Fl_Slider Class Reference

The Fl_Slider widget contains a sliding knob inside a box. More...

#include <Fl_Slider.H>

Inheritance diagram for Fl_Slider:

Public Member Functions
void	bounds (double a, double b)
	Sets the minimum (a) and maximum (b) values for the valuator widget. More...
	Fl_Slider (int X, int Y, int W, int H, const char *L=0)
	Creates a new Fl_Slider widget using the given position, size, and label string. More...
	Fl_Slider (uchar t, int X, int Y, int W, int H, const char *L)
	Creates a new Fl_Slider widget using the given type, position, size, and label string.
int	handle (int) FL_OVERRIDE
	Handles the specified event. More...
int	scrollvalue (int pos, int size, int first, int total)
	Sets the size and position of the sliding knob in the box. More...
Fl_Boxtype	slider () const
	Gets the slider box type.
void	slider (Fl_Boxtype c)
	Sets the slider box type.
float	slider_size () const
	Get the dimensions of the moving piece of slider.
void	slider_size (double v)
	Set the dimensions of the moving piece of slider. More...
Public Member Functions inherited from Fl_Valuator
void	bounds (double a, double b)
	Sets the minimum (a) and maximum (b) values for the valuator widget.
double	clamp (double)
	Clamps the passed value to the valuator range.
virtual int	format (char *)
	Uses internal rules to format the fields numerical value into the character array pointed to by the passed parameter. More...
double	increment (double, int)
	Adds n times the step value to the passed value. More...
double	maximum () const
	Gets the maximum value for the valuator. More...
void	maximum (double a)
	Sets the maximum value for the valuator. More...
double	minimum () const
	Gets the minimum value for the valuator. More...
void	minimum (double a)
	Sets the minimum value for the valuator. More...
void	precision (int digits)
	Sets the step value to 1.0 / 10digits. More...
void	range (double a, double b)
	Sets the minimum and maximum values for the valuator. More...
double	round (double)
	Round the passed value to the nearest step increment. More...
double	step () const
	Gets or sets the step value. More...
void	step (double a, int b)
	See double Fl_Valuator::step() const
void	step (double s)
	See double Fl_Valuator::step() const.
void	step (int a)
	See double Fl_Valuator::step() const
double	value () const
	Gets the floating point(double) value. More...
int	value (double)
	Sets the current value. More...
Public Member Functions inherited from Fl_Widget
void	_clear_fullscreen ()
void	_set_fullscreen ()
void	activate ()
	Activates the widget. More...
unsigned int	active () const
	Returns whether the widget is active. More...
int	active_r () const
	Returns whether the widget and all of its parents are active. More...
Fl_Align	align () const
	Gets the label alignment. More...
void	align (Fl_Align alignment)
	Sets the label alignment. More...
long	argument () const
	Gets the current user data (long) argument that is passed to the callback function. More...
void	argument (long v)
	Sets the current user data (long) argument that is passed to the callback function. More...
virtual class Fl_Gl_Window *	as_gl_window ()
	Returns an Fl_Gl_Window pointer if this widget is an Fl_Gl_Window. More...
virtual class Fl_Gl_Window const *	as_gl_window () const
virtual Fl_Group *	as_group ()
	Returns an Fl_Group pointer if this widget is an Fl_Group. More...
virtual Fl_Group const *	as_group () const
virtual Fl_Window *	as_window ()
	Returns an Fl_Window pointer if this widget is an Fl_Window. More...
virtual Fl_Window const *	as_window () const
void	bind_deimage (Fl_Image *img)
	Sets the image to use as part of the widget label when in the inactive state. More...
void	bind_deimage (int f)
	Bind the inactive image to the widget, so the widget will delete the image when it is no longer needed. More...
void	bind_image (Fl_Image *img)
	Sets the image to use as part of the widget label when in the active state. More...
void	bind_image (int f)
	Bind the image to the widget, so the widget will delete the image when it is no longer needed. More...
Fl_Boxtype	box () const
	Gets the box type of the widget. More...
void	box (Fl_Boxtype new_box)
	Sets the box type for the widget. More...
Fl_Callback_p	callback () const
	Gets the current callback function for the widget. More...
void	callback (Fl_Callback *cb)
	Sets the current callback function for the widget. More...
void	callback (Fl_Callback *cb, Fl_Callback_User_Data *p, bool auto_free)
	Sets the current callback function and managed user data for the widget. More...
void	callback (Fl_Callback *cb, void *p)
	Sets the current callback function and data for the widget. More...
void	callback (Fl_Callback0 *cb)
	Sets the current callback function for the widget. More...
void	callback (Fl_Callback1 *cb, long p=0)
	Sets the current callback function for the widget. More...
unsigned int	changed () const
	Checks if the widget value changed since the last callback. More...
void	clear_active ()
	Marks the widget as inactive without sending events or changing focus. More...
void	clear_changed ()
	Marks the value of the widget as unchanged. More...
void	clear_damage (uchar c=0)
	Clears or sets the damage flags. More...
void	clear_output ()
	Sets a widget to accept input. More...
void	clear_visible ()
	Hides the widget. More...
void	clear_visible_focus ()
	Disables keyboard focus navigation with this widget. More...
Fl_Color	color () const
	Gets the background color of the widget. More...
void	color (Fl_Color bg)
	Sets the background color of the widget. More...
void	color (Fl_Color bg, Fl_Color sel)
	Sets the background and selection color of the widget. More...
Fl_Color	color2 () const
	For back compatibility only. More...
void	color2 (unsigned a)
	For back compatibility only. More...
int	contains (const Fl_Widget *w) const
	Checks if w is a child of this widget. More...
void	copy_label (const char *new_label)
	Sets the current label. More...
void	copy_tooltip (const char *text)
	Sets the current tooltip text. More...
uchar	damage () const
	Returns non-zero if draw() needs to be called. More...
void	damage (uchar c)
	Sets the damage bits for the widget. More...
void	damage (uchar c, int x, int y, int w, int h)
	Sets the damage bits for an area inside the widget. More...
int	damage_resize (int, int, int, int)
	Internal use only.
void	deactivate ()
	Deactivates the widget. More...
Fl_Image *	deimage ()
	Gets the image that is used as part of the widget label when in the inactive state. More...
const Fl_Image *	deimage () const
	Gets the image that is used as part of the widget label when in the inactive state. More...
void	deimage (Fl_Image &img)
	Sets the image to use as part of the widget label when in the inactive state. More...
