radio buttons in the same
-group.</P>
+group.
-<H2>Text</H2>
+\section common_text Text
-<P>FLTK provides several text widgets for displaying and receiving text:</P>
+FLTK provides several text widgets for displaying and receiving text:
-<UL>
- <LI>Fl_Input - A one-line text input field.</LI>
+\li Fl_Input - A one-line text input field.
- <LI>Fl_Output - A one-line text output field.</LI>
+\li Fl_Output - A one-line text output field.
- <LI>Fl_Multiline_Input - A multi-line text input field.</LI>
+\li Fl_Multiline_Input - A multi-line text input field.
- <LI>Fl_Multiline_Output - A multi-line text output field.</LI>
+\li Fl_Multiline_Output - A multi-line text output field.
- <LI>Fl_Text_Display - A multi-line text display widget.</LI>
+\li Fl_Text_Display - A multi-line text display widget.
- <LI>Fl_Text_Editor - A multi-line text editing widget.</LI>
+\li Fl_Text_Editor - A multi-line text editing widget.
- <LI>Fl_Help_View - A HTML text display widget.</LI>
-</UL>
+\li Fl_Help_View - A HTML text display widget.
-<P>The <TT>Fl_Output</TT> and <TT>Fl_Multiline_Output</TT>
+The <tt>Fl_Output</tt> and <tt>Fl_Multiline_Output</tt>
widgets allow the user to copy text from the output field but
-not change it.</P>
+not change it.
-<P>The <TT>value()</TT> method is used to get or set the
-string that is displayed:</P>
+The <tt>value()</tt> method is used to get or set the
+string that is displayed:
\code
Fl_Input *input = new Fl_Input(x, y, width, height, "label");
input->value("Now is the time for all good men...");
\endcode
-<P>The string is copied to the widget's own storage when you set
-the <tt>value()</tt> of the widget.</P>
+The string is copied to the widget's own storage when you set
+the <tt>value()</tt> of the widget.
-<P>The <TT>Fl_Text_Display</TT> and <TT>Fl_Text_Editor</TT>
-widgets use an associated <TT>Fl_Text_Buffer</TT> class for the
-value, instead of a simple string.</P>
+The <tt>Fl_Text_Display</tt> and <tt>Fl_Text_Editor</tt>
+widgets use an associated <tt>Fl_Text_Buffer</tt> class for the
+value, instead of a simple string.
<!-- NEED 4in -->
-<H2>Valuators</H2>
-
-<P>Unlike text widgets, valuators keep track of numbers instead of
-strings. FLTK provides the following valuators:</P>
-
-<UL>
+\section common_valuators Valuators
- <LI>Fl_Counter - A widget with arrow buttons that shows the
- current value.</LI>
+Unlike text widgets, valuators keep track of numbers instead of
+strings. FLTK provides the following valuators:
- <LI>Fl_Dial - A round knob.</LI>
+\li Fl_Counter - A widget with arrow buttons that shows the current value.
- <LI>Fl_Roller - An SGI-like dolly widget.</LI>
+\li Fl_Dial - A round knob.
- <LI>Fl_Scrollbar - A standard scrollbar widget.</LI>
+\li Fl_Roller - An SGI-like dolly widget.
- <LI>Fl_Slider - A scrollbar with a knob.</LI>
+\li Fl_Scrollbar - A standard scrollbar widget.
- <LI>Fl_Value_Slider - A slider that shows the current value.</LI>
+\li Fl_Slider - A scrollbar with a knob.
-</UL>
+\li Fl_Value_Slider - A slider that shows the current value.
\image html valuators.gif "Figure 3-2: FLTK valuator widgets"
-<P>The <TT>value()</TT> method gets and sets the current value
-of the widget. The <TT>minimum()</TT> and <TT>maximum()</TT>
+The <tt>value()</tt> method gets and sets the current value
+of the widget. The <tt>minimum()</tt> and <tt>maximum()</tt>
methods set the range of values that are reported by the
-widget.</P>
+widget.
