QuadTreeModel< T > Class Template Reference

An abstract implementation of a quad-tree data model. More...

#include <QuadTreeModel.h++>

Inheritance diagram for QuadTreeModel< T >:

Signals
void	dataChanged ()
	Emitted when the model has changed in some significant way. More...
void	itemAdded (const QPoint &location)
	Emitted when a new item has been added to the model. More...
void	itemModified (const QPoint &location)
	Emitted when an item in the model has changed. More...
void	itemRemoved (const QPoint &location)
	Emitted when an item has been removed from the model. More...

Public Member Functions
	QuadTreeModel (const QRect &region, uint maxItemsPerQuad=1)
	Constructs a new QuadTreeModel with the given range and density. More...
virtual	~QuadTreeModel ()
	Destructor. More...
void	clear ()
	Removes all items from the model. More...
bool	addItem (T *item)
	Adds an item to the model. More...
bool	removeItem (T *item)
	Removes an item from the model. More...
void	updateItem (T *item)
	Notifies the model that the given item has changed. More...
T *	itemAtLocation (const QPoint &location) const
	Returns the item at the given location in the model. More...
QList< T * >	itemsInRegion (const QRect &region) const
	Returns a list of all items in the model that are within the given region. More...
QList< T * >	items () const
	Returns all of the items in the model. More...
QRect	region () const
	Returns the region covered by this model. More...
uint	itemCount () const
	Returns the number of items in the model. More...
bool	isEmpty () const
	Tests if the model is empty. More...
bool	setVisibleRegion (const QRect &visibleRegion)
	Sets the visible region for the model. More...
QRect	visibleRegion () const
	Returns the current visible region. More...

Protected Attributes
uint	_maxItemsPerQuad
QRect	_region
QRect	_visibleRegion
uint	_itemCount

Detailed Description

template<class T>
class quark::gui::QuadTreeModel< T >

An abstract implementation of a quad-tree data model.

A quad-tree is a data structure that represents a collection of objects which have locations within a 2-D plane. It provides fast lookup of items by coordinate or by rectangular region. Subclasses must implement locationForItem() to return the location (that is, the 2-D coordinates) of a data item.

Template Parameters

T	The type of the objects contained in this model. This type must define a location() method that takes no arguments and returns a QPoint.

Author

Mark Lindner

Constructor & Destructor Documentation

QuadTreeModel()

QuadTreeModel	(	const QRect &	region,
		uint	maxItemsPerQuad = 1
	)

Constructs a new QuadTreeModel with the given range and density.

Parameters

region	The region covered by this model.
maxItemsPerQuad	The maximum number of items that a quad can contain before it is subdivided.

~QuadTreeModel()

virtual ~QuadTreeModel ( )

virtual

Destructor.

Member Function Documentation

addItem()

bool addItem

(

T *

item

)

Adds an item to the model.

Parameters

item	The item to add.

Returns

true if the item was added, or false if there is already an item in the model at the location of this item.

clear()

void clear

(

)

Removes all items from the model.

dataChanged

void dataChanged ( )

signalinherited

Emitted when the model has changed in some significant way.

isEmpty()

bool isEmpty ( ) const

inlineinherited

Tests if the model is empty.

itemAdded

void itemAdded ( const QPoint &  location )

signalinherited

Emitted when a new item has been added to the model.

Parameters

location

The item's location.

itemAtLocation()

T* itemAtLocation

(

const QPoint &

location

)

const

Returns the item at the given location in the model.

Parameters

point

The location.

Returns

The item at the given location, or NULL if there is none.

itemCount()

uint itemCount ( ) const

inlineinherited

Returns the number of items in the model.

itemModified

void itemModified ( const QPoint &  location )

signalinherited

Emitted when an item in the model has changed.

Parameters

location

The item's location.

itemRemoved

void itemRemoved ( const QPoint &  location )

signalinherited

Emitted when an item has been removed from the model.

Parameters

location

The item's location.

items()

QList<T *> items

(

)

const

Returns all of the items in the model.

itemsInRegion()

QList<T *> itemsInRegion

(

const QRect &

region

)

const

Returns a list of all items in the model that are within the given region.

Parameters

region

The region.

Returns

The (possibly empty) list of items in the region.

region()

QRect region ( ) const

inlineinherited

Returns the region covered by this model.

removeItem()

bool removeItem

(

T *

item

)

Removes an item from the model.

Parameters

item	The item to remove.

Returns

true if the item was removed, or false if the model does not contain this item.

setVisibleRegion()

bool setVisibleRegion ( const QRect &  visibleRegion )

inherited

Sets the visible region for the model.

When a data item is added to, removed from, or changed in the model, the corresponding notification signal will only be emitted if that item's location was within the visible region.

Parameters

The	new visible region.

Returns

true on success, or false if the specified region is neither empty nor contained within the model's region.

updateItem()

void updateItem

(

T *

item

)

Notifies the model that the given item has changed.

The model will emit the appropriate signal to notifiy views of the change.

Parameters

item	The item that changed.

visibleRegion()

QRect visibleRegion ( ) const

inlineinherited

Returns the current visible region.

Member Data Documentation

_itemCount

uint _itemCount

protectedinherited

_maxItemsPerQuad

uint _maxItemsPerQuad

protectedinherited

_region

QRect _region

protectedinherited

_visibleRegion

QRect _visibleRegion

protectedinherited

---

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

• QuadTreeModel.h++