wxRegion Class Reference

#include </home/zeitlin/src/wx/github/interface/wx/region.h>

Inheritance diagram for wxRegion:

---

Detailed Description

A wxRegion represents a simple or complex region on a device context or window.

This class uses reference counting and copy-on-write internally so that assignments between two instances of this class are very cheap. You can therefore use actual objects instead of pointers without efficiency problems. If an instance of this class is changed it will create its own data internally so that other instances, which previously shared the data using the reference counting, are not affected.

Predefined objects/pointers:

• wxNullRegion

Library:  wxCore

Category:  Data Structures, Graphics Device Interface (GDI)

参照:

wxRegionIterator

Public Member Functions
	wxRegion ()
	Default constructor.
	wxRegion (wxCoord x, wxCoord y, wxCoord width, wxCoord height)
	Constructs a rectangular region with the given position and size.
	wxRegion (const wxPoint &topLeft, const wxPoint &bottomRight)
	Constructs a rectangular region from the top left point and the bottom right point.
	wxRegion (const wxRect &rect)
	Constructs a rectangular region a wxRect object.
	wxRegion (const wxRegion &region)
	Copy constructor, uses Reference Counting.
	wxRegion (size_t n, const wxPoint *points, wxPolygonFillMode fillStyle=wxODDEVEN_RULE)
	Constructs a region corresponding to the polygon made of n points in the provided array.
	wxRegion (const wxBitmap &bmp)
	Constructs a region using a bitmap.
	wxRegion (const wxBitmap &bmp, const wxColour &transColour, int tolerance=0)
	Constructs a region using the non-transparent pixels of a bitmap.
virtual	~wxRegion ()
	Destructor.
virtual void	Clear ()
	Clears the current region.
wxRegionContain	Contains (wxCoord x, wxCoord y) const
	Returns a value indicating whether the given point is contained within the region.
wxRegionContain	Contains (const wxPoint &pt) const
	Returns a value indicating whether the given point is contained within the region.
wxRegionContain	Contains (wxCoord x, wxCoord y, wxCoord width, wxCoord height) const
	Returns a value indicating whether the given rectangle is contained within the region.
wxRegionContain	Contains (const wxRect &rect) const
	Returns a value indicating whether the given rectangle is contained within the region.
wxBitmap	ConvertToBitmap () const
	Convert the region to a black and white bitmap with the white pixels being inside the region.
bool	Intersect (wxCoord x, wxCoord y, wxCoord width, wxCoord height)
	Finds the intersection of this region and another, rectangular region, specified using position and size.
bool	Intersect (const wxRect &rect)
	Finds the intersection of this region and another, rectangular region.
bool	Intersect (const wxRegion &region)
	Finds the intersection of this region and another region.
virtual bool	IsEmpty () const
	Returns true if the region is empty, false otherwise.
bool	IsEqual (const wxRegion &region) const
	Returns true if the region is equal to, i.e.
bool	Subtract (const wxRect &rect)
	Subtracts a rectangular region from this region.
bool	Subtract (const wxRegion &region)
	Subtracts a region from this region.
bool	Union (wxCoord x, wxCoord y, wxCoord width, wxCoord height)
	Finds the union of this region and another, rectangular region, specified using position and size.
bool	Union (const wxRect &rect)
	Finds the union of this region and another, rectangular region.
bool	Union (const wxRegion &region)
	Finds the union of this region and another region.
bool	Union (const wxBitmap &bmp)
	Finds the union of this region and the non-transparent pixels of a bitmap.
bool	Union (const wxBitmap &bmp, const wxColour &transColour, int tolerance=0)
	Finds the union of this region and the non-transparent pixels of a bitmap.
bool	Xor (wxCoord x, wxCoord y, wxCoord width, wxCoord height)
	Finds the Xor of this region and another, rectangular region, specified using position and size.
bool	Xor (const wxRect &rect)
	Finds the Xor of this region and another, rectangular region.
bool	Xor (const wxRegion &region)
	Finds the Xor of this region and another region.
wxRegion &	operator= (const wxRegion &region)
	Assignment operator, using Reference Counting.
void	GetBox (wxCoord &x, wxCoord &y, wxCoord &width, wxCoord &height) const
	Returns the outer bounds of the region.
wxRect	GetBox () const
	Returns the outer bounds of the region.
bool	Offset (wxCoord x, wxCoord y)
	Moves the region by the specified offsets in horizontal and vertical directions.
bool	Offset (const wxPoint &pt)
	Moves the region by the specified offsets in horizontal and vertical directions.

List of all members.

---

Constructor & Destructor Documentation

wxRegion::wxRegion

(

)

Default constructor.

