The BGridLayout class a BLayout subclass that arranges the items it holds in a grid. More...

Inheritance diagram for BGridLayout:

Public Member Functions
	BGridLayout (float horizontal=B_USE_DEFAULT_SPACING, float vertical=B_USE_DEFAULT_SPACING)
	Create a BGridLayout with horizontal space between columns and vertical space between rows.
	BGridLayout (BMessage *from)
	Archive constructor.
virtual	~BGridLayout ()
	Destructor method.
virtual bool	AddItem (BLayoutItem *item)
	Adds item to this layout in the first empty cell available, or in a new column in the first row if there are no emtpy cells.
virtual bool	AddItem (int32 index, BLayoutItem *item)
	BGridLayout::AddItem(BLayoutItem*)
virtual bool	AddItem (BLayoutItem *item, int32 column, int32 row, int32 columnCount=1, int32 rowCount=1)
	Adds item to this layout at column and row. item may also occupy additional cells if columnCount or rowCount are greater than 1.
virtual BLayoutItem *	AddView (BView *child)
	Adds child to this layout in the first empty cell available, or in a new column in the first row if there are no emtpy cells.
virtual BLayoutItem *	AddView (int32 index, BView *child)
	BGridLayout::AddView(BView*)
virtual BLayoutItem *	AddView (BView *child, int32 column, int32 row, int32 columnCount=1, int32 rowCount=1)
	Adds child to this layout at column and row. child may also occupy additional cells if columnCount or rowCount are greater than `1`.
void	AlignLayoutWith (BTwoDimensionalLayout *other, enum orientation orientation)
	Align the BLayoutItem's in the specified orientation within two or more BTwoDimensionalLayout's.
virtual BAlignment	Alignment ()
virtual status_t	Archive (BMessage *into, bool deep=true) const
	Archives this layout into archive. If deep is true, also archives the items in this layout, calling ItemArchived() for each one.
virtual BAlignment	BaseAlignment ()
	Method to be implemented in derived classes return the preferred alignment for this BAbstractLayout.
virtual BSize	BaseMaxSize ()
	Method to be implemented in derived classes return the maximum size constraint for this BAbstractLayout.
virtual BSize	BaseMinSize ()
	Method to be implemented in derived classes return the minimum size constraint for this BAbstractLayout.
virtual BSize	BasePreferredSize ()
	Method to be implemented in derived classes return the preferred size constraint for this BAbstractLayout.
float	ColumnWeight (int32 column) const
	Returns the weight for the specified column.
int32	CountColumns () const
	Returns the number of active columns in this layout.
int32	CountRows () const
	Returns the number of active rows in this layout.
virtual BRect	Frame ()
	Return the bounding frame of this item.
virtual void	GetHeightForWidth (float width, float min, float max, float *preferred)
	Get this BLayoutItem's height constraints for a given width.
void	GetInsets (float left, float top, float right, float bottom) const
	Get the insets for the BTwoDimensionalLayout (in pixels).
virtual bool	HasHeightForWidth ()
	Returns whether or not this BLayoutItem's height constraints are dependent on its width.
float	HorizontalSpacing () const
	Returns the spacing between columns for this layout.
virtual bool	IsVisible ()
	Return the current local visibility of this item. If an item is not visible, it will not be given space by the BLayout it resides in.
BLayout *	Layout () const
	Returns the BLayout this BLayoutItem resides in.
float	MaxColumnWidth (int32 column) const
	Returns the maximum width for column.
float	MaxRowHeight (int32 row) const
	Returns the maximum height for row.
virtual BSize	MaxSize ()
float	MinColumnWidth (int32 column) const
	Returns the minimum width for column.
float	MinRowHeight (int row) const
	Returns the minimum height for row.
virtual BSize	MinSize ()
virtual status_t	Perform (perform_code d, void *arg)
	Perform some action (Internal method defined for binary compatibility purposes).
virtual BSize	PreferredSize ()
float	RowWeight (int32 row) const
	Returns the weight of the specified row.
void	SetColumnWeight (int32 column, float weight)
