The Fl_Tabs widget is a container widget that displays a set of tabs, with each tab representing a different child widget. More...

#include <Fl_Tabs.H>

Inheritance diagram for Fl_Tabs:

Public Types
enum	{ OVERFLOW_COMPRESS = 0 , OVERFLOW_CLIP , OVERFLOW_PULLDOWN , OVERFLOW_DRAG }

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 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.

int	handle (int) FL_OVERRIDE
	Handle all events in the tabs area and forward the rest to the selected child.

void	handle_overflow (int ov)
	Set a method to handle an overflowing tab bar.

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_Align	tab_align () const
	Gets the tab label alignment.

void	tab_align (Fl_Align a)
	Sets the tab label alignment.

Fl_Widget *	value ()
	Gets the currently visible widget/tab.

int	value (Fl_Widget *)
	Sets the widget to become the current visible widget/tab.

virtual Fl_Widget *	which (int event_x, int event_y)
	Return a pointer to the child widget with a tab at the given coordinates.

virtual	~Fl_Tabs ()
	Delete allocated resources and destroy all children.

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.

Fl_Group const *	as_group () const FL_OVERRIDE

Fl_Group *	as_group () FL_OVERRIDE
	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.

virtual int	delete_child (int n)
	Removes the widget at `index` from the group and deletes it.

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
	Returns the group's resizable widget.

void	resizable (Fl_Widget &o)
	Sets the group's resizable widget.

void	resizable (Fl_Widget *o)
	The resizable widget defines both the resizing box and the resizing behavior of the group and 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 class Fl_Gl_Window const *	as_gl_window () const

virtual Fl_Window *	as_window ()
	Returns an Fl_Window pointer if this widget is an Fl_Window.

virtual Fl_Window const *	as_window () const

void	bind_deimage (Fl_Image *img)
	Sets the image to use as part of the widget label when in the inactive state.

void	bind_deimage (int f)
	Bind the inactive image to the widget, so the widget will delete the image when it is no longer needed.

void	bind_image (Fl_Image *img)
	Sets the image to use as part of the widget label when in the active state.

void	bind_image (int f)
	Bind the image to the widget, so the widget will delete the image when it is no longer needed.

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, Fl_Callback_User_Data p, bool auto_free)
	Sets the current callback function and managed user data for the widget.

void	callback (Fl_Callback cb, void p)
	Sets the current callback function and data 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 when in the inactive state.

const Fl_Image *	deimage () const
	Gets the image that is used as part of the widget label when in the inactive state.

void	deimage (Fl_Image &img)
	Sets the image to use as part of the widget label when in the inactive state.

void	deimage (Fl_Image *img)
	Sets the image to use as part of the widget label when in the inactive state.

int	deimage_bound () const
	Returns whether the inactive image is managed by the widget.

void	do_callback (Fl_Callback_Reason reason=FL_REASON_UNKNOWN)
	Calls the widget callback function with default arguments.

void	do_callback (Fl_Widget *widget, long arg, Fl_Callback_Reason reason=FL_REASON_UNKNOWN)
	Calls the widget callback function with arbitrary arguments.

void	do_callback (Fl_Widget widget, void arg=0, Fl_Callback_Reason reason=FL_REASON_UNKNOWN)
	Calls the widget callback function with arbitrary arguments.

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 when in the active state.

const Fl_Image *	image () const
	Gets the image that is used as part of the widget label when in the active state.

void	image (Fl_Image &img)
	Sets the image to use as part of the widget label when in the active state.

void	image (Fl_Image *img)
	Sets the image to use as part of the widget label when in the active state.

int	image_bound () const
	Returns whether the image is managed by the widget.

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.

bool	needs_keyboard () const
	Returns whether this widget needs a keyboard.

void	needs_keyboard (bool needs)
	Sets whether this widget needs a keyboard.

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.

int	shortcut_label () const
	Returns whether the widget's label uses '&' to indicate shortcuts.

void	shortcut_label (int value)
	Sets whether the widget's label uses '&' to indicate shortcuts.

