xtd::forms::image_list Class Reference

Inheritance diagram for xtd::forms::image_list:

Definition

Provides methods to manage a collection of xtd::drawing::image objects. This class cannot be inherited.

Header

#include <xtd/forms/image_list>

Namespace

xtd::forms

Library

xtd.forms

Remarks

image_list is typically used by other controls, such as the list_view, tree_view, or tool_bar. You can add bitmaps or icons to the image_list, and the other controls are able to use the images as they require.

image_list uses a handle to manage the list of images. The handle is not created until certain operations, such as getting the handle or calling draw, are performed on the image list. Performing other operations, such as setting the color_depth or image_size will cause the handle to be recreated. Therefore, you should perform these operations before you add images to the image_list.

Examples

The following code example demonstrates the use of image_list class.

#include <xtd/xtd>
 
namespace example {
  class form1 : public form {
  public:
    form1() {
      text("Image list example");
      client_size({300, 250});
      controls().add_range({picture, button_previous, button_next});
      
      pictures.image_size({128, 128});
      
      picture.back_color(system_colors::window());
      picture.border_style(forms::border_style::fixed_3d);
      picture.bounds({75, 25, 150, 150});
      picture.size_mode(picture_box_size_mode::center_image);
      picture.click += delegate_ {
        load_images();
      };
      
      button_previous.auto_repeat(true);
      button_previous.image(button_images::previous());
      button_previous.location({75, 200});
      button_previous.enabled(false);
      button_previous.click += delegate_ {
        if (current_image_index > 0) picture.image(pictures.images()[--current_image_index]);
        button_previous.enabled(current_image_index > 0);
        button_next.enabled(current_image_index < pictures.images().count() - 1);
      };
      
      button_next.auto_repeat(true);
      button_next.image(button_images::next());
      button_next.location({150, 200});
      button_next.enabled(false);
      button_next.click += delegate_ {
        if (current_image_index < pictures.images().count()) picture.image(pictures.images()[++current_image_index]);
        button_previous.enabled(current_image_index > 0);
        button_next.enabled(current_image_index < pictures.images().count() - 1);
      };
      
      show();
      load_images();
    }
    
  private:
    void load_images() {
      auto dialog = open_file_dialog {};
      dialog.multiselect(true);
      dialog.filter("All Image Files|*.bmp;*.gif;*.jpg;*.jpeg;*.png;*.tif;*.tiff;*.xpm|Bitmap Files|*.bmp|Gif Files|*.gif|Jpeg Files|*.jpg;*.jpeg|Png Files|*.png|Tiff Files|*.tif;*.tiff|xpm Files|*.xpm");
      if (dialog.show_dialog() == dialog_result::ok) {
        pictures.images().clear();
        for (auto file : dialog.file_names())
          pictures.images().add(drawing::image::from_file(file));
        current_image_index = 0;
        picture.image(pictures.images()[current_image_index]);
        button_previous.enabled(current_image_index > 0);
        button_next.enabled(current_image_index < pictures.images().count() - 1);
      }
    }
    
    size_t current_image_index = 0;
    image_list pictures;
    picture_box picture;
    button button_previous;
    button button_next;
  };
}
 
auto main() -> int {
  application::run(example::form1 {});
}

Public Aliases
using	image_collection
	Encapsulates the collection of xtd::drawing::image objects in an image_list.

Public Fields
static image_list	empty
	Represents an image_list empty.
static constexpr xtd::size	npos
	Represents a value that is not a valid position in a collection.
static constexpr xtd::size	bpos
	Represents the index of the first valid element in a collection.
static constexpr xtd::size	epos
	Represents the index of the last valid element in a collection.

Public Constructors
	image_list ()
	Initialize a new instance ao image_list class.

Public Properties
intptr	handle () const noexcept
	Gets the handle of the image list object.
bool	handle_created () const noexcept
	Gets a value indicating whether the underlying Win32 handle has been created.
image_collection &	images ()
	Gets the xtd::forms::image_list::image_collection for this image list.
const image_collection &	images () const noexcept
	Gets the xtd::forms::image_list::image_collection for this image list.
const drawing::size	image_size () const noexcept
	Gets the size of the images in the image list.
const image_list &	image_size (const drawing::size &value)
	Sets the size of the images in the image list.
const xtd::any_object &	tag () const noexcept
	Gets an object that contains additional data about the image_list.
image_list &	tag (const xtd::any_object &tag)
	Sets an object that contains additional data about the image_list.

Public Methods
bool	equals (const xtd::object &obj) const noexcept override
	Determines whether the specified object is equal to the current object.
bool	equals (const image_list &other) const noexcept override
	Determines whether the specified object is equal to the current object.
xtd::size	get_hash_code () const noexcept override
	Serves as a hash function for a particular type.

