wxSizer Class Reference
[Window Layout]

#include <wx/sizer.h>

Inheritance diagram for wxSizer:

Detailed Description

wxSizer is the abstract base class used for laying out subwindows in a window. You cannot use wxSizer directly; instead, you will have to use one of the sizer classes derived from it. Currently there are wxBoxSizer, wxStaticBoxSizer, wxGridSizer, wxFlexGridSizer, wxWrapSizer and wxGridBagSizer.

The layout algorithm used by sizers in wxWidgets is closely related to layout in other GUI toolkits, such as Java's AWT, the GTK toolkit or the Qt toolkit. It is based upon the idea of the individual subwindows reporting their minimal required size and their ability to get stretched if the size of the parent window has changed.

This will most often mean that the programmer does not set the original size of a dialog in the beginning, rather the dialog will be assigned a sizer and this sizer will be queried about the recommended size. The sizer in turn will query its children, which can be normal windows, empty space or other sizers, so that a hierarchy of sizers can be constructed. Note that wxSizer does not derive from wxWindow and thus does not interfere with tab ordering and requires very little resources compared to a real window on screen.

What makes sizers so well fitted for use in wxWidgets is the fact that every control reports its own minimal size and the algorithm can handle differences in font sizes or different window (dialog item) sizes on different platforms without problems. If e.g. the standard font as well as the overall design of Motif widgets requires more space than on Windows, the initial dialog size will automatically be bigger on Motif than on Windows.

Sizers may also be used to control the layout of custom drawn items on the window. The wxSizer::Add(), wxSizer::Insert(), and wxSizer::Prepend() functions return a pointer to the newly added wxSizerItem. Just add empty space of the desired size and attributes, and then use the wxSizerItem::GetRect() method to determine where the drawing operations should take place.

Please notice that sizers, like child windows, are owned by the library and will be deleted by it which implies that they must be allocated on the heap. However if you create a sizer and do not add it to another sizer or window, the library wouldn't be able to delete such an orphan sizer and in this, and only this, case it should be deleted explicitly.

wxPython Note: If you wish to create a sizer class in wxPython you should derive the class from wxPySizer in order to get Python-aware capabilities for the various virtual methods.

wxSizer flags

The "flag" argument accepted by wxSizeItem constructors and other functions, e.g. wxSizer::Add(), is OR-combination of the following flags. Two main behaviours are defined using these flags. One is the border around a window: the border parameter determines the border width whereas the flags given here determine which side(s) of the item that the border will be added. The other flags determine how the sizer item behaves when the space allotted to the sizer changes, and is somewhat dependent on the specific kind of sizer used.

wxTOP wxBOTTOM wxLEFT wxRIGHT wxALL	These flags are used to specify which side(s) of the sizer item the border width will apply to.
wxEXPAND	The item will be expanded to fill the space assigned to the item.
wxSHAPED	The item will be expanded as much as possible while also maintaining its aspect ratio.
wxFIXED_MINSIZE	Normally wxSizers will use GetAdjustedBestSize() to determine what the minimal size of window items should be, and will use that size to calculate the layout. This allows layouts to adjust when an item changes and its best size becomes different. If you would rather have a window item stay the size it started with then use wxFIXED_MINSIZE.
wxRESERVE_SPACE_EVEN_IF_HIDDEN	Normally wxSizers don't allocate space for hidden windows or other items. This flag overrides this behavior so that sufficient space is allocated for the window even if it isn't visible. This makes it possible to dynamically show and hide controls without resizing parent dialog, for example. (Available since 2.8.8.)
wxALIGN_CENTER wxALIGN_CENTRE wxALIGN_LEFT wxALIGN_RIGHT wxALIGN_TOP wxALIGN_BOTTOM wxALIGN_CENTER_VERTICAL wxALIGN_CENTRE_VERTICAL wxALIGN_CENTER_HORIZONTAL wxALIGN_CENTRE_HORIZONTAL	The wxALIGN flags allow you to specify the alignment of the item within the space allotted to it by the sizer, adjusted for the border if any.