void	deimage (Fl_Image *img)
	Sets the image to use as part of the widget label when in the inactive state. More...
int	deimage_bound () const
	Returns whether the inactive image is managed by the widget. More...
void	do_callback (Fl_Callback_Reason reason=FL_REASON_UNKNOWN)
	Calls the widget callback function with default arguments. More...
void	do_callback (Fl_Widget *widget, long arg, Fl_Callback_Reason reason=FL_REASON_UNKNOWN)
	Calls the widget callback function with arbitrary arguments. More...
void	do_callback (Fl_Widget *widget, void *arg=0, Fl_Callback_Reason reason=FL_REASON_UNKNOWN)
	Calls the widget callback function with arbitrary arguments. More...
virtual void	draw ()=0
	Draws the widget. More...
void	draw_label (int, int, int, int, Fl_Align) const
	Draws the label in an arbitrary bounding box with an arbitrary alignment. More...
int	h () const
	Gets the widget height. More...
virtual int	handle (int event)
	Handles the specified event. More...
virtual void	hide ()
	Makes a widget invisible. More...
int	horizontal_label_margin ()
	Get the spacing between the label and the horizontal edge of the widget. More...
void	horizontal_label_margin (int px)
	Set the spacing between the label and the horizontal edge of the widget. More...
Fl_Image *	image ()
	Gets the image that is used as part of the widget label when in the active state. More...
const Fl_Image *	image () const
	Gets the image that is used as part of the widget label when in the active state. More...
void	image (Fl_Image &img)
	Sets the image to use as part of the widget label when in the active state. More...
void	image (Fl_Image *img)
	Sets the image to use as part of the widget label when in the active state. More...
int	image_bound () const
	Returns whether the image is managed by the widget. More...
int	inside (const Fl_Widget *wgt) const
	Checks if this widget is a child of wgt. More...
int	is_label_copied () const
	Returns whether the current label was assigned with copy_label(). More...
const char *	label () const
	Gets the current label text. More...
void	label (const char *text)
	Sets the current label pointer. More...
void	label (Fl_Labeltype a, const char *b)
	Shortcut to set the label text and type in one call. More...
int	label_image_spacing ()
	Return the gap size between the label and the image. More...
void	label_image_spacing (int gap)
	Set the gap between the label and the image in pixels. More...
Fl_Color	labelcolor () const
	Gets the label color. More...
void	labelcolor (Fl_Color c)
	Sets the label color. More...
Fl_Font	labelfont () const
	Gets the font to use. More...
void	labelfont (Fl_Font f)
	Sets the font to use. More...
Fl_Fontsize	labelsize () const
	Gets the font size in pixels. More...
void	labelsize (Fl_Fontsize pix)
	Sets the font size in pixels. More...
Fl_Labeltype	labeltype () const
	Gets the label type. More...
void	labeltype (Fl_Labeltype a)
	Sets the label type. More...
void	measure_label (int &ww, int &hh) const
	Sets width ww and height hh accordingly with the label size. More...
bool	needs_keyboard () const
	Returns whether this widget needs a keyboard. More...
void	needs_keyboard (bool needs)
	Sets whether this widget needs a keyboard. More...
unsigned int	output () const
	Returns if a widget is used for output only. More...
Fl_Group *	parent () const
	Returns a pointer to the parent widget. More...
void	parent (Fl_Group *p)
	Internal use only - "for hacks only". More...
void	position (int X, int Y)
	Repositions the window or widget. More...
void	redraw ()
	Schedules the drawing of the widget. More...
void	redraw_label ()
	Schedules the drawing of the label. More...
virtual void	resize (int x, int y, int w, int h)
	Changes the size or position of the widget. More...
Fl_Color	selection_color () const
	Gets the selection color. More...
void	selection_color (Fl_Color a)
	Sets the selection color. More...
void	set_active ()
	Marks the widget as active without sending events or changing focus. More...
void	set_changed ()
	Marks the value of the widget as changed. More...
void	set_output ()
	Sets a widget to output only. More...
void	set_visible ()
	Makes the widget visible. More...
void	set_visible_focus ()
	Enables keyboard focus navigation with this widget. More...
int	shortcut_label () const
	Returns whether the widget's label uses '&' to indicate shortcuts. More...
void	shortcut_label (int value)
	Sets whether the widget's label uses '&' to indicate shortcuts. More...
virtual void	show ()
	Makes a widget visible. More...
void	size (int W, int H)
	Changes the size of the widget. More...
int	take_focus ()
	Gives the widget the keyboard focus. More...
unsigned int	takesevents () const
	Returns if the widget is able to take events. More...
int	test_shortcut ()
	Returns true if the widget's label contains the entered '&x' shortcut. More...
const char *	tooltip () const
	Gets the current tooltip text. More...
void	tooltip (const char *text)
	Sets the current tooltip text. More...
Fl_Window *	top_window () const
	Returns a pointer to the top-level window for the widget. More...
Fl_Window *	top_window_offset (int &xoff, int &yoff) const
	Finds the x/y offset of the current widget relative to the top-level window. More...
uchar	type () const
	Gets the widget type. More...
void	type (uchar t)
	Sets the widget type. More...
int	use_accents_menu ()
	Returns non zero if MAC_USE_ACCENTS_MENU flag is set, 0 otherwise.
void *	user_data () const
	Gets the user data for this widget. More...
void	user_data (Fl_Callback_User_Data *v, bool auto_free)
	Sets the user data for this widget.
void	user_data (void *v)
	Sets the user data for this widget.
int	vertical_label_margin ()
	Get the spacing between the label and the vertical edge of the widget. More...
void	vertical_label_margin (int px)
	Set the spacing between the label and the vertical edge of the widget. More...
unsigned int	visible () const
	Returns whether a widget is visible. More...
unsigned int	visible_focus () const
	Checks whether this widget has a visible focus. More...
void	visible_focus (int v)
	Modifies keyboard focus navigation. More...
int	visible_r () const
	Returns whether a widget and all its parents are visible. More...
int	w () const
	Gets the widget width. More...
Fl_When	when () const
	Returns the conditions under which the callback is called. More...
void	when (uchar i)
	Sets the flags used to decide when a callback is called. More...
Fl_Window *	window () const
	Returns a pointer to the nearest parent window up the widget hierarchy. More...
int	x () const
	Gets the widget position in its window. More...
int	y () const
	Gets the widget position in its window. More...
virtual	~Fl_Widget ()
	Destroys the widget. More...