<!-- NEED 5in -->
-<H2>Groups</H2>
+\section common_groups Groups
-<P>The <TT>Fl_Group</TT> widget class is used as a general
+The <tt>Fl_Group</tt> widget class is used as a general
purpose "container" widget. Besides grouping radio
buttons, the groups are used to encapsulate windows, tabs, and
scrolled windows. The following group classes are available
-with FLTK:</P>
+with FLTK:
-<UL>
+\li Fl_Double_Window - A double-buffered window on the screen.
- <LI>Fl_Double_Window - A double-buffered window on the screen.</LI>
+\li Fl_Gl_Window - An OpenGL window on the screen.
- <LI>Fl_Gl_Window - An OpenGL window on the screen.</LI>
+\li Fl_Group - The base container class; can be used to group
+ any widgets together.
- <LI>Fl_Group - The base container class; can be used to group
- any widgets together.</LI>
+\li Fl_Pack - A collection of widgets that are packed into the group area.
- <LI>Fl_Pack - A collection of widgets that are packed into the group area.</LI>
+\li Fl_Scroll - A scrolled window area.
- <LI>Fl_Scroll - A scrolled window area.</LI>
+\li Fl_Tabs - Displays child widgets as tabs.
- <LI>Fl_Tabs - Displays child widgets as tabs.</LI>
+\li Fl_Tile - A tiled window area.
- <LI>Fl_Tile - A tiled window area.</LI>
+\li Fl_Window - A window on the screen.
- <LI>Fl_Window - A window on the screen.</LI>
+\li Fl_Wizard - Displays one group of widgets at a time.
- <LI>Fl_Wizard - Displays one group of widgets at a time.</LI>
+\section common_sizeposition Setting the Size and Position of Widgets
-</UL>
-
-<H2>Setting the Size and Position of Widgets</H2>
-
-<P>The size and position of widgets is usually set when you
+The size and position of widgets is usually set when you
create them. You can access them with the <tt>x()</tt>,
-<tt>y()</tt>, <tt>w()</tt>, and <tt>h()</tt> methods.</P>
+<tt>y()</tt>, <tt>w()</tt>, and <tt>h()</tt> methods.
-<P>You can change the size and position by using the
-<TT>position()</TT>, <TT> resize()</TT>, and <TT>size()</TT>
-methods:</P>
+You can change the size and position by using the
+<tt>position()</tt>, <tt> resize()</tt>, and <tt>size()</tt>
+methods:
\code
button->position(x, y);
@@ -176,69 +161,65 @@ group->resize(x, y, width, height);
window->size(width, height);
\endcode
-<P>If you change a widget's size or position after it is
+If you change a widget's size or position after it is
displayed you will have to call <tt>redraw()</tt> on the
-widget's parent.</P>
+widget's parent.
-<H2><A NAME="colors">Colors</A></H2>
+<A NAME="colors"></A> <!-- For old HTML links only ! -->
+\section common_colors Colors
-<P>FLTK stores the colors of widgets as an 32-bit unsigned
+FLTK stores the colors of widgets as an 32-bit unsigned
number that is either an index into a color palette of 256
colors or a 24-bit RGB color. The color palette is <i>not</i>
the X or WIN32 colormap, but instead is an internal table with
-fixed contents.</P>
+fixed contents.
