@node Part III Static Objects
@chapter Static Objects

@ifnottex

@menu
* Box Object:          Box Object
* Frame Object:        Frame Object
* LabelFrame Object:   LabelFrame Object
* Text Object:         Text Object
* Bitmap Object:       Bitmap Object
* Pixmap Object:       Pixmap Object
* Clock Object:        Clock Object
* Chart Object:        Chart Object
@end menu


@end ifnottex


@node Box Object
@section Box Object

Boxes are simply used to give the dialogue forms a nicer appearance.
They can be used to visually group other objects together. The bottom
of each form is a box.

@ifnottex

@menu
* Adding Box Objects:  Adding Box Objects
* Box Types:           Box Types
* Box Attributes:      Box Attributes
* Remarks:             Box Remarks
@end menu

@end ifnottex


@node Adding Box Objects
@subsection Adding Box Objects

To add a box to a form you use the routine
@findex fl_add_box()
@anchor{fl_add_box()}
@example
FL_OBJECT *fl_add_box(int type, FL_Coord x, FL_Coord y,
                      FL_Coord w, FL_Coord h, const char *label);
@end example
@noindent
The meaning of the parameters is as usual. The label is per default
placed in the center of the box.


@node Box Types
@subsection Box Types

The following types are available:
@table @code
@tindex FL_UP_BOX
@anchor{FL_UP_BOX}
@item FL_UP_BOX
A box that comes out of the screen.

@tindex FL_DOWN_BOX
@anchor{FL_DOWN_BOX}
@item @code{FL_DOWN_BOX}
A box that goes down into the screen.

@tindex FL_FLAT_BOX
@anchor{FL_FLAT_BOX}
@item FL_FLAT_BOX
A flat box without a border.

@tindex FL_BORDER_BOX
@anchor{FL_BORDER_BOX}
@item FL_BORDER_BOX
A flat box with just a border.

@tindex FL_FRAME_BOX
@anchor{FL_FRAME_BOX}
@item FL_FRAME_BOX
A flat box with an engraved frame.

@tindex FL_SHADOW_BOX
@anchor{FL_SHADOW_BOX}
@item FL_SHADOW_BOX
A flat box with a shadow.

@tindex FL_ROUNDED_BOX
@anchor{FL_ROUNDED_BOX}
@item FL_ROUNDED_BOX
A rounded box.

@tindex FL_RFLAT_BOX
@anchor{FL_RFLAT_BOX}
@item FL_RFLAT_BOX
A rounded box without a border.

@tindex FL_RSHADOW_BOX
@anchor{FL_RSHADOW_BOX}
@item FL_RSHADOW_BOX
A rounded box with a shadow.

@tindex FL_OVAL_BOX
@anchor{FL_OVAL_BOX}
@item FL_OVAL_BOX
An elliptic box.

@tindex FL_NO_BOX
@anchor{FL_NO_BOX}
@item FL_NO_BOX
No box at all, only a centered label.
@end table


@node Box Attributes
@subsection Box Attributes

The first color argument (@code{col1}) to
@code{@ref{fl_set_object_color()}} controls the color of the box, the
second (@code{col2}) is not used.


@node Box Remarks
@subsection Remarks

No interaction takes place with boxes.

Do not use @code{FL_NO_BOX} type if the label is to change during the
execution of the program.


@node Frame Object
@section Frame Object

Frames are simply used to give the dialogue forms a nicer appearance.
They can be used to visually group other objects together. Frames are
almost the same as a box, except that the interior of the bounding box
is not filled. Use of frames can speed up drawing in certain
situations. For example, to place a group of radio buttons within an
@code{FL_ENGRAVED_FRAME}. If we were to use an @code{FL_FRAME_BOX} to
group the buttons, visually they would look the same. However, the
latter is faster as we don't have to fill the interior of the bounding
box and can also reduce flicker. Frames are useful in decorating free
objects and canvases.


@ifnottex

@menu
* Adding Frame Objects:   Adding Frame Objects
* Frame Types:            Frame Types
* Frame Attributes:       Frame Attributes
* Remarks:                Frame Remarks
@end menu

@end ifnottex


@node Adding Frame Objects
@subsection Adding Frame Objects

To add a frame to a form you use the routine
@example
FL_OBJECT *fl_add_frame(int type, FL_Coord x, FL_Coord y,
                        FL_Coord w, FL_Coord h, const char *label);
@end example
@noindent
The meaning of the parameters is as usual except that the frame is
drawn outside of the bounding box (so a flat box of the same size just
fills the inside of the frame without any gaps). The label is by
default placed centered inside the frame.


@node Frame Types
@subsection Frame Types

The following types are available:
@table @code
@tindex FL_NO_FRAME
@item FL_NO_FRAME
Nothing is drawn.
@tindex FL_UP_FRAME
@item FL_UP_FRAME
A frame appears coming out of the screen.
@tindex FL_DOWN_FRAME
@item FL_DOWN_FRAME
A frame that goes down into the screen.
@tindex FL_BORDER_FRAME
@item FL_BORDER_FRAME
A frame with a simple outline.
@tindex FL_ENGRAVED_FRAME
@item FL_ENGRAVED_FRAME
A frame appears to be engraved.
@tindex FL_EMBOSSED_FRAME
@item FL_EMBOSSED_FRAME
A frame appears embossed.
@tindex FL_ROUNDED_FRAME
@item FL_ROUNDED_FRAME
A rounded frame.
@tindex FL_OVAL_FRAME
@item FL_OVAL_FRAME
An elliptic box.
@end table


@node Frame Attributes
@subsection Frame Attributes

The first color argument (@code{col1}) of
@code{@ref{fl_set_object_color()}} controls the color of the frame if
applicable, the second (@code{col2}) is not used. The boxtype
attribute does not apply to the frame class.


@node Frame Remarks
@subsection Remarks

No interaction takes place with frames.

It may be faster to use frames instead of boxes for text that is truly
static. See @file{freedraw.c} for an example use of frame objects.


@node LabelFrame Object
@section LabelFrame Object

A label frame is almost the same as a frame except that the label is
placed on the frame (See Fig. 15.1) instead of inside or outside of
the bounding box as in a regular frame.

@ifnottex

@menu
* Adding LabelFrame Objects:  Adding LabelFrame Objects
* LabelFrame Types:           LabelFrame Types
* LabelFrame Attributes:      LabelFrame Attributes
* Remarks:                    LabelFrames Remarks
@end menu

@end ifnottex


@node Adding LabelFrame Objects
@subsection Adding LabelFrame Objects

To add a labelframe to a form you use the routine
@findex fl_add_labelframe()
@anchor{fl_add_labelframe()}
@example
FL_OBJECT *fl_add_labelframe(int type, FL_Coord x, FL_Coord y,
                             FL_Coord w, FL_Coord h, const char *label);
@end example
@noindent
The meaning of the parameters is as usual except that the frame is
drawn outside of the bounding box (so a flat box of the same size just
fills the inside of the frame without any gaps). The label is by
default placed on the upper left hand part of the frame. Its position
can changed (within limits) via calls of
@code{@ref{fl_set_object_lalign()}}.

@ifhtml
@center @image{images/labelframe}
@end ifhtml
@ifnothtml
@center @image{images/labelframe,7cm}
@end ifnothtml


@node LabelFrame Types
@subsection LabelFrame Types

The following types are available:
@table @code
@tindex FL_NO_FRAME
@item FL_NO_FRAME
Nothing is drawn.
@tindex FL_UP_FRAME
@item FL_UP_FRAME
A frame appears coming out of the screen.
@tindex FL_DOWN_FRAME
@item FL_DOWN_FRAME
A frame that goes down into the screen.
@tindex FL_BORDER_FRAME
@item FL_BORDER_FRAME
A frame with a simple outline.
@tindex FL_ENGRAVED_FRAME
@item FL_ENGRAVED_FRAME
A frame appears to be engraved.
@tindex FL_EMBOSSED_FRAME
@item FL_EMBOSSED_FRAME
A frame appears embossed.
@tindex FL_ROUNDED_FRAME
@item FL_ROUNDED_FRAME
A rounded frame.
@tindex FL_OVAL_FRAME
@item FL_OVAL_FRAME
An elliptic box.
@end table


