Fl_Tabs Class Reference

The Fl_Tabs widget is the "file card tabs" interface that allows you to put lots and lots of buttons and switches in a panel, as popularized by many toolkits. More...

#include <Fl_Tabs.H>

Inheritance diagram for Fl_Tabs:

Public Member Functions
void	client_area (int &rx, int &ry, int &rw, int &rh, int tabh=0)
	Returns the position and size available to be used by its children.
	Fl_Tabs (int, int, int, int, const char *=0)
	Creates a new Fl_Tabs widget using the given position, size, and label string.
int	handle (int)
	Handles the specified event.
Fl_Widget *	push () const
	Returns the tab group for the tab the user has currently down-clicked on and remains over until FL_RELEASE.
int	push (Fl_Widget *)
	This is called by the tab widget's handle() method to set the tab group widget the user last FL_PUSH'ed on.
Fl_Widget *	value ()
	Gets the currently visible widget/tab.
int	value (Fl_Widget *)
	Sets the widget to become the current visible widget/tab.
Fl_Widget *	which (int event_x, int event_y)
	Return the widget of the tab the user clicked on at event_x / event_y.
Public Member Functions inherited from Fl_Group
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.
virtual Fl_Group *	as_group ()
	Returns an Fl_Group pointer if this widget is an Fl_Group.
void	begin ()
	Sets the current group so you can build the widget tree by just constructing the widgets.
Fl_Widget *	child (int n) const
	Returns array()[n].
int	children () const
	Returns how many child widgets the group has.
void	clear ()
	Deletes all child widgets from memory recursively.
unsigned int	clip_children ()
	Returns the current clipping mode.
void	clip_children (int c)
	Controls whether the group widget clips the drawing of child widgets to its bounding box.
void	end ()
	Exactly the same as current(this->parent()).
int	find (const Fl_Widget &o) const
	See int Fl_Group::find(const Fl_Widget *w) const.
int	find (const Fl_Widget *) const
	Searches the child array for the widget and returns the index.
	Fl_Group (int, int, int, int, const char *=0)
	Creates a new Fl_Group widget using the given position, size, and label string.
void	focus (Fl_Widget *W)
void	forms_end ()
	This is for forms compatibility only.
void	init_sizes ()
	Resets the internal array of widget sizes and positions.
void	insert (Fl_Widget &, int i)
	The widget is removed from its current group (if any) and then inserted into this group.
void	insert (Fl_Widget &o, Fl_Widget *before)
	This does insert(w, find(before)).
void	remove (Fl_Widget &)
	Removes a widget from the group but does not delete it.
void	remove (Fl_Widget *o)
	Removes the widget o from the group.
void	remove (int index)
	Removes the widget at index from the group but does not delete it.
Fl_Widget *	resizable () const
	See void Fl_Group::resizable(Fl_Widget *box)
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.
void	resize (int, int, int, int)
	Resizes the Fl_Group widget and all of its children.
virtual	~Fl_Group ()
	The destructor also deletes all the children.
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_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.
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 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.
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.
void	redraw_tabs ()
Protected Member Functions inherited from Fl_Group
void	draw_child (Fl_Widget &widget) const
	Forces a child to redraw.
void	draw_children ()
	Draws all children of the group.
void	draw_outside_label (const Fl_Widget &widget) const
	Parents normally call this to draw outside labels of child widgets.
int *	sizes ()
	Returns the internal array of widget sizes and positions.
void	update_child (Fl_Widget &widget) const
	Draws a child only if it needs it.
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_Group
static Fl_Group *	current ()
	Returns the currently active group.
static void	current (Fl_Group *g)
	Sets the current group.
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_Tabs widget is the "file card tabs" interface that allows you to put lots and lots of buttons and switches in a panel, as popularized by many toolkits.

Clicking the tab makes a child visible() by calling show() on it, and all other children are made invisible by calling hide() on them. Usually the children are Fl_Group widgets containing several widgets themselves.

Each child makes a card, and its label() is printed on the card tab, including the label font and style. The selection color of that child is used to color the tab, while the color of the child determines the background color of the pane.

