The BLayout class provides an interface, and some basic implementation to manage the positioning and sizing of BLayoutItem s. More...

Inherits BLayoutItem.

Inherited by BAbstractLayout.

Public Member Functions
	BLayout ()
	Default constructor.

	BLayout (BMessage *archive)
	Archive constructor.

virtual	~BLayout ()
	Destructor, deletes all BLayoutItem's that this layout manages, and detaches from this BLayout's owner view if there is one.

virtual status_t	Perform (perform_code d, void *arg)
	Perform some action (Internal method defined for binary compatibility purposes).

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 Children
virtual BLayoutItem *	AddView (BView *child)
	Creates a BLayoutItem to represent a BView, and adds that item to this layout.

virtual BLayoutItem *	AddView (int32 index, BView *child)
	Creates a BLayoutItem to represent child, and adds that item at index to this layout. child is added to this BLayout's target view.

virtual bool	AddItem (BLayoutItem *item)
	Adds a BLayoutItem to this layout, and adds the BView it represents to this BLayout's target view.

virtual bool	AddItem (int32 index, BLayoutItem *item)
	Adds item to this layout, and adds the BView item represents to this BLayout's target view.

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 the 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.

BLayoutContext *	LayoutContext () const
	Returns the BLayoutContext this BLayout is currently operating in, or `NULL`.

Public Member Functions inherited from BLayoutItem
	BLayoutItem (BMessage *from)
	Archive constructor.

virtual status_t	Archive (BMessage *into, bool deep=true) const
	Archive the object into a BMessage.

BLayout *	Layout () const
	Returns the BLayout this BLayoutItem resides in.

virtual status_t	Perform (perform_code d, void *arg)
	Perform some action (Internal method defined for binary compatibility purposes).

bool	RemoveSelf ()
	Remove this layout item from the BLayout it is a part of.

virtual BView *	View ()
	Return the BView this item is representing, or `NULL` if it does not represent any view.

virtual BSize	MinSize ()=0
	Returns the minimum desirable size for this item.

virtual BSize	MaxSize ()=0
	Returns the maximum desirable size for this item.

virtual BSize	PreferredSize ()=0
	Returns the preferred size for this item.

virtual BAlignment	Alignment ()=0
	Returns the requested alignment for this item.

virtual bool	HasHeightForWidth ()
	Returns whether or not this BLayoutItem's height constraints are dependent on its width.

virtual void	GetHeightForWidth (float width, float min, float max, float *preferred)
	Get this BLayoutItem's height constraints for a given width.

virtual void	SetExplicitMinSize (BSize size)=0
	Set this item's explicit min size, to be used in MinSize().

virtual void	SetExplicitMaxSize (BSize size)=0
	Set this item's explicit max size, to be used in MaxSize().

virtual void	SetExplicitPreferredSize (BSize size)=0
	Set this item's explicit preferred size, to be used in PreferredSize().

void	SetExplicitSize (BSize size)
	Set the explicity size to size.

virtual void	SetExplicitAlignment (BAlignment alignment)=0
	Set this item's explicit alignment, to be used in Alignment().

virtual bool	IsVisible ()=0
	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.

virtual void	SetVisible (bool visible)=0
	Set the local visibility of this item.

virtual BRect	Frame ()=0
	Return the bounding frame of this item.

virtual void	SetFrame (BRect frame)=0
	Set the bounding frame of this item.

void	AlignInFrame (BRect frame)
	Position this BLayoutItem within frame, given the value returned by Alignment(), and the size constraints for this item.

void *	LayoutData () const
	Retrieve arbitrary data attached to this BLayoutItem.

void	SetLayoutData (void *data)
	Attach arbitrary data to this BLayoutItem.

Public Member Functions inherited from BArchivable
	BArchivable ()
	Constructor. Does nothing.