@node LabelFrame Attributes
@subsection Attributes

The first color in the call of @code{@ref{fl_set_object_color()}}
controls the color of the frame if applicable. The second color
controls the background color of the label. Boxtype attribute does not
apply to the labelframe class


@node LabelFrames Remarks
@subsection Remarks

No interaction takes place with labelframes.

You can not draw a label inside or outside of the frame box. If you
try, say, by requesting @code{FL_ALIGN_CENTER}, the label is drawn
using @code{FL_ALIGN_TOP_LEFT}.


@node Text Object
@section Text Object

Text objects simply consist of a label possibly placed in a box.

@ifnottex

@menu
* Adding Text Objects:   Adding Text Objects
* Text Types:            Text Types
* Text Attributes:       Text Attributes
* Remarks:               Text Remarks
@end menu

@end ifnottex


@node Adding Text Objects
@subsection Adding Text Objects


To add a text to a form you use the routine
@findex fl_add_text()
@anchor{fl_add_text()}
@example
FL_OBJECT *fl_add_text(int type, FL_Coord x, FL_Coord y,
                       FL_Coord w, FL_Coord h, const char *label);
@end example
@noindent
The meaning of the parameters is as usual. The label is by default
placed flushed left in the bounding box.


@node Text Types
@subsection Text Types

@tindex FL_NORMAL_TEXT
Only one type of text exists: @code{FL_NORMAL_TEXT}.


@node Text Attributes
@subsection Text Attributes

To set or change the text shown, use @code{@ref{fl_set_object_label()}}.

Any boxtype can be used for text.

The first color argument (@code{col1}) of
@code{@ref{fl_set_object_color()}} controls the color of the box the
text is placed into, the second (@code{col2}) is not used. The color of
the text itself is controlled by calls of
@code{@ref{fl_set_object_lcol()}} as usual.

If the text is to change dynamically, boxtype @code{NO_BOX} should
not be used for the object.


@node Text Remarks
@subsection Remarks

No interaction takes place with text objects.

Don't use boxtype @code{FL_NO_BOX} if the text is to change
dynamically. Note that there is almost no difference between a box
with a label and a text. The only difference lies in the position
where the text is placed and the fact that text is clipped to the
bounding box. Text is normally placed inside the box at the left side.
This helps you putting different lines of text below each other.
Labels inside boxes are default centered in the box. You can change
the position of the text inside the box using the routine
@code{@ref{fl_set_object_lalign()}}. In contrast to boxes different
alignments for text always place the text inside the box rather than
outside the box.


@node Bitmap Object
@section Bitmap Object

A bitmap is a simple bitmap shown on a form.

@ifnottex

@menu
* Adding Bitmap Objects:   Adding Bitmap Objects
* Bitmap Types:            Bitmap Types
* Bitmap Interaction:      Bitmap Interaction
* Other Bitmap Routines:   Other Bitmap Routines
* Bitmap Attributes:       Bitmap Attributes
* Remarks:                 Bitmap Remarks
@end menu

@end ifnottex


@node Adding Bitmap Objects
@subsection Adding Bitmap Objects

To add a bitmap to a form you use the routine
@findex fl_add_bitmap()
@anchor{fl_add_bitmap()}
@example
FL_OBJECT *fl_add_bitmap(int type, FL_Coord x, FL_Coord y,
                         FL_Coord w, FL_Coord h, const char *label);
@end example
The meaning of the parameters is as usual. The label is by default
placed below the bitmap. The bitmap is empty on creation.


@node Bitmap Types
@subsection Bitmap Types

@tindex FL_NORMAL_BITMAP
Only the type @code{FL_NORMAL_BITMAP} is available.


@node Bitmap Interaction
@subsection Bitmap Interaction

No interaction takes place with a bitmap. For bitmaps that interact
see @ref{Adding Button Objects}, on how to create a button with a
bitmap on top of it. (You can also place a hidden button over it if
you want something to happen when pressing the mouse on a static
bitmap.)


@node Other Bitmap Routines
@subsection Other Bitmap Routines

To set the actual bitmap being displayed use
@findex fl_set_bitmap_data()
@anchor{fl_set_bitmap_data()}
@findex fl_set_bitmap_file()
@anchor{fl_set_bitmap_file()}
@example
void fl_set_bitmap_data(FL_OBJECT *obj, int w, int h,
                         unsigned char *bits);
void fl_set_bitmap_file(FL_OBJECT *obj, const char *file);
@end example
@noindent
@code{bits} contains the bitmap data as a character string.
@code{file} is the name of the file that contains the bitmap data. A
number of bitmaps can be found in @file{/usr/include/X11/bitmaps} or
similar places. The X program @code{bitmap} can be used to create
bitmaps.

Two additional routines are provided to make a Bitmap from a bitmap
file or data
@findex fl_read_bitmapfile()
@anchor{fl_read_bitmapfile()}
@findex fl_create_from_bitmapdata()
@anchor{fl_create_from_bitmapdata()}
@example
Pixmap fl_read_bitmapfile(Window win, const char *filename,
                          unsigned *width, unsigned *height,
                          int *hotx, int *hoty)
Pixmap fl_create_from_bitmapdata(Window win, const char *data,
                                 int width, int height);
@end example
@noindent
where @code{win} is any window ID in your application and the other
parameters have the obvious meanings. If there is no window created
yet, the return value of @code{@ref{fl_default_window()}} may be used.

Note: bitmaps created by the above routines have a depth of 1 and
should be displayed using @code{XCopyPlane()}.


@node Bitmap Attributes
@subsection Bitmap Attributes

The label color as set by @code{@ref{fl_set_object_lcol()}} controls
both the foreground color of the bitmap and the color of the label
(i.e.@: they are always identical).

The first color argument (@code{col1}) to
@code{@ref{fl_set_object_color()}} sets the background color of the
bitmap (and the color of the box), the second (@code{col2}) is not
used.

@node Bitmap Remarks
@subsection Remarks

See @file{demo33.c} for a demo of a bitmap.


@node Pixmap Object
@section Pixmap Object

A pixmap is a simple pixmap (color icon) shown on a form.

@ifnottex

@menu
* Adding Pixmap Objects:   Adding Pixmap Objects
* Pixmap Types:            Pixmap Types
* Pixmap Interaction:      Pixmap Interaction
* Other Pixmap Routines:   Other Pixmap Routines
* Pixmap Attributes:       Pixmap Attributes
* Remarks:                 Pixmap Remarks
@end menu

@end ifnottex


@node Adding Pixmap Objects
@subsection Adding Pixmap Objects

To add a pixmap to a form use the routine
@findex fl_add_pixmap()
@anchor{fl_add_pixmap()}
@example
FL_OBJECT *fl_add_pixmap(int type, FL_Coord x, FL_Coord y,
                         FL_Coord w, FL_Coord h, const char *label)
@end example
@noindent
The meaning of the parameters is as usual. The label is by default
placed below the pixmap. The pixmap is empty on creation.


@node Pixmap Types
@subsection Pixmap Types

@tindex FL_NORMAL_PIXMAP
Only the type @code{FL_NORMAL_PIXMAP} is available.


@node Pixmap Interaction
@subsection Pixmap Interaction

No interaction takes place with a pixmap. For pixmap that interacts
see @ref{Adding Button Objects}, on how to create a button with a pixmap
on top of it. (You can also place a hidden button over it if you want
something to happen when pressing the mouse on a static pixmap.)