	Set the weight for column to weight.
virtual void	SetExplicitAlignment (BAlignment alignment)
	Set this item's explicit alignment, to be used in Alignment().
virtual void	SetExplicitMaxSize (BSize size)
	Set this item's explicit max size, to be used in MaxSize().
virtual void	SetExplicitMinSize (BSize size)
	Set this item's explicit min size, to be used in MinSize().
virtual void	SetExplicitPreferredSize (BSize size)
	Set this item's explicit preferred size, to be used in PreferredSize().
virtual void	SetFrame (BRect frame)
	Set the bounding frame of this item.
void	SetHorizontalSpacing (float spacing)
	Set the spacing between columns for this layout.
void	SetInsets (float left, float top, float right, float bottom)
	Set the insets for this BTwoDimensionalLayout (in pixels).
void	SetMaxColumnWidth (int32 column, float width)
	Sets the maximum width for column to width.
void	SetMaxRowHeight (int32 row, float height)
	Sets the maximum height for row to width.
void	SetMinColumnWidth (int32 column, float width)
	Sets the minimum width for column to width.
void	SetMinRowHeight (int32 row, float height)
	Sets the minimum height for row to width.
void	SetRowWeight (int32 row, float weight)
	Set the weight for row to weight.
void	SetSpacing (float horizontal, float vertical)
	Set the spacing between columns and rows for this layout.
void	SetVerticalSpacing (float spacing)
	Set the spacing between rows for this layout.
virtual void	SetVisible (bool visible)
	Set the local visibility of this item.
float	VerticalSpacing () const
	Returns the spacing between rows for this layout.
BView targeting and attachment information.
BView *	Owner () const
	Returns the Owner of this layout, i.e. the view this layout manages.
BView *	TargetView () const
	Returns the target view of this layout.
virtual BView *	View ()
	Returns the same BView* as BLayout::Owner(), this method is inherited from BLayoutItem.
Adding, removing, counting and accessing BLayout children
virtual bool	RemoveView (BView *child)
	Removes and deletes all BLayoutItem representing a BView from this layout.
virtual bool	RemoveItem (BLayoutItem *item)
	Removes a BLayoutItem from this layout, and also removes the view it represents from this BLayout's target view.
virtual BLayoutItem *	RemoveItem (int32 index)
	Remove the BLayoutItem at index.
BLayoutItem *	ItemAt (int32 index) const
	Get the BLayoutItem at index. Returns `NULL` if index is out of bounds.
int32	CountItems () const
	Get the number of BLayoutItem s in this layout.
int32	IndexOfItem (const BLayoutItem *item) const
	Get the index of a BLayoutItem in this layout.
int32	IndexOfView (BView *child) const
	Get the index of child in this layout.
Methods triggering or related to laying out this BLayout.
virtual void	Relayout (bool immediate=false)
	Request this BLayout to reposition and resize its items as required.
void	LayoutItems (bool force=false)
	If there is no layout currently ongoing, and force is `false`, creates a new BLayoutContext and calls the DoLayout() method of this BLayout and any BLayout s nested in this BLayout.
Utility methods for BLayout subclasses
Utility methods for the BLayout class to attach and retrieve arbitrary data for a BLayoutItem.
void *	LayoutData () const
	Retrieve arbitrary data attached to this BLayoutItem.
void	SetLayoutData (void *data)
	Attach arbitrary data to this BLayoutItem.
Getting and setting the current on-screen positioning of a BLayoutItem.
void	AlignInFrame (BRect frame)
	Position this BLayoutItem within frame, given the value returned by Alignment(), and the size constraints for this item.
Static Public Member Functions
static BArchivable *	Instantiate (BMessage *from)
	Static member to restore objects from messages.
Protected Member Functions
virtual status_t	AllArchived (BMessage *into) const
	Method relating to the use of `BArchiver`.
virtual status_t	AllUnarchived (const BMessage *from)
	Unarchives the BLayoutItem's for this layout, calling ItemUnarchived() for each one.
virtual void	AncestorVisibilityChanged (bool shown)
	Hook method inherited from BLayoutItem, classes derived from BLayout must include the BLayout version of this method in their implementation.
virtual void	AttachedToLayout ()
	Hook method inherited from BLayoutItem, classes derived from BLayout must include the BLayout version of this method in their implementation.
virtual void	DetachedFromLayout (BLayout *layout)
	Hook method inherited from BLayoutItem, classes derived from BLayout must include the BLayout version of this method in their implementation.
virtual void	DoLayout ()
	Implemented by derived classes to position and resize the items in this layout.
virtual void	GetColumnRowConstraints (enum orientation orientation, int32 index, ColumnRowConstraints *constraints)
	Fill in the ColumnRowConstraints for a certain column or row in the BTwoDimensionalLayout.
virtual void	GetItemDimensions (BLayoutItem item, Dimensions dimensions)
	Tell the base class what column and row a BLayoutItem is in as well as how many columns and rows it covers.
virtual bool	HasMultiColumnItems ()
	Tests whether or not this BTwoDimensionalLayout contains any BLayoutItem's spanning more than one column.
virtual bool	HasMultiRowItems ()
	Tests whether or not this BTwoDimensionalLayout contains any BLayoutItem's spanning more than one row.
virtual int32	InternalCountColumns ()
	Get the number of columns in the BTwoDimensionalLayout.
virtual int32	InternalCountRows ()
	Get the number of rows in the BTwoDimensionalLayout.
virtual bool	ItemAdded (BLayoutItem *item, int32 atIndex)
	Hook method called when item is added to this layout.
virtual status_t	ItemArchived (BMessage into, BLayoutItem item, int32 index) const
	Hook for derived classes to add data specific to item to the into BMessage. item resides at index.
virtual void	ItemRemoved (BLayoutItem *item, int32 fromIndex)
	Hook method called when item is removed from this layout.
virtual status_t	ItemUnarchived (const BMessage from, BLayoutItem item, int32 index)
	Hook for derived classes to retrieve data specific to item from the from BMessage. item resides at index.
virtual void	LayoutInvalidated (bool children=false)
	Hook called from InvalidateLayout().
virtual void	OwnerChanged (BView *was)
	Hook method called when this layout is attached to a BView.
BTwoDimensionalLayout Hook methods
These methods are called automatically as needed during layout, and provide the BTwoDimensionalLayout class with the necessary information to properly layout the BLayoutItem in this BTwoDimensionalLayout.
virtual void	PrepareItems (enum orientation orientation)
	Prepare the BLayoutItem in this BTwoDimensionalLayout subclass for layout within a certain orientation.
Subclass helpers.
These methods are meant to ease the development of BLayout subclasses.
bool	AncestorsVisible () const
	Get the visibility of the ancestors of this layout.
BRect	LayoutArea ()
	Returns the on-screen area this layout has received to lay out its items in.
void	VisibilityChanged (bool show)
	Method to be called by derived classes in their SetVisible() implementation. Calls AncestorVisibilityChanged() on the items in this BLayout.
Invalidation and state mutators and accessors.
virtual void	InvalidateLayout (bool children=false)
	Invalidate this layout and any cached data this layout has relating to positioning and sizing of its items.
void	RequireLayout ()
	Flag this layout as stale, i.e. any cached data may still be valid, but the items need to be repositioned or resized.
bool	IsValid ()
	Returns whether this layout has been invalidated (via BLayout::InvalidateLayout()) and has not yet been validated (by doing a layout, or by its ResetLayoutInvalidation() method.
void	EnableLayoutInvalidation ()
	Re-enable layout invalidation after a call to DisableLayoutInvalidation().
void	DisableLayoutInvalidation ()
	Disable layout invalidation notifications, i.e. calls to this object's InvalidateLayout() method.
void	ResetLayoutInvalidation ()
	Reset layout invalidation, causing InvalidateLayout calls to proceed again. This method should be called once any cached data has been validated, or updated to valid values.

Detailed Description

The BGridLayout class a BLayout subclass that arranges the items it holds in a grid.

Each item in a BGridLayout receives a rectangular area which can span more than a single row or column. The indexing of columns and rows is zero based, starting in the top-left.

Warning:: This class is not yet finalized, if you use it in your software assume that it will break some time in the future.

Constructor & Destructor Documentation

BGridLayout::BGridLayout ( BMessage * from )

Archive constructor.

Parameters:

from	The message to build the BGridLayout from.

BGridLayout::~BGridLayout ( ) [virtual]

Destructor method.

Standard Destructor.

Member Function Documentation

BLayoutItem * BGridLayout::AddItem	(	BLayoutItem *	item,
		int32	column,
		int32	row,
		int32	columnCount = `1`,
		int32	rowCount = `1`
	)		`[virtual]`

Adds item to this layout at column and row. item may also occupy additional cells if columnCount or rowCount are greater than 1.

Fails and returns NULL if the requested area is occupied, or if internal memory allocations fail.

BLayoutItem * BGridLayout::AddView	(	BView *	child,
		int32	column,
		int32	row,
		int32	columnCount = `1`,
		int32	rowCount = `1`
	)		`[virtual]`

Adds child to this layout at column and row. child may also occupy additional cells if columnCount or rowCount are greater than 1.

Fails and returns NULL if the requested area is occupied, or if internal memory allocations fail.

void BTwoDimensionalLayout::AlignLayoutWith	(	BTwoDimensionalLayout *	other,
		enum orientation orientation
	)		`[inherited]`

Align the BLayoutItem's in the specified orientation within two or more BTwoDimensionalLayout's.

When two (or more) BTwoDimensionalLayout's are aligned within a certain orientation, then the BLayoutItem's within those BTwoDimensionalLayout's will have identical widths or heights (depending on how the BTwoDimensionalLayout's are aligned.)

If you align two BGroupLayout's horizontally for example, then the BLayoutItem at index 0 in both BGroupLayout's will be given the same horizontal area. The same is true for the BLayoutItem at index 1, 2, etc. Not all BTwoDimensionalLayout's have to have an item at each index for the alignment to proceed.

Parameters:

other	The BTwoDimensionalLayout to be aligned with.
orientation	The orientation on which to be aligned.

BAlignment BAbstractLayout::Alignment ( ) [virtual, inherited]

Returns the requested alignment for this item.

The value returned from this method is used in BLayoutItem::AlignInFrame(), which BLayouts use to position and resize items. In a vertical BGroupLayout, for example, although each item recieves the same horizontal area, each item can use that area differently, aligning to the left, right or center for example.

The return value for this method is composed (using BLayoutUtils::ComposeAlignment()) from the values returned by BaseAlignment() and ExplicitAlignment()

Implements BLayoutItem.

virtual status_t BGridLayout::AllArchived ( BMessage * into ) const [protected, virtual]

Method relating to the use of BArchiver.

This hook function is called once the first BArchiver that was created in an archiving session is either destroyed, or has its Finish() method called. Implementations of this method can be used, in conjunction with BArchiver::IsArchived(), to reference objects in your archive that you do not own, depending on whether or not those objects were archived by their owners. Implementations of this method should call the implementation of their parent class, the same as for the Archive() method.

Warning:: To guarantee that your AllArchived() method will be called during archival, you must create a BArchiver object in your Archive() implementation.; You should archive any objects you own in your Archive() method implementation, and NOT your AllArchived() method.

See also:: BArchiver BArchiver::Finish()

Reimplemented from BTwoDimensionalLayout.

bool BLayout::AncestorsVisible ( ) const [inherited]

Get the visibility of the ancestors of this layout.

If a BLayout is connected to a BView, this will always return true. If a BLayout is nested in another layout (it was passed to AddItem()), then this will reflect the visibility of this BLayout's parent layout. If any layout is hidden (by BLayout::SetVisible()) between this layout and its target BView's layout, then this method will return false.

float BGridLayout::ColumnWeight ( int32 column ) const

Returns the weight for the specified column.

Returns:: The column weight as a float.

int32 BGridLayout::CountColumns ( ) const

Returns the number of active columns in this layout.

Returns:: The number of active columns in the layout.

int32 BGridLayout::CountRows ( ) const

Returns the number of active rows in this layout.

Returns:: the number of active rows in the layout.

virtual void BAbstractLayout::DetachedFromLayout ( BLayout * layout ) [protected, virtual, inherited]

Hook method inherited from BLayoutItem, classes derived from BLayout must include the BLayout version of this method in their implementation.

Parameters:

layout The BLayout that this BLayout was detached from.

Reimplemented from BLayout.

virtual BRect BAbstractLayout::Frame ( ) [virtual, inherited]

Return the bounding frame of this item.

The returned BRect is in the coordinate system of the target view of the BLayout this item belongs to.

Implements BLayoutItem.

virtual void BGridLayout::GetColumnRowConstraints	(	enum orientation orientation	,
		int32	index,
		ColumnRowConstraints *	constraints
	)		`[protected, virtual]`

Fill in the ColumnRowConstraints for a certain column or row in the BTwoDimensionalLayout.

This method is used to communicate the size constraints and weight for a given row/column in the BTwoDimensionalLayout.

Implements BTwoDimensionalLayout.

virtual void BTwoDimensionalLayout::GetHeightForWidth	(	float	width,
		float *	min,
		float *	max,
		float *	preferred
	)		`[virtual, inherited]`

Get this BLayoutItem's height constraints for a given width.

If a BLayoutItem does not have height for width constraints (HasHeightForWidth() returns false) it does not need to implement this method.

Note:: It is prudent to compare min, max, preferred to NULL before dereferencing them.

Reimplemented from BLayoutItem.

void BTwoDimensionalLayout::GetInsets	(	float *	left,
		float *	top,
		float *	right,
		float *	bottom
	)		const `[inherited]`

Get the insets for the BTwoDimensionalLayout (in pixels).

Passing NULL for any parameter is not an error, those parameters will be ignored.

See also:: BTwoDimensionalLayout::SetInsets();

virtual bool BTwoDimensionalLayout::HasHeightForWidth ( ) [virtual, inherited]

Returns whether or not this BLayoutItem's height constraints are dependent on its width.

Note:: By default, this method returns false.

Reimplemented from BLayoutItem.

virtual bool BGridLayout::HasMultiColumnItems ( ) [protected, virtual]

Tests whether or not this BTwoDimensionalLayout contains any BLayoutItem's spanning more than one column.

The BTwoDimensionalLayout implementation returns false.

Reimplemented from BTwoDimensionalLayout.

virtual bool BGridLayout::HasMultiRowItems ( ) [protected, virtual]

Tests whether or not this BTwoDimensionalLayout contains any BLayoutItem's spanning more than one row.

The BTwoDimensionalLayout implementation returns false.

Reimplemented from BTwoDimensionalLayout.

float BGridLayout::HorizontalSpacing ( ) const

Returns the spacing between columns for this layout.

Returns:: The spacing between columns for the layout.

int32 BLayout::IndexOfItem ( const BLayoutItem * item ) const [inherited]

Get the index of a BLayoutItem in this layout.

Parameters:

item	The BLayoutItem whose index you want.

Return values:

-1	item was not found in this BLayout.

int32 BLayout::IndexOfView ( BView * child ) const [inherited]

Get the index of child in this layout.

Note:: This finds the index of views added through BLayout::AddView(), not the index of an item which represents child that was added through BLayout::AddItem().

static BArchivable* BGridLayout::Instantiate ( BMessage * archive ) [static]

Static member to restore objects from messages.

You should always check that the archive argument actually corresponds to your class. The automatic functions, such as instantiate_object() and BUnarchiver::InstantiateObject() will not choose the wrong class but manual calls to this member might be faulty. You can verify that archive stores an object of your calss with the validate_instantiation() function.

Parameters:

archive The message with the data of the object to restore.

Return values:

You	should return a pointer to the object you create with `archive`, or `NULL` if unarchival fails.

Warning:: The default implementation will always return NULL. Even though it is possible to store plain BArchivable objects, it is impossible to restore them.

See also:: instantiate_object(BMessage *from); BUnarchiver::InstantiateObject()

Reimplemented from BArchivable.

virtual int32 BGridLayout::InternalCountColumns ( ) [protected, virtual]

Get the number of columns in the BTwoDimensionalLayout.

Returns:: The number of columns in the BTwoDimensionalLayout.

Implements BTwoDimensionalLayout.

virtual int32 BGridLayout::InternalCountRows ( ) [protected, virtual]

Get the number of rows in the BTwoDimensionalLayout.

Returns:: The number of rows in the BTwoDimensionalLayout.

Implements BTwoDimensionalLayout.

void BLayout::InvalidateLayout ( bool children = false ) [virtual, inherited]

Invalidate this layout and any cached data this layout has relating to positioning and sizing of its items.

Invalidating a BLayout also invalidates the view it is connected to (if there is one) and the BLayout this layout (or this BLayout's view) resides in.

Although this method is virtual, you should not override it, override the BLayout::LayoutInvalidated() hook instead.

This method should be called whenever the layout becomes invalid. This might happen if the size constraints of an item in this layout change, this layout is given more or less space than it previously had, or an object in this layout has had its InvalidateLayout() method called.

See also:: BView::InvalidateLayout(), BLayoutItem::InvalidateLayout(), BLayout::LayoutInvalidated()

Reimplemented from BLayoutItem.

virtual bool BAbstractLayout::IsVisible ( ) [virtual, inherited]

Return the current local visibility of this item. If an item is not visible, it will not be given space by the BLayout it resides in.

A simple implementation would return the last thing passed to SetVisible(). A more complex implementation may deal with a BView that could be hidden in any number of ways.

Implements BLayoutItem.

virtual bool BGridLayout::ItemAdded	(	BLayoutItem *	item,
		int32	atIndex
	)		`[protected, virtual]`

Hook method called when item is added to this layout.

Parameters:

item	The BLayoutItem that is being added.
atIndex	The index of the BLayoutItem.

Return values:

true	success
false	failure, item will not be added.

Note:: This is a good time to allocate data for a BLayoutItem and attach it to item via BLayoutItem::SetLayoutData().

Reimplemented from BAbstractLayout.

virtual status_t BGridLayout::ItemArchived	(	BMessage *	into,
		BLayoutItem *	item,
		int32	index
	)		const `[protected, virtual]`

Hook for derived classes to add data specific to item to the into BMessage. item resides at index.

Note:: The same archive is passed to BLayout::ItemArchived() for all items, so any data added for each item will be stored in an array.

Reimplemented from BTwoDimensionalLayout.

virtual void BGridLayout::ItemRemoved	(	BLayoutItem *	item,
		int32	fromIndex
	)		`[protected, virtual]`

Hook method called when item is removed from this layout.

Parameters:

item	The BLayoutItem being removed.
fromIndex	The index where item used to reside.

When this hook is called, item is not yet completely removed. It can no longer be accessed with LayoutItemAt(), nor does it contribute to the value of CountItems(), but the item has not yet had its ItemDetached() hook called.

Note:: This is a good time to delete the data you've attached to item via BLayoutItem::SetLayoutData().

Reimplemented from BAbstractLayout.

virtual status_t BGridLayout::ItemUnarchived	(	const BMessage *	from,
		BLayoutItem *	item,
		int32	index
	)		`[protected, virtual]`

Hook for derived classes to retrieve data specific to item from the from BMessage. item resides at index.

