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Xfc::Gdk::Region Class Reference

A GdkRegion C++ wrapper class. More...

#include <xfc/gdk/region.hh>

Inheritance diagram for Xfc::Gdk::Region:

List of all members.

Public Types

• typedef sigc::slot< void,
  GdkSpan * > SpansIntersectForeachSlot

  Signature of the callback slot to be called on each span in the intersection of a region and an array of spans.
  

Public Member Functions

Constructors

• Region ()

  Constructs a new empty region with a reference count of 1 that the caller owns.
  

• Region (const std::vector< Point > &points, FillRule fill_rule)

  Construct a new region using the polygon defined by a number of points.
  

• Region (const Rectangle &rectangle)

  Constructs a new region containing the area rectangle.
  

• Region (GdkRegion *region, bool copy)

  Construct a new region from an existing GdkRegion.
  

• Region (const Region &src)

  Copy constructor.
  

• virtual ~Region ()

  Destructor.
  

• Region & operator= (const Region &src)

  Assignment operator.
  

Accessors

• GdkRegion * gdk_region () const

  Get a pointer to the GdkRegion structure.
  

• operator GdkRegion * () const

  Conversion operator; safely converts a Region to a GdkRegion pointer.
  

• Rectangle get_clipbox () const

  Gets the smallest rectangle which includes the entire region.
  

• void get_clipbox (Rectangle &rectangle) const

  Gets the smallest rectangle which includes the entire region.
  

• std::vector< Rectangle > get_rectangles () const

  Obtains the area covered by the region as a list of rectangles.
  

• bool empty () const

  Returns true if the region is empty.
  

• bool equal (const Region &other) const

  Returns true if this region and other are the same.
  

• bool point_in (int x, int y) const

  Returns true if a point is in the region.
  

• bool point_in (const Point &point) const

  Returns true if a point is in the region.
  

• OverlapType rect_in (const Rectangle &rectangle) const

  Tests whether a rectangle is within a region.
  

• bool operator== (const Region &other) const

  Equality operator; compares this region with other.
  

• bool operator!= (const Region &other) const

  Inequality operator; compares this region with other.
  

Methods

• void offset (int dx, int dy)

  Moves a region the specified distance.
  

• void shrink (int dx, int dy)

  Resizes a region by the specified amount.
  

• void union_with (const Rectangle &rectangle)

  Sets the area of the region to the union of the areas of the region and rectangle.
  

• void union_with (const Region &other)

  Sets the area of the region to the union of the areas of the region and other.
  

• void intersect (const Region &other)

  Sets the area of the region to the intersection of the areas of the region and other.
  

• void subtract (const Region &other)

  Subtracts the area of the region from the area other.
  

• void xor_with (const Region &other)

  Sets the area of the region to the exclusive-OR of the areas of the region and other.
  

• void spans_intersect_foreach (const std::vector< Span > &spans, bool sorted, const SpansIntersectForeachSlot &slot)

  Calls slot on each span in the intersection of the region and spans.
  

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Detailed Description

A GdkRegion C++ wrapper class.

Region is an object that represents an arbitrary set of pixels on the screen, and is usually used for clipping graphical operations (see Gdk::GC::set_clip(const Region&)).

Note: dynamically allocated objects must either be unreferenced or assigned to a smart pointer. Stack objects are automatically unreferenced when they go out of scope.

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Member Typedef Documentation

typedef sigc::slot<void, GdkSpan*> Xfc::Gdk::Region::SpansIntersectForeachSlot

Signature of the callback slot to be called on each span in the intersection of a region and an array of spans. Example: Method signature for SpansIntersectForeachSlot. void method(GdkSpan *span); // span: A GdkSpan. This is the type of slot passed to spans_intersect_foreach().

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Constructor & Destructor Documentation

Xfc::Gdk::Region::Region (  const std::vector< Point > &  points, FillRule  fill_rule )

Construct a new region using the polygon defined by a number of points. Parameters: points  A reference to a vector of Point that holds the points defining the polygon. fill_rule  Specifies which pixels are included in the region when the polygon overlaps itself. The region is created with a reference count of 1 that the caller owns.

Xfc::Gdk::Region::Region (  const Rectangle &  rectangle  )

Constructs a new region containing the area rectangle. Parameters: rectangle  A Gdk::Rectangle. The region is created with a reference count of 1 that the caller owns.