@node Other Pixmap Routines
@subsection Other Pixmap Routines


A pixmap file (usually with extension @code{.xpm}) is an ASCII file
that contains the definition of the pixmap as a @code{char} pointer
array that can be included directly into a C (or C++) source file.

To set the actual pixmap being displayed, use one of the following
routines:
@findex fl_set_pixmap_file()
@anchor{fl_set_pixmap_file()}
@findex fl_set_pixmap_data()
@anchor{fl_set_pixmap_data()}
@example
void fl_set_pixmap_file(FL_OBJECT *obj, const char *file);
void fl_set_pixmap_data(FL_OBJECT *obj, char **data);
@end example
@noindent
In the first routine, you specify the pixmap by the filename
@code{file} that contains it. In the second routine, you
@code{#include} the pixmap at compile time and use the pixmap data (an
array of @code{char} pointers) directly. Note that both of these
functions do not free the old pixmaps associated with the object. If
you're writing a pixmap browser type applications, be sure to free the
old pixmaps by calling
@findex fl_free_pixmap_pixmap()
@anchor{fl_free_pixmap_pixmap()}
@example
void fl_free_pixmap_pixmap(FL_OBJECT *obj);
@end example
@noindent
on the pixmap object prior to calling these two routines. This
function, in addition to freeing the pixmap and the mask, also frees
the colors the pixmap allocated.

To obtain the pixmap ID currently being displayed, the following
routine can be used
@findex fl_get_pixmap_pixmap()
@anchor{fl_get_pixmap_pixmap()}
@example
Pixmap fl_get_pixmap_pixmap(FL_OBJECT *obj, Pixmap *id,
                            Pixmap *mask);
@end example
@noindent
In some situations, you might already have a pixmap resource ID,
e.g.@: from @code{@ref{fl_read_pixmapfile()}} (see below in the
"Remarks" subsection) you can use the following routine to change the
the pixmap
@findex fl_set_pixmap_pixmap()
@anchor{fl_set_pixmap_pixmap()}
@example
void fl_set_pixmap_pixmap(FL_OBJECT *obj, Pixmap id,
                          Pixmap mask);
@end example
@noindent
where @code{mask} is used for transparency (see
@code{@ref{fl_read_pixmapfile()}}). Use 0 for mask if no special
clipping attributes are desired.

This routine does not free the pixmap ID nor the mask already
associated with the object. Thus if you no longer need the old
pixmaps, they should be freed prior to changing the pixmaps using
the function @code{@ref{fl_free_pixmap_pixmap()}}.

Pixmaps are by default displayed centered inside the bounding box.
However, this can be changed using the following routine
@findex fl_set_pixmap_align()
@anchor{fl_set_pixmap_align()}
@example
void fl_set_pixmap_align(FL_OBJECT *obj, int align,
                         int dx, int dy);
@end example
@noindent
where @code{align} is the same as that used for labels. @xref{Label
Attributes and Fonts}, for a list. @code{dx} and @code{dy} are extra
margins to leave in addition to the object border width. By default,
@code{dx} and @code{dy} are set to 3. Note that although you can place
a pixmap outside of the bounding box, it probably is not a good idea.


@node Pixmap Attributes
@subsection Pixmap Attributes

By default, if a pixmap has more colors than that available in the
colormap, the library will use substitute colors that are judged
"close enough". This closeness is defined as the difference between
the requested color and the color found being smaller than some
pre-set threshold values between 0 and 65535 (0 means exact match).
The default thresholds are 40000 for red, 30000 for green and 50000
for blue. To change these defaults, use the following routine
@findex fl_set_pixmap_colorcloseness()
@anchor{fl_set_pixmap_colorcloseness()}
@example
void fl_set_pixmap_colorcloseness(int red, int green, int blue);
@end example 