Note:: The same archive is passed to BLayout::ItemArchived() for all items, so any data added for each item will be stored in an array. You should pass index to the BMessage methods you will be using in this method.

Reimplemented from BTwoDimensionalLayout.

BRect BLayout::LayoutArea ( ) [inherited]

Returns the on-screen area this layout has received to lay out its items in.

The return value is in the coordinate space of this BLayout's target view. If this BLayout is attached directly to a BView, then LayoutArea().LeftTop() == B_ORIGIN .

void * BLayoutItem::LayoutData ( ) const [inherited]

Retrieve arbitrary data attached to this BLayoutItem.

Note:: This method should only be called by a BLayout subclass.

virtual void BTwoDimensionalLayout::LayoutInvalidated ( bool children = false ) [protected, virtual, inherited]

Hook called from InvalidateLayout().

Override this method to clean out an cached layout info. It is good practice to recreate such info only on demand, eg when MinSize() or friends are called.

If children is true, then you should invalidate any information on child objects as well, and propagate the invalidation to them.

Reimplemented from BAbstractLayout.

void BLayout::LayoutItems ( bool force = false ) [inherited]

If there is no layout currently ongoing, and force is false, creates a new BLayoutContext and calls the DoLayout() method of this BLayout and any BLayout s nested in this BLayout.

This method also guarantees that the owner view of this layout (as returned by BLayout::Owner()) performs a layout as well (if it is suitable to do so).

Parameters:

force Force the LayoutItems.

float BGridLayout::MaxColumnWidth ( int32 column ) const

Returns the maximum width for column.

Parameters:

column The column to get the maximum width of.

Returns:: The maximum width for column as a float.

BSize BAbstractLayout::MaxSize ( ) [virtual, inherited]

Returns the maximum desirable size for this item.

The return value for this method is composed (using BLayoutUtils::ComposeSize()) from the values returned by BaseMaxSize() and ExplicitMaxSize().

Implements BLayoutItem.

float BGridLayout::MinColumnWidth ( int32 column ) const

Returns the minimum width for column.

Parameters:

column The column to get the minimum width of.

Returns:: The minimum width for column as a float.

BSize BAbstractLayout::MinSize ( ) [virtual, inherited]

Returns the minimum desirable size for this item.

The return value for this method is composed (using BLayoutUtils::ComposeSize()) from the values returned by BaseMinSize() and ExplicitMinSize().

Implements BLayoutItem.

virtual void BAbstractLayout::OwnerChanged ( BView * was ) [protected, virtual, inherited]

Hook method called when this layout is attached to a BView.

Parameters:

was	The previous owner of this BLayout, for new BLayout s, this will be `NULL`.

Reimplemented from BLayout.

BSize BAbstractLayout::PreferredSize ( ) [virtual, inherited]

Returns the preferred size for this item.

The return value for this method is composed (using BLayoutUtils::ComposeSize()) from the values returned by BasePreferredSize() and ExplicitPreferredSize().

Implements BLayoutItem.

void BTwoDimensionalLayout::PrepareItems ( enum orientation orientation ) [protected, virtual, inherited]

Prepare the BLayoutItem in this BTwoDimensionalLayout subclass for layout within a certain orientation.

This is a good place to update cache information that will be used in other hook methods, for example.

Reimplemented in BGroupLayout.

void BLayout::Relayout ( bool immediate = false ) [virtual, inherited]

Request this BLayout to reposition and resize its items as required.

If immediate is false, and there is already a request to have the window this layout resides in re-laid-out, then the layout will happen at that time. If immediate is true, and there is no such pending request, nor is this BLayout's parent layout in the process of laying out its items, then this BLayout will now layout its items.

Parameters:

immediate Whether or not to Relayout immediately or wait for pending requests first.

Reimplemented from BLayoutItem.

bool BLayout::RemoveItem ( BLayoutItem * item ) [virtual, inherited]

Removes a BLayoutItem from this layout, and also removes the view it represents from this BLayout's target view.