Xfc::Gdk::Region::Region (  GdkRegion *  region, bool  copy )

Construct a new region from an existing GdkRegion. Parameters: region  A pointer to a GdkRegion. copy  Set true if region should be copied. If copy is false the Region takes over the reference count of region. The new Region created has a reference count of 1 that the caller owns.

Xfc::Gdk::Region::Region (  const Region &  src  )

Copy constructor. Parameters: src  The source region.

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Member Function Documentation

void Xfc::Gdk::Region::get_clipbox (  Rectangle &  rectangle  )  const

Gets the smallest rectangle which includes the entire region. Parameters: rectangle  The location to store the smallest rectangle which includes all of the region.

Rectangle Xfc::Gdk::Region::get_clipbox (   )  const

Gets the smallest rectangle which includes the entire region. Returns: The smallest rectangle which includes all of the region.

std::vector<Rectangle> Xfc::Gdk::Region::get_rectangles (   )  const

Obtains the area covered by the region as a list of rectangles. Returns: A vector of Rectangle that holds the list of rectangles.

void Xfc::Gdk::Region::intersect (  const Region &  other  )

Sets the area of the region to the intersection of the areas of the region and other. Parameters: other  A Region. The resulting area is the set of pixels contained in both the region and other.

void Xfc::Gdk::Region::offset (  int  dx, int  dy )

Moves a region the specified distance. Parameters: dx  The distance to move the region horizontally. dy  The distance to move the region vertically.

bool Xfc::Gdk::Region::operator!= (  const Region &  other  )  const

Inequality operator; compares this region with other. Parameters: other  The region to compare. Returns: true if the two regions compare unequal.

Region& Xfc::Gdk::Region::operator= (  const Region &  src  )

Assignment operator. Parameters: src  The source region.

bool Xfc::Gdk::Region::operator== (  const Region &  other  )  const

Equality operator; compares this region with other. Parameters: other  The region to compare. Returns: true if the two regions compare equal.

bool Xfc::Gdk::Region::point_in (  const Point &  point  )  const

Returns true if a point is in the region. Parameters: point  The Point to test. Returns: true if the point is in the region.

bool Xfc::Gdk::Region::point_in (  int  x, int  y )  const

Returns true if a point is in the region. Parameters: x  The X coordinate of a point. y  The Y coordinate of a point. Returns: true if the point is in the region.

OverlapType Xfc::Gdk::Region::rect_in (  const Rectangle &  rectangle  )  const

Tests whether a rectangle is within a region. Parameters: rectangle  A Gdk::Rectangle. Returns: OVERLAP_RECTANGLE_IN, OVERLAP_RECTANGLE_OUT, or OVERLAP_RECTANGLE_PART, depending on whether the rectangle is inside, outside, or partly inside the Region, respectively.

void Xfc::Gdk::Region::shrink (  int  dx, int  dy )

Resizes a region by the specified amount. Parameters: dx  The number of pixels to shrink the region horizontally. dy  The number of pixels to shrink the region vertically. Positive values shrink the region. Negative values expand it.

void Xfc::Gdk::Region::spans_intersect_foreach (  const std::vector< Span > &  spans, bool  sorted, const SpansIntersectForeachSlot &  slot )

Calls slot on each span in the intersection of the region and spans. Parameters: spans  A reference to a vector of Span that holds the list of Span to test. sorted  Set true if spans is sorted wrt. the y coordinate. slot  The slot to call on each span in the intersection.

void Xfc::Gdk::Region::subtract (  const Region &  other  )

Subtracts the area of the region from the area other. Parameters: other  A Region. The resulting area is the set of pixels contained in the region but not in other.

void Xfc::Gdk::Region::union_with (  const Region &  other  )

Sets the area of the region to the union of the areas of the region and other. Parameters: other  A Region. The resulting area is the set of pixels contained in either the region or other.

void Xfc::Gdk::Region::union_with (  const Rectangle &  rectangle  )

Sets the area of the region to the union of the areas of the region and rectangle. Parameters: rectangle  A Gdk::Rectangle. The resulting area is the set of pixels contained in either region or rect.

void Xfc::Gdk::Region::xor_with (  const Region &  other  )

Sets the area of the region to the exclusive-OR of the areas of the region and other. Parameters: other  A Region. The resulting area is the set of pixels contained in the region or other, but not in both.

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

• region.hh

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Copyright © 2004-2005 The XFC Development Team

XFC 4.3