CYIStreamer Class Reference

Detailed Description

A class that implements a scene node streamer.

The streamer class manages a list of streamable items. When these items are in the 'streaming region', they get streamed in. When these items are out of the 'streaming region', they get streamed out. The streaming region (and whether a given item is within the streaming region or not) is defined by the subclass implementation of CYIStreamer.

The streamable items are created automatically when an instance of CYINodeAdapter is assigned to the streamer. New items are also created (or removed) as needed when the adapter notifies that new items have been added. If the associated adapter is removed from the streamer, all existing streamable items are removed.

When a streamable item is streamed in, the associated CYINodeAdapter instance is used to create a scene node for it. When a streamable item is streamed out, that scene node is released back to the associated CYINodeAdapter instance.

In order to use a CYIStreamer object, a subclass must be made that implements the pure virtual functions. These functions handle the actual attachment of scene nodes to a scene tree. Typically, the class that implements a streamer would be a subclass of CYISceneNode. The subclass of CYIStreamer must call CYIStreamer::Init to initialize the streamer.

Note

Indices used in the streamer are 0-based and without gaps. Subclasses of the streamer may remap those indices to a different range. For example, a CYISceneView subclass of this streamer class may insert items within its children list, but offset them by a specific amount to account for a header. A CYISceneView subclass may also 'reverse' the order of items within its children list. Subclasses of this streamer must ensure that the indices provided by streamer functions are remapped to the indices used by the streamer subclass.

#include <streamer/YiStreamer.h>

Inheritance diagram for CYIStreamer:

Public Member Functions
	CYIStreamer ()
virtual	~CYIStreamer ()
void	SetAdapter (std::unique_ptr< CYINodeAdapter > pAdapter)
const CYINodeAdapter *	GetAdapter () const
CYINodeAdapter *	GetAdapter ()
bool	RequestFocusOnItem (uint32_t uIndex, CYIFocus::FOCUS_DIRECTION eDirection=CYIFocus::FOCUS_FORWARD, CYIFocus::FOCUS_ROOT_RULE eFocusRootRule=CYIFocus::FOCUS_ROOT_DESCENDANTS_UPDATE_CONTEXT, const CYIAABB &previousFocusRect=CYIAABB())
bool	IsStreamedIn (uint32_t uIndex) const
CYISceneNode *	GetStreamedNode (uint32_t uIndex) const
uint32_t	GetItemIndex (CYISceneNode *pStreamableItem) const

Protected Member Functions
void	Init (CYISceneManager *pSceneManager)
void	UpdateStreamedStateOfAllItems ()
virtual void	StreamedIn (uint32_t uIndex, CYISceneNode *pStreamedItem)
virtual void	OnStreamedIn (uint32_t uIndex, CYISceneNode *pStreamedItem)
virtual void	StreamedOut (uint32_t uIndex, CYISceneNode *pStreamedItem)
virtual void	OnStreamedOut (uint32_t uIndex, CYISceneNode *pStreamedItem)
virtual void	InsertItem (uint32_t uIndex, std::unique_ptr< CYISceneNode > pItem)=0
virtual std::unique_ptr< CYISceneNode >	RemoveItem (uint32_t uIndex, CYISceneNode *pItem)=0
virtual void	ReorderItem (uint32_t uFromIndex, uint32_t uToIndex, CYISceneNode *pItem)=0
virtual bool	IsItemInStreamingRegion (CYISceneNode *pItem) const =0
virtual CYISceneNode *	GetItem (uint32_t uIndex) const =0
virtual bool	CanBeStreamedOut (uint32_t uIndex, CYISceneNode *pNode) const =0
virtual void	OnFocusGainedForItem (uint32_t uIndex)
virtual void	FocusGainedForItem (uint32_t uIndex)
virtual void	OnFocusLostForItem (uint32_t uIndex)
virtual void	FocusLostForItem (uint32_t uIndex)

Friends
class	CYIStreamerSlots
class	CYIStreamableView

Constructor & Destructor Documentation

CYIStreamer::CYIStreamer

(

)

virtual CYIStreamer::~CYIStreamer ( )

virtual

Member Function Documentation

virtual bool CYIStreamer::CanBeStreamedOut ( uint32_t  uIndex, CYISceneNode *  pNode  ) const

protectedpure virtual

Checks if the streamable item at index uIndex can be streamed out. The implementation may require some nodes to remain streamed in, even if the node is outside of the streaming region.

virtual void CYIStreamer::FocusGainedForItem ( uint32_t  uIndex )

protectedvirtual

A function called when focus enters the tree rooted at the item at index uIndex.

Warning

Overrides must call the base class implementation.

See also

OnFocusGainedForItem

Reimplemented in CYIListView.

virtual void CYIStreamer::FocusLostForItem ( uint32_t  uIndex )

protectedvirtual

A function called when focus leaves the tree rooted at the item at index uIndex.

Warning

Overrides must call the base class implementation.

See also

OnFocusLostForItem

Reimplemented in CYIListView.

const CYINodeAdapter* CYIStreamer::GetAdapter

(

)

const

See also

SetAdapter

CYINodeAdapter* CYIStreamer::GetAdapter

(

)

See also

SetAdapter

virtual CYISceneNode* CYIStreamer::GetItem ( uint32_t  uIndex ) const

protectedpure virtual

Fetches and returns the streamable item at index uIndex.

Note

See CYIStreamer for details on item indices.

uint32_t CYIStreamer::GetItemIndex

(

CYISceneNode *

pStreamableItem

)

const

Returns the index of the streamable item pStreamableItem. If pStreamableItem is not a streamable item, std::numeric_limits<uint32_t>::max() is returned.