Library: wxCore

Category: Window Layout

See also:: Sizers Overview


Public Member Functions
	wxSizer ()
virtual	~wxSizer ()
wxSizerItem *	Add (wxWindow *window, const wxSizerFlags &flags)
wxSizerItem *	Add (wxWindow window, int proportion=0, int flag=0, int border=0, wxObject userData=NULL)
wxSizerItem *	Add (wxSizer *sizer, const wxSizerFlags &flags)
wxSizerItem *	Add (wxSizer sizer, int proportion=0, int flag=0, int border=0, wxObject userData=NULL)
wxSizerItem *	Add (int width, int height, int proportion=0, int flag=0, int border=0, wxObject *userData=NULL)
wxSizerItem *	AddSpacer (int size)
wxSizerItem *	AddStretchSpacer (int prop=1)
virtual wxSize	CalcMin ()
virtual void	Clear (bool delete_windows=false)
wxSize	ComputeFittingClientSize (wxWindow *window)
wxSize	ComputeFittingWindowSize (wxWindow *window)
virtual bool	Detach (wxWindow *window)
virtual bool	Detach (wxSizer *sizer)
bool	Detach (size_t index)
wxSize	Fit (wxWindow *window)
void	FitInside (wxWindow *window)
wxWindow *	GetContainingWindow () const
wxSizerItem *	GetItem (wxWindow *window, bool recursive=false)
wxSizerItem *	GetItem (wxSizer *sizer, bool recursive=false)
wxSizerItem *	GetItem (size_t index)
wxSizerItem *	GetItemById (int id, bool recursive=false)
wxSize	GetMinSize ()
wxPoint	GetPosition () const
wxSize	GetSize () const
bool	Hide (wxWindow *window, bool recursive=false)
bool	Hide (wxSizer *sizer, bool recursive=false)
bool	Hide (size_t index)
wxSizerItem *	Insert (size_t index, wxWindow *window, const wxSizerFlags &flags)
wxSizerItem *	Insert (size_t index, wxWindow window, int proportion=0, int flag=0, int border=0, wxObject userData=NULL)
wxSizerItem *	Insert (size_t index, wxSizer *sizer, const wxSizerFlags &flags)
wxSizerItem *	Insert (size_t index, wxSizer sizer, int proportion=0, int flag=0, int border=0, wxObject userData=NULL)
wxSizerItem *	Insert (size_t index, int width, int height, int proportion=0, int flag=0, int border=0, wxObject *userData=NULL)
wxSizerItem *	InsertSpacer (size_t index, int size)
wxSizerItem *	InsertStretchSpacer (size_t index, int prop=1)
bool	IsShown (wxWindow *window) const
bool	IsShown (wxSizer *sizer) const
bool	IsShown (size_t index) const
virtual void	Layout ()
wxSizerItem *	Prepend (wxWindow *window, const wxSizerFlags &flags)
wxSizerItem *	Prepend (wxWindow window, int proportion=0, int flag=0, int border=0, wxObject userData=NULL)
wxSizerItem *	Prepend (wxSizer *sizer, const wxSizerFlags &flags)
wxSizerItem *	Prepend (wxSizer sizer, int proportion=0, int flag=0, int border=0, wxObject userData=NULL)
wxSizerItem *	Prepend (int width, int height, int proportion=0, int flag=0, int border=0, wxObject *userData=NULL)
wxSizerItem *	PrependSpacer (int size)
wxSizerItem *	PrependStretchSpacer (int prop=1)
virtual void	RecalcSizes ()
bool	Remove (wxWindow *window)
virtual bool	Remove (wxSizer *sizer)
bool	Remove (size_t index)
bool	Replace (wxWindow oldwin, wxWindow newwin, bool recursive=false)
bool	Replace (wxSizer oldsz, wxSizer newsz, bool recursive=false)
virtual bool	Replace (size_t index, wxSizerItem *newitem)
void	SetDimension (int x, int y, int width, int height)
void	SetDimension (const wxPoint &pos, const wxSize &size)
void	SetItemMinSize (wxWindow *window, int width, int height)
void	SetItemMinSize (wxSizer *sizer, int width, int height)
void	SetItemMinSize (size_t index, int width, int height)
void	SetMinSize (const wxSize &size)
void	SetMinSize (int width, int height)
void	SetSizeHints (wxWindow *window)
void	SetVirtualSizeHints (wxWindow *window)
bool	Show (wxWindow *window, bool show=true, bool recursive=false)
bool	Show (wxSizer *sizer, bool show=true, bool recursive=false)
bool	Show (size_t index, bool show=true)

wxSizerItemList &	GetChildren ()
const wxSizerItemList &	GetChildren () const

Constructor & Destructor Documentation

wxSizer::wxSizer ( )

The constructor. Note that wxSizer is an abstract base class and may not be instantiated.

virtual wxSizer::~wxSizer ( ) [virtual]

The destructor.

Member Function Documentation

wxSizerItem* wxSizer::Add	(	wxWindow *	window,
		const wxSizerFlags &	flags
	)

Appends a child to the sizer.

wxSizer itself is an abstract class, but the parameters are equivalent in the derived classes that you will instantiate to use it so they are described here:

Parameters:

	window	The window to be added to the sizer. Its initial size (either set explicitly by the user or calculated internally when using wxDefaultSize) is interpreted as the minimal and in many cases also the initial size.
	flags	A wxSizerFlags object that enables you to specify most of the above parameters more conveniently.

wxSizerItem* wxSizer::Add	(	wxWindow *	window,
		int	proportion = `0`,
		int	flag = `0`,
		int	border = `0`,
		wxObject *	userData = `NULL`
	)

Appends a child to the sizer.

wxSizer itself is an abstract class, but the parameters are equivalent in the derived classes that you will instantiate to use it so they are described here:

Parameters:

	window	The window to be added to the sizer. Its initial size (either set explicitly by the user or calculated internally when using wxDefaultSize) is interpreted as the minimal and in many cases also the initial size.
	proportion	Although the meaning of this parameter is undefined in wxSizer, it is used in wxBoxSizer to indicate if a child of a sizer can change its size in the main orientation of the wxBoxSizer - where 0 stands for not changeable and a value of more than zero is interpreted relative to the value of other children of the same wxBoxSizer. For example, you might have a horizontal wxBoxSizer with three children, two of which are supposed to change their size with the sizer. Then the two stretchable windows would get a value of 1 each to make them grow and shrink equally with the sizer's horizontal dimension.
	flag	OR-combination of flags affecting sizer's behavior. See wxSizer flags list for details.
	border	Determines the border width, if the flag parameter is set to include any border flag.
	userData	Allows an extra object to be attached to the sizer item, for use in derived classes when sizing information is more complex than the proportion and flag will allow for.

wxSizerItem* wxSizer::Add	(	wxSizer *	sizer,
		const wxSizerFlags &	flags
	)

Appends a child to the sizer.

wxSizer itself is an abstract class, but the parameters are equivalent in the derived classes that you will instantiate to use it so they are described here:

Parameters:

	sizer	The (child-)sizer to be added to the sizer. This allows placing a child sizer in a sizer and thus to create hierarchies of sizers (typically a vertical box as the top sizer and several horizontal boxes on the level beneath).
	flags	A wxSizerFlags object that enables you to specify most of the above parameters more conveniently.

wxSizerItem* wxSizer::Add	(	wxSizer *	sizer,
		int	proportion = `0`,
		int	flag = `0`,
		int	border = `0`,
		wxObject *	userData = `NULL`
	)

Appends a child to the sizer.

