FLTK 1.3.4
Fl_Group Class Reference

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

#include <Fl_Group.H>

Inheritance diagram for Fl_Group:
Fl_Widget Fl_Browser_ Fl_Color_Chooser Fl_Help_View Fl_Input_Choice Fl_Pack Fl_Scroll Fl_Spinner Fl_Table Fl_Tabs Fl_Text_Display Fl_Tile Fl_Tree Fl_Window Fl_Wizard

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_Groupas_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_Widgetchild (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_Widgetresizable () 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. More...
 
void argument (long v)
 Sets the current user data (long) argument that is passed to the callback function. More...
 
virtual class Fl_Gl_Windowas_gl_window ()
 Returns an Fl_Gl_Window pointer if this widget is an Fl_Gl_Window. More...
 
virtual Fl_Windowas_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_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. More...
 
void deactivate ()
 Deactivates the widget. More...
 
Fl_Imagedeimage ()
 Gets the image that is used as part of the widget label. More...
 
const Fl_Imagedeimage () 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_Imageimage ()
 Gets the image that is used as part of the widget label. More...
 
const Fl_Imageimage () 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...
 
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...
 
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_Groupparent () 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_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...
 
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_Windowtop_window () const
 Returns a pointer to the top-level window for the widget. More...
 
Fl_Windowtop_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 (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_Windowwindow () 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...
 

Static Public Member Functions

static Fl_Groupcurrent ()
 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)
 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 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.

The tab and arrow keys are used to move the focus between widgets of this group, and to other groups. The only modifier grabbed is shift (for shift-tab), so that ctrl-tab, alt-up, and such are free for the app to use as shortcuts.

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
NULLif 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_Help_View, Fl_Tabs, Fl_Window, Fl_Scroll, 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]eventthe kind of event received
Return values
0if the event was not used or understood
1if the event was used and can be deleted
See Also
Fl_Event

Reimplemented from Fl_Widget.

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

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:

resizebox1.png


resizebox2.png

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_Tree, Fl_Help_View, Fl_Text_Display, Fl_Window, Fl_Input_Choice, Fl_Spinner, Fl_Scroll, Fl_Overlay_Window, and Fl_Tile.

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: