FLTK 1.3.9: Fl_Scrollbar Class Reference

FLTK 1.3.9

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Public Member Functions | Protected Member Functions | List of all members
Fl_Scrollbar Class Reference

The Fl_Scrollbar widget displays a slider with arrow buttons at the ends of the scrollbar. More...

`#include <Fl_Scrollbar.H>`

Inheritance diagram for Fl_Scrollbar:

## Public Member Functions
| Fl_Scrollbar (int X, int Y, int W, int H, const char *L=0)
| Creates a new Fl_Scrollbar widget with given position, size, and label.
int | handle (int)
| Handles the specified event.
int | linesize () const
| Get the size of step, in lines, that the arror keys move.
void | linesize (int i)
| This number controls how big the steps are that the arrow keys do.
int | value () const
| Gets the integer value (position) of the slider in the scrollbar.
int | value (int p)
| Sets the value (position) of the slider in the scrollbar.
int | value (int pos, int windowSize, int first, int total)
| Sets the position, size and range of the slider in the scrollbar.
| ~Fl_Scrollbar ()
| Destroys the Scrollbar.
Public Member Functions inherited from Fl_Slider
void | bounds (double a, double b)
| Sets the minimum (a) and maximum (b) values for the valuator widget.
| 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.
| 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)
| Handles the specified event.
int | scrollvalue (int pos, int size, int first, int total)
| Sets the size and position of the sliding knob in the box.
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.
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.
double | increment (double, int)
| Adds n times the step value to the passed value.
double | maximum () const
| Gets the maximum value for the valuator.
void | maximum (double a)
| Sets the maximum value for the valuator.
double | minimum () const
| Gets the minimum value for the valuator.
void | minimum (double a)
| Sets the minimum value for the valuator.
void | precision (int digits)
| Sets the step value to 1.0 / 10digits.
void | range (double a, double b)
| Sets the minimum and maximum values for the valuator.
double | round (double)
| Round the passed value to the nearest step increment.
double | step () const
| Gets or sets the step value.
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.
int | value (double)
| Sets the current value.
Public Member Functions inherited from Fl_Widget
void | _clear_fullscreen ()
void | _set_fullscreen ()
void | activate ()
| Activates the widget.
unsigned int | active () const
| Returns whether the widget is active.
int | active_r () const
| Returns whether the widget and all of its parents are active.
Fl_Align | align () const
| Gets the label alignment.
void | align (Fl_Align alignment)
| Sets the label alignment.
long | argument () const
| Gets the current user data (long) argument that is passed to the callback function.
void | argument (long v)
| Sets the current user data (long) argument that is passed to the callback function.
virtual class Fl_Gl_Window * | as_gl_window ()
| Returns an Fl_Gl_Window pointer if this widget is an Fl_Gl_Window.
virtual Fl_Group * | as_group ()
| Returns an Fl_Group pointer if this widget is an Fl_Group.
virtual Fl_Window * | as_window ()
| Returns an Fl_Window pointer if this widget is an Fl_Window.
Fl_Boxtype | box () const
| Gets the box type of the widget.
void | box (Fl_Boxtype new_box)
| Sets the box type for the widget.
Fl_Callback_p | callback () const
| Gets the current callback function for the widget.
void | callback (Fl_Callback *cb)
| Sets the current callback function for the widget.
void | callback (Fl_Callback *cb, void *p)
| Sets the current callback function for the widget.
void | callback (Fl_Callback0 *cb)
| Sets the current callback function for the widget.
void | callback (Fl_Callback1 *cb, long p=0)
| Sets the current callback function for the widget.
unsigned int | changed () const
| Checks if the widget value changed since the last callback.
void | clear_active ()
| Marks the widget as inactive without sending events or changing focus.
void | clear_changed ()
| Marks the value of the widget as unchanged.
void | clear_damage (uchar c=0)
| Clears or sets the damage flags.
void | clear_output ()
| Sets a widget to accept input.
void | clear_visible ()
| Hides the widget.
void | clear_visible_focus ()
| Disables keyboard focus navigation with this widget.
Fl_Color | color () const
| Gets the background color of the widget.
void | color (Fl_Color bg)
| Sets the background color of the widget.
void | color (Fl_Color bg, Fl_Color sel)
| Sets the background and selection color of the widget.
Fl_Color | color2 () const
| For back compatibility only.
void | color2 (unsigned a)
| For back compatibility only.
int | contains (const Fl_Widget *w) const
| Checks if w is a child of this widget.
void | copy_label (const char *new_label)
| Sets the current label.
void | copy_tooltip (const char *text)
| Sets the current tooltip text.