The size of the tabs is controlled by the bounding box of the children (there should be some space between the children and the edge of the Fl_Tabs), and the tabs may be placed "inverted" on the bottom - this is determined by which gap is larger. It is easiest to lay this out in fluid, using the fluid browser to select each child group and resize them until the tabs look the way you want them to.

The background area behind and to the right of the tabs is "transparent", exposing the background detail of the parent. The value of Fl_Tabs::box() does not affect this area. So if Fl_Tabs is resized by itself without the parent, force the appropriate parent (visible behind the tabs) to redraw() to prevent artifacts.

See "Resizing Caveats" below on how to keep tab heights constant. See "Callback's Use Of when()" on how to control the details of how clicks invoke the callback().

A typical use of the Fl_Tabs widget:

// Typical use of Fl_Tabs
Fl_Tabs *tabs = new Fl_Tabs(10,10,300,200);
{
    Fl_Group *grp1 = new Fl_Group(20,30,280,170,"Tab1");
    {
        ..widgets that go in tab#1..
    }
    grp1->end();
    Fl_Group *grp2 = new Fl_Group(20,30,280,170,"Tab2");
    {
        ..widgets that go in tab#2..
    }
    grp2->end();
}
tabs->end();

Default Appearance

The appearance of each "tab" is taken from the label() and color() of the child group corresponding to that "tab" and panel. Where the "tabs" appear depends on the position and size of the child groups that make up the panels within the Fl_Tab, i.e. whether there is more space above or below them. The height of the "tabs" depends on how much free space is available.

Fl_Tabs Default Appearance

Highlighting The Selected Tab

The selected "tab" can be highlighted further by setting the selection_color() of the Fl_Tab itself, e.g.

..
tabs = new Fl_Tabs(..);
tabs->selection_color(FL_DARK3);
..

The result of the above looks like:

Highlighting the selected tab

Uniform Tab and Panel Appearance

In order to have uniform tab and panel appearance, not only must the color() and selection_color() for each child group be set, but also the selection_color() of the Fl_Tab itself any time a new "tab" is selected. This can be achieved within the Fl_Tab callback, e.g.

void MyTabCallback(Fl_Widget *w, void*) {
  Fl_Tabs *tabs = (Fl_Tabs*)w;
  // When tab changed, make sure it has same color as its group
  tabs->selection_color( (tab->value())->color() );
}
..
int main(..) {
  // Define tabs widget
  tabs = new Fl_Tabs(..);
  tabs->callback(MyTabCallback);
 
  // Create three tabs each colored differently
  grp1 = new Fl_Group(.. "One");
   grp1->color(9);
   grp1->selection_color(9);
  grp1->end();
 
  grp2 = new Fl_Group(.. "Two");
   grp2->color(10);
   grp2->selection_color(10);
  grp2->end();
 
  grp3 = new Fl_Group(.. "Three");
   grp3->color(14);
   grp3->selection_color(14);
  grp3->end();
  ..
  // Make sure default tab has same color as its group
  tabs->selection_color( (tab->value())->color() );
  ..
  return Fl::run();
}

The result of the above looks like:

Fl_Tabs with uniform colors

Resizing Caveats

When Fl_Tabs is resized vertically, the default behavior scales the tab's height as well as its children. To keep the tab height constant during resizing, set the tab widget's resizable() to one of the tab's child groups, i.e.

tabs = new Fl_Tabs(..);
grp1 = new Fl_Group(..);
..
grp2 = new Fl_Group(..);
..
tabs->end();
tabs->resizable(grp1);        // keeps tab height constant

Callback's Use Of when()

As of FLTK 1.3.3, Fl_Tabs() supports the following flags for when():

• FL_WHEN_NEVER – callback never invoked (all flags off)
• FL_WHEN_CHANGED – if flag set, invokes callback when a tab has been changed (on click or keyboard navigation)
• FL_WHEN_NOT_CHANGED – if flag set, invokes callback when the tabs remain unchanged (on click or keyboard navigation)
• FL_WHEN_RELEASE – if flag set, invokes callback on RELEASE of mouse button or keyboard navigation

Notes:

1. The above flags can be logically OR-ed (|) or added (+) to combine behaviors.
2. The default value for when() is FL_WHEN_RELEASE (inherited from Fl_Widget).
3. If FL_WHEN_RELEASE is the only flag specified, the behavior will be as if (FL_WHEN_RELEASE|FL_WHEN_CHANGED) was specified.
4. The value of changed() will be valid during the callback.
5. If both FL_WHEN_CHANGED and FL_WHEN_NOT_CHANGED are specified, the callback is invoked whether the tab has been changed or not. The changed() method can be used to determine the cause.
6. FL_WHEN_NOT_CHANGED can happen if someone clicks on an already selected tab, or if a keyboard navigation attempt results in no change to the tabs, such as using the arrow keys while at the left or right end of the tabs.