This constructor creates an invalid, or null, object, i.e. calling IsOk() on it returns false and IsEmpty() returns true.

wxRegion::wxRegion	(	wxCoord	x,
		wxCoord	y,
		wxCoord	width,
		wxCoord	height
	)

Constructs a rectangular region with the given position and size.

wxRegion::wxRegion	(	const wxPoint &	topLeft,
		const wxPoint &	bottomRight
	)

Constructs a rectangular region from the top left point and the bottom right point.

wxRegion::wxRegion

(

const wxRect &

rect

)

Constructs a rectangular region a wxRect object.

wxRegion::wxRegion

(

const wxRegion &

region

)

Copy constructor, uses Reference Counting.

wxRegion::wxRegion	(	size_t	n,
		const wxPoint *	points,
		wxPolygonFillMode	fillStyle = wxODDEVEN_RULE
	)

Constructs a region corresponding to the polygon made of n points in the provided array.

fillStyle parameter may have values wxWINDING_RULE or wxODDEVEN_RULE.

wxRegion::wxRegion

(

const wxBitmap &

bmp

)

Constructs a region using a bitmap.

See Union() for more details.

wxRegion::wxRegion	(	const wxBitmap &	bmp,
		const wxColour &	transColour,
		int	tolerance = 0
	)

Constructs a region using the non-transparent pixels of a bitmap.

See Union() for more details.

virtual wxRegion::~wxRegion

(

)

[virtual]

Destructor.

See reference-counted object destruction for more info.

---

Member Function Documentation

virtual void wxRegion::Clear

(

)

[virtual]

Clears the current region.

The object becomes invalid, or null, after being cleared.

wxRegionContain wxRegion::Contains	(	wxCoord	x,
		wxCoord	y
	)		const

Returns a value indicating whether the given point is contained within the region.

This method always returns wxOutRegion for an invalid region but may, nevertheless, be safely called in this case.

Returns:

The return value is one of wxOutRegion and wxInRegion.

wxRegionContain wxRegion::Contains	(	wxCoord	x,
		wxCoord	y,
		wxCoord	width,
		wxCoord	height
	)		const

Returns a value indicating whether the given rectangle is contained within the region.

This method always returns wxOutRegion for an invalid region but may, nevertheless, be safely called in this case.

Returns:

One of wxOutRegion, wxPartRegion or wxInRegion.

注:

On Windows, only wxOutRegion and wxInRegion are returned; a value wxInRegion then indicates that all or some part of the region is contained in this region.

wxRegionContain wxRegion::Contains

(

const wxRect &

rect

)

const

Returns a value indicating whether the given rectangle is contained within the region.

This method always returns wxOutRegion for an invalid region but may, nevertheless, be safely called in this case.

Returns:

One of wxOutRegion, wxPartRegion or wxInRegion.

注:

On Windows, only wxOutRegion and wxInRegion are returned; a value wxInRegion then indicates that all or some part of the region is contained in this region.

wxRegionContain wxRegion::Contains

(

const wxPoint &

pt

)

const

Returns a value indicating whether the given point is contained within the region.

This method always returns wxOutRegion for an invalid region but may, nevertheless, be safely called in this case.

Returns:

The return value is one of wxOutRegion and wxInRegion.

wxBitmap wxRegion::ConvertToBitmap

(

)

const

Convert the region to a black and white bitmap with the white pixels being inside the region.

This method can't be used for invalid region.

wxRect wxRegion::GetBox

(

)

const

Returns the outer bounds of the region.

This method returns 0-sized bounding box for invalid regions.

void wxRegion::GetBox	(	wxCoord &	x,
		wxCoord &	y,
		wxCoord &	width,
		wxCoord &	height
	)		const

Returns the outer bounds of the region.

This method returns 0-sized bounding box for invalid regions.

bool wxRegion::Intersect	(	wxCoord	x,
		wxCoord	y,
		wxCoord	width,
		wxCoord	height
	)

Finds the intersection of this region and another, rectangular region, specified using position and size.

This method always fails, i.e. returns false, if this region is invalid but may nevertheless be safely used even in this case.

Returns:

true if successful, false otherwise.

注意:

Creates the intersection of the two regions, that is, the parts which are in both regions. The result is stored in this region.

bool wxRegion::Intersect

(

const wxRect &

rect

)

Finds the intersection of this region and another, rectangular region.

This method always fails, i.e. returns false, if this region is invalid but may nevertheless be safely used even in this case.

Returns:

true if successful, false otherwise.

注意:

Creates the intersection of the two regions, that is, the parts which are in both regions. The result is stored in this region.

bool wxRegion::Intersect

(

const wxRegion &

region

)

Finds the intersection of this region and another region.

This method always fails, i.e. returns false, if this region is invalid but may nevertheless be safely used even in this case.

Returns:

true if successful, false otherwise.

注意:

Creates the intersection of the two regions, that is, the parts which are in both regions. The result is stored in this region.

virtual bool wxRegion::IsEmpty

(

)

const [virtual]

Returns true if the region is empty, false otherwise.