	BArchivable (BMessage *from)
	Constructor. Does important behind-the-scenes work in the unarchiving process.

virtual	~BArchivable ()
	Destructor. Does nothing.

virtual status_t	AllArchived (BMessage *archive) const
	Method relating to the use of `BArchiver`.

virtual status_t	AllUnarchived (const BMessage *archive)
	Method relating to the use of `BUnarchiver`.

virtual status_t	Archive (BMessage *into, bool deep=true) const
	Archive the object into a BMessage.

virtual status_t	Perform (perform_code d, void *arg)
	Perform some action (Internal method defined for binary compatibility purposes).

Protected Member Functions
virtual status_t	AllArchived (BMessage *archive) const
	Method relating to the use of `BArchiver`.

Hook Methods
virtual bool	ItemAdded (BLayoutItem *item, int32 atIndex)
	Hook method called when item is added to this layout.

virtual void	ItemRemoved (BLayoutItem *item, int32 fromIndex)
	Hook method called when item is removed from this layout.

virtual void	LayoutInvalidated (bool children)

virtual void	DoLayout ()=0
	Implemented by derived classes to position and resize the items in this layout.

virtual void	OwnerChanged (BView *was)
	Hook method called when this layout is attached to a BView.

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	AncestorVisibilityChanged (bool shown)
	Hook method inherited from BLayoutItem, classes derived from BLayout must include the BLayout version of this method in their implementation.

virtual status_t	AllArchived (BMessage *into) const
	Method relating to the use of `BArchiver`.

virtual status_t	AllUnarchived (const BMessage *from)
	Method relating to the use of `BUnarchiver`.

Hook methods

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.

Archiving
These methods relate to the archiving or unarchiving of this object and the BLayoutItem's it contains Since Haiku R1
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 status_t	AllUnarchived (const BMessage *from)
	Unarchives the BLayoutItem's for this layout, calling ItemUnarchived() for each one.

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 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.

Additional Inherited Members
Static Public Member Functions inherited from BArchivable
static BArchivable *	Instantiate (BMessage *archive)
	Static member to restore objects from messages.

Detailed Description

The BLayout class provides an interface, and some basic implementation to manage the positioning and sizing of BLayoutItem s.

BLayouts can be attached to a BView, managing the BLayoutItem's and BView's that reside in that view, or can be nested within another BLayout as a BLayoutItem.

Before adding a BLayoutItem to a BLayout, that layout must have a target view. When a BLayout is attached directly to a BView via BView::SetLayout() then that BView becomes the target of the layout. When a BLayout is nested in another BLayout (via BLayout::AddItem()) the nested BLayout inherits the target of the layout its nested in, if it does not have a target already. You can retrieve the target view for a layout with the TargetView() method. When adding a BLayoutItem to a BLayout, the item's view (as returned by BLayoutItem::View()) is added to the BLayout's target view.

BView* topView = new BGroupView();
BLayout* topLayout = topView->GetLayout();
 
BLayout* nestedLayout = new BGroupLayout(B_HORIZONTAL);
topLayout->AddItem(nestedLayout);
 
BLayout* veryNestedLayout = new BGroupLayout(B_VERTICAL);
nestedLayout->AddItem(veryNestedLayout);

After executing this code, veryNestedLayout, nestedLayout, and topLayout all have the same target view: topView.

Continuing with the same objects...

BLayout* nestedLayoutWithView = (new BGroupView())->GetLayout();

topLayout->AddItem(nestedLayoutWithView);

nestedLayoutWithView does have a target view of topView. This is because nestedLayoutWithView is attached directly to a BView.

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

Since: Haiku R1

Constructor & Destructor Documentation

◆ BLayout() [1/2]

BLayout::BLayout ( )

Default constructor.

After this constructor has finished, this BLayout holds no BLayoutItem's and does not have a target BView.

Warning: Because a new BLayout does not have a target BView, calls to the AddItem() and AddView() methods will fail.

Since: Haiku R1

◆ BLayout() [2/2]

BLayout::BLayout ( BMessage * archive )

Archive constructor.