@node Pixmap Remarks
@subsection Remarks

The following routines may come in handy to read a pixmap file into a
pixmap
@findex fl_read_pixmapfile()
@anchor{fl_read_pixmapfile()}
@example
Pixmap fl_read_pixmapfile(Window win, const char *filename,
                          unsigned *width, unsigned *height,
                          Pixmap *shape_mask, int *hotx, int *hoty,
                          FL_COLOR tran);
@end example
@noindent
where @code{win} is the window in which the pixmap is to be displayed.
If the window is yet to be created, you can use the default window,
returned by a call of @code{@ref{fl_default_window()}}. Parameter
@code{shape_mask} is a pointer to an already existing @code{Pixmap},
which, if not @code{NULL}, is used as a clipping mask to achieve
transparency. @code{hotx} and @code{hoty} are the center of the pixmap
(useful if the pixmap is to be used as a cursor). Parameter
@code{tran} is currently not used.

If you have already had the pixmap data in memory, the following
routine may be used
@findex fl_create_from_pixmapdata()
@anchor{fl_create_from_pixmapdata()}
@example
Pixmap fl_create_from_pixmapdata(Window win, char **data,
                                 unsigned *width, unsigned *height,
                                 Pixmap *shape_mask, int *hotx,
                                 int *hoty, FL_COLOR tran);
@end example
@noindent
All parameters have the same meaning as for @code{fl_read_pixmapfile}.

Note that the Forms Library handles transparency, if specified in the
pixmap file or data, for pixmap and pixmapbutton objects. However,
when using @code{@ref{fl_read_pixmapfile()}} or
@code{@ref{fl_create_from_pixmapdata()}}, the application programmer
is responsible to set the clip mask in an appropriate GCs.

Finally there is a routine that can be used to free a Pixmap
@findex fl_free_pixmap()
@anchor{fl_free_pixmap()}
@example
void fl_free_pixmap(Pixmap id);
@end example
@noindent
You will need the XPM library (version 3.4c or later) developed by
Arnaud Le Hors and GROUPE BULL (@email{lehors@@sophia.inria.fr}) to
use pixmap. The XPM library can be obtained from many X
distribution/mirror sites via anonymous FTP, e.g.@:
(@uref{ftp://ftp.x.org/contrib/libraries/}. Its home page is
@uref{http://old.koalateam.com/lehors/xpm.html}.


@node Clock Object
@section Clock Object

A clock object simply displays a clock on the form

@ifnottex

@menu
* Adding Clock Objects:   Adding Clock Objects
* Clock Types:            Clock Types
* Clock Interaction:      Clock Interaction
* Other Clock Routines:   Other Clock Routines
* Clock Attributes:       Clock Attributes
* Remarks:                Clock Remarks
@end menu

@end ifnottex


@node Adding Clock Objects
@subsection Adding Clock Objects

To add a clock to a form you use the routine
@findex fl_add_clock()
@anchor{fl_add_clock()}
@example
FL_OBJECT *fl_add_clock(int type, FL_Coord x, FL_Coord y,
                        FL_Coord w, FL_Coord h, char label[])
@end example
@noindent
The meaning of the parameters is as usual. The label is by default
placed below the clock.


@node Clock Types
@subsection Clock Types

The following types are available:
@table @code
@tindex FL_ANALOG_CLOCK
@item FL_ANALOG_CLOCK
An analog clock complete with the second hand.
@tindex FL_DIGITAL_CLOCK
@item FL_DIGITAL_CLOCK
A digital clock.
@end table

@node Clock Interaction
@subsection Clock Interaction

No interaction takes place with clocks.


@node Other Clock Routines
@subsection Other Clock Routines

To get the displayed time (local time as modified by the adjustment
described below) use the following routine
@findex fl_get_clock()
@anchor{fl_get_clock()}
@example
void fl_get_clock(FL_OBJECT *obj, int *h, int *m, int *s);
@end example
@noindent
Upon function return the parameters are set as follows: @code{h} is
between 0-23, indicating the hour, @code{m} is between 0-59, indicating
the minutes, and @code{s} is between 0-59, indicating the seconds.