-<P>There are symbols for naming some of the more common colors:</P>
+There are symbols for naming some of the more common colors:
-<UL>
- <LI><TT>FL_BLACK</TT></LI>
+\li <tt>FL_BLACK</tt>
- <LI><TT>FL_RED</TT></LI>
+\li <tt>FL_RED</tt>
- <LI><TT>FL_GREEN</TT></LI>
+\li <tt>FL_GREEN</tt>
- <LI><TT>FL_YELLOW</TT></LI>
+\li <tt>FL_YELLOW</tt>
- <LI><TT>FL_BLUE</TT></LI>
+\li <tt>FL_BLUE</tt>
- <LI><TT>FL_MAGENTA</TT></LI>
+\li <tt>FL_MAGENTA</tt>
- <LI><TT>FL_CYAN</TT></LI>
+\li <tt>FL_CYAN</tt>
- <LI><TT>FL_WHITE</TT></LI>
+\li <tt>FL_WHITE</tt>
- <LI>FL_WHITE</LI>
-</UL>
+\li FL_WHITE
-<P>These symbols are the default colors for all FLTK widgets. They are
+These symbols are the default colors for all FLTK widgets. They are
explained in more detail in the chapter
-<A HREF="enumerations.html#colors">Enumerations</A></P>
+<A HREF="enumerations.html#colors">Enumerations</A>
-<UL>
- <LI><TT>FL_FOREGROUND_COLOR</TT> </LI>
+\li <tt>FL_FOREGROUND_COLOR</tt>
- <LI><TT>FL_BACKGROUND_COLOR</TT> </LI>
+\li <tt>FL_BACKGROUND_COLOR</tt>
- <LI><TT>FL_INACTIVE_COLOR</TT> </LI>
+\li <tt>FL_INACTIVE_COLOR</tt>
- <LI><TT>FL_SELECTION_COLOR</TT> </LI>
-</UL>
+\li <tt>FL_SELECTION_COLOR</tt>
-<P>RGB colors can be set using the <TT>fl_rgb_color()</TT>
-function:</P>
+RGB colors can be set using the <tt>fl_rgb_color()</tt> function:
\code
Fl_Color c = fl_rgb_color(85, 170, 255);
\endcode
-<P>The widget color is set using the <TT>color()</TT> method:</P>
+The widget color is set using the <tt>color()</tt> method:
\code
button->color(FL_RED);
\endcode
-<P>Similarly, the label color is set using the <TT>labelcolor()</TT>
-method:</P>
+Similarly, the label color is set using the <tt>labelcolor()</tt>
+method:
\code
button->labelcolor(FL_WHITE);
@@ -247,35 +228,35 @@ button->labelcolor(FL_WHITE);
<A NAME="boxtypes"></A> <!-- For old HTML links only ! -->
\section common_boxtypes Box Types
-<P>The type <TT>Fl_Boxtype</TT> stored and returned in Fl_Widget::box()
+The type <tt>Fl_Boxtype</tt> stored and returned in Fl_Widget::box()
is an enumeration defined in Enumerations.H.
-Figure 3-3 shows the standard box types included with FLTK.</P>
+Figure 3-3 shows the standard box types included with FLTK.
\image html boxtypes.gif "Figure 3-3: FLTK box types"
-<P><TT>FL_NO_BOX</TT> means nothing is drawn at all, so whatever is
-already on the screen remains. The <TT>FL_..._FRAME</TT> types only
+<tt>FL_NO_BOX</tt> means nothing is drawn at all, so whatever is
+already on the screen remains. The <tt>FL_..._FRAME</tt> types only
draw their edges, leaving the interior unchanged. The blue color in
-Figure 3-3 is the area that is not drawn by the frame types.</P>
+Figure 3-3 is the area that is not drawn by the frame types.
-<H3>Making Your Own Boxtypes</H3>
+\subsection common_boxtypes Making Your Own Boxtypes
-<P>You can define your own boxtypes by making a small function that draws
-the box and adding it to the table of boxtypes.</P>
+You can define your own boxtypes by making a small function that draws
+the box and adding it to the table of boxtypes.
<CENTER><TABLE WIDTH="80%" BORDER="1" CELLPADDING="5" CELLSPACING="0" BGCOLOR="#cccccc">
<TR>
<TD><B>Note:</B>
- <P>This interface has changed in FLTK 2.0!</P>
+ <P>This interface has changed in FLTK 2.0!