wxSizer itself is an abstract class, but the parameters are equivalent in the derived classes that you will instantiate to use it so they are described here:

Parameters:

	sizer	The (child-)sizer to be added to the sizer. This allows placing a child sizer in a sizer and thus to create hierarchies of sizers (typically a vertical box as the top sizer and several horizontal boxes on the level beneath).
	proportion	Although the meaning of this parameter is undefined in wxSizer, it is used in wxBoxSizer to indicate if a child of a sizer can change its size in the main orientation of the wxBoxSizer - where 0 stands for not changeable and a value of more than zero is interpreted relative to the value of other children of the same wxBoxSizer. For example, you might have a horizontal wxBoxSizer with three children, two of which are supposed to change their size with the sizer. Then the two stretchable windows would get a value of 1 each to make them grow and shrink equally with the sizer's horizontal dimension.
	flag	OR-combination of flags affecting sizer's behavior. See wxSizer flags list for details.
	border	Determines the border width, if the flag parameter is set to include any border flag.
	userData	Allows an extra object to be attached to the sizer item, for use in derived classes when sizing information is more complex than the proportion and flag will allow for.

wxSizerItem* wxSizer::Add	(	int	width,
		int	height,
		int	proportion = `0`,
		int	flag = `0`,
		int	border = `0`,
		wxObject *	userData = `NULL`
	)

Appends a spacer child to the sizer.

wxSizer itself is an abstract class, but the parameters are equivalent in the derived classes that you will instantiate to use it so they are described here.

width and height specify the dimension of a spacer to be added to the sizer. Adding spacers to sizers gives more flexibility in the design of dialogs; imagine for example a horizontal box with two buttons at the bottom of a dialog: you might want to insert a space between the two buttons and make that space stretchable using the proportion flag and the result will be that the left button will be aligned with the left side of the dialog and the right button with the right side - the space in between will shrink and grow with the dialog.

Parameters:

	width	Width of the spacer.
	height	Height of the spacer.
	proportion	Although the meaning of this parameter is undefined in wxSizer, it is used in wxBoxSizer to indicate if a child of a sizer can change its size in the main orientation of the wxBoxSizer - where 0 stands for not changeable and a value of more than zero is interpreted relative to the value of other children of the same wxBoxSizer. For example, you might have a horizontal wxBoxSizer with three children, two of which are supposed to change their size with the sizer. Then the two stretchable windows would get a value of 1 each to make them grow and shrink equally with the sizer's horizontal dimension.
	flag	OR-combination of flags affecting sizer's behavior. See wxSizer flags list for details.
	border	Determines the border width, if the flag parameter is set to include any border flag.
	userData	Allows an extra object to be attached to the sizer item, for use in derived classes when sizing information is more complex than the proportion and flag will allow for.

wxSizerItem* wxSizer::AddSpacer ( int size )

Adds non-stretchable space to the sizer. More readable way of calling:

        wxSizer::Add(size, size, 0).

wxSizerItem* wxSizer::AddStretchSpacer ( int prop = 1 )

Adds stretchable space to the sizer. More readable way of calling:

        wxSizer::Add(0, 0, prop).

virtual wxSize wxSizer::CalcMin ( ) [virtual]

This method is abstract and has to be overwritten by any derived class. Here, the sizer will do the actual calculation of its children's minimal sizes.

Reimplemented in wxGridBagSizer, and wxBoxSizer.

virtual void wxSizer::Clear ( bool delete_windows = false ) [virtual]

Detaches all children from the sizer. If delete_windows is true then child windows will also be deleted.

wxSize wxSizer::ComputeFittingClientSize ( wxWindow * window )

Computes client area size for window so that it matches the sizer's minimal size. Unlike GetMinSize(), this method accounts for other constraints imposed on window, namely display's size (returned size will never be too large for the display) and maximum window size if previously set by wxWindow::SetMaxSize().