CYISceneNode* CYIStreamer::GetStreamedNode

(

uint32_t

uIndex

)

const

Returns the streamed node for index uIndex. Returns nullptr if the item at index uIndex is not currently streamed in, or if uIndex is out-of-bounds.

void CYIStreamer::Init ( CYISceneManager *  pSceneManager )

protected

Initializes this streamer using the scene manager pSceneManager.

Note

This function must be called by implementations of CYIStreamer.

virtual void CYIStreamer::InsertItem ( uint32_t  uIndex, std::unique_ptr< CYISceneNode >  pItem  )

protectedpure virtual

Inserts the streamable item pItem at index uIndex.

Note

See CYIStreamer for details on item indices.

virtual bool CYIStreamer::IsItemInStreamingRegion ( CYISceneNode *  pItem ) const

protectedpure virtual

Checks if the streamable item pItem is currently in the streaming region.

bool CYIStreamer::IsStreamedIn

(

uint32_t

uIndex

)

const

Returns true if the item at index uIndex is currently streamed in, false otherwise. false is also returned if uIndex is out-of-bounds.

virtual void CYIStreamer::OnFocusGainedForItem ( uint32_t  uIndex )

protectedvirtual

A function called when focus enters the tree rooted at the item at index uIndex.

Reimplemented in CYIListView.

virtual void CYIStreamer::OnFocusLostForItem ( uint32_t  uIndex )

protectedvirtual

A function called when focus leaves the tree rooted at the item at index uIndex.

Reimplemented in CYIListView.

virtual void CYIStreamer::OnStreamedIn ( uint32_t  uIndex, CYISceneNode *  pStreamedItem  )

protectedvirtual

A function called when the item at index uIndex is streamed in. The streamed node (as provided by the associated adapter) is provided as pStreamedItem. This function is called after the item has been attached to the scene tree. Subclasses can override this function to perform post-streaming logic.

Note

In some streamer implementations, the position of the streamed items is not set until later in the frame (e.g. after the layout pass). This function being called is only an indication that a new node has been attached to the scene tree.

Reimplemented in CYIListView.

virtual void CYIStreamer::OnStreamedOut ( uint32_t  uIndex, CYISceneNode *  pStreamedItem  )

protectedvirtual

A function called when the item at index uIndex is streamed out. The streamed node (as provided by the associated adapter) is provided as pStreamedItem. This function is called before the item has been detached from the scene tree. Subclasses can override this function to perform post-streaming logic.

Reimplemented in CYIListView.

virtual std::unique_ptr<CYISceneNode> CYIStreamer::RemoveItem ( uint32_t  uIndex, CYISceneNode *  pItem  )

protectedpure virtual

Removes the streamable item pItem from the CYIStreamer implementation. The item pItem is expected to be at index uIndex.

Warning

The item pItem must not be deleted.

Note

See CYIStreamer for details on item indices.

virtual void CYIStreamer::ReorderItem ( uint32_t  uFromIndex, uint32_t  uToIndex, CYISceneNode *  pItem  )

protectedpure virtual

Moves the streamable item pItem from index uFromIndex to index uToIndex.

Note

The new index of the item assumes that the item has been removed from the items list. For example, if the items list contains 'A, B, C, D' and 'ReorderItem(pNode, 0, 1)' is called, the new items list would be 'B, A, C, D'.

See CYIStreamer for details on item indices.

bool CYIStreamer::RequestFocusOnItem	(	uint32_t	uIndex,
		CYIFocus::FOCUS_DIRECTION	eDirection = CYIFocus::FOCUS_FORWARD,
		CYIFocus::FOCUS_ROOT_RULE	eFocusRootRule = CYIFocus::FOCUS_ROOT_DESCENDANTS_UPDATE_CONTEXT,
		const CYIAABB &	previousFocusRect = CYIAABB()
	)

Assigns focus within the streamable item at uIndex. Returns false if uIndex does not represent a streamable item or the streamable item at uIndex does not contain a focusable view.

See also

CYISceneView::RequestFocus

void CYIStreamer::SetAdapter

(

std::unique_ptr< CYINodeAdapter >

pAdapter

)

Sets an adapter for use with this streamer.

When a new adapter is set, n new items are created in the streamer (where n matches the value returned by the adapter's GetItemsCount() function).

Note

If an adapter was already set on the streamer, all of the streamer items will be streamed out and removed, and the old adapter will be deleted.

virtual void CYIStreamer::StreamedIn ( uint32_t  uIndex, CYISceneNode *  pStreamedItem  )

protectedvirtual

A function called when the item at index uIndex is streamed in. The streamed node (as provided by the associated adapter) is provided as pStreamedItem. This function is called after the item has been attached to the scene tree. Subclasses can override this function to perform post-streaming logic.

Note

In some streamer implementations, the position of the streamed items is not set until later in the frame (e.g. after the layout pass). This function being called is only an indication that a new node has been attached to the scene tree.

Warning

Overrides must call the base class implementation.

See also

OnStreamedIn()

virtual void CYIStreamer::StreamedOut ( uint32_t  uIndex, CYISceneNode *  pStreamedItem  )

protectedvirtual

A function called when the item at index uIndex is streamed out. The streamed node (as provided by the associated adapter) is provided as pStreamedItem. This function is called before the item has been detached from the scene tree. Subclasses can override this function to perform post-streaming logic.

Warning

Overrides must call the base class implementation.

See also

OnStreamedOut()

void CYIStreamer::UpdateStreamedStateOfAllItems ( )

protected

Causes the streamer to re-check the streamed state of all exiting items. Items that are now in the streaming region will be streamed in, and items that are no longer in the streaming region will be streamed out.

Friends And Related Function Documentation

friend class CYIStreamableView

friend

friend class CYIStreamerSlots

friend

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

• streamer/YiStreamer.h