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 (Fl_Callback_User_Data *v, bool auto_free)
	Sets the user data for this widget.

void	user_data (void *v)
	Sets the user data for this widget.

unsigned int	visible () const
	Returns whether a widget is visible.

unsigned int	visible_focus () const
	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	check_overflow_menu ()
	Check if the tabs overflow and sets the has_overflow_menu flag accordingly.

virtual void	clear_tab_positions ()
	Clear internal array of tab positions and widths.

void	draw () FL_OVERRIDE
	Draw the tabs area, the optional pulldown button, and all children.

void	draw_overflow_menu_button ()
	Draw square button-like graphics with a down arrow in the top or bottom right corner.

virtual void	draw_tab (int x1, int x2, int W, int H, Fl_Widget *o, int flags, int sel)
	Draw a tab in the top or bottom tabs area.

void	handle_overflow_menu ()
	This is called when the user clicks the overflow pulldown menu button.

virtual int	hit_close (Fl_Widget *o, int event_x, int event_y)
	Check whether the coordinates fall within the "close" button area of the tab.

virtual int	hit_overflow_menu (int event_x, int event_y)
	Determine if the coordinates are in the area of the overflow menu button.

virtual int	hit_tabs_area (int event_x, int event_y)
	Determine if the coordinates are within the tabs area.

int	on_insert (Fl_Widget *, int) FL_OVERRIDE
	Make sure that we redraw all tabs when new children are added.

int	on_move (int, int) FL_OVERRIDE
	Make sure that we redraw all tabs when children are moved.

void	on_remove (int) FL_OVERRIDE
	Make sure that we redraw all tabs when new children are removed.

virtual void	redraw_tabs ()
	Redraw all tabs (and only the tabs).

void	resize (int, int, int, int) FL_OVERRIDE
	Make sure that we redraw all tabs when the widget size changes.

virtual int	tab_height ()
	Return space (height) in pixels usable for tabs.

virtual int	tab_positions ()
	Calculate tab positions and widths.

Protected Member Functions inherited from Fl_Group
Fl_Rect *	bounds ()
	Returns the internal array of widget sizes and positions.

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 () const
	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 rectangle around the widget.

void	draw_focus (Fl_Boxtype t, int x, int y, int w, int h, Fl_Color bg) const
	Draws a focus box for the widget at the given position and size.

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.

Protected Attributes
int	has_overflow_menu
	set in OVERFLOW_PULLDOWN mode if tabs overflow. The actual menu array is created only on demand

int	overflow_type

Fl_Align	tab_align_
	tab label alignment

int	tab_count
	Array size of tab positions etc.

int *	tab_flags
	Array of tab flag of tabs per child.

int	tab_offset
	for pulldown and drag overflow, this is the horizontal offset when the tabs bar is dragged by the user

int *	tab_pos
	Array of x-offsets of tabs per child + 1.

int *	tab_width
	Array of widths of tabs per child.

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 widget, void data)
	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 , NEEDS_KEYBOARD = 1<<20 , IMAGE_BOUND = 1<<21 , DEIMAGE_BOUND = 1<<22 , AUTO_DELETE_USER_DATA = 1<<23 , USERFLAG3 = 1<<29 , USERFLAG2 = 1<<30 , USERFLAG1 = 1<<31 }
	flags possible values enumeration. More...

Detailed Description

The Fl_Tabs widget is a container widget that displays a set of tabs, with each tab representing a different child widget.

The user can select a tab by clicking on it, and the corresponding child widget will be displayed. The Fl_Tabs widget is useful for organizing a large number of controls or other widgets into a compact space, allowing the user to switch between different sets of controls as needed.

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. '&' in labels are used to prefix a shortcut that is drawn underlined and that activates the corresponding tab; repeated '&&' avoids that.

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();

Fl_Group
The Fl_Group class is the FLTK container widget.
Definition Fl_Group.H:56

Fl_Group::end
void end()
Exactly the same as current(this->parent()).
Definition Fl_Group.cxx:73

Fl_Tabs
The Fl_Tabs widget is a container widget that displays a set of tabs, with each tab representing a di...
Definition Fl_Tabs.H:239

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);

..

Fl_Widget::selection_color
Fl_Color selection_color() const
Gets the selection color.
Definition Fl_Widget.H:451

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( (tabs->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();

}

Fl_Tabs::value
Fl_Widget * value()
Gets the currently visible widget/tab.
Definition Fl_Tabs.cxx:668

Fl_Widget
Fl_Widget is the base class for all widgets in FLTK.
Definition Fl_Widget.H:104

Fl_Widget::color
Fl_Color color() const
Gets the background color of the widget.
Definition Fl_Widget.H:433

Fl_Widget::w
int w() const
Gets the widget width.
Definition Fl_Widget.H:349

Fl_Widget::callback
Fl_Callback_p callback() const
Gets the current callback function for the widget.
Definition Fl_Widget.H:687

Fl::run
static int run()
Calls Fl::wait()repeatedly as long as any windows are displayed.
Definition Fl.cxx:604

The result of the above looks like:

Fl_Tabs with uniform colors

If Fl_Tabs has no children, the widget will be drawn as a flat rectangle in the background color set by color().

Close Button on Tabs

The Fl_Tabs widget allows you to specify that a child widget should display a close button in its tab. If the FL_WHEN_CLOSED flag is set for the child widget, an "X" symbol will be displayed to the left of the label text in the tab. When the close button is clicked, the child widget's callback function will be called with the FL_REASON_CLOSED reason. It is then the responsibility of the child widget to remove itself from the Fl_Tabs container.

Tabs that are in a compressed state will not display a close button until they are fully expanded.

Overflowing Tabs

When the combined width of the tabs exceeds that of the Fl_Tabs widget, the tabs will overflow. Fl_Tabs provides four options for managing tabs overflow:

Fl_Tabs::OVERFLOW_COMPRESS: proportionally compress the tabs to the left and right of the selected tab until they all fit within the widget.
Fl_Tabs::OVERFLOW_CLIP: clips any tabs that extend beyond the right edge of the Fl_Tabs widget, making some tabs unreachable.
Fl_Tabs::OVERFLOW_PULLDOWN: doesn't compress the tabs but instead generates a pulldown menu at the right end of the tabs area, displaying all available tabs.
Fl_Tabs::OVERFLOW_DRAG: maintains the tabs' original sizes, allowing horizontal dragging of the tabs area using the mouse, a horizontal mouse wheel, or the horizontal scrolling gesture on touchpads.

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

Fl_Group::resizable
void resizable(Fl_Widget &o)
Sets the group's resizable widget.
Definition Fl_Group.H:144

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:

The above flags can be logically OR-ed (|) or added (+) to combine behaviors.
The default value for when() is FL_WHEN_RELEASE (inherited from Fl_Widget).
If FL_WHEN_RELEASE is the only flag specified, the behavior will be as if (FL_WHEN_RELEASE|FL_WHEN_CHANGED) was specified.
The value of changed() will be valid during the callback.
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.
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.
Fl::callback_reason() returns FL_REASON_SELECTED or FL_REASON_RESELECTED

Member Enumeration Documentation

◆ anonymous enum

anonymous enum

Enumerator
OVERFLOW_COMPRESS	Tabs will be compressed and overlaid on top of each other.
OVERFLOW_CLIP	Only the first tabs that fit will be displayed.
OVERFLOW_PULLDOWN	Tabs that do not fit will be placed in a pull-down menu.
OVERFLOW_DRAG	The tab bar can be dragged horizontally to reveal additional 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

◆ clear_tab_positions()

void Fl_Tabs::clear_tab_positions ( )

protectedvirtual

Clear internal array of tab positions and widths.

See also: tab_positions().

◆ 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 ( void )

protectedvirtual

Draw the tabs area, the optional pulldown button, and all children.

Reimplemented from Fl_Group.

◆ draw_tab()

void Fl_Tabs::draw_tab	(	int	x1,
		int	x2,
		int	W,
		int	H,
		Fl_Widget *	o,
		int	flags,
		int	what
	)

protectedvirtual

Draw a tab in the top or bottom tabs area.

Tabs can be selected, or on the left or right side of the selected tab. If overlapping, left tabs are drawn bottom to top using clipping. The selected tab is then the topmost, followed by the right side tabs drawn top to bottom.

Tabs with the FL_WHEN_CLOSE bit set will draw a cross on their left side only if they are not compressed/overlapping.

Parameters

[in]	x1	horizontal position of the left edge of the tab
[in]	x2	horizontal position of the following tab
[in]	W,H	width and height of the tab
[in]	o	the child widget that corresponds to this tab
[in]	flags	if bit 1 is set, this tab is overlapped by another tab
[in]	what	can be LEFT, SELECTED, or RIGHT to indicate if the tab is to the left side or the right side of the selected tab, or the selected tab itself

◆ handle()

int Fl_Tabs::handle ( int event )

virtual

Handle all events in the tabs area and forward the rest to the selected child.

Parameters

[in] event handle this event

Returns: 1 if the event was handled

Reimplemented from Fl_Group.

◆ handle_overflow()

void Fl_Tabs::handle_overflow ( int ov )

Set a method to handle an overflowing tab bar.

The Fl_Tabs widget allows you to specify how to handle the situation where there are more tabs than can be displayed at once. The available options are:

OVERFLOW_COMPRESS: Tabs will be compressed and overlaid on top of each other.
OVERFLOW_CLIP: Only the first tabs that fit will be displayed.
OVERFLOW_PULLDOWN: Tabs that do not fit will be placed in a pull-down menu.
OVERFLOW_DRAG: The tab bar can be dragged horizontally to reveal additional tabs.

You can set the desired behavior using the overflow() method.

Parameters

ov	overflow type

See also: OVERFLOW_COMPRESS, OVERFLOW_CLIP, OVERFLOW_PULLDOWN, OVERFLOW_DRAG

◆ handle_overflow_menu()

void Fl_Tabs::handle_overflow_menu ( )

protected

This is called when the user clicks the overflow pulldown menu button.

This method creates a menu item array that contains the titles of all tabs in the Fl_Tabs group. Visible and invisible tabs are separated by dividers to indicate their state.

The menu is then presented until the user selects an item or cancels. The chosen tab is then selected and made visible.

The menu item array is the deleted.

◆ hit_close()

int Fl_Tabs::hit_close	(	Fl_Widget *	o,
		int	event_x,
		int	event_y
	)

protectedvirtual

Check whether the coordinates fall within the "close" button area of the tab.

The Fl_Tabs::hit_close() method checks whether the given event coordinates fall within the area of the "close" button on the tab of the specified child widget. This method should be called after the Fl_Tabs::which() method, which updates a lookup table used to determine the width of each tab.

Parameters

o	check the tab of this widget
event_x,event_y	event coordinates

Returns: 1 if we hit the close button, and 0 otherwise

◆ hit_overflow_menu()

int Fl_Tabs::hit_overflow_menu	(	int	event_x,
		int	event_y
	)

protectedvirtual

Determine if the coordinates are in the area of the overflow menu button.

Parameters

event_x,event_y event coordinates

Returns: 1 if we hit the overflow menu button, and 0 otherwise

◆ hit_tabs_area()

int Fl_Tabs::hit_tabs_area	(	int	event_x,
		int	event_y
	)

protectedvirtual

Determine if the coordinates are within the tabs area.

Parameters

event_x,event_y event coordinates

Returns: 1 if we hit the tabs area, and 0 otherwise

◆ on_insert()

int Fl_Tabs::on_insert	(	Fl_Widget *	candidate,
		int	index
	)

protectedvirtual

Make sure that we redraw all tabs when new children are added.

Reimplemented from Fl_Group.

◆ on_move()

int Fl_Tabs::on_move	(	int	a,
		int	b
	)

protectedvirtual

Make sure that we redraw all tabs when children are moved.

Reimplemented from Fl_Group.

◆ on_remove()

void Fl_Tabs::on_remove ( int index )

protectedvirtual

Make sure that we redraw all tabs when new children are removed.

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().

◆ redraw_tabs()

void Fl_Tabs::redraw_tabs ( )

protectedvirtual

Redraw all tabs (and only the tabs).

This method sets the Fl_Tab's damage flags so the tab area is redrawn.

◆ resize()

void Fl_Tabs::resize	(	int	X,
		int	Y,
		int	W,
		int	H
	)

protectedvirtual

Make sure that we redraw all tabs when the widget size changes.

Reimplemented from Fl_Group.

◆ tab_align() [1/2]

Fl_Align Fl_Tabs::tab_align ( ) const

inline

Gets the tab label alignment.

See also: tab_align(Fl_Align)

◆ tab_align() [2/2]

void Fl_Tabs::tab_align ( Fl_Align a )

inline

Sets the tab label alignment.

The default is FL_ALIGN_CENTER so tab labels are centered, but since the label space is measured (per label) to fit the labels, there wouldn't be any difference if labels were aligned left or right.

If you want to show an image (icon) next to the group's label you can set a different label alignment. FL_ALIGN_IMAGE_NEXT_TO_TEXT is the recommended alignment to show the icon left of the text.

◆ tab_height()

int Fl_Tabs::tab_height ( )

protectedvirtual

Return space (height) in pixels usable for tabs.

The calculated height is the largest space between all children and the upper and lower widget boundaries, respectively. If the space at the bottom is larger than at the top, the value will be negative and the tabs should be placed at the bottom.

Returns: Vertical space that can be used for the tabs.

Return values

>	0 To put the tabs at the top of the widget.
<	0 To put the tabs on the bottom.
Full	height, if children() == 0.

◆ tab_positions()

int Fl_Tabs::tab_positions ( )

protectedvirtual

Calculate tab positions and widths.

This protected method calculates the horizontal display positions and widths of all tabs. If the number of children 'nc' (see below) is > 0 three internal arrays are allocated, otherwise the arrays are free'd and the pointers are set to NULL. Note that the first array is larger (nc+1).

tab_pos[nc+1] : The left edges of each tab plus a fake left edge for a tab past the right-hand one.
tab_width[nc] : The width of each tab
tab_flags[nc] : Flags, bit 0 is set if the tab is compressed

If needed, these arrays are (re)allocated.

These positions are actually of the left edge of the slope. They are either separated by the correct distance or by EXTRASPACE or by zero.

In OVERFLOW_COMPRESS mode, tab positions and widths are compressed to make the entire tabs bar fit into the width of Fl_Tabs while keeping the selected tab fully visible.

In other overflow modes, the tabs area may be dragged horizontally using tab_offset. The tab_pos array is not adjusted to the horizontal offset, but starts at this->x() plus the box's left margin.

The protected variable tab_count is set to the currently allocated size, i.e. the number of children (nc).

Returns: Index of the selected item

Return values

-1	If the number of children is 0 (zero).

Note: Return values in 1.3 were not documented. Return values before Sep 2023 were documented as 1 based index and 0 if there were no children. This was actually never the case. It always returned a 0 based index and the (useless) value of also 0 if there were no children. The current version return -1 if there are no children.; For this method to work, only on single child should be selected. Calling the method value() before calling tab_positions() will ensure that exactly one child is selected and return a pointer to that child.

See also: clear_tab_positions()

◆ value() [1/2]

Fl_Widget * Fl_Tabs::value ( )

Gets the currently visible widget/tab.

The Fl_Tabs::value() method returns a pointer to the currently visible child widget of the Fl_Tabs container. The visible child is the first child that is currently being displayed, or the last child if none of the children are being displayed.

If child widgets have been added, moved, or deleted, this method ensures that only one tab is visible at a time.

Returns: a pointer to the currently visible child

◆ value() [2/2]

int Fl_Tabs::value ( Fl_Widget * newvalue )

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

The Fl_Tabs::value() method allows you to set a particular child widget of the Fl_Tabs container to be the currently visible widget. If the specified widget is a child of the Fl_Tabs container, it will be made visible and all other children will be hidden. The method returns 1 if the value was changed, and 0 if the specified value was already set.

Parameters

[in] newvalue a poiner to a child widget

Returns: 1 if a different tab was chosen; 0 if there was no change (new value already set)

◆ which()

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

virtual

Return a pointer to the child widget with a tab at the given coordinates.

The Fl_Tabs::which() method returns a pointer to the child widget of the Fl_Tabs container that corresponds to the tab at the given event coordinates. If the event coordinates are outside the area of the tabs or if the Fl_Tabs container has no children, the method returns NULL.

Parameters

event_x,event_y event coordinates

Returns: pointer to the selected child widget, or NULL

Member Data Documentation

◆ overflow_type

int Fl_Tabs::overflow_type

protected

See also: OVERFLOW_COMPRESS, OVERFLOW_CLIP, etc.

◆ tab_count

int Fl_Tabs::tab_count

protected

Array size of tab positions etc.

See also: tab_positions()

◆ tab_flags

int* Fl_Tabs::tab_flags

protected

Array of tab flag of tabs per child.

See also: tab_positions()

◆ tab_pos

int* Fl_Tabs::tab_pos

protected

Array of x-offsets of tabs per child + 1.

See also: tab_positions()

◆ tab_width

int* Fl_Tabs::tab_width

protected

Array of widths of tabs per child.

See also: tab_positions()

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

Fl_Tabs.H
Fl_Tabs.cxx

Public Types

Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ anonymous enum

Constructor & Destructor Documentation

◆ Fl_Tabs()

Member Function Documentation

◆ clear_tab_positions()

◆ client_area()

◆ draw()

◆ draw_tab()

◆ handle()

◆ handle_overflow()

◆ handle_overflow_menu()

◆ hit_close()

◆ hit_overflow_menu()

◆ hit_tabs_area()

◆ on_insert()

◆ on_move()

◆ on_remove()

◆ push() [1/2]

◆ push() [2/2]

◆ redraw_tabs()

◆ resize()

◆ tab_align() [1/2]

◆ tab_align() [2/2]

◆ tab_height()

◆ tab_positions()

◆ value() [1/2]

◆ value() [2/2]

◆ which()

Member Data Documentation

◆ overflow_type

◆ tab_count

◆ tab_flags

◆ tab_pos

◆ tab_width