FLTK 1.4.0: Fl_Flex Class Reference

Fl_Flex is a container (layout) widget for one row or one column of widgets. More...

#include <Fl_Flex.H>

Inheritance diagram for Fl_Flex:

Public Types
enum	{ VERTICAL = 0 , HORIZONTAL = 1 , COLUMN = 0 , ROW = 1 }

Public Member Functions
virtual void	end ()
	Ends automatic child addition and resizes all children. More...

void	fixed (Fl_Widget &w, int size)
	Set the horizontal or vertical size of a child widget. More...

int	fixed (Fl_Widget *w) const
	Return whether the given widget has a fixed size or resizes dynamically. More...

void	fixed (Fl_Widget *w, int size)
	Set the horizontal or vertical size of a child widget. More...

	Fl_Flex (int direction)
	Construct a new Fl_Flex widget specifying its layout. More...

	Fl_Flex (int w, int h, int direction)
	Construct a new Fl_Flex widget specifying its layout and size. More...

	Fl_Flex (int X, int Y, int W, int H, const char *L=0)
	Construct a new Fl_Flex widget with the given position, size, and label. More...

	Fl_Flex (int x, int y, int w, int h, int direction)
	Construct a new Fl_Flex widget specifying its layout, position, and size. More...

int	gap () const
	Return the gap size of the widget. More...

void	gap (int g)
	Set the gap size of the widget. More...

int	horizontal () const
	Returns non-zero (true) if Fl_Flex alignment is horizontal (row mode). More...

void	layout ()
	Calculates the layout of the widget and redraws it. More...

int	margin () const
	Returns the left margin size of the widget. More...

int	margin (int left, int top, int right, int bottom) const
	Returns all (four) margin sizes of the widget. More...

void	margin (int left, int top, int right, int bottom)
	Set the margin sizes at all four edges of the Fl_Flex widget. More...

void	margin (int m, int g=-1)
	Set the margin and optionally the gap size of the widget. More...

bool	need_layout () const
	Returns whether layout calculation is required. More...

void	need_layout (int set)
	Set or reset the request to calculate the layout of children. More...

void	resize (int x, int y, int w, int h) FL_OVERRIDE
	Resize the container and calculate all child positions and sizes. More...

int	spacing () const
	Gets the number of extra pixels of blank space that are added between the children. More...

void	spacing (int i)
	Sets the number of extra pixels of blank space that are added between the children. More...

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. More...

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. 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...

unsigned int	clip_children ()
	Returns the current clipping mode. More...

void	clip_children (int c)
	Controls whether the group widget clips the drawing of child widgets to its bounding box. More...

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

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

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. More...

	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) FL_OVERRIDE
	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 (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	remove (int index)
	Removes the widget at `index` from the group but does not delete it. More...

Fl_Widget *	resizable () const
	Returns the group's resizable widget. More...

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

void	resizable (Fl_Widget *o)
	The resizable widget defines both the resizing box and the resizing behavior of the group and its children. More...

void	resize (int, int, int, int) FL_OVERRIDE
	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_Window *	as_gl_window ()
	Returns an Fl_Gl_Window pointer if this widget is an Fl_Gl_Window. More...

virtual class Fl_Gl_Window const *	as_gl_window () const

virtual Fl_Group *	as_group ()
	Returns an Fl_Group pointer if this widget is an Fl_Group. More...

virtual Fl_Group const *	as_group () const

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

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. More...

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. More...

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

void	bind_image (int f)
	Bind the image to the widget, so the widget will delete the image when it is no longer needed. 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)
	Sets the current callback function for the widget. More...

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. More...

void	callback (Fl_Callback cb, void p)
	Sets the current callback function and data 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.

void	deactivate ()
	Deactivates the widget. More...

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

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

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

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

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

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

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

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

virtual void	draw ()=0
	Draws the widget. 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 int	handle (int event)
	Handles the specified event. More...

virtual void	hide ()
	Makes a widget invisible. More...

int	horizontal_label_margin ()
	Get the spacing between the label and the horizontal edge of the widget. More...

void	horizontal_label_margin (int px)
	Set the spacing between the label and the horizontal edge of the widget. More...

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

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

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

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

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

int	label_image_spacing ()
	Return the gap size between the label and the image. More...

void	label_image_spacing (int gap)
	Set the gap between the label and the image in pixels. 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...

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

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

virtual void	resize (int x, int y, int w, int h)
	Changes the size or position of the widget. 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...

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

void	shortcut_label (int value)
	Sets whether the widget's label uses '&' to indicate shortcuts. 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_Window *	top_window () const
	Returns a pointer to the top-level window for the widget. More...

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. 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 (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.

int	vertical_label_margin ()
	Get the spacing between the label and the vertical edge of the widget. More...

void	vertical_label_margin (int px)
	Set the spacing between the label and the vertical edge of the widget. More...

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

unsigned int	visible_focus () const
	Checks whether this widget has a visible focus. More...

void	visible_focus (int v)
	Modifies keyboard focus navigation. 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 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...

Protected Member Functions
virtual int	alloc_size (int size) const
	Return new size to be allocated for array of fixed size widgets. More...

void	draw () FL_OVERRIDE
	Draw the widget. More...

void	init (int t=VERTICAL)

void	on_remove (int) FL_OVERRIDE
	Allow derived groups to act when a child widget is removed from the group. More...

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

void	draw () FL_OVERRIDE
	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.

virtual int	on_insert (Fl_Widget *, int)
	Allow derived groups to act when a widget is added as a child. More...

virtual int	on_move (int, int)
	Allow derived groups to act when a widget is moved within the group. More...

virtual void	on_remove (int)
	Allow derived groups to act when a child widget is removed from the group. 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.

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. More...

void	draw_focus (Fl_Boxtype t, int X, int Y, int W, int H) const
	Draws a focus rectangle around the widget. More...

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. More...

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
Static Public Member Functions inherited from Fl_Group
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 widget, void data)
	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 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 , MAXIMIZED = 1<<24 , POPUP = 1<<25 , USERFLAG3 = 1<<29 , USERFLAG2 = 1<<30 , USERFLAG1 = 1<<31 }
	flags possible values enumeration. More...

Detailed Description

Fl_Flex is a container (layout) widget for one row or one column of widgets.

It provides flexible positioning of its children either in one row or in one column.

Fl_Flex is designed to be as simple as possible. You can set individual widget sizes or let Fl_Flex position and size the widgets to fit in the container. All "flexible" (i.e. non-fixed size) widgets are assigned the same width or height, respectively. For details see below.

You can set the margins around all children at the inner side of the box frame (if any). Fl_Flex supports setting different margin sizes on top, bottom, left, and right sides. The default margin size is 0 on all edges of the container.

You can set the gap size between all children. The gap size is always the same between all of its children. This is similar to the 'spacing' of Fl_Pack. The default gap size is 0.

Fl_Flex can either consist of a single row, i.e. type(Fl_Flex::HORIZONTAL) or a single column, i.e. type(Fl_Flex::VERTICAL). The default value is Fl_Flex::VERTICAL for consistency with Fl_Pack but you can use type() to assign a row (Fl_Flex::HORIZONTAL) layout.

If type() == Fl_Flex::HORIZONTAL widgets are resized horizontally to fit in the container and their height is the full Fl_Flex height minus border size and margins. You can set a fixed widget width by using fixed().

If type() == Fl_Flex::VERTICAL widgets are resized vertically to fit in the container and their width is the full Fl_Flex width minus border size and margins. You can set a fixed widget height by using fixed().

To create arbitrary spacing you can use invisible boxes of flexible or fixed sizes (see example below).

Alternate constructors let you specify the layout as Fl_Flex::HORIZONTAL or Fl_Flex::VERTICAL directly. Fl_Flex::ROW is an alias of Fl_Flex::HORIZONTAL and Fl_Flex::COLUMN is an alias of Fl_Flex::VERTICAL.

The default box type is FL_NO_BOX as inherited from Fl_Group. You may need to set a box type with a solid background depending on your layout.

Important: You should always make sure that the Fl_Flex container cannot be resized smaller than its designed minimal size. This can usually be done by setting a size_range() on the window as shown in the example below. Fl_Flex does not take care of sensible sizes. If it is resized too small the behavior is undefined, i.e. widgets may overlap and/or shrink to zero size.

Hint: In many cases Fl_Flex can be used as a drop-in replacement for Fl_Pack. This is the recommended single row/column container since FLTK 1.4.0. Its resizing behavior is much more predictable (as expected) than that of Fl_Pack which "resizes itself to shrink-wrap itself around all of the children".

Fl_Flex containers can be nested so you can create flexible layouts with multiple columns and rows. However, if your UI design is more complex you may want to use Fl_Grid instead.

