This appendix describes all of the fl_ functions. For a
description of the FLTK classes, see Appendix
A.
Function List by Name
Function List by Category
- Drawing Functions
- Color
- Text
- Symbols
- Fast Drawing
- Complex Drawing
|
- Drawing Functions (cont'd)
- Clipping
- Overlay Drawing
- Offscreen Drawing
- Dialog Functions
- Filename Functions
- Image Functions
- Box Types
- System Related Functions
|
Include Files
#include <FL/fl_ask.H>
Prototype
void fl_alert(const char *, ...);
Description
Same as fl_message() except for the "!" symbol.
Include Files
#include <FL/fl_ask.H>
Prototype
int fl_ask(const char *, ...);
Description
Displays a printf-style message in a pop-up box with an
"Yes" and "No" button and waits for the user
to hit a button. The return value is 1 if the user hits Yes, 0
if they pick No. The enter key is a shortcut for Yes and ESC is
a shortcut for No.
Note: Use of this function is strongly
discouraged, and it will be removed in FLTK 2.0. Instead, use fl_choice() instead and provide
unambiguous verbs in place of "Yes" and "No".
Include Files
#include <FL/fl_ask.H>
Prototype
void fl_beep(int type = FL_BEEP_DEFAULT)
Description
Sounds an audible notification; the default type argument
sounds a simple "beep" sound. Other values for type may use
a system or user-defined sound file:
- FL_BEEP_DEFAULT - Make a generic "beep" sound.
- FL_BEEP_MESSAGE - Make a sound appropriate for an
informational message.
- FL_BEEP_ERROR - Make a sound appropriate for an
error message.
- FL_BEEP_QUESTION - Make a sound appropriate for
a question.
- FL_BEEP_PASSWORD - Make a sound appropriate for
a password prompt.
- FL_BEEP_NOTIFICATION - Make a sound appropriate for
an event notification ("you have mail", etc.)
Include Files
#include <FL/fl_ask.H>
Prototype
int fl_choice(const char *q, const char *b0, const char *b1, const char *b2, ...);
Description
Shows the message with three buttons below it marked with the
strings b0, b1, and b2. Returns 0,
1, or 2 depending on which button is hit. ESC is a shortcut for
button 0 and the enter key is a shortcut for button 1. Notice
the buttons are positioned "backwards". You can hide
buttons by passing NULL as their labels.
Include Files
#include <FL/Enumerations.H>
Prototype
Fl_Color fl_color_average(Fl_Color c1, Fl_Color c2, float weight);
Description
Returns the weighted average color between the two colors.
The red, green, and blue values are averaged using the following
formula:
color = c1 * weight + c2 * (1 - weight)
Thus, a weight value of 1.0 will return the
first color, while a value of 0.0 will return the second color.
Include Files
#include <FL/Fl_Color_Chooser.H>
Prototype
int fl_color_chooser(const char *title, double &r, double &g, double &b);
int fl_color_chooser(const char *title, uchar &r, uchar &g, uchar &b);
Description
The double version takes RGB values in the range
0.0 to 1.0. The uchar version takes RGB values in
the range 0 to 255. The title argument specifies the
label (title) for the window.

fl_color_chooser() pops up a window to let the user
pick an arbitrary RGB color. They can pick the hue and
saturation in the "hue box" on the left (hold down
CTRL to just change the saturation), and the brighness using the
vertical slider. Or they can type the 8-bit numbers into the
RGB
Fl_Value_Input fields, or drag the mouse across them to
adjust them. The pull-down menu lets the user set the input
fields to show RGB, HSV, or 8-bit RGB (0 to 255).
This returns non-zero if the user picks ok, and updates the
RGB values. If the user picks cancel or closes the window this
returns zero and leaves RGB unchanged.
If you use the color chooser on an 8-bit screen, it will
allocate all the available colors, leaving you no space to
exactly represent the color the user picks! You can however use
fl_rectf() to fill a
region with a simulated color using dithering.
Include File
#include <FL/fl_draw.H>
Prototype
Fl_Color fl_color_cube(int r, int g, int b);
Description
Returns a color out of the color cube. r must be in
the range 0 to FL_NUM_RED (5) minus 1. g must be in the
range 0 to FL_NUM_GREEN (8) minus 1. b must be in the
range 0 to FL_NUM_BLUE (5) minus 1.