uchar | damage () const
| Returns non-zero if draw() needs to be called.
void | damage (uchar c)
| Sets the damage bits for the widget.
void | damage (uchar c, int x, int y, int w, int h)
| Sets the damage bits for an area inside the widget.
int | damage_resize (int, int, int, int)
| Internal use only.
void | deactivate ()
| Deactivates the widget.
Fl_Image * | deimage ()
| Gets the image that is used as part of the widget label.
const Fl_Image * | deimage () const
void | deimage (Fl_Image &img)
| Sets the image to use as part of the widget label.
void | deimage (Fl_Image *img)
| Sets the image to use as part of the widget label.
void | do_callback ()
| Calls the widget callback.
void | do_callback (Fl_Widget *o, long arg)
| Calls the widget callback.
void | do_callback (Fl_Widget *o, void *arg=0)
| Calls the widget callback.
virtual void | draw ()=0
| Draws the widget.
void | draw_label (int, int, int, int, Fl_Align) const
| Draws the label in an arbitrary bounding box with an arbitrary alignment.
int | h () const
| Gets the widget height.
virtual int | handle (int event)
| Handles the specified event.
virtual void | hide ()
| Makes a widget invisible.
Fl_Image * | image ()
| Gets the image that is used as part of the widget label.
const Fl_Image * | image () const
void | image (Fl_Image &img)
| Sets the image to use as part of the widget label.
void | image (Fl_Image *img)
| Sets the image to use as part of the widget label.
int | inside (const Fl_Widget *wgt) const
| Checks if this widget is a child of `wgt`.
int | is_label_copied () const
| Returns whether the current label was assigned with copy_label().
const char * | label () const
| Gets the current label text.
void | label (const char *text)
| Sets the current label pointer.
void | label (Fl_Labeltype a, const char *b)
| Shortcut to set the label text and type in one call.
Fl_Color | labelcolor () const
| Gets the label color.
void | labelcolor (Fl_Color c)
| Sets the label color.
Fl_Font | labelfont () const
| Gets the font to use.
void | labelfont (Fl_Font f)
| Sets the font to use.
Fl_Fontsize | labelsize () const
| Gets the font size in pixels.
void | labelsize (Fl_Fontsize pix)
| Sets the font size in pixels.
Fl_Labeltype | labeltype () const
| Gets the label type.
void | labeltype (Fl_Labeltype a)
| Sets the label type.
void | measure_label (int &ww, int &hh) const
| Sets width ww and height hh accordingly with the label size.
unsigned int | output () const
| Returns if a widget is used for output only.
Fl_Group * | parent () const
| Returns a pointer to the parent widget.
void | parent (Fl_Group *p)
| Internal use only - "for hacks only".
void | position (int X, int Y)
| Repositions the window or widget.
void | redraw ()
| Schedules the drawing of the widget.
void | redraw_label ()
| Schedules the drawing of the label.
virtual void | resize (int x, int y, int w, int h)
| Changes the size or position of the widget.
Fl_Color | selection_color () const
| Gets the selection color.
void | selection_color (Fl_Color a)
| Sets the selection color.
void | set_active ()
| Marks the widget as active without sending events or changing focus.
void | set_changed ()
| Marks the value of the widget as changed.
void | set_output ()
| Sets a widget to output only.
void | set_visible ()
| Makes the widget visible.
void | set_visible_focus ()
| Enables keyboard focus navigation with this widget.
virtual void | show ()
| Makes a widget visible.
void | size (int W, int H)
| Changes the size of the widget.
int | take_focus ()
| Gives the widget the keyboard focus.
unsigned int | takesevents () const
| Returns if the widget is able to take events.
int | test_shortcut ()
| Returns true if the widget's label contains the entered '&x' shortcut.
const char * | tooltip () const
| Gets the current tooltip text.
void | tooltip (const char *text)
| Sets the current tooltip text.
Fl_Window * | top_window () const
| Returns a pointer to the top-level window for the widget.
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.
uchar | type () const
| Gets the widget type.
void | type (uchar t)
| Sets the widget type.
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.
void | user_data (void *v)
| Sets the user data for this widget.
unsigned int | visible () const
| Returns whether a widget is visible.
unsigned int | visible_focus ()
| Checks whether this widget has a visible focus.
void | visible_focus (int v)
| Modifies keyboard focus navigation.
int | visible_r () const
| Returns whether a widget and all its parents are visible.
int | w () const
| Gets the widget width.
Fl_When | when () const
| Returns the conditions under which the callback is called.
void | when (uchar i)
| Sets the flags used to decide when a callback is called.
Fl_Window * | window () const
| Returns a pointer to the nearest parent window up the widget hierarchy.
int | x () const
| Gets the widget position in its window.
int | y () const
| Gets the widget position in its window.
virtual | ~Fl_Widget ()
| Destroys the widget.

