xtd::drawing::imaging::color_palette Class Reference

Inheritance diagram for xtd::drawing::imaging::color_palette:

Definition

Defines an array of colors that make up a color palette. The colors are 32-bit ARGB colors. Not inheritable.

Namespace

xtd::drawing::imaging

Library

xtd.drawing

Remarks

You are not allowed to construct a color_palette object directly. If you created a color_palette object, you could then manipulate the palette size for a particular image, which is not allowed. Use the image.palette property to obtain a color_palette object.

The colors in the palette are limited to 32-bit ARGB colors. A 32-bit ARGB color has 8 bits each for alpha, red, green, and blue values. The lowest 8 bits make up the blue bit, the next 8 bits are green, the next 8 bits are red, and the most significant 8 bits are alpha. This means each component can vary from 0 to 255. Fully on is 255 and fully off is 0. Alpha is used to make the color value transparent (alpha = 0) or opaque (alpha = 255). The number of intensity levels in the image can be increased without increasing the number of colors used. This process creates what is called a halftone, and it offers increased contrast at a cost of decreased resolution.

Public Properties
const std::vector< color > &	entries () const noexcept
	Gets an array of color structures.
int32	flags () const noexcept
	Gets a value that specifies how to interpret the color information in the array of colors.

Public Methods
bool	equals (const color_palette &value) const noexcept override
virtual bool	equals (const object &obj) const noexcept
	Determines whether the specified object is equal to the current object.
template<typename object_a_t , typename object_b_t >
static bool	equals (const object_a_t &object_a, const object_b_t &object_b) noexcept
	Determines whether the specified object instances are considered equal.

Additional Inherited Members
Public Member Functions inherited from xtd::object
	object ()=default
	Create a new instance of the ultimate base class object.
virtual size_t	get_hash_code () const noexcept
	Serves as a hash function for a particular type.
virtual type_object	get_type () const noexcept
	Gets the type of the current instance.
template<typename object_t >
xtd::uptr< object_t >	memberwise_clone () const
	Creates a shallow copy of the current object.
virtual xtd::ustring	to_string () const noexcept
	Returns a xtd::ustring that represents the current object.
Public Member Functions inherited from xtd::iequatable< color_palette >
virtual bool	equals (const color_palette &) const noexcept=0
	Indicates wheth er the current object is equal to another object of the same type.
Static Public Member Functions inherited from xtd::object
template<typename object_a_t , typename object_b_t >
static bool	equals (const object_a_t &object_a, const object_b_t &object_b) noexcept
	Determines whether the specified object instances are considered equal.
template<typename object_a_t , typename object_b_t >
static bool	reference_equals (const object_a_t &object_a, const object_b_t &object_b) noexcept
	Determines whether the specified object instances are the same instance.

Member Function Documentation

entries()

const std::vector< color > & xtd::drawing::imaging::color_palette::entries ( ) const

inlinenoexcept

Gets an array of color structures.

Returns

The array of color structure that make up this color_palette.

equals() [1/2]

virtual bool xtd::object::equals ( const object &  obj ) const

virtualnoexcept

Determines whether the specified object is equal to the current object.

Parameters

obj	The object to compare with the current object.

Returns

true if the specified object is equal to the current object. otherwise, false.

Examples

The following code example compares the current instance with another object.

#include <xtd/console>
 
using namespace xtd;
 
auto main() -> int {
  auto object1 = new_ptr<object>();
  auto object2 = new_ptr<object>();
  
  auto object3 = object2;
  console::write_line(object1->equals(*object3));
  console::write_line(*object1 == *object3);
  object3 = object1;
  console::write_line(object1->equals(*object3));
  console::write_line(*object1 == *object3);
}
 
// This code produces the following output:
//
// false
// false
// true
// true

Reimplemented from xtd::object.

equals() [2/2]

template<typename object_a_t , typename object_b_t >

static bool xtd::object::equals ( const object_a_t &  object_a, const object_b_t &  object_b  )

inlinestaticnoexcept

Determines whether the specified object instances are considered equal.

Parameters

object_a	The first object to compare.
object_b	The second object to compare.

Returns

true if object_a is the same instance as object_b or if both are null references or if object_a(object_b) returns true. otherwise, false.

Examples

The following code example compares different objects.

#include <xtd/console>
 
using namespace xtd;
 
auto main() -> int {
  ustring s1 = "Tom";
  ustring s2 = "Carol";
  console::write_line("object::equals(\"{0}\", \"{1}\") => {2}", s1, s2, object::equals(s1, s2));
  
  s1 = "Tom";
  s2 = "Tom";
  console::write_line("object::equals(\"{0}\", \"{1}\") => {2}", s1, s2, object::equals(s1, s2));
  
  s1 = "";
  s2 = "Tom";
  console::write_line("object::equals(\"{0}\", \"{1}\") => {2}", s1, s2, object::equals(s1, s2));
  
  s1 = "Carol";
  s2 = "";
  console::write_line("object::equals(\"{0}\", \"{1}\") => {2}", s1, s2, object::equals(s1, s2));
  
  s1 = "";
  s2 = "";
  console::write_line("object::equals(\"{0}\", \"{1}\") => {2}", s1, s2, object::equals(s1, s2));
}
 
// This code produces the following output:
//
// object::equals("Tom", "Carol") => false
// object::equals("Tom", "Tom") => true
// object::equals("", "Tom") => false
// object::equals("Carol", "") => false
// object::equals("", "") => true

flags()

int32 xtd::drawing::imaging::color_palette::flags ( ) const

inlinenoexcept

Gets a value that specifies how to interpret the color information in the array of colors.

Remarks

The following flag values are valid:

• 0x00000001 The color values in the array contain alpha information.
• 0x00000002 The colors in the array are grayscale values.
• 0x00000004 The colors in the array are halftone values.

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

• xtd.drawing/include/xtd/drawing/imaging/color_palette.h