Additional Inherited Members
	object ()=default
	Create a new instance of the ultimate base class object.
virtual type_object	get_type () const noexcept
	Gets the type of the current instance.
template<class object_t>
xtd::unique_ptr_object< object_t >	memberwise_clone () const
	Creates a shallow copy of the current object.
virtual xtd::string	to_string () const noexcept
	Returns a xtd::string that represents the current object.
virtual bool	equals (const image_list &) const noexcept=0
	Indicates whether the current object is equal to another object of the same type.
template<class object_a_t, class 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<class object_a_t, class 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.
	component ()
	Initialises a new instance of the component class.
virtual bool	can_raise_events () const noexcept
	Gets a value indicating whether the component can raise an event.
bool	design_mode () const noexcept
	Gets a value that indicates whether the component is currently in design mode.

Member Typedef Documentation

image_collection

using xtd::forms::image_list::image_collection

Encapsulates the collection of xtd::drawing::image objects in an image_list.

Constructor & Destructor Documentation

image_list()

xtd::forms::image_list::image_list

(

)

Initialize a new instance ao image_list class.

Member Function Documentation

handle()

intptr xtd::forms::image_list::handle ( ) const

noexcept

Gets the handle of the image list object.

Returns

The handle for the image list. The default is 0.

handle_created()

bool xtd::forms::image_list::handle_created ( ) const

noexcept

Gets a value indicating whether the underlying Win32 handle has been created.

Returns

true if the Handle has been created; otherwise, false. The default is false.

images() [1/2]

image_collection & xtd::forms::image_list::images

(

)

Gets the xtd::forms::image_list::image_collection for this image list.

Returns

The collection of images.

Remarks

If the image collection has not yet been created, it is created when you retrieve this property.

images() [2/2]

const image_collection & xtd::forms::image_list::images ( ) const

noexcept

Gets the xtd::forms::image_list::image_collection for this image list.

Returns

The collection of images.

Remarks

If the image collection has not yet been created, it is created when you retrieve this property.

image_size() [1/2]

const drawing::size xtd::forms::image_list::image_size ( ) const

noexcept

Gets the size of the images in the image list.

Returns

The xtd::drawing::size that defines the height and width, in pixels, of the images in the list. The default size is 16 by 16. The maximum size is 256 by 256.

image_size() [2/2]

const image_list & xtd::forms::image_list::image_size

(

const drawing::size &

value

)

Sets the size of the images in the image list.

Parameters

value

The xtd::drawing::size that defines the height and width, in pixels, of the images in the list. The default size is 16 by 16. The maximum size is 256 by 256.

Remarks

Setting the image_size property prior to adding images to the image collection causes the images to be resized to the image size specified.

When you set the image_size property to a new value, the handle for the image list is recreated.

Because setting the image_size property causes the handle to be recreated, you should set image_size prior to setting the Images property. When the handle for the image_list has been created, setting the color_depth or image_size properties in code, after setting the images property, will cause the collection of images set for the images property to be deleted.

tag() [1/2]

const xtd::any_object & xtd::forms::image_list::tag ( ) const

noexcept

Gets an object that contains additional data about the image_list.

Returns

A object that contains additional data about the image_list.

tag() [2/2]

image_list & xtd::forms::image_list::tag

(

const xtd::any_object &

tag

)

Sets an object that contains additional data about the image_list.

Parameters

tag	A object that contains additional data about the image_list.

equals() [1/2]

bool xtd::forms::image_list::equals ( const xtd::object & obj ) const

overridevirtualnoexcept

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.

Reimplemented from xtd::object.

equals() [2/2]

bool xtd::forms::image_list::equals ( const image_list & other ) const

overridenoexcept

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

Parameters

other

The object to compare with the current object.

Returns

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

get_hash_code()

xtd::size xtd::forms::image_list::get_hash_code ( ) const

overridevirtualnoexcept

Serves as a hash function for a particular type.

Returns

A hash code for the current object.

Reimplemented from xtd::object.

Member Data Documentation

empty

image_list xtd::forms::image_list::empty

static

Represents an image_list empty.

npos

xtd::size xtd::forms::image_list::npos

inlinestaticconstexpr

Represents a value that is not a valid position in a collection.

Remarks

This constant is typically used to indicate the absence of an index or a failed search operation. It is equivalent to the maximum value of xtd::size.

bpos

xtd::size xtd::forms::image_list::bpos

inlinestaticconstexpr

Represents the index of the first valid element in a collection.

Remarks

Unlike xtd::npos (which means "no position"), xtd::bpos points to the first accessible element of a collection. It is equivalent to 0.

epos

xtd::size xtd::forms::image_list::epos

inlinestaticconstexpr

Represents the index of the last valid element in a collection.

Remarks

Unlike xtd::npos (which means "no position"), xtd::epos points to the last accessible element of a collection. It is equivalent to items.count() - 1.

Note

This constant is provided for readability and convenience. For example, items[xtd::epos] directly accesses the last element without manually subtracting one from the collection count.

Remarks

The epos is equivalent to ~1_z. With bitwise operator the code is more concise.

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

• xtd.forms/include/xtd/forms/image_list.hpp