To get the closest color to a 8-bit set of R,G,B values use:
fl_color_cube(R * (FL_NUM_RED - 1) / 255,
G * (FL_NUM_GREEN - 1) / 255,
B * (FL_NUM_BLUE - 1) / 255);
Include Files
#include <FL/Enumerations.H>
Prototype
Fl_Color fl_contrast(Fl_Color fg, Fl_Color bg);
Description
Returns the foreground color if it contrasts sufficiently
with the background color. Otherwise, returns
FL_WHITE or FL_BLACK depending on
which color provides the best contrast.
Include Files
#include <FL/fl_draw.H>
Prototype
void fl_cursor(Fl_Cursor cursor, Fl_Color fg, Fl_Color bg);
Description
Sets the cursor for the current window to the specified shape
and colors. The cursors are defined in the <FL/Enumerations.H>
header file.
Include Files
#include <FL/Enumerations.H>
Prototype
Fl_Color fl_darker(Fl_Color c);
Description
Returns a darker version of the specified color.
Include Files
#include <FL/Fl_File_Chooser.H>
Prototype
char *fl_dir_chooser(const char * message, const char *fname, int relative = 0);
Description
The fl_dir_chooser() function displays a Fl_File_Chooser dialog
so that the user can choose a directory.
message is a string used to title the window.
fname is a default filename to fill in the chooser
with. If this is NULL then the last filename that was
choosen is used. The first time the file chooser is called this
defaults to a blank string.
relative specifies whether the returned filename
should be relative (any non-zero value) or absolute (0). The
default is to return absolute paths.
The returned value points at a static buffer that is only
good until the next time fl_dir_chooser() is called.
Include Files
#include <FL/Fl_File_Chooser.H>
Prototype
char *fl_file_chooser(const char * message, const char *pattern, const char *fname, int relative = 0);
Description
FLTK provides a "tab completion" file chooser that
makes it easy to choose files from large directories. This file
chooser has several unique features, the major one being that
the Tab key completes filenames like it does in Emacs or tcsh,
and the list always shows all possible completions.
fl_file_chooser() pops up the file chooser, waits
for the user to pick a file or Cancel, and then returns a
pointer to that filename or NULL if Cancel is chosen.
message is a string used to title the window.
pattern is used to limit the files listed in a
directory to those matching the pattern. This matching is done by
fl_filename_match().
Multiple patterns can be used by separating them with tabs, like
"*.jpg\t*.png\t*.gif\t*". In addition, you can provide
human-readable labels with the patterns inside parenthesis, like
"JPEG Files (*.jpg)\tPNG Files (*.png)\tGIF Files (*.gif)\tAll Files (*)".
Pass NULL to show all files.
fname is a default filename to fill in the chooser
with. If this is NULL then the last filename that was
choosen is used (unless that had a different pattern, in which
case just the last directory with no name is used). The first
time the file chooser is called this defaults to a blank string.
relative specifies whether the returned filename
should be relative (any non-zero value) or absolute (0). The
default is to return absolute paths.
The returned value points at a static buffer that is only
good until the next time fl_file_chooser() is called.
Include Files
#include <FL/Fl_File_Chooser.H>
Prototype
void fl_file_chooser_callback(void (*cb)(const char *));
Description
Sets a function that is called every time the user clicks a
file in the currently popped-up file chooser. This could be used
to preview the contents of the file. It has to be reasonably
fast, and cannot create FLTK windows.
Include Files
#include <FL/Fl_File_Chooser.H>
Prototype
void fl_file_chooser_ok_label(const char *l);
Description
Sets the label that is shown on the "OK" button in the file
chooser. The default label (fl_ok) can be restored by
passing a NULL pointer for the label string.
Include Files
#include <FL/filename.H>
Prototype
int fl_filename_absolute(char *to, int tolen, const char *from);
int fl_filename_absolute(char *to, const char *from);
Description
Converts a relative pathname to an absolute pathname. If
from does not start with a slash, the current working
directory is prepended to from with any occurances of
. and x/.. deleted from the result. The
absolute pathname is copied to to; from and
to may point to the same buffer.
fl_filename_absolute returns non-zero if any changes
were made.