Parameters:

item	The BLayoutItem to be removed

Warning:: item is not deleted, you must delete it manually, or add it to another BLayout.; item->View(), even when it is removed from the target view, is not deleted. If you want it deleted, you must delete it yourself!

Return values:

true	success
false	failure

BLayoutItem * BLayout::RemoveItem ( int32 index ) [virtual, inherited]

Remove the BLayoutItem at index.

See also:: RemoveItem(BLayoutItem*)

Returns:: The BLayoutItem that was removed.

bool BLayout::RemoveView ( BView * child ) [virtual, inherited]

Removes and deletes all BLayoutItem representing a BView from this layout.

Parameters:

child The BView to be removed.

Return values:

true	success
false	failure

float BGridLayout::RowWeight ( int32 row ) const

Returns the weight of the specified row.

Returns:: The weight of the row.

void BGridLayout::SetColumnWeight	(	int32	column,
		float	weight
	)

Set the weight for column to weight.

Parameters:

column	The column to set.
weight	The weight to set.

virtual void BTwoDimensionalLayout::SetFrame ( BRect frame ) [virtual, inherited]

Set the bounding frame of this item.

frame is in the coordinate system of the target view of the BLayout that this item belongs to.

Reimplemented from BAbstractLayout.

void BGridLayout::SetHorizontalSpacing ( float spacing )

Set the spacing between columns for this layout.

Parameters:

spacing The number of pixels of spacing to set.

void BTwoDimensionalLayout::SetInsets	(	float	left,
		float	top,
		float	right,
		float	bottom
	)		`[inherited]`

Set the insets for this BTwoDimensionalLayout (in pixels).

Set the spacing around the edges of this BTwoDimensionalLayout. If you pass B_USE_DEFAULT_SPACING for a certain parameter, that parameter will be replaced with the value returned by BControlLook::DefaultItemSpacing().

See also:: BTwoDimensionalLayout::GetInsets();

void BLayoutItem::SetLayoutData ( void * data ) [inherited]

Attach arbitrary data to this BLayoutItem.

Note:: This method should only be called by a BLayout subclass.

void BGridLayout::SetMaxColumnWidth	(	int32	column,
		float	width
	)

Sets the maximum width for column to width.

Parameters:

column	The column to set the maximum width of.
width	The width to set.

void BGridLayout::SetMinColumnWidth	(	int32	column,
		float	width
	)

Sets the minimum width for column to width.

Parameters:

column	The column to set the minimum width of.
width	The width to set.

void BGridLayout::SetRowWeight	(	int32	row,
		float	weight
	)

Set the weight for row to weight.

Parameters:

row	The row number.
weight	The

void BGridLayout::SetSpacing	(	float	horizontal,
		float	vertical
	)

Set the spacing between columns and rows for this layout.

Parameters:

horizontal	The number of horizontal pixels of spacing to set.
vertical	The number of vertical pixels of spacing to set.

void BGridLayout::SetVerticalSpacing ( float spacing )

Set the spacing between rows for this layout.

Parameters:

spacing The number of pixels of spacing to set.

BView * BLayout::TargetView ( ) const [inherited]

Returns the target view of this layout.

The target view of a layout becomes the parent of any BView's in this layout, as well as the BView's returned by BLayoutItem::View() for each BLayoutItem in this layout.

float BGridLayout::VerticalSpacing ( ) const

Returns the spacing between rows for this layout.

Returns:: The spacing between rows for the layout.

void BLayout::VisibilityChanged ( bool show ) [protected, inherited]

Method to be called by derived classes in their SetVisible() implementation. Calls AncestorVisibilityChanged() on the items in this BLayout.

Parameters:

show	`true` to show, `false` to hide.

Public Member Functions

Static Public Member Functions

Protected Member Functions

Subclass helpers.

Invalidation and state mutators and accessors.

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation