Fl_Group Class Reference

The Fl_Group class is the FLTK container widget. More...

`#include <Fl_Group.H>`

Inheritance diagram for Fl_Group:

## Public Member Functions

Fl_Widget *& | _ddfdesign_kludge ()
| This is for forms compatibility only.
void | add (Fl_Widget &)
| The widget is removed from its current group (if any) and then added to the end of this group.
void | add (Fl_Widget *o)
| See void Fl_Group::add(Fl_Widget &w)
void | add_resizable (Fl_Widget &o)
| Adds a widget to the group and makes it the resizable widget.
Fl_Widget *const * | array () const
| Returns a pointer to the array of children. More...
virtual Fl_Group * | as_group ()
| Returns an Fl_Group pointer if this widget is an Fl_Group. More...
void | begin ()
| Sets the current group so you can build the widget tree by just constructing the widgets. More...
Fl_Widget * | child (int n) const
| Returns array()[n]. More...
int | children () const
| Returns how many child widgets the group has.
void | clear ()
| Deletes all child widgets from memory recursively. More...
void | clip_children (int c)
| Controls whether the group widget clips the drawing of child widgets to its bounding box. More...
unsigned int | clip_children ()
| Returns the current clipping mode. More...
void | end ()
| Exactly the same as current(this->parent()). More...
int | find (const Fl_Widget *) const
| Searches the child array for the widget and returns the index. More...
int | find (const Fl_Widget &o) const
| See int Fl_Group::find(const Fl_Widget *w) const.
| Fl_Group (int, int, int, int, const char *=0)
| Creates a new Fl_Group widget using the given position, size, and label string. More...
void | focus (Fl_Widget *W)
void | forms_end ()
| This is for forms compatibility only.
int | handle (int)
| Handles the specified event. More...
void | init_sizes ()
| Resets the internal array of widget sizes and positions. More...
void | insert (Fl_Widget &, int i)
| The widget is removed from its current group (if any) and then inserted into this group. More...
void | insert (Fl_Widget &o, Fl_Widget *before)
| This does insert(w, find(before)). More...
void | remove (int index)
| Removes the widget at `index` from the group but does not delete it. More...
void | remove (Fl_Widget &)
| Removes a widget from the group but does not delete it. More...
void | remove (Fl_Widget *o)
| Removes the widget `o` from the group. More...
void | resizable (Fl_Widget &o)
| See void Fl_Group::resizable(Fl_Widget *box)
void | resizable (Fl_Widget *o)
| The resizable widget defines the resizing box for the group. More...
Fl_Widget * | resizable () const
| See void Fl_Group::resizable(Fl_Widget *box)
void | resize (int, int, int, int)
| Resizes the Fl_Group widget and all of its children. More...
virtual | ~Fl_Group ()
| The destructor also deletes all the children. 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.
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 Fl_Window * | as_window ()
| Returns an Fl_Window pointer if this widget is an Fl_Window. 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, void *p)
| Sets 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_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_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. More...
void | deactivate ()
| Deactivates the widget. More...
Fl_Image * | deimage ()
| Gets the image that is used as part of the widget label. More...
const Fl_Image * | deimage () const
void | deimage (Fl_Image *img)
| Sets the image to use as part of the widget label. More...
void | deimage (Fl_Image &img)
| Sets the image to use as part of the widget label. More...
void | do_callback ()
| Calls the widget callback. More...
void | do_callback (Fl_Widget *o, long arg)
| Calls the widget callback. More...
void | do_callback (Fl_Widget *o, void *arg=0)
| Calls the widget callback. 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 void | hide ()
| Makes a widget invisible. More...
Fl_Image * | image ()
| Gets the image that is used as part of the widget label. More...
const Fl_Image * | image () const
void | image (Fl_Image *img)
| Sets the image to use as part of the widget label. More...
void | image (Fl_Image &img)
| Sets the image to use as part of the widget label. More...
int | inside (const Fl_Widget *wgt) const
| Checks if this widget is a child of `wgt`. 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...
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...
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...
Fl_Color | selection_color () const
| Gets the selection color. More...
void | selection_color (Fl_Color a)
| Sets the selection color. 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...
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...
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 (void *v)
| Sets the user data for this widget. More...
unsigned int | visible () const
| Returns whether a widget is visible. More...
void | visible_focus (int v)
| Modifies keyboard focus navigation. More...
unsigned int | visible_focus ()
| Checks whether this widget has a visible focus. 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 primary Fl_Window widget. 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...

## Static Public Member Functions

static Fl_Group * | current ()
| Returns the currently active group. More...
static void | current (Fl_Group *g)
| Sets the current group. More...
Static Public Member Functions inherited from Fl_Widget
static void | default_callback (Fl_Widget *cb, void *d)
| Sets the default callback for all widgets. 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 Member Functions

void | draw ()
| Draws the widget. More...
void | draw_child (Fl_Widget &widget) const
| Forces a child to redraw. More...
void | draw_children ()
| Draws all children of the group. More...
void | draw_outside_label (const Fl_Widget &widget) const
| Parents normally call this to draw outside labels of child widgets. More...
int * | sizes ()
| Returns the internal array of widget sizes and positions. More...
void | update_child (Fl_Widget &widget) const
| Draws a child only if it needs it. 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. More...
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. More...
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. 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

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_Group class is the FLTK container widget.

It maintains an array of child widgets. These children can themselves be any widget including Fl_Group. The most important subclass of Fl_Group is Fl_Window, however groups can also be used to control radio buttons or to enforce resize behavior.

## Constructor & Destructor Documentation

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

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

The default boxtype is FL_NO_BOX.

Fl_Group::~Fl_Group | ( |  | ) |

virtual

The destructor also deletes all the children.

This allows a whole tree to be deleted at once, without having to keep a pointer to all the children in the user code.

It is allowed that the Fl_Group and all of its children are automatic (local) variables, but you must declare the Fl_Group first, so that it is destroyed last.

If you add static or automatic (local) variables to an Fl_Group, then it is your responsibility to remove (or delete) all such static or automatic child widgets before destroying the group - otherwise the child widgets' destructors would be called twice!

## Member Function Documentation

Fl_Widget *const * Fl_Group::array | ( |  | ) | const

Returns a pointer to the array of children.

This pointer is only valid until the next time a child is added or removed.

virtual Fl_Group* Fl_Group::as_group | ( |  | ) |

inlinevirtual

Returns an Fl_Group pointer if this widget is an Fl_Group.

Use this method if you have a widget (pointer) and need to know whether this widget is derived from Fl_Group. If it returns non-NULL, then the widget in question is derived from Fl_Group, and you can use the returned pointer to access its children or other Fl_Group-specific methods.

Example:

void my_callback (Fl_Widget *w, void *) {
Fl_Group *g = w->as_group();
if (g)
printf ("This group has %d children\n",g->children());
else
printf ("This widget is not a group!\n");
}

Return values

  NULL | if this widget is not derived from Fl_Group.

Note
  This method is provided to avoid dynamic_cast.

See Also
  Fl_Widget::as_window(), Fl_Widget::as_gl_window()

Reimplemented from Fl_Widget.

void Fl_Group::begin | ( |  | ) |

Sets the current group so you can build the widget tree by just constructing the widgets.

begin() is automatically called by the constructor for Fl_Group (and thus for Fl_Window as well). begin() is exactly the same as current(this). Don't forget to end() the group or window!

Fl_Widget* Fl_Group::child | ( | int | n | ) | const

inline

Returns array()[n].

No range checking is done!

void Fl_Group::clear | ( |  | ) |

Deletes all child widgets from memory recursively.

This method differs from the remove() method in that it affects all child widgets and deletes them from memory.

void Fl_Group::clip_children | ( | int | c | ) |

inline

Controls whether the group widget clips the drawing of child widgets to its bounding box.

Set `c` to 1 if you want to clip the child widgets to the bounding box.

The default is to not clip (0) the drawing of child widgets.

unsigned int Fl_Group::clip_children | ( |  | ) |

inline

Returns the current clipping mode.

Returns
  true, if clipping is enabled, false otherwise.

See Also
  void Fl_Group::clip_children(int c)

Fl_Group * Fl_Group::current | ( |  | ) |

static

Returns the currently active group.

The Fl_Widget constructor automatically does current()->add(widget) if this is not null. To prevent new widgets from being added to a group, call Fl_Group::current(0).

void Fl_Group::current | ( | Fl_Group * | g | ) |

static

Sets the current group.

See Also
  Fl_Group::current()

void Fl_Group::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()

Implements Fl_Widget.

Reimplemented in Fl_Table, Fl_Tree, Fl_Text_Display, Fl_Scroll, Fl_Window, Fl_Tabs, Fl_Pack, and Fl_Glut_Window.

void Fl_Group::draw_child | ( | Fl_Widget & | widget | ) | const

protected

Forces a child to redraw.

This draws a child widget, if it is not clipped. The damage bits are cleared after drawing.

void Fl_Group::draw_children | ( |  | ) |

protected

Draws all children of the group.

This is useful, if you derived a widget from Fl_Group and want to draw a special border or background. You can call draw_children() from the derived draw() method after drawing the box, border, or background.

void Fl_Group::draw_outside_label | ( | const Fl_Widget & | widget | ) | const

protected

Parents normally call this to draw outside labels of child widgets.

void Fl_Group::end | ( |  | ) |

Exactly the same as current(this->parent()).