To display a time other than the local time, use the following routine
@findex fl_set_clock_adjustment()
@anchor{fl_set_clock_adjustment()}
@example
long fl_set_clock_adjustment(FL_OBJECT *obj, long adj);
@end example
@noindent
where @code{adj} is in seconds. For example, to display a time that is
one hour behind the local time, an adjustment of @code{3600} can be
used. The function returns the old adjustment value.

By default, the digital clock uses 24hr system. You can switch the
display to 12hr system (am-pm) by using the following routine
@findex fl_set_clock_ampm()
@anchor{fl_set_clock_ampm()}
@example
void fl_set_clock_ampm(FL_OBJECT *obj, int yes_no)
@end example


@node Clock Attributes
@subsection Clock Attributes

Never use @code{FL_NO_BOX} as the boxtype for a digital clock.

The first color argument (@code{col1}) of
@code{@ref{fl_set_object_color()}} controls the color of the
background, the second (@code{col2}) is the color of the hands.

@node Clock Remarks
@subsection Remarks

See @file{flclock.c} for an example of the use of clocks. @xref{Misc.
Functions}, for other time related routines.


@node Chart Object
@section Chart Object

The chart object gives you an easy way to display a number of
different types of charts like bar-charts, pie-charts, line-charts,
etc. They can either be used to display some fixed chart or a changing
chart (e.g. a strip-chart). Values in the chart can be changed and new
values can be added which makes the chart move to the left, i.e., new
entries appear at the right and old entries disappear at the left.
This can be used to e.g. monitor processes.

@ifnottex

@menu
* Adding Chart Objects:    Adding Chart Objects
* Chart Types:             Chart Types
* Chart Interaction:       Chart Interaction
* Other Chart Routines:    Other Chart Routines
* Chart Attributes:        Chart Attributes
* Remarks:                 Chart Remarks
@end menu

@end ifnottex


@node Adding Chart Objects
@subsection Adding Chart Objects

To add a chart object to a form use the routine
@findex fl_add_chart()
@anchor{fl_add_chart()}
@example
FL_OBJECT *fl_add_chart(int type, FL_Coord x, FL_Coord y,
                        FL_Coord w, FL_Coord h, const char *label);
@end example
@noindent
It shows an empty box on the screen with the label below it.


@node Chart Types
@subsection Chart Types

The following types are available:
@table @code
@tindex FL_BAR_CHART
@item FL_BAR_CHART
A bar-chart
@tindex FL_HORBAR_CHART
@item FL_HORBAR_CHART
A horizontal bar-chart
@tindex FL_LINE_CHART
@item FL_LINE_CHART
A line-chart
@tindex FL_FILLED_CHART
@item FL_FILLED_CHART
A line-chart but the area below curve is filled
@tindex FL_SPIKE_CHART
@item FL_SPIKE_CHART
A chart with a vertical spike for each value
@tindex FL_PIE_CHART
@item FL_PIE_CHART
A pie-chart
@tindex FL_SPECIALPIE_CHART
@item FL_SPECIALPIE_CHART
A pie-chart with displaced first item
@end table

All charts except pie-charts can display positive and negative data.
Pie-charts will ignore values that are less then or equal 0. The
maximum number of values displayed in the chart can be set using the
routine @code{@ref{fl_set_chart_maxnumb()}}. The argument must be not
larger than @code{FL_CHART_MAX} which currently is 512. Switching
between different types can be done without any complications.


@node Chart Interaction
@subsection Chart Interaction

No interaction takes place with charts.


@node Other Chart Routines
@subsection Other Chart Routines

There are a number of routines to change the values in the chart and
to change its behavior. To clear a chart use the routine
@findex fl_clear_chart()
@anchor{fl_clear_chart()}
@example
void fl_clear_chart(FL_OBJECT *obj);
@end example

To add an item to a chart use
@findex fl_add_chart_value()
@anchor{fl_add_chart_value()}
@example
void fl_add_chart_value(FL_OBJECT *obj, double val,
                        const char *text, FL_COLOR col);
@end example
@noindent
Here @code{val} is the value of the item, @code{text} is the label to
be associated with the item (can be empty) and @code{col} is an index
into the colormap (@code{FL_RED} etc.) that is the color of this item.
The chart will be redrawn each time you add an item. This might not be
appropriate if you are filling a chart with values. In this case put
the calls between calls of @code{@ref{fl_freeze_form()}} and
@code{@ref{fl_unfreeze_form()}}.