</TD>
</TR>
</TABLE></CENTER>
-<H4>The Drawing Function</H4>
+\par The Drawing Function
-<P>The drawing function is passed the bounding box and background color
-for the widget:</P>
+The drawing function is passed the bounding box and background color
+for the widget:
\code
void xyz_draw(int x, int y, int w, int h, Fl_Color c) {
@@ -285,8 +266,8 @@ void xyz_draw(int x, int y, int w, int h, Fl_Color c) {
<!-- NEED 3in -->
-<P>A simple drawing function might fill a rectangle with the
-given color and then draw a black outline:</P>
+A simple drawing function might fill a rectangle with the
+given color and then draw a black outline:
\code
void xyz_draw(int x, int y, int w, int h, Fl_Color c) {
@@ -297,183 +278,167 @@ void xyz_draw(int x, int y, int w, int h, Fl_Color c) {
}
\endcode
-<H4><A name="fl_down">Fl_Boxtype fl_down(Fl_Boxtype)</A></H4>
+<A name="fl_down"></A> <!-- For old HTML links only ! -->
+\par Fl_Boxtype fl_down(Fl_Boxtype)
-<P><tt>fl_down</tt> returns the "pressed" or "down" version of a box.
+<tt>fl_down</tt> returns the "pressed" or "down" version of a box.
If no "down" version of a given box exists, the behavior of this function
is undefined and some random box or frame is returned.
See also: <A HREF="drawing.html#fl_frame">fl_frame drawing</A>.
-<H4><A name="fl_frame">Fl_Boxtype fl_frame(Fl_Boxtype)</A></H4>
+<A name="fl_frame"></A> <!-- For old HTML links only ! -->
+\par Fl_Boxtype fl_frame(Fl_Boxtype)
-<P><tt>fl_frame</tt> returns the unfilled, frame-only version of a box.
+<tt>fl_frame</tt> returns the unfilled, frame-only version of a box.
If no frame version of a given box exists, the behavior of this function
is undefined and some random box or frame is returned.
See also: <A HREF="drawing.html#fl_frame">fl_frame drawing</A>.
-<H4><A name="fl_box">Fl_Boxtype fl_box(Fl_Boxtype)</A></H4>
+<A name="fl_box"></A> <!-- For old HTML links only ! -->
+\par Fl_Boxtype fl_box(Fl_Boxtype)
-<P><tt>fl_box</tt> returns the filled version of a frame.
+<tt>fl_box</tt> returns the filled version of a frame.
If no filled version of a given frame exists, the behavior of this function
is undefined and some random box or frame is returned.
-See also: <TT><A HREF="#fl_frame">fl_frame</A></TT>.
+See also: <tt><A HREF="#fl_frame">fl_frame</A></tt>.
-<H4>Adding Your Box Type</H4>
+\par Adding Your Box Type
-<P>The <TT>Fl::set_boxtype()</TT> method adds or replaces the
-specified box type:</P>
+The <tt>Fl::set_boxtype()</tt> method adds or replaces the specified box type:
\code
#define XYZ_BOX FL_FREE_BOXTYPE
Fl::set_boxtype(XYZ_BOX, xyz_draw, 1, 1, 2, 2);
\endcode
-
-<P>The last 4 arguments to <TT>Fl::set_boxtype()</TT> are the
+The last 4 arguments to <tt>Fl::set_boxtype()</tt> are the
offsets for the x, y, width, and height values that should be
-subtracted when drawing the label inside the box.</P>
+subtracted when drawing the label inside the box.
-<P>A complete box design contains four box types in this order:
-a filled, neutral box (<TT>UP_BOX</TT>), a filled, depressed box
-(<TT>DOWN_BOX</TT>), and the same as outlines only (<TT>UP_FRAME</TT>
-and <TT>DOWN_FRAME</TT>). The function
-<TT><A HREF="#fl_down">fl_down(Fl_Boxtype)</A></TT>
+A complete box design contains four box types in this order:
+a filled, neutral box (<tt>UP_BOX</tt>), a filled, depressed box
+(<tt>DOWN_BOX</tt>), and the same as outlines only (<tt>UP_FRAME</tt>
+and <tt>DOWN_FRAME</tt>). The function
+<tt><A HREF="#fl_down">fl_down(Fl_Boxtype)</A></tt>
expects the neutral design on a boxtype with a numerical
value evenly divideable by two.
-<TT><A HREF="#fl_frame">fl_frame(Fl_Boxtype)</A></TT>
-expects the <TT>UP_BOX</TT> design at a value divideable by four.</P>
+<tt><A HREF="#fl_frame">fl_frame(Fl_Boxtype)</A></tt>
+expects the <tt>UP_BOX</tt> design at a value divideable by four.