Protected Member Functions
void	draw () FL_OVERRIDE
	Draws the widget. More...
void	draw (int, int, int, int)
int	handle (int, int, int, int, int)
Protected Member Functions inherited from Fl_Valuator
	Fl_Valuator (int X, int Y, int W, int H, const char *L)
	Creates a new Fl_Valuator widget using the given position, size, and label string. More...
void	handle_drag (double newvalue)
	Called during a drag operation, after an FL_WHEN_CHANGED event is received and before the callback.
void	handle_push ()
	Stores the current value in the previous value.
void	handle_release ()
	Called after an FL_WHEN_RELEASE event is received and before the callback.
int	horizontal () const
	Tells if the valuator is an FL_HORIZONTAL one.
double	previous_value () const
	Gets the previous floating point value before an event changed it.
void	set_value (double v)
	Sets the current floating point value.
double	softclamp (double)
	Clamps the value, but accepts v if the previous value is not already out of range.
virtual void	value_damage ()
	Asks for partial redraw. More...
Protected Member Functions inherited from Fl_Widget
void	clear_flag (unsigned int c)
	Clears a flag in the flags mask.
void	draw_backdrop () const
	If FL_ALIGN_IMAGE_BACKDROP is set, the image or deimage will be drawn.
void	draw_box () const
	Draws the widget box according its box style.
void	draw_box (Fl_Boxtype t, Fl_Color c) const
	Draws a box of type t, of color c at the widget's position and size.
void	draw_box (Fl_Boxtype t, int x, int y, int w, int h, Fl_Color c) const
	Draws a box of type t, of color c at the position X,Y and size W,H.
void	draw_focus () const
	Draws a focus rectangle around the widget. More...
void	draw_focus (Fl_Boxtype t, int X, int Y, int W, int H) const
	Draws a focus rectangle around the widget. More...
void	draw_focus (Fl_Boxtype t, int x, int y, int w, int h, Fl_Color bg) const
	Draws a focus box for the widget at the given position and size. More...
void	draw_label () const
	Draws the widget's label at the defined label position. More...
void	draw_label (int, int, int, int) const
	Draws the label in an arbitrary bounding box. More...
	Fl_Widget (int x, int y, int w, int h, const char *label=0L)
	Creates a widget at the given position and size. More...
unsigned int	flags () const
	Gets the widget flags mask.
void	h (int v)
	Internal use only. More...
void	set_flag (unsigned int c)
	Sets a flag in the flags mask.
void	w (int v)
	Internal use only. More...
void	x (int v)
	Internal use only. More...
void	y (int v)
	Internal use only. More...