The first form accepts a maximum length (tolen) for
the destination buffer, while the second form assumes that the
destination buffer is at least FL_PATH_MAX characters
in length.
Include Files
#include <FL/filename.H>
Prototype
int fl_filename_expand(char *to, int tolen, const char *from);
int fl_filename_expand(char *to, const char *from);
Description
This function replaces environment variables and home
directories with the corresponding strings. Any occurrence of
$X is replaced by getenv("X"); if
$X is not defined in the environment, the occurrence is
not replaced. Any occurence of ~X is replaced by user
X's home directory; if user X does not exist,
the occurrence is not replaced. Any resulting double slashes
cause everything before the second slash to be deleted.
The result is copied to to, and from and
to may point to the same buffer.
fl_filename_expand() returns non-zero if any changes
were made.
The first form accepts a maximum length (tolen) for
the destination buffer, while the second form assumes that the
destination buffer is at least FL_PATH_MAX characters
in length.
Include Files
#include <FL/filename.H>
Prototype
const char *fl_filename_ext(const char *f);
Description
Returns a pointer to the last period in
fl_filename_name(f), or a pointer to the trailing
nul if none is found.
Include Files
#include <FL/filename.H>
Prototype
int fl_filename_isdir(const char *f);
Description
Returns non-zero if the file exists and is a directory.
Include Files
#include <FL/filename.H>
Prototype
int fl_filename_list(const char *d, dirent ***list, Fl_File_Sort_F *sort = fl_numericsort);
Description
This is a portable and const-correct wrapper for the
scandir() function. d is the name of a
directory; it does not matter if it has a trailing slash or not.
For each file in that directory a "dirent" structure
is created. The only portable thing about a dirent is that
dirent.d_name is the nul-terminated file name.
An array of pointers to these dirent's is created and a
pointer to the array is returned in *list. The number
of entries is given as a return value. If there is an error
reading the directory a number less than zero is returned, and
errno has the reason; errno does not work
under WIN32.
The name of directory always ends in a forward slash '/'.
The sort argument specifies a sort function to be used
when on the array of filenames. The following standard sort functions
are provided with FLTK:
- fl_alphasort - The files are sorted in
ascending alphabetical order; upper- and lowercase
letters are compared according to their ASCII ordering -
uppercase before lowercase.
- fl_casealphasort - The files are sorted in
ascending alphabetical order; upper- and lowercase
letters are compared equally - case is not significant.
- fl_casenumericsort - The files are sorted
in ascending "alphanumeric" order, where an
attempt is made to put unpadded numbers in consecutive
order; upper- and lowercase letters are compared equally
- case is not significant.
- fl_numericsort - The files are sorted in
ascending "alphanumeric" order, where an
attempt is made to put unpadded numbers in consecutive
order; upper- and lowercase letters are compared
according to their ASCII ordering - uppercase before
lowercase.
You can free the returned list of files with the following
code:
for (int i = return_value; i > 0;) {
free((void*)(list[--i]));
}
free((void*)list);
Include Files
#include <FL/filename.H>
Prototype
int fl_filename_match(const char *f, const char *pattern);
Description
Returns non-zero if f matches pattern. The
following syntax is used by pattern:
- * matches any sequence of 0 or more
characters.
- ? matches any single character.
- [set] matches any character in the set. Set
can contain any single characters, or a-z to represent a
range. To match ] or - they must be the first
characters. To match ^ or ! they must not be the first
characters.
- [^set] or [!set] matches any
character not in the set.
- {X|Y|Z} or {X,Y,Z} matches any one of the
subexpressions literally.
- \x quotes the character x so it has no
special meaning.
- x all other characters must be matched
exactly.
Include Files
#include <FL/filename.H>
Prototype
const char *fl_filename_name(const char *f);
Description
Returns a pointer to the character after the last slash, or
to the start of the filename if there is none.
Include Files
#include <FL/filename.H>
Prototype
int fl_filename_relative(char *to, int tolen, const char *from);
int fl_filename_relative(char *to, const char *from);
Description
Converts an absolute pathname to an relative pathname. The
relative pathname is copied to to; from and
to may point to the same buffer.
fl_filename_relative returns non-zero if any changes
were made.
The first form accepts a maximum length (tolen) for
the destination buffer, while the second form assumes that the
destination buffer is at least FL_PATH_MAX characters
in length.