<A NAME="labels"></A> <!-- For old HTML links only ! -->
\section common_labels Labels and Label Types
-<P>The <TT>label()</TT>, <TT>align()</TT>, <TT>labelfont()</TT>,
-<TT>labelsize()</TT>, <TT>labeltype()</TT>, <TT>image()</TT>, and
-<TT>deimage()</TT> methods control the labeling of widgets.</P>
+The <tt>label()</tt>, <tt>align()</tt>, <tt>labelfont()</tt>,
+<tt>labelsize()</tt>, <tt>labeltype()</tt>, <tt>image()</tt>, and
+<tt>deimage()</tt> methods control the labeling of widgets.
-<H3>label()</H3>
+\par label()
-<P>The <TT>label()</TT> method sets the string that is displayed
+The <tt>label()</tt> method sets the string that is displayed
for the label. Symbols can be included with the label string by
escaping them using the "@" symbol - "@@" displays a single at
-sign. Figure 3-4 shows the available symbols.</P>
+sign. Figure 3-4 shows the available symbols.
\image html symbols.gif "Figure 3-4: FLTK label symbols"
<!-- NEED 2in -->
-<P>The @ sign may also be followed by the following optional
-"formatting" characters, in this order:</P>
+The @ sign may also be followed by the following optional
+"formatting" characters, in this order:
-<UL>
+\li '#' forces square scaling, rather than distortion to the widget's shape.
- <LI>'#' forces square scaling, rather than distortion to
- the widget's shape.</LI>
+\li +[1-9] or -[1-9] tweaks the scaling a little bigger or smaller.
- <LI>+[1-9] or -[1-9] tweaks the scaling a little bigger
- or smaller.</LI>
+\li '$' flips the symbol horizontaly, '%' flips it verticaly.
- <LI>'$' flips the symbol horizontaly, '%' flips it verticaly.</LI>
+\li [0-9] - rotates by a multiple of 45 degrees. '5' and '6' do no rotation
+ while the others point in the direction of that key on a numeric keypad.
+ '0', followed by four more digits rotates the symbol by that amount in
+ degrees.
- <LI>[0-9] - rotates by a multiple of 45 degrees. '5' and
- '6' do no rotation while the others point in the
- direction of that key on a numeric keypad. '0', followed by four
- more digits rotates the symbol by that amount in degrees.</LI>
-
-</UL>
-
-<P>Thus, to show a very large arrow pointing downward you would use the
+Thus, to show a very large arrow pointing downward you would use the
label string "@+92->".
-<H3>align()</H3>
-
-<P>The <TT>align()</TT> method positions the label. The following
-constants are defined and may be OR'd together as needed:</P>
-
-<UL>
-
- <LI><TT>FL_ALIGN_CENTER</TT> - center the label in the widget.</LI>
-
- <LI><TT>FL_ALIGN_TOP</TT> - align the label at the top of the widget.</LI>
+\par align()
- <LI><TT>FL_ALIGN_BOTTOM</TT> - align the label at the bottom of the
- widget.</LI>
+The <tt>align()</tt> method positions the label. The following
+constants are defined and may be OR'd together as needed:
- <LI><TT>FL_ALIGN_LEFT</TT> - align the label to the left of the widget.</LI>
+\li <tt>FL_ALIGN_CENTER</tt> - center the label in the widget.
- <LI><TT>FL_ALIGN_RIGHT</TT> - align the label to the right of the
- widget.</LI>
+\li <tt>FL_ALIGN_TOP</tt> - align the label at the top of the widget.
- <LI><TT>FL_ALIGN_INSIDE</TT> - align the label inside the widget.</LI>
+\li <tt>FL_ALIGN_BOTTOM</tt> - align the label at the bottom of the
+ widget.
- <LI><TT>FL_ALIGN_CLIP</TT> - clip the label to the widget's bounding
- box.</LI>
+\li <tt>FL_ALIGN_LEFT</tt> - align the label to the left of the widget.
- <LI><TT>FL_ALIGN_WRAP</TT> - wrap the label text as needed.</LI>
+\li <tt>FL_ALIGN_RIGHT</tt> - align the label to the right of the
+ widget.
- <LI><TT>FL_TEXT_OVER_IMAGE</TT> - show the label text over the image.</LI>
+\li <tt>FL_ALIGN_INSIDE</tt> - align the label inside the widget.
- <LI><TT>FL_IMAGE_OVER_TEXT</TT> - show the label image over the text (default).</LI>
+\li <tt>FL_ALIGN_CLIP</tt> - clip the label to the widget's bounding
+ box.
-</UL>
+\li <tt>FL_ALIGN_WRAP</tt> - wrap the label text as needed.
-<H3><A NAME="labeltypes">labeltype()</A></H3>
+\li <tt>FL_TEXT_OVER_IMAGE</tt> - show the label text over the image.
-<P>The <TT>labeltype()</TT> method sets the type of the label. The
-following standard label types are included:</P>
+\li <tt>FL_IMAGE_OVER_TEXT</tt> - show the label image over the text (default).
-<UL>
+<A NAME="labeltypes"></A> <!-- For old HTML links only ! -->
+\par labeltype()
- <LI><TT>FL_NORMAL_LABEL</TT> - draws the text.</LI>
+The <tt>labeltype()</tt> method sets the type of the label. The
+following standard label types are included:
- <LI><TT>FL_NO_LABEL</TT> - does nothing.</LI>
+\li <tt>FL_NORMAL_LABEL</tt> - draws the text.
- <LI><TT>FL_SHADOW_LABEL</TT> - draws a drop shadow under
- the text.</LI>
+\li <tt>FL_NO_LABEL</tt> - does nothing.
- <LI><TT>FL_ENGRAVED_LABEL</TT> - draws edges as though
- the text is engraved.</LI>
+\li <tt>FL_SHADOW_LABEL</tt> - draws a drop shadow under the text.
- <LI><TT>FL_EMBOSSED_LABEL</TT> - draws edges as thought
- the text is raised.</LI>
+\li <tt>FL_ENGRAVED_LABEL</tt> - draws edges as though the text is engraved.
- <LI><TT>FL_ICON_LABEL</TT> - draws the icon associated
- with the text.</LI>
+\li <tt>FL_EMBOSSED_LABEL</tt> - draws edges as thought the text is raised.
-</UL>
+\li <tt>FL_ICON_LABEL</tt> - draws the icon associated with the text.
-<H3>image() and deimage()</H3>
+\par image() and deimage()
-<P>The <TT>image()</TT> and <TT>deimage()</TT> methods set an image that
-will be displayed with the widget. The <TT>deimage()</TT> method sets the
-image that is shown when the widget is inactive, while the <TT>image()</TT>
-method sets the image that is shown when the widget is active.</P>
+The <tt>image()</tt> and <tt>deimage()</tt> methods set an image that
+will be displayed with the widget. The <tt>deimage()</tt> method sets the
+image that is shown when the widget is inactive, while the <tt>image()</tt>
+method sets the image that is shown when the widget is active.
-<P>To make an image you use a subclass of
-<A HREF="drawing.html#Fl_Image"><TT>Fl_Image</TT></A>.</P>
+To make an image you use a subclass of
+<A HREF="drawing.html#Fl_Image"><tt>Fl_Image</tt></A>.
-<H4>Making Your Own Label Types</H4>
+\par Making Your Own Label Types
-<P>Label types are actually indexes into a table of functions
+Label types are actually indexes into a table of functions
that draw them. The primary purpose of this is to use this to
draw the labels in ways inaccessible through the
-<TT>fl_font</TT> mechanisim (e.g. <TT>FL_ENGRAVED_LABEL</TT>) or
-with program-generated letters or symbology.</P>
+<tt>fl_font</tt> mechanisim (e.g. <tt>FL_ENGRAVED_LABEL</tt>) or
+with program-generated letters or symbology.
<CENTER><TABLE WIDTH="80%" BORDER="1" CELLPADDING="5" CELLSPACING="0" BGCOLOR="#cccccc">
<TR>
<TD><B>Note:</B>
- <P>This interface has changed in FLTK 2.0!</P>
+ <P>This interface has changed in FLTK 2.0!