By default, the label is drawn in a tiny font in black. You can change
the font style, size or color using the following routine
@findex fl_set_chart_lstyle()
@anchor{fl_set_chart_lstyle()}
@findex fl_set_chart_lsize()
@anchor{fl_set_chart_lsize()}
@findex fl_set_chart_lcolor()
@anchor{fl_set_chart_lcolor()}
@example
void fl_set_chart_lstyle(FL_OBJECT *obj, int fontstyle);
void fl_set_chart_lsize(FL_OBJECT *obj, int fontsize);
void fl_set_chart_lcolor(FL_OBJECT *obj, FL_COLOR color);
@end example
@noindent
Note that @code{@ref{fl_set_chart_lcolor()}} only affects the label
color of subsequent items, not the items already created.

You can also insert a new value at a particular place using
@findex fl_insert_chart_value()
@anchor{fl_insert_chart_value()}
@example
void fl_insert_chart_value(FL_OBJECT *obj, int index,
                           double val, const char *text,
                           FL_COLOR col);
@end example
@noindent
@code{index} is the index before which the new item should be
inserted. The first item is number 1. So, for example, to make a
strip-chart where the new value appears at the left, each time insert
the new value before index 1.

To replace the value of a particular item use the routine
@findex fl_replace_chart_value()
@anchor{fl_replace_chart_value()}
@example
void fl_replace_chart_value(FL_OBJECT *obj, int index,
                            double val, const char *text,
                            FL_COLOR col);
@end example
@noindent
Here @code{index} is the index of the value to be replaced. The first
value has an index of 1, etc.

Normally, bar-charts and line-charts are automatically scaled in the
vertical direction such that all values can be displayed. This is
often not wanted when new values are added from time to time. To set
the minimal and maximal value displayed use the routine
@findex fl_set_chart_bounds()
@anchor{fl_set_chart_bounds()}
@example
void fl_set_chart_bounds(FL_OBJECT *obj, double min, double max)'
@end example
@noindent
To return to automatic scaling call it with both @code{min} and
@code{max} being set to @code{0.0}. To obtain the current bounds, use
the following routine
@findex fl_get_chart_bounds()
@anchor{fl_get_chart_bounds()}
@example
void fl_get_chart_bounds(FL_OBJECT *obj, double *min, double *max)'
@end example

Also the width of the bars and distance between the points in a
line-chart are normally scaled. To change this use
@findex fl_set_chart_autosize()
@anchor{fl_set_chart_autosize()}
@example
void fl_set_chart_autosize(FL_OBJECT *obj, int autosize);
@end example
@noindent
with @code{autosize} being set to false (0). In this case the width of
the bars will be such that the maximum number of items fits in the
box. This maximal number (defaults to
@tindex FL_CHART_MAX
@code{FL_CHART_MAX}) can be changed
using
@findex fl_set_chart_maxnumb()
@anchor{fl_set_chart_maxnumb()}
@example
void fl_set_chart_maxnumb(FL_OBJECT *obj, int maxnumb);
@end example
@noindent
where @code{maxnumb} is the maximal number of items to be displayed,
which may not be larger than @code{FL_CHART_MAX}.


@node Chart Attributes
@subsection Chart Attributes

Don't use boxtype @code{FL_NO_BOX} for a chart object if it changes
value.

The first color argument (@code{col1}) to
@code{@ref{fl_set_object_color()}} controls the color of the box, the
argument (@code{col2}) isn't used.


@node Chart Remarks
@subsection Remarks

See @file{chartall.c} and @file{chartstrip.c} for examples of the use
of chart objects.