Additional Inherited Members
Static Public Member Functions inherited from Fl_Widget
static void	default_callback (Fl_Widget *widget, void *data)
	The default callback for all widgets that don't set a callback. More...
static unsigned int	label_shortcut (const char *t)
	Returns the Unicode value of the '&x' shortcut in a given text. More...
static int	test_shortcut (const char *, const bool require_alt=false)
	Returns true if the given text t contains the entered '&x' shortcut. More...
Protected Types inherited from Fl_Widget
enum	{   INACTIVE = 1<<0 , INVISIBLE = 1<<1 , OUTPUT = 1<<2 , NOBORDER = 1<<3 ,   FORCE_POSITION = 1<<4 , NON_MODAL = 1<<5 , SHORTCUT_LABEL = 1<<6 , CHANGED = 1<<7 ,   OVERRIDE = 1<<8 , VISIBLE_FOCUS = 1<<9 , COPIED_LABEL = 1<<10 , CLIP_CHILDREN = 1<<11 ,   MENU_WINDOW = 1<<12 , TOOLTIP_WINDOW = 1<<13 , MODAL = 1<<14 , NO_OVERLAY = 1<<15 ,   GROUP_RELATIVE = 1<<16 , COPIED_TOOLTIP = 1<<17 , FULLSCREEN = 1<<18 , MAC_USE_ACCENTS_MENU = 1<<19 ,   NEEDS_KEYBOARD = 1<<20 , IMAGE_BOUND = 1<<21 , DEIMAGE_BOUND = 1<<22 , AUTO_DELETE_USER_DATA = 1<<23 ,   MAXIMIZED = 1<<24 , POPUP = 1<<25 , USERFLAG3 = 1<<29 , USERFLAG2 = 1<<30 ,   USERFLAG1 = 1<<31 }
	flags possible values enumeration. More...