Constructor & Destructor Documentation

Fl_Tabs()

Fl_Tabs::Fl_Tabs	(	int	X,
		int	Y,
		int	W,
		int	H,
		const char *	l = 0
	)

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

The default boxtype is FL_THIN_UP_BOX.

Use add(Fl_Widget*) to add each child, which are usually Fl_Group widgets. The children should be sized to stay away from the top or bottom edge of the Fl_Tabs widget, which is where the tabs will be drawn.

All children of Fl_Tabs should have the same size and exactly fit on top of each other. They should only leave space above or below where the tabs will go, but not on the sides. If the first child of Fl_Tabs is set to "resizable()", the riders will not resize when the tabs are resized.

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. A kludge has been done so the Fl_Tabs and all of its children can be automatic (local) variables, but you must declare the Fl_Tabs widget first so that it is destroyed last.

Member Function Documentation

client_area()

void Fl_Tabs::client_area	(	int &	rx,
		int &	ry,
		int &	rw,
		int &	rh,
		int	tabh = 0
	)

Returns the position and size available to be used by its children.

If there isn't any child yet the tabh parameter will be used to calculate the return values. This assumes that the children's labelsize is the same as the Fl_Tabs' labelsize and adds a small border.

If there are already children, the values of child(0) are returned, and tabh is ignored.

Note

Children should always use the same positions and sizes.

tabh can be one of

• 0: calculate label size, tabs on top
• -1: calculate label size, tabs on bottom
• > 0: use given tabh value, tabs on top (height = tabh)
• < -1: use given tabh value, tabs on bottom (height = -tabh)

Parameters

[in]	tabh	position and optional height of tabs (see above)
[out]	rx,ry,rw,rh	(x,y,w,h) of client area for children

Since

FLTK 1.3.0

draw()

void Fl_Tabs::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()

Reimplemented from Fl_Group.

handle()

int Fl_Tabs::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_Group.

push() [1/2]

Fl_Widget * Fl_Tabs::push ( ) const

inline

Returns the tab group for the tab the user has currently down-clicked on and remains over until FL_RELEASE.

Otherwise, returns NULL.

While the user is down-clicked on a tab, the return value is the tab group for that tab. But as soon as the user releases, or drags off the tab with the button still down, the return value will be NULL.

See also

push(Fl_Widget*).

push() [2/2]

int Fl_Tabs::push

(

Fl_Widget *

o

)

This is called by the tab widget's handle() method to set the tab group widget the user last FL_PUSH'ed on.

Set back to zero on FL_RELEASE.

As of this writing, the value is mainly used by draw_tab() to determine whether or not to draw a 'down' box for the tab when it's clicked, and to turn it off if the user drags off it.

See also

push().

value() [1/2]

Fl_Widget * Fl_Tabs::value

(

)

Gets the currently visible widget/tab.

The value() is the first visible child (or the last child if none are visible) and this also hides any other children. This allows the tabs to be deleted, moved to other groups, and show()/hide() called without it screwing up.

value() [2/2]

int Fl_Tabs::value

(

Fl_Widget *

newvalue

)

Sets the widget to become the current visible widget/tab.

Setting the value hides all other children, and makes this one visible, if it is really a child.

Returns

1 if there was a change (new value different from previous),
0 if there was no change (new value already set)

which()

Fl_Widget * Fl_Tabs::which	(	int	event_x,
		int	event_y
	)

Return the widget of the tab the user clicked on at event_x / event_y.

This is used for event handling (clicks) and by fluid to pick tabs.

Returns

The child widget of the tab the user clicked on, or
0 if there are no children or if the event is outside of the tabs area.

---

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

• Fl_Tabs.H
• Fl_Tabs.cxx