Example:

Example code:

  #include <FL/Fl.H>
  #include <FL/Fl_Double_Window.H>
  #include <FL/Fl_Flex.H>
  #include <FL/Fl_Box.H>
  #include <FL/Fl_Button.H>
 
  int main(int argc, char **argv) {
    Fl_Double_Window window(410, 40, "Simple Fl_Flex Demo");
    Fl_Flex flex(5, 5, 400, 30, Fl_Flex::HORIZONTAL);
    Fl_Button b1(0, 0, 0, 0, "File");
    Fl_Button b2(0, 0, 0, 0, "Save");
    Fl_Box    bx(0, 0, 0, 0);
    Fl_Button b3(0, 0, 0, 0, "Exit");
    flex.fixed(bx, 60); // set fix width of invisible box
    flex.gap(10);
    flex.end();
    window.resizable(flex);
    window.end();
    window.size_range(300, 30);
    window.show(argc, argv);
    return Fl::run();
}

Since: 1.4.0

Member Enumeration Documentation

◆ anonymous enum

anonymous enum

Enumerator
VERTICAL	vertical layout (one column)
HORIZONTAL	horizontal layout (one row)
COLUMN	alias for VERTICAL
ROW	alias for HORIZONTAL

Constructor & Destructor Documentation

◆ Fl_Flex() [1/4]

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

Construct a new Fl_Flex widget with the given position, size, and label.

You can set type(Fl_Flex::HORIZONTAL) or type(Fl_Flex::VERTICAL). The default is type(Fl_Flex::VERTICAL).

Parameters

[in]	X,Y	position
[in]	W,H	size (width and height)
[in]	L	label (optional)

See also: Fl_Flex::Fl_Flex(int direction); Fl_Flex::Fl_Flex(int w, int h, int direction); Fl_Flex::Fl_Flex(int x, int y, int w, int h, int direction); Fl_Flex::Fl_Flex(int x, int y, int w, int h, const char *L)

◆ Fl_Flex() [2/4]

Fl_Flex::Fl_Flex ( int direction )

Construct a new Fl_Flex widget specifying its layout.

Use Fl_Flex::HORIZONTAL (aka Fl_Flex::ROW) or Fl_Flex::VERTICAL (aka Fl_Flex::COLUMN) as the direction argument.

This constructor sets the position and size to (0, 0, 0, 0) which is suitable for nested Fl_Flex widgets. Use one of the other constructors to set the desired position and size as well.

Parameters

[in] direction horizontal (row) or vertical (column) layout

See also: Fl_Flex::Fl_Flex(int w, int h, int direction); Fl_Flex::Fl_Flex(int x, int y, int w, int h, int direction); Fl_Flex::Fl_Flex(int x, int y, int w, int h, const char *L)

◆ Fl_Flex() [3/4]

Fl_Flex::Fl_Flex	(	int	w,
		int	h,
		int	direction
	)

Construct a new Fl_Flex widget specifying its layout and size.

Use Fl_Flex::HORIZONTAL (aka Fl_Flex::ROW) or Fl_Flex::VERTICAL (aka Fl_Flex::COLUMN) as the direction argument.

This constructor sets the position to (x = 0, y = 0) which is suitable for nested Fl_Flex widgets. Use one of the other constructors to set the desired position as well.

Parameters

[in]	w,h	widget size
[in]	direction	horizontal (row) or vertical (column) layout

See also: Fl_Flex::Fl_Flex(int direction); Fl_Flex::Fl_Flex(int x, int y, int w, int h, int direction); Fl_Flex::Fl_Flex(int x, int y, int w, int h, const char *L)

◆ Fl_Flex() [4/4]

Fl_Flex::Fl_Flex	(	int	x,
		int	y,
		int	w,
		int	h,
		int	direction
	)

Construct a new Fl_Flex widget specifying its layout, position, and size.

Use Fl_Flex::HORIZONTAL (aka Fl_Flex::ROW) or Fl_Flex::VERTICAL (aka Fl_Flex::COLUMN) as the direction argument.

This constructor sets the position and size of the widget which is suitable for top level Fl_Flex widgets but does not set a widget label. Use Fl_Widget::label() to set one if desired.