Parameters

archive The archive message.

Since: Haiku R1

◆ ~BLayout()

BLayout::~BLayout ( )

virtual

Destructor, deletes all BLayoutItem's that this layout manages, and detaches from this BLayout's owner view if there is one.

Destructor method.

Each BLayoutItem's BView (as returned by BLayoutItem::View()) is also removed from their parent.

Note: Because nested BLayout's are treated as BLayoutItem's, any layouts nested in this BLayout will be deleted.

Since: Haiku R1

Standard Destructor.

Since: Haiku R1

Member Function Documentation

◆ AddItem() [1/2]

bool BLayout::AddItem ( BLayoutItem * item )

virtual

Adds a BLayoutItem to this layout, and adds the BView it represents to this BLayout's target view.

Parameters

item	The BLayoutItem to be added.

Returns: true if the item was added, false otherwise.

Since: Haiku R1

Reimplemented in BGridLayout, and BGroupLayout.

◆ AddItem() [2/2]

bool BLayout::AddItem	(	int32	index,
		BLayoutItem *	item
	)

virtual

Adds item to this layout, and adds the BView item represents to this BLayout's target view.

Parameters

item	The BLayoutItem to be added.
index	The index at which to add `item`.

If index is out of bounds, item will be added at the end. If index is somewhere between the first and last indices, then items from index to the end will be shuffled over by one.

Returns: true if the item was added, false otherwise.

Since: Haiku R1

Reimplemented in BGridLayout, and BGroupLayout.

◆ AddView() [1/2]

BLayoutItem * BLayout::AddView ( BView * child )

virtual

Creates a BLayoutItem to represent a BView, and adds that item to this layout.

child is added to this BLayout's target view.

Returns: The BLayoutItem created to represent child, or NULL if there was an error.

Parameters

child The BView to be added to this BLayout.

Since: Haiku R1

Reimplemented in BGridLayout, and BGroupLayout.

◆ AddView() [2/2]

BLayoutItem * BLayout::AddView	(	int32	index,
		BView *	child
	)

virtual

Creates a BLayoutItem to represent child, and adds that item at index to this layout. child is added to this BLayout's target view.

Since: Haiku R1

Reimplemented in BGridLayout, and BGroupLayout.

◆ AllArchived()

virtual status_t BLayout::AllArchived ( BMessage * into ) const

protectedvirtual

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()

Since: Haiku R1

Reimplemented from BLayoutItem.

Reimplemented in BAbstractLayout, BCardLayout, BGridLayout, BGroupLayout, and BTwoDimensionalLayout.

◆ AllUnarchived()

status_t BLayout::AllUnarchived ( const BMessage * from )

protectedvirtual

Unarchives the BLayoutItem's for this layout, calling ItemUnarchived() for each one.

Since: Haiku R1

Reimplemented from BLayoutItem.

Reimplemented in BAbstractLayout, BCardLayout, BGridLayout, BGroupLayout, and BTwoDimensionalLayout.

◆ AncestorsVisible()

bool BLayout::AncestorsVisible ( ) const

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.

Since: Haiku R1

◆ AncestorVisibilityChanged()

void BLayout::AncestorVisibilityChanged ( bool shown )

protectedvirtual

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

Since: Haiku R1

Reimplemented from BLayoutItem.

Reimplemented in BAbstractLayout.

◆ Archive()

status_t BLayout::Archive	(	BMessage *	archive,
		bool	deep = `true`
	)		const

virtual

Archives this layout into archive. If deep is true, also archives the items in this layout, calling ItemArchived() for each one.

Since: Haiku R1

Reimplemented from BLayoutItem.

Reimplemented in BAbstractLayout, BCardLayout, BGridLayout, BGroupLayout, and BTwoDimensionalLayout.

◆ AttachedToLayout()

void BLayout::AttachedToLayout ( )

protectedvirtual

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

Since: Haiku R1

Reimplemented from BLayoutItem.

Reimplemented in BAbstractLayout.

◆ CountItems()

int32 BLayout::CountItems ( ) const

Get the number of BLayoutItem s in this layout.

Since: Haiku R1

◆ DetachedFromLayout()

void BLayout::DetachedFromLayout ( BLayout * layout )

protectedvirtual

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.

Since: Haiku R1

Reimplemented from BLayoutItem.

Reimplemented in BAbstractLayout.

◆ DisableLayoutInvalidation()

void BLayout::DisableLayoutInvalidation ( )

Disable layout invalidation notifications, i.e. calls to this object's InvalidateLayout() method.

Since: Haiku R1

◆ DoLayout()

void BLayout::DoLayout ( )

protectedpure virtual

Implemented by derived classes to position and resize the items in this layout.

Since: Haiku R1

Implemented in BCardLayout, and BTwoDimensionalLayout.

◆ EnableLayoutInvalidation()

void BLayout::EnableLayoutInvalidation ( )

Re-enable layout invalidation after a call to DisableLayoutInvalidation().

Since: Haiku R1

◆ IndexOfItem()

int32 BLayout::IndexOfItem ( const BLayoutItem * item ) const

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.

Since: Haiku R1

◆ IndexOfView()

int32 BLayout::IndexOfView ( BView * child ) const

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().

Since: Haiku R1

◆ InvalidateLayout()

void BLayout::InvalidateLayout ( bool children = false )

virtual

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()

Since: Haiku R1

Reimplemented from BLayoutItem.

◆ IsValid()

bool BLayout::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.

Since: Haiku R1

◆ ItemAdded()

bool BLayout::ItemAdded	(	BLayoutItem *	item,
		int32	atIndex
	)

protectedvirtual

Hook method called when item is added to this layout.

Parameters

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

Returns: true on succcess, false if 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().

Since: Haiku R1

Reimplemented in BAbstractLayout, BCardLayout, BGridLayout, and BGroupLayout.

◆ ItemArchived()

status_t BLayout::ItemArchived	(	BMessage *	into,
		BLayoutItem *	item,
		int32	index
	)		const

protectedvirtual

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.

Since: Haiku R1

Reimplemented in BAbstractLayout, BCardLayout, BGridLayout, BGroupLayout, and BTwoDimensionalLayout.

◆ ItemAt()

BLayoutItem * BLayout::ItemAt ( int32 index ) const

Get the BLayoutItem at index. Returns NULL if index is out of bounds.

Since: Haiku R1

◆ ItemRemoved()

void BLayout::ItemRemoved	(	BLayoutItem *	item,
		int32	fromIndex
	)

protectedvirtual

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().

Since: Haiku R1

Reimplemented in BAbstractLayout, BCardLayout, BGridLayout, and BGroupLayout.

◆ ItemUnarchived()

status_t BLayout::ItemUnarchived	(	const BMessage *	from,
		BLayoutItem *	item,
		int32	index
	)

protectedvirtual

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.

Since: Haiku R1

Reimplemented in BAbstractLayout, BCardLayout, BGridLayout, BGroupLayout, and BTwoDimensionalLayout.

◆ LayoutArea()

BRect BLayout::LayoutArea ( )

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 .

Since: Haiku R1

◆ LayoutContext()

BLayoutContext * BLayout::LayoutContext ( ) const

Returns the BLayoutContext this BLayout is currently operating in, or NULL.

Since: Haiku R1

◆ LayoutInvalidated()

void BLayout::LayoutInvalidated ( bool children )

protectedvirtual

Hook method called when this layout becomes invalid. This is a good place to clear any caches your object might hold.

Parameters

children Whether or not child layouts have also been invalidated.

Since: Haiku R1

Reimplemented from BLayoutItem.

Reimplemented in BAbstractLayout, BCardLayout, and BTwoDimensionalLayout.

◆ LayoutItems()

void BLayout::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.

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.

Since: Haiku R1

◆ Owner()

BView * BLayout::Owner ( ) const

Returns the Owner of this layout, i.e. the view this layout manages.

Since: Haiku R1

Referenced by BLayoutBuilder::Cards< ParentBuilder >::Cards(), BLayoutBuilder::Grid< ParentBuilder >::Grid(), and BLayoutBuilder::Group< ParentBuilder >::Group().

◆ OwnerChanged()

void BLayout::OwnerChanged ( BView * was )

protectedvirtual

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`.

Since: Haiku R1

Reimplemented in BAbstractLayout.

◆ Perform()

virtual status_t BLayout::Perform	(	perform_code	d,
		void *	arg
	)

virtual

Perform some action (Internal method defined for binary compatibility purposes).

Reimplemented from BLayoutItem.

Reimplemented in BAbstractLayout, BCardLayout, BGridLayout, BGroupLayout, and BTwoDimensionalLayout.

◆ Relayout()

void BLayout::Relayout ( bool immediate = false )

virtual

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.

Since: Haiku R1

Reimplemented from BLayoutItem.

◆ RemoveItem() [1/2]

bool BLayout::RemoveItem ( BLayoutItem * item )

virtual

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!

Returns: true if the item was removed, false otherwise.

Since: Haiku R1

◆ RemoveItem() [2/2]

BLayoutItem * BLayout::RemoveItem ( int32 index )

virtual

Remove the BLayoutItem at index.

See also: RemoveItem(BLayoutItem*)

Returns: The BLayoutItem that was removed.

Since: Haiku R1

◆ RemoveView()

bool BLayout::RemoveView ( BView * child )

virtual

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

Parameters

child The BView to be removed.

Returns: true if the item was removed, false otherwise.

Since: Haiku R1

◆ RequireLayout()

void BLayout::RequireLayout ( )

Flag this layout as stale, i.e. any cached data may still be valid, but the items need to be repositioned or resized.

Since: Haiku R1

◆ ResetLayoutInvalidation()

void BLayout::ResetLayoutInvalidation ( )

protected

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.

Since: Haiku R1

◆ TargetView()

BView * BLayout::TargetView ( ) const

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.

Since: Haiku R1

◆ View()

BView * BLayout::View ( )

virtual

Returns the same BView* as BLayout::Owner(), this method is inherited from BLayoutItem.

Since: Haiku R1

Reimplemented from BLayoutItem.

◆ VisibilityChanged()

void BLayout::VisibilityChanged ( bool show )

protected

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.

Since: Haiku R1

Public Member Functions

Protected Member Functions

Subclass Helpers

Invalidation and State Mutators and Accessors

Archiving

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ BLayout() [1/2]

◆ BLayout() [2/2]

◆ ~BLayout()

Member Function Documentation

◆ AddItem() [1/2]

◆ AddItem() [2/2]

◆ AddView() [1/2]

◆ AddView() [2/2]

◆ AllArchived()

◆ AllUnarchived()

◆ AncestorsVisible()

◆ AncestorVisibilityChanged()

◆ Archive()

◆ AttachedToLayout()

◆ CountItems()

◆ DetachedFromLayout()

◆ DisableLayoutInvalidation()

◆ DoLayout()

◆ EnableLayoutInvalidation()

◆ IndexOfItem()

◆ IndexOfView()

◆ InvalidateLayout()

◆ IsValid()

◆ ItemAdded()

◆ ItemArchived()

◆ ItemAt()

◆ ItemRemoved()

◆ ItemUnarchived()

◆ LayoutArea()

◆ LayoutContext()

◆ LayoutInvalidated()

◆ LayoutItems()

◆ Owner()

◆ OwnerChanged()

◆ Perform()

◆ Relayout()

◆ RemoveItem() [1/2]

◆ RemoveItem() [2/2]

◆ RemoveView()

◆ RequireLayout()

◆ ResetLayoutInvalidation()

◆ TargetView()

◆ View()

◆ VisibilityChanged()