</TD>
</TR>
</TABLE></CENTER>
-<H5>Label Type Functions</H5>
+\par Label Type Functions
-<P>To setup your own label type you will need to write two
+To setup your own label type you will need to write two
functions: one to draw and one to measure the label. The draw
-function is called with a pointer to a <TT>Fl_Label</TT>
+function is called with a pointer to a <tt>Fl_Label</tt>
structure containing the label information, the bounding box for
-the label, and the label alignment:</P>
+the label, and the label alignment:
\code
void xyz_draw(const Fl_Label *label, int x, int y, int w, int h, Fl_Align align) {
@@ -481,13 +446,13 @@ void xyz_draw(const Fl_Label *label, int x, int y, int w, int h, Fl_Align align)
}
\endcode
-<P>The label should be drawn <I>inside</I> this bounding box,
-even if <TT>FL_ALIGN_INSIDE</TT> is not enabled. The function
-is not called if the label value is <TT>NULL</TT>.</P>
+The label should be drawn <I>inside</I> this bounding box,
+even if <tt>FL_ALIGN_INSIDE</tt> is not enabled. The function
+is not called if the label value is <tt>NULL</tt>.
-<P>The measure function is called with a pointer to a
-<TT>Fl_Label</TT> structure and references to the width and
-height:</P>
+The measure function is called with a pointer to a
+<tt>Fl_Label</tt> structure and references to the width and
+height:
\code
void xyz_measure(const Fl_Label *label, int &w, int &h) {
@@ -495,13 +460,13 @@ void xyz_measure(const Fl_Label *label, int &w, int &h) {
}
\endcode
-<P>The function should measure the size of the label and set
-<TT>w</TT> and <TT>h</TT> to the size it will occupy.</P>
+The function should measure the size of the label and set
+<tt>w</tt> and <tt>h</tt> to the size it will occupy.
-<H5>Adding Your Label Type</H5>
+\par Adding Your Label Type
-<P>The <TT>Fl::set_labeltype</TT> method creates a label type
-using your draw and measure functions:</P>
+The <tt>Fl::set_labeltype</tt> method creates a label type
+using your draw and measure functions:
\code
#define XYZ_LABEL FL_FREE_LABELTYPE
@@ -509,47 +474,48 @@ using your draw and measure functions:</P>
Fl::set_labeltype(XYZ_LABEL, xyz_draw, xyz_measure);
\endcode
-<P>The label type number <TT>n</TT> can be any integer value
-starting at the constant <TT>FL_FREE_LABELTYPE</TT>. Once you
-have added the label type you can use the <TT>labeltype()</TT>
-method to select your label type.</P>
+The label type number <tt>n</tt> can be any integer value
+starting at the constant <tt>FL_FREE_LABELTYPE</tt>. Once you
+have added the label type you can use the <tt>labeltype()</tt>
+method to select your label type.
-<P>The <TT>Fl::set_labeltype</TT> method can also be used to overload
-an existing label type such as <TT>FL_NORMAL_LABEL</TT>.</P>
+The <tt>Fl::set_labeltype</tt> method can also be used to overload
+an existing label type such as <tt>FL_NORMAL_LABEL</tt>.
-<H4><A NAME="add_symbol">Making your own symbols</A></H4>
+<A NAME="add_symbol"></A> <!-- For old HTML links only ! -->
+\par Making your own symbols
-<P>It is also possible to define your own drawings and add
+It is also possible to define your own drawings and add
them to the symbol list, so they can be rendered as part of
-any label.</P>
+any label.
-<P>To create a new symbol, you implement a drawing function
+To create a new symbol, you implement a drawing function
<tt>void drawit(Fl_Color c)</tt> which typically uses the
<a href="drawing.html#complex">complex drawing functions</a>
to generate a vector shape inside a two-by-two units sized box
around the origin. This function is then linked into the symbols
-table using <tt>fl_add_symbol</tt>:</P>
+table using <tt>fl_add_symbol</tt>:
\code
int fl_add_symbol(const char *name, void (*drawit)(Fl_Color), int scalable)
\endcode
-<P><i>name</i> is the name of the symbol without the "@"; <i>scalable</I>
+<i>name</i> is the name of the symbol without the "@"; <i>scalable</I>
must be set to 1 if the symbol is generated using scalable vector drawing
-functions.</P>
+functions.
\code
int fl_draw_symbol(const char *name,int x,int y,int w,int h,Fl_Color col)
\endcode
-<P>This function draws a named symbol fitting the given rectangle.
+This function draws a named symbol fitting the given rectangle.
-<H2>Callbacks</H2>
+\section common_callbacks Callbacks
-<P>Callbacks are functions that are called when the value of a
-widget changes. A callback function is sent a <TT>Fl_Widget</TT>
+Callbacks are functions that are called when the value of a
+widget changes. A callback function is sent a <tt>Fl_Widget</tt>
pointer of the widget that changed and a pointer to data that
-you provide:</P>
+you provide:
\code
void xyz_callback(Fl_Widget *w, void *data) {
@@ -557,9 +523,9 @@ void xyz_callback(Fl_Widget *w, void *data) {
}
\endcode
-<P>The <TT>callback()</TT> method sets the callback function for a
+The <tt>callback()</tt> method sets the callback function for a
widget. You can optionally pass a pointer to some data needed for the
-callback:</P>
+callback:
\code
int xyz_data;
@@ -567,9 +533,9 @@ int xyz_data;
button->callback(xyz_callback, &xyz_data);
\endcode
-<P>Normally callbacks are performed only when the value of the
+Normally callbacks are performed only when the value of the
widget changes. You can change this using the Fl_Widget::when()
-method:</P>
+method:
\code
button->when(FL_WHEN_NEVER);
@@ -589,22 +555,22 @@ button->when(FL_WHEN_CHANGED | FL_WHEN_NOT_CHANGED);
widget may still be accessed by FLTK after your callback
is completed. Instead, use the Fl::delete_widget()
method to mark your widget for deletion when it is safe
- to do so.</p>
+ to do so.
<p><B>Hint:</B>
<P>Many programmers new to FLTK or C++ try to use a
non-static class method instead of a static class method
or function for their callback. Since callbacks are done
- outside a C++ class, the <TT>this</TT> pointer is not
- initialized for class methods.</P>
+ outside a C++ class, the <tt>this</tt> pointer is not
+ initialized for class methods.
<P>To work around this problem, define a static method
in your class that accepts a pointer to the class, and
then have the static method call the class method(s) as
needed. The data pointer you provide to the
- <TT>callback()</TT> method of the widget can be a
- pointer to the instance of your class.</P>
+ <tt>callback()</tt> method of the widget can be a
+ pointer to the instance of your class.
\code
class Foo {
@@ -621,11 +587,11 @@ w->callback(my_static_callback, (void *)this);
</TR>
</TABLE></CENTER>
-<H2>Shortcuts</H2>
+\section common_shortcuts Shortcuts
-<P>Shortcuts are key sequences that activate widgets such as
-buttons or menu items. The <TT>shortcut()</TT> method sets the
-shortcut for a widget:</P>
+Shortcuts are key sequences that activate widgets such as
+buttons or menu items. The <tt>shortcut()</tt> method sets the
+shortcut for a widget:
\code
button->shortcut(FL_Enter);
@@ -636,11 +602,11 @@ button->shortcut(FL_CTRL + FL_ALT + 'b');
button->shortcut(0); // no shortcut
\endcode
-<P>The shortcut value is the key event value - the ASCII value
+The shortcut value is the key event value - the ASCII value
or one of the special keys like
-<a href="enumerations.html#key_values"><TT>FL_Enter</TT></a> -
+<a href="enumerations.html#key_values"><tt>FL_Enter</tt></a> -
combined with any modifiers like <KBD>Shift</KBD>,
-<KBD>Alt</KBD>, and <KBD>Control</KBD>.</P>
+<KBD>Alt</KBD>, and <KBD>Control</KBD>.
<hr>
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