The returned value is suitable for passing to wxWindow::SetClientSize() or wxWindow::SetMinClientSize().

Since:: 2.8.8

See also:: ComputeFittingWindowSize(), Fit()

wxSize wxSizer::ComputeFittingWindowSize ( wxWindow * window )

Like ComputeFittingClientSize(), but converts the result into window size. The returned value is suitable for passing to wxWindow::SetSize() or wxWindow::SetMinSize().

Since:: 2.8.8

See also:: ComputeFittingClientSize(), Fit()

virtual bool wxSizer::Detach ( wxWindow * window ) [virtual]

Detach the child window from the sizer without destroying it.

This method does not cause any layout or resizing to take place, call Layout() to update the layout "on screen" after detaching a child from the sizer.

Returns true if the child item was found and detached, false otherwise.

See also:: Remove()

virtual bool wxSizer::Detach ( wxSizer * sizer ) [virtual]

Detach the child sizer from the sizer without destroying it.

This method does not cause any layout or resizing to take place, call Layout() to update the layout "on screen" after detaching a child from the sizer.

Returns true if the child item was found and detached, false otherwise.

See also:: Remove()

bool wxSizer::Detach ( size_t index )

Detach a item at position index from the sizer without destroying it.

This method does not cause any layout or resizing to take place, call Layout() to update the layout "on screen" after detaching a child from the sizer. Returns true if the child item was found and detached, false otherwise.

See also:: Remove()

wxSize wxSizer::Fit ( wxWindow * window )

Tell the sizer to resize the window so that its client area matches the sizer's minimal size (ComputeFittingClientSize() is called to determine it). This is commonly done in the constructor of the window itself, see sample in the description of wxBoxSizer.

Returns:: The new window size.

See also:: ComputeFittingClientSize(), ComputeFittingWindowSize()

void wxSizer::FitInside ( wxWindow * window )

Tell the sizer to resize the virtual size of the window to match the sizer's minimal size. This will not alter the on screen size of the window, but may cause the addition/removal/alteration of scrollbars required to view the virtual area in windows which manage it.

See also:: wxScrolled::SetScrollbars(), SetVirtualSizeHints()

wxSizerItemList& wxSizer::GetChildren ( )

Returns the list of the items in this sizer.

The elements of type-safe wxList wxSizerItemList are pointers to objects of type wxSizerItem.

const wxSizerItemList& wxSizer::GetChildren ( ) const

Returns the list of the items in this sizer.

The elements of type-safe wxList wxSizerItemList are pointers to objects of type wxSizerItem.

wxWindow* wxSizer::GetContainingWindow ( ) const

Returns the window this sizer is used in or NULL if none.

wxSizerItem* wxSizer::GetItem	(	wxWindow *	window,
		bool	recursive = `false`
	)

Finds wxSizerItem which holds the given window. Use parameter recursive to search in subsizers too. Returns pointer to item or NULL.

wxSizerItem* wxSizer::GetItem	(	wxSizer *	sizer,
		bool	recursive = `false`
	)

Finds wxSizerItem which holds the given sizer. Use parameter recursive to search in subsizers too. Returns pointer to item or NULL.

wxSizerItem* wxSizer::GetItem ( size_t index )

Finds wxSizerItem which is located in the sizer at position index. Use parameter recursive to search in subsizers too. Returns pointer to item or NULL.

wxSizerItem* wxSizer::GetItemById	(	int	id,
		bool	recursive = `false`
	)

Finds item of the sizer which has the given id. This id is not the window id but the id of the wxSizerItem itself. This is mainly useful for retrieving the sizers created from XRC resources. Use parameter recursive to search in subsizers too. Returns pointer to item or NULL.

wxSize wxSizer::GetMinSize ( )

Returns the minimal size of the sizer.