Include Files
#include <FL/filename.H>
Prototype
char *fl_filename_setext(char *to, int tolen, const char *ext);
char *fl_filename_setext(char *to, const char *ext);
Description
Replaces the extension in to with the extension in
ext. Returns a pointer to to.
The first form accepts a maximum length (tolen) for
the destination buffer, while the second form assumes that the
destination buffer is at least FL_PATH_MAX characters
in length.
Include File
#include <FL/fl_draw.H>
Prototype
Fl_Color fl_gray_ramp(int i);
Description
Returns a gray color value from black (i == 0) to
white (i == FL_NUM_GRAY - 1). FL_NUM_GRAY is
defined to be 24 in the current FLTK release. To get the closest
FLTK gray value to an 8-bit grayscale color 'I' use:
fl_gray_ramp(I * (FL_NUM_GRAY - 1) / 255)
Include File
#include <FL/Enumerations.H>
Prototype
Fl_Color fl_inactive(Fl_Color c);
Description
Returns the inactive, dimmed version of the give color
Include Files
#include <FL/fl_ask.H>
Prototype
const char *fl_input(const char *label, const char *deflt = 0, ...);
Description
Pops up a window displaying a string, lets the user edit it,
and return the new value. The cancel button returns
NULL. The returned pointer is only valid until the
next time fl_input() is called. Due to
back-compatability, the arguments to any printf commands in the
label are after the default value.
Include Files
#include <FL/Enumerations.H>
Prototype
Fl_Color fl_lighter(Fl_Color c);
Description
Returns a lighter version of the specified color.
Include Files
#include <FL/fl_ask.H>
Prototype
void fl_message(const char *, ...);
Description
Displays a printf-style message in a pop-up box with an
"OK" button, waits for the user to hit the button.
The message will wrap to fit the window, or may be many lines by
putting \n characters into it. The enter key is a
shortcut for the OK button.
A message text can be further formatted with html tags by
adding <html> at the beginning of the message.
See Fl_Help_View for
details.
The message text is limited to 1024 characters.
Include Files
#include <FL/fl_ask.H>
Prototype
void fl_message_font(Fl_Font fontid, uchar size);
Description
Changes the font and font size used for the messages in all
the popups.
Include Files
#include <FL/fl_ask.H>
Prototype
Fl_Widget *fl_message_icon();
Description
Returns a pointer to the box at the left edge of all the
popups. You can alter the font, color, label, or image before
calling the functions.
Include Files
#include <FL/filename.H>
Prototype
void fl_open_uri(const char *uri, char *msg = (char *)0, int msglen = 0);
Description
fl_open_uri() opens the specified Uniform Resource Identifier (URI) using an operating-system dependent program or interface. For URIs using the "ftp", "http", or "https" schemes, the system default web browser is used to open the URI, while "mailto" and "news" URIs are typically opened using the system default mail reader and "file" URIs are opened using the file system navigator.
On success, the (optional) msg buffer is filled with the command that was run to open the URI; on Windows, this will always be "open uri".
On failure, the msg buffer is filled with an English error message.
Include Files
#include <FL/fl_ask.H>
Prototype
const char *fl_password(const char *label, const char *deflt = 0, ...);
Description
Same as fl_input(), except an Fl_Secret_Input field is
used.
Include File
#include <FL/Fl_Shared_Image.H>
Prototype
void fl_register_images();
Description
Registers the extra image file formats that are not provided
as part of the core FLTK library for use with the Fl_Shared_Image
class.
This function is provided in the fltk_images
library.
Include File
#include <FL/fl_draw.H>
Prototype
Fl_Color fl_rgb_color(uchar r, uchar g, uchar b);
Fl_Color fl_rgb_color(uchar g);
Description
Returns the 24-bit RGB color value for the specified 8-bit
RGB or grayscale values.
Include Files
#include <FL/fl_show_colormap.H>
Prototype
Fl_Color fl_show_colormap(Fl_Color oldcol)
Description
fl_show_colormap() pops up a panel of the 256 colors
you can access with fl_color() and lets
the user pick one of them. It returns the new color index, or
the old one if the user types ESC or clicks outside the window.
From Roker, 15:52 Oct 04, 2007 (score=3)
How the file_chooser_callback finds its canvas to display the file preview?
[ Reply ] |