Always returns true if the region is invalid.

bool wxRegion::IsEqual

(

const wxRegion &

region

)

const

Returns true if the region is equal to, i.e.

covers the same area as, another one.

If both this region and region are both invalid, they are considered to be equal.

bool wxRegion::Offset

(

const wxPoint &

pt

)

Moves the region by the specified offsets in horizontal and vertical directions.

This method can't be called if the region is invalid as it doesn't make sense to offset it then. Attempts to do it will result in assert failure.

Returns:

true if successful, false otherwise (the region is unchanged then).

bool wxRegion::Offset	(	wxCoord	x,
		wxCoord	y
	)

Moves the region by the specified offsets in horizontal and vertical directions.

This method can't be called if the region is invalid as it doesn't make sense to offset it then. Attempts to do it will result in assert failure.

Returns:

true if successful, false otherwise (the region is unchanged then).

wxRegion& wxRegion::operator=

(

const wxRegion &

region

)

Assignment operator, using Reference Counting.

bool wxRegion::Subtract

(

const wxRegion &

region

)

Subtracts a region from this region.

This method always fails, i.e. returns false, if this region is invalid but may nevertheless be safely used even in this case.

Returns:

true if successful, false otherwise.

注意:

This operation combines the parts of 'this' region that are not part of the second region. The result is stored in this region.

bool wxRegion::Subtract

(

const wxRect &

rect

)

Subtracts a rectangular region from this region.

This method always fails, i.e. returns false, if this region is invalid but may nevertheless be safely used even in this case.

Returns:

true if successful, false otherwise.

注意:

This operation combines the parts of 'this' region that are not part of the second region. The result is stored in this region.

bool wxRegion::Union

(

const wxRect &

rect

)

Finds the union of this region and another, rectangular region.

This method can be used even if this region is invalid and has the natural behaviour in this case, i.e. makes this region equal to the given rectangle.

Returns:

true if successful, false otherwise.

注意:

This operation creates a region that combines all of this region and the second region. The result is stored in this region.

bool wxRegion::Union	(	wxCoord	x,
		wxCoord	y,
		wxCoord	width,
		wxCoord	height
	)

Finds the union of this region and another, rectangular region, specified using position and size.

This method can be used even if this region is invalid and has the natural behaviour in this case, i.e. makes this region equal to the given rectangle.

Returns:

true if successful, false otherwise.

注意:

This operation creates a region that combines all of this region and the second region. The result is stored in this region.

bool wxRegion::Union	(	const wxBitmap &	bmp,
		const wxColour &	transColour,
		int	tolerance = 0
	)

Finds the union of this region and the non-transparent pixels of a bitmap.

Colour to be treated as transparent is specified in the transColour argument, along with an optional colour tolerance value.

Returns:

true if successful, false otherwise.

注意:

This operation creates a region that combines all of this region and the second region. The result is stored in this region.

bool wxRegion::Union

(

const wxRegion &

region

)

Finds the union of this region and another region.

This method can be used even if this region is invalid and has the natural behaviour in this case, i.e. makes this region equal to the given region.

Returns:

true if successful, false otherwise.

注意:

This operation creates a region that combines all of this region and the second region. The result is stored in this region.

bool wxRegion::Union

(

const wxBitmap &

bmp

)

Finds the union of this region and the non-transparent pixels of a bitmap.

The bitmap's mask is used to determine transparency. If the bitmap doesn't have a mask, the bitmap's full dimensions are used.

Returns:

true if successful, false otherwise.

注意:

This operation creates a region that combines all of this region and the second region. The result is stored in this region.

bool wxRegion::Xor

(

const wxRect &

rect

)

Finds the Xor of this region and another, rectangular region.

This method can be used even if this region is invalid and has the natural behaviour in this case, i.e. makes this region equal to the given rectangle.

Returns:

true if successful, false otherwise.

注意:

This operation creates a region that combines all of this region and the second region, except for any overlapping areas. The result is stored in this region.

bool wxRegion::Xor	(	wxCoord	x,
		wxCoord	y,
		wxCoord	width,
		wxCoord	height
	)

Finds the Xor of this region and another, rectangular region, specified using position and size.

This method can be used even if this region is invalid and has the natural behaviour in this case, i.e. makes this region equal to the given rectangle.

Returns:

true if successful, false otherwise.

注意:

This operation creates a region that combines all of this region and the second region, except for any overlapping areas. The result is stored in this region.

bool wxRegion::Xor

(

const wxRegion &

region

)

Finds the Xor of this region and another region.

This method can be used even if this region is invalid and has the natural behaviour in this case, i.e. makes this region equal to the given region.

Returns:

true if successful, false otherwise.

注意:

This operation creates a region that combines all of this region and the second region, except for any overlapping areas. The result is stored in this region.