Parameters

[in]	x,y	widget position
[in]	w,h	widget size
[in]	direction	horizontal (row) or vertical (column) layout

See also: Fl_Flex::Fl_Flex(int direction); Fl_Flex::Fl_Flex(int w, int h, int direction); Fl_Flex::Fl_Flex(int x, int y, int w, int h, const char *L)

Member Function Documentation

◆ alloc_size()

int Fl_Flex::alloc_size ( int size ) const

protectedvirtual

Return new size to be allocated for array of fixed size widgets.

This method is called when the array of fixed size widgets needs to be expanded. The current size is provided (size can be 0). The default method adds 8 to the current size.

This can be used in derived classes to change the allocation strategy. Note that this method only queries the new size which shall be allocated but does not allocate the memory.

Parameters

[in] size current size

Returns: int new size (to be allocated)

◆ draw()

void Fl_Flex::draw ( void )

protectedvirtual

Draw the widget.

This will finally calculate the layout of the widget and of all its children if necessary and draw the widget.

Some changes of included children may require a new layout to be calculated. If this is the case the user may need to call layout() to make sure everything is calculated properly.

See also: layout()

Implements Fl_Widget.

◆ end()

void Fl_Flex::end ( )

virtual

Ends automatic child addition and resizes all children.

This marks the Fl_Flex widget as changed (need_layout(1)) which forces the widget to calculate its layout depending on all children and whether they have been assigned fix sizes or not right before it is drawn.

See also: need_layout(int); draw()

◆ fixed() [1/3]

void Fl_Flex::fixed	(	Fl_Widget &	w,
		int	size
	)

inline

Set the horizontal or vertical size of a child widget.

Parameters

[in]	w	widget to be affected
[in]	size	width (Fl_Flex::HORIZONTAL) or height (Fl_Flex::VERTICAL)

See also: fixed(Fl_Widget *w, int size)

◆ fixed() [2/3]

int Fl_Flex::fixed ( Fl_Widget * w ) const

Return whether the given widget has a fixed size or resizes dynamically.

Parameters

[in] w widget

Returns: whether the widget has a fixed size

Return values

1	the widget has a fixed size
0	the widget resizes dynamically

◆ fixed() [3/3]

void Fl_Flex::fixed	(	Fl_Widget *	child,
		int	size
	)

Set the horizontal or vertical size of a child widget.

This sets either the width or height of a child widget, depending on the type() of the Fl_Flex container (Fl_Flex::HORIZONTAL or Fl_Flex::VERTICAL). The other dimension is set to the full width or height of the Fl_Flex widget minus border and margin sizes.

This can be used to set a fixed widget width or height of children of Fl_Flex so they are not resized dynamically.

If size is 0 (zero) or negative the widget size is reset to flexible size.

Parameters

[in]	child	widget to be affected
[in]	size	width (Fl_Flex::HORIZONTAL) or height (Fl_Flex::VERTICAL)

◆ gap() [1/2]

int Fl_Flex::gap ( ) const

inline

Return the gap size of the widget.

Returns: gap size between all child widgets.

◆ gap() [2/2]

void Fl_Flex::gap ( int g )

inline

Set the gap size of the widget.

The gap size is some free space between child widgets. The size must be >= 0. Negative values are clamped to 0.

Parameters

[in] g gap size

◆ horizontal()

int Fl_Flex::horizontal ( ) const

inline

Returns non-zero (true) if Fl_Flex alignment is horizontal (row mode).

Returns: non-zero if Fl_Flex alignment is horizontal

Return values

1	if type() == Fl_Flex::HORIZONTAL
0	if type() == Fl_Flex::VERTICAL

See class Fl_Flex documentation for details.

◆ layout()

void Fl_Flex::layout ( )

Calculates the layout of the widget and redraws it.

If you change widgets in the Fl_Flex container you should call this method to force recalculation of child widget sizes and positions. This can be useful (necessary) if you hide(), show(), add() or remove() children.

Call this method if you need to recalculate widget positions for usage in an algorithm that places widgets at certain positions or when you need to display (show) or hide one or more children depending on the current layout (for instance a side bar).

This method also calls redraw() on the Fl_Flex widget.

◆ margin() [1/4]

int Fl_Flex::margin ( ) const

inline

Returns the left margin size of the widget.

This returns the left margin of the widget which is not necessarily the same as all other margins.

Note: This method is useful if you never set different margin sizes.

See also: int margin(int *left, int *top, int *right, int *bottom) to get all four margin values.

Returns: size of left margin.

◆ margin() [2/4]

int Fl_Flex::margin	(	int *	left,
		int *	top,
		int *	right,
		int *	bottom
	)		const

inline

Returns all (four) margin sizes of the widget.

