+----Fl_Adjuster, Fl_Counter, Fl_Dial, Fl_Roller,
Fl_Slider, Fl_Value_Input, Fl_Value_Output,
The Fl_Valuator class controls a single floating-point value
and provides a consistent interface to set the value, range, and step,
and insures that callbacks are done the same for every object.
There are probably more of these classes in FLTK than any others:
In the above diagram each box surrounds an actual subclass. These
are further differentiated by setting the
type() of the widget to the symbolic value labeling the
widget. The ones labelled "0" are the default versions with a
type(0). For consistency the symbol FL_VERTICAL is
defined as zero.
Creates a new Fl_Valuator widget using the given position,
size, and label string. The default boxtype is FL_NO_BOX.
Destroys the valuator.
Sets the minimum (a) and maximum (b) values for
the valuator widget.
This value is true if the user has moved the slider. It is
turned off by value(x) and just before doing a callback
(the callback can turn it back on if desired).
Clamps the passed value to the valuator range.
Clears the changed() flag.
Uses internal rules to format the fields numerical value into
the character array pointed to by the passed parameter.
The actual format used depends on the current step value. If
the step value has been set to zero then a %g format is used.
If the step value is non-zero, then a %.*f format is used,
where the precision is calculated to show sufficient digits
for the current step value. An integer step value, such as 1
or 1.0, gives a precision of 0, so the formatted value will
appear as an integer.
This method is used by the Fl_Value_... group of widgets to
format the current value into a text string.
The return value is the length of the formatted text.
The formatted value is written into in buffer.
buffer should have space for at least 128 bytes.
You may override this function to create your own text formatting.
Adds n times the step value to the passed value. If
step was set to zero it uses fabs(maximum() - minimum()) /
Gets or sets the maximum value for the valuator.
Gets or sets the minimum value for the valuator.
Sets the step value to 1/10digits.
Sets the minimum and maximum values for the valuator. When
the user manipulates the widget, the value is limited to this
range. This clamping is done after rounding to the step
value (this makes a difference if the range is not a multiple of
The minimum may be greater than the maximum. This has the
effect of "reversing" the object so the larger values
are in the opposite direction. This also switches which end of
the filled sliders is filled.
Some widgets consider this a "soft" range. This
means they will stop at the range, but if the user releases and
grabs the control again and tries to move it further, it is
The range may affect the display. You must redraw()
the widget after changing the range.
Round the passed value to the nearest step increment. Does
nothing if step is zero.
Sets the changed() flag.
Gets or sets the step value. As the user moves the mouse the
value is rounded to the nearest multiple of the step value. This
is done before clamping it to the range. For most widgets
the default step is zero.
For precision the step is stored as the ratio of two
integers, A/B. You can set these integers directly. Currently
setting a floating point value sets the nearest A/1 or 1/B value
Gets or sets the current value. The new value is not
clamped or otherwise changed before storing it. Use
clamp() or round() to modify the value before
calling value(). The widget is redrawn if the new value
is different than the current one. The initial value is zero.
From Eivind Tagseth, 02:06 Nov 05, 2003 (score=4)
The increment method completely ignores the maximum and minimum values set.
[ Reply ]
From duncan.gibson, 08:59 Jan 28, 2006 (score=3)
The explanation text for format() is completely unclear. The name implies to me that you pass in a printf-type format string, but this gives a segmentation fault, because in fact it is expecting a pointer to a char array into which it can copy a formatted string.
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