## Protected Member Functions
void | draw ()
| Draws the widget.
Protected Member Functions inherited from Fl_Slider
void | draw ()
| Draws the widget.
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.
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.
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 ()
| draws a focus rectangle around the widget
void | draw_focus (Fl_Boxtype t, int x, int y, int w, int h) const
| Draws a focus box for the widget at the given position and size.
void | draw_label () const
| Draws the widget's label at the defined label position.
void | draw_label (int, int, int, int) const
| Draws the label in an arbitrary bounding box.
| Fl_Widget (int x, int y, int w, int h, const char *label=0L)
| Creates a widget at the given position and size.
unsigned int | flags () const
| Gets the widget flags mask.
void | h (int v)
| Internal use only.
void | set_flag (unsigned int c)
| Sets a flag in the flags mask.
void | w (int v)
| Internal use only.
void | x (int v)
| Internal use only.
void | y (int v)
| Internal use only.

## Additional Inherited Members
Static Public Member Functions inherited from Fl_Widget
static void | default_callback (Fl_Widget *cb, void *d)
| The default callback for all widgets that don't set a callback.
static unsigned int | label_shortcut (const char *t)
| Returns the Unicode value of the '&x' shortcut in a given text.
static int | test_shortcut (const char *, const bool require_alt=false)
| Returns true if the given text `t` contains the entered '&x' shortcut.
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 , USERFLAG3 = 1<<29 , USERFLAG2 = 1<<30 , USERFLAG1 = 1<<31 }
| flags possible values enumeration. More...

## Detailed Description

The Fl_Scrollbar widget displays a slider with arrow buttons at the ends of the scrollbar.

Clicking on the arrows move up/left and down/right by linesize(). Scrollbars also accept FL_SHORTCUT events: the arrows move by linesize(), and vertical scrollbars take Page Up/Down (they move by the page size minus linesize()) and Home/End (they jump to the top or bottom).

Scrollbars have step(1) preset (they always return integers). If desired you can set the step() to non-integer values. You will then have to use casts to get at the floating-point versions of value() from Fl_Slider.

## Constructor & Destructor Documentation

## ◆ Fl_Scrollbar()

Fl_Scrollbar::Fl_Scrollbar | ( | int | X,
|  | int | Y,
|  | int | W,
|  | int | H,
|  | const char * | L = `0`
| ) |  |

Creates a new Fl_Scrollbar widget with given position, size, and label.

You need to do type(FL_HORIZONTAL) if you want a horizontal scrollbar.

## Member Function Documentation

## ◆ draw()

void Fl_Scrollbar::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 = &scroll; // scroll is an embedded Fl_Scrollbar
s->draw(); // calls Fl_Scrollbar::draw()
Fl_Widget
Fl_Widget is the base class for all widgets in FLTK.
Definition Fl_Widget.H:101

Implements Fl_Widget.

## ◆ handle()

int Fl_Scrollbar::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.

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.

## ◆ linesize()

void Fl_Scrollbar::linesize | ( | int | i | ) |
| inline

This number controls how big the steps are that the arrow keys do.

In addition page up/down move by the size last sent to value() minus one linesize(). The default is 16.

## ◆ value() [1/3]

int Fl_Scrollbar::value | ( |  | ) | const
| inline

Gets the integer value (position) of the slider in the scrollbar.

You can get the floating point value with Fl_Slider::value().

See also
  Fl_Scrollbar::value(int p)
  Fl_Scrollbar::value(int pos, int size, int first, int total)

## ◆ value() [2/3]

int Fl_Scrollbar::value | ( | int | p | ) |
| inline

Sets the value (position) of the slider in the scrollbar.

See also
  Fl_Scrollbar::value()
  Fl_Scrollbar::value(int pos, int size, int first, int total)

## ◆ value() [3/3]

int Fl_Scrollbar::value | ( | int | pos,
|  | int | windowSize,
|  | int | first,
|  | int | total
| ) |  |
| inline

Sets the position, size and range of the slider in the scrollbar.

Parameters

  [in] | pos | position, first line displayed
  [in] | windowSize | number of lines displayed
  [in] | first | number of first line
  [in] | total | total number of lines

You should call this every time your window changes size, your data changes size, or your scroll position changes (even if in response to a callback from this scrollbar). All necessary calls to redraw() are done.

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

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

- Fl_Scrollbar.H
- Fl_Scrollbar.cxx