This is either the combined minimal size of all the children and their borders or the minimal size set by SetMinSize(), depending on which is bigger. Note that the returned value is client size, not window size. In particular, if you use the value to set toplevel window's minimal or actual size, use wxWindow::SetMinClientSize() or wxWindow::SetClientSize(), not wxWindow::SetMinSize() or wxWindow::SetSize().

wxPoint wxSizer::GetPosition ( ) const

Returns the current position of the sizer.

wxSize wxSizer::GetSize ( ) const

Returns the current size of the sizer.

bool wxSizer::Hide	(	wxWindow *	window,
		bool	recursive = `false`
	)

Hides the child window.

To make a sizer item disappear, use Hide() followed by Layout().

Use parameter recursive to hide elements found in subsizers. Returns true if the child item was found, false otherwise.

See also:: IsShown(), Show()

bool wxSizer::Hide	(	wxSizer *	sizer,
		bool	recursive = `false`
	)

Hides the child sizer.

To make a sizer item disappear, use Hide() followed by Layout().

Use parameter recursive to hide elements found in subsizers. Returns true if the child item was found, false otherwise.

See also:: IsShown(), Show()

bool wxSizer::Hide ( size_t index )

Hides the item at position index.

To make a sizer item disappear, use Hide() followed by Layout().

Use parameter recursive to hide elements found in subsizers. Returns true if the child item was found, false otherwise.

See also:: IsShown(), Show()

wxSizerItem* wxSizer::Insert	(	size_t	index,
		wxWindow *	window,
		const wxSizerFlags &	flags
	)

Insert a child into the sizer before any existing item at index.

See Add() for the meaning of the other parameters.

wxSizerItem* wxSizer::Insert	(	size_t	index,
		wxWindow *	window,
		int	proportion = `0`,
		int	flag = `0`,
		int	border = `0`,
		wxObject *	userData = `NULL`
	)

Insert a child into the sizer before any existing item at index.

See Add() for the meaning of the other parameters.

wxSizerItem* wxSizer::Insert	(	size_t	index,
		wxSizer *	sizer,
		const wxSizerFlags &	flags
	)

Insert a child into the sizer before any existing item at index.

See Add() for the meaning of the other parameters.

wxSizerItem* wxSizer::Insert	(	size_t	index,
		wxSizer *	sizer,
		int	proportion = `0`,
		int	flag = `0`,
		int	border = `0`,
		wxObject *	userData = `NULL`
	)

Insert a child into the sizer before any existing item at index.

See Add() for the meaning of the other parameters.

wxSizerItem* wxSizer::Insert	(	size_t	index,
		int	width,
		int	height,
		int	proportion = `0`,
		int	flag = `0`,
		int	border = `0`,
		wxObject *	userData = `NULL`
	)

Insert a child into the sizer before any existing item at index.

See Add() for the meaning of the other parameters.

wxSizerItem* wxSizer::InsertSpacer	(	size_t	index,
		int	size
	)

Inserts non-stretchable space to the sizer. More readable way of calling wxSizer::Insert(size, size, 0).

wxSizerItem* wxSizer::InsertStretchSpacer	(	size_t	index,
		int	prop = `1`
	)

Inserts stretchable space to the sizer. More readable way of calling wxSizer::Insert(0, 0, prop).

bool wxSizer::IsShown ( wxWindow * window ) const

Returns true if the window is shown.

See also:: Hide(), Show(), wxSizerItem::IsShown()

bool wxSizer::IsShown ( wxSizer * sizer ) const

Returns true if the sizer is shown.

See also:: Hide(), Show(), wxSizerItem::IsShown()

bool wxSizer::IsShown ( size_t index ) const

Returns true if the item at index is shown.

See also:: Hide(), Show(), wxSizerItem::IsShown()

virtual void wxSizer::Layout ( ) [virtual]

Call this to force layout of the children anew, e.g. after having added a child to or removed a child (window, other sizer or space) from the sizer while keeping the current dimension.

wxSizerItem* wxSizer::Prepend	(	wxWindow *	window,
		const wxSizerFlags &	flags
	)