Any new widgets added to the widget tree will be added to the parent of the group.

int Fl_Group::find | ( | const Fl_Widget * | o | ) | const

Searches the child array for the widget and returns the index.

Returns children() if the widget is NULL or not found.

void Fl_Group::focus | ( | Fl_Widget * | W | ) |

inline

Deprecated:
  This is for backwards compatibility only. You should use W->take_focus() instead.

See Also
  Fl_Widget::take_focus();

int Fl_Group::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.

Reimplemented in Fl_Tree, Fl_Table, Fl_Window, Fl_Spinner, Fl_Scroll, Fl_Table_Row, Fl_Text_Display, Fl_Tile, Fl_Tabs, Fl_Text_Editor, and Fl_Glut_Window.

void Fl_Group::init_sizes | ( |  | ) |

Resets the internal array of widget sizes and positions.

The Fl_Group widget keeps track of the original widget sizes and positions when resizing occurs so that if you resize a window back to its original size the widgets will be in the correct places. If you rearrange the widgets in your group, call this method to register the new arrangement with the Fl_Group that contains them.

If you add or remove widgets, this will be done automatically.

Note
  The internal array of widget sizes and positions will be allocated and filled when the next resize() occurs.

See Also
  sizes()

void Fl_Group::insert | ( | Fl_Widget & | o,
|  | int | index
| ) |  |

The widget is removed from its current group (if any) and then inserted into this group.

It is put at index n - or at the end, if n >= children(). This can also be used to rearrange the widgets inside a group.

void Fl_Group::insert | ( | Fl_Widget & | o,
|  | Fl_Widget * | before
| ) |  |

inline

This does insert(w, find(before)).

This will append the widget if `before` is not in the group.

void Fl_Group::remove | ( | int | index | ) |

Removes the widget at `index` from the group but does not delete it.

This method does nothing if `index` is out of bounds.

This method differs from the clear() method in that it only affects a single widget and does not delete it from memory.

Since
  FLTK 1.3.0

void Fl_Group::remove | ( | Fl_Widget & | o | ) |

Removes a widget from the group but does not delete it.

This method does nothing if the widget is not a child of the group.

This method differs from the clear() method in that it only affects a single widget and does not delete it from memory.

Note
  If you have the child's index anyway, use remove(int index) instead, because this doesn't need a child lookup in the group's table of children. This can be much faster, if there are lots of children.

void Fl_Group::remove | ( | Fl_Widget * | o | ) |

inline

Removes the widget `o` from the group.

See Also
  void remove(Fl_Widget&)

void Fl_Group::resizable | ( | Fl_Widget * | o | ) |

inline

The resizable widget defines the resizing box for the group.

When the group is resized it calculates a new size and position for all of its children. Widgets that are horizontally or vertically inside the dimensions of the box are scaled to the new size. Widgets outside the box are moved.

In these examples the gray area is the resizable:

The resizable may be set to the group itself, in which case all the contents are resized. This is the default value for Fl_Group, although NULL is the default for Fl_Window and Fl_Pack.

If the resizable is NULL then all widgets remain a fixed size and distance from the top-left corner.

It is possible to achieve any type of resize behavior by using an invisible Fl_Box as the resizable and/or by using a hierarchy of child Fl_Group's.

void Fl_Group::resize | ( | int | X,
|  | int | Y,
|  | int | W,
|  | int | H
| ) |  |

virtual

Resizes the Fl_Group widget and all of its children.

The Fl_Group widget first resizes itself, and then it moves and resizes all its children according to the rules documented for Fl_Group::resizable(Fl_Widget*)

See Also
  Fl_Group::resizable(Fl_Widget*)
  Fl_Group::resizable()
  Fl_Widget::resize(int,int,int,int)

Reimplemented from Fl_Widget.

Reimplemented in Fl_Table, Fl_Help_View, Fl_Text_Display, Fl_Window, Fl_Input_Choice, Fl_Spinner, Fl_Scroll, Fl_Tile, and Fl_Overlay_Window.

int * Fl_Group::sizes | ( |  | ) |

protected

Returns the internal array of widget sizes and positions.

If the sizes() array does not exist, it will be allocated and filled with the current widget sizes and positions.

Note
  You should never need to use this method directly, unless you have special needs to rearrange the children of a Fl_Group. Fl_Tile uses this to rearrange its widget positions.

See Also
  init_sizes()

Todo:
  Should the internal representation of the sizes() array be documented?

void Fl_Group::update_child | ( | Fl_Widget & | widget | ) | const

protected

Draws a child only if it needs it.

This draws a child widget, if it is not clipped and if any damage() bits are set. The damage bits are cleared after drawing.

See Also
  Fl_Group::draw_child(Fl_Widget& widget) const

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

- Fl_Group.H
- Fl_Group.cxx
- forms_compatability.cxx

- © 1998-2012 by Bill Spitzak and others.