Detailed Description

The Fl_Slider widget contains a sliding knob inside a box.

It is often used as a scrollbar. Moving the box all the way to the top/left sets it to the minimum(), and to the bottom/right to the maximum(). The minimum() may be greater than the maximum() to reverse the slider direction.

Use void Fl_Widget::type(int) to set how the slider is drawn, which can be one of the following:

• FL_VERTICAL - Draws a vertical slider (this is the default).
• FL_HORIZONTAL - Draws a horizontal slider.
• FL_VERT_FILL_SLIDER - Draws a filled vertical slider, useful as a progress or value meter.
• FL_HOR_FILL_SLIDER - Draws a filled horizontal slider, useful as a progress or value meter.
• FL_VERT_NICE_SLIDER - Draws a vertical slider with a nice looking control knob.
• FL_HOR_NICE_SLIDER - Draws a horizontal slider with a nice looking control knob.

Constructor & Destructor Documentation

Fl_Slider()

Fl_Slider::Fl_Slider	(	int	X,
		int	Y,
		int	W,
		int	H,
		const char *	L = 0
	)

Creates a new Fl_Slider widget using the given position, size, and label string.

The default boxtype is FL_DOWN_BOX.

Member Function Documentation

bounds()

void Fl_Slider::bounds	(	double	a,
		double	b
	)

Sets the minimum (a) and maximum (b) values for the valuator widget.

if at least one of the values is changed, a partial redraw is asked.

draw()

void Fl_Slider::draw ( )

protectedvirtual

Draws the widget.

Never call this function directly. FLTK will schedule redrawing whenever needed. If your widget must be redrawn as soon as possible, call redraw() instead.

Override this function to draw your own widgets.

If you ever need to call another widget's draw method from within your own draw() method, e.g. for an embedded scrollbar, you can do it (because draw() is virtual) like this:

Fl_Widget *s = &scrollbar; // scrollbar is an embedded Fl_Scrollbar
s->draw();                 // calls Fl_Scrollbar::draw()

Implements Fl_Widget.

Reimplemented in Fl_Value_Slider.

handle()

int Fl_Slider::handle ( int  event )

virtual

Handles the specified event.

You normally don't call this method directly, but instead let FLTK do it when the user interacts with the widget.

When implemented in a widget, this function must return 0 if the widget does not use the event or 1 otherwise.

Most of the time, you want to call the inherited handle() method in your overridden method so that you don't short-circuit events that you don't handle. In this last case you should return the callee retval.

One exception to the rule in the previous paragraph is if you really want to override the behavior of the base class. This requires knowledge of the details of the inherited class.

In rare cases you may want to return 1 from your handle() method although you don't really handle the event. The effect would be to filter event processing, for instance if you want to dismiss non-numeric characters (keypresses) in a numeric input widget. You may "ring the bell" or show another visual indication or drop the event silently. In such a case you must not call the handle() method of the base class and tell FLTK that you consumed the event by returning 1 even if you didn't do anything with it.

Parameters

[in]

event

the kind of event received

Return values

0	if the event was not used or understood
1	if the event was used and can be deleted

See also

Fl_Event

Reimplemented from Fl_Widget.

Reimplemented in Fl_Value_Slider.

scrollvalue()

int Fl_Slider::scrollvalue	(	int	pos,
		int	size,
		int	first,
		int	total
	)

Sets the size and position of the sliding knob in the box.

Parameters

[in]	pos	position of first line displayed
[in]	size	size of window in lines
[in]	first	number of first line
[in]	total	total number of lines Returns Fl_Valuator::value(p)

slider_size()

void Fl_Slider::slider_size

(

double

v

)

Set the dimensions of the moving piece of slider.

This is the fraction of the size of the entire widget. If you set this to 1 then the slider cannot move. The default value is .08.

For the "fill" sliders this is the size of the area around the end that causes a drag effect rather than causing the slider to jump to the mouse.

---

The documentation for this class was generated from the following files:

• Fl_Slider.H
• Fl_Slider.cxx