All margin sizes are returned in the given arguments. If any argument is NULL the respective value is not returned.

Parameters

[in]	left	returns left margin if not `NULL`
[in]	top	returns top margin if not `NULL`
[in]	right	returns right margin if not `NULL`
[in]	bottom	returns bottom margin if not `NULL`

Returns: whether all margins are equal

Return values

1	all margins have the same size
0	at least one margin has a different size

◆ margin() [3/4]

void Fl_Flex::margin	(	int	left,
		int	top,
		int	right,
		int	bottom
	)

inline

Set the margin sizes at all four edges of the Fl_Flex widget.

The margin is the free space inside the widget border around all child widgets.

You must use all four parameters of this method to set the four margins in the order left, top, right, bottom. Negative values are set to 0 (zero).

To set all margins to equal sizes, use margin(int m) which sets all four margins to the same size.

Parameters

[in] left,top,right,bottom margin sizes, must be >= 0

See also: margin(int, int)

◆ margin() [4/4]

void Fl_Flex::margin	(	int	m,
		int	g = `-1`
	)

inline

Set the margin and optionally the gap size of the widget.

This method can be used to set both the margin and the gap size.

If you don't use the second parameter g or supply a negative value the gap size is not changed.

The margin is the free space inside the widget border around all child widgets.

This method sets the margin to the same size at all four edges of the Fl_Flex widget.

The gap size g is the free space between child widgets. Negative values do not change the gap value. This is the default if this argument is omitted.

Parameters

[in]	m	margin size, must be >= 0
[in]	g	gap size (ignored, if negative)

See also: gap(int)

◆ need_layout() [1/2]

bool Fl_Flex::need_layout ( ) const

inline

Returns whether layout calculation is required.

This should rarely be needed by user code. Used internally in draw().

◆ need_layout() [2/2]

void Fl_Flex::need_layout ( int set )

inline

Set or reset the request to calculate the layout of children.

This is intended for internal use but can also be used by user code to request layout calculation before the widget is drawn.

Call this if you changed attributes or sizes of children to ensure that the layout is calculated properly. Changing other Fl_Flex attributes or resizing the widget does this automatically.

Note: Never call this with 'set == 0' because this would defeat its purpose to recalculate the layout before the widget is drawn.

◆ on_remove()

void Fl_Flex::on_remove ( int index )

protectedvirtual

Allow derived groups to act when a child widget is removed from the group.

Widgets derived from Fl_Group may store additional data for their children. Overriding this method will allow derived classes to remove these data structures just before the child is removed.

Parameters

index remove the child at this position in the array_

Reimplemented from Fl_Group.

◆ resize()

void Fl_Flex::resize	(	int	x,
		int	y,
		int	w,
		int	h
	)

virtual

Resize the container and calculate all child positions and sizes.

Parameters

[in]	x,y	position
[in]	w,h	width and height

Reimplemented from Fl_Widget.

◆ spacing() [1/2]

int Fl_Flex::spacing ( ) const

inline

Gets the number of extra pixels of blank space that are added between the children.

This method is the same as 'int gap()' and is defined to enable using Fl_Flex as a drop-in replacement of Fl_Pack.

See also: int gap()

◆ spacing() [2/2]

void Fl_Flex::spacing ( int i )

inline

Sets the number of extra pixels of blank space that are added between the children.

This method is the same as 'gap(int)' and is defined to enable using Fl_Flex as a drop-in replacement of Fl_Pack.

See also: void gap(int)

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

Fl_Flex.H
Fl_Flex.cxx

Public Types

Public Member Functions

Protected Member Functions

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ anonymous enum

Constructor & Destructor Documentation

◆ Fl_Flex() [1/4]

◆ Fl_Flex() [2/4]

◆ Fl_Flex() [3/4]

◆ Fl_Flex() [4/4]

Member Function Documentation

◆ alloc_size()

◆ draw()

◆ end()

◆ fixed() [1/3]

◆ fixed() [2/3]

◆ fixed() [3/3]

◆ gap() [1/2]

◆ gap() [2/2]

◆ horizontal()

◆ layout()

◆ margin() [1/4]

◆ margin() [2/4]

◆ margin() [3/4]

◆ margin() [4/4]

◆ need_layout() [1/2]

◆ need_layout() [2/2]

◆ on_remove()

◆ resize()

◆ spacing() [1/2]

◆ spacing() [2/2]