gtkmm: Gdk::Visual Class Reference
A Gdk::Visual describes a particular video hardware display format. More...
Public Member Functions | |
virtual | ~Visual () |
GdkVisual* | gobj () |
Provides access to the underlying C GObject. | |
const GdkVisual* | gobj () const |
Provides access to the underlying C GObject. | |
GdkVisual* | gobj_copy () |
Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs. | |
Glib::RefPtr< Screen > | get_screen () |
Gets the screen to which this visual belongs. | |
Glib::RefPtr< const Screen > | get_screen () const |
Gets the screen to which this visual belongs. | |
VisualType | get_visual_type () const |
Returns the type of visual this is (PseudoColor, TrueColor, etc). | |
int | get_depth () const |
Returns the bit depth of this visual. | |
ByteOrder | get_byte_order () |
Returns the byte order of this visual. | |
int | get_colormap_size () const |
Returns the size of a colormap for this visual. | |
int | get_bits_per_rgb () const |
Returns the number of significant bits per red, green and blue value. | |
void | get_red_pixel_details (guint32& mask, int& shift, int& precision) const |
Obtains values that are needed to calculate red pixel values in TrueColor and DirectColor. | |
void | get_green_pixel_details (guint32& mask, int& shift, int& precision) const |
Obtains values that are needed to calculate green pixel values in TrueColor and DirectColor. | |
void | get_blue_pixel_details (guint32& mask, int& shift, int& precision) const |
Obtains values that are needed to calculate blue pixel values in TrueColor and DirectColor. | |
Public Member Functions inherited from Glib::Object | |
void * | get_data (const QueryQuark &key) |
void | set_data (const Quark &key, void *data) |
void | set_data (const Quark &key, void *data, DestroyNotify notify) |
void | remove_data (const QueryQuark &quark) |
void * | steal_data (const QueryQuark &quark) |
void | set_property_value (const Glib::ustring &property_name, const Glib::ValueBase &value) |
void | get_property_value (const Glib::ustring &property_name, Glib::ValueBase &value) const |
void | set_property (const Glib::ustring &property_name, const PropertyType &value) |
void | get_property (const Glib::ustring &property_name, PropertyType &value) const |
void | connect_property_changed (const Glib::ustring &property_name, const sigc::slot< void > &slot) |
sigc::connection | connect_property_changed_with_return (const Glib::ustring &property_name, const sigc::slot< void > &slot) |
void | freeze_notify () |
void | thaw_notify () |
virtual void | reference () const |
virtual void | unreference () const |
GObject * | gobj_copy () const |
Glib::RefPtr< Glib::Object > | wrap (GObject *object, bool take_copy=false) |
Static Public Member Functions | |
static GType | get_type () |
Get the GType for this class, for use with the underlying GObject type system. | |
static Glib::RefPtr< Visual > | get_system () |
Get the system's default visual for the default GDK screen. | |
static Glib::RefPtr< Visual > | get_best () |
Get the visual with the most available colors for the default GDK screen. | |
static Glib::RefPtr< Visual > | get_best (int depth) |
Get the best visual with depth depth for the default GDK screen. | |
static Glib::RefPtr< Visual > | get_best (VisualType visual_type) |
Get the best visual of the given visual_type for the default GDK screen. | |
static Glib::RefPtr< Visual > | get_best (int depth, VisualType visual_type) |
Combines get_best_with_depth() and get_best_with_type(). | |
static int | get_best_depth () |
Get the best available depth for the default GDK screen. | |
static VisualType | get_best_type () |
Return the best available visual type for the default GDK screen. |
Protected Member Functions | |
Visual () | |
Protected Member Functions inherited from Glib::Object | |
Object () | |
Object (const Glib::ConstructParams &construct_params) | |
Object (GObject *castitem) | |
virtual | ~Object () |
ObjectBase () | |
ObjectBase (const char *custom_type_name) | |
ObjectBase (const std::type_info &custom_type_info) | |
virtual | ~ObjectBase ()=0 |
void | initialize (GObject *castitem) |
Related Functions | |
(Note that these are not member functions.) | |
Glib::RefPtr< Gdk::Visual > | wrap (GdkVisual* object, bool take_copy=false) |
A Glib::wrap() method for this object. |
Additional Inherited Members | |
Public Types inherited from Glib::Object | |
typedef void(* | DestroyNotify )(gpointer data) |
Detailed Description
A Gdk::Visual describes a particular video hardware display format.
It includes information about the number of bits used for each color, the way the bits are translated into an RGB value for display, and the way the bits are stored in memory. For example, a piece of display hardware might support 24-bit color, 16-bit color, or 8-bit color; meaning 24/16/8-bit pixel sizes. For a given pixel size, pixels can be in different formats; for example the "red" element of an RGB pixel may be in the top 8 bits of the pixel, or may be in the lower 4 bits.
There are several standard visuals. The visual returned by Gdk::Screen::get_system_visual() is the system's default visual.
A number of methods are provided for determining the "best" available visual. For the purposes of making this determination, higher bit depths are considered better, and for visuals of the same bit depth, GDK_VISUAL_PSEUDO_COLOR is preferred at 8bpp, otherwise, the visual types are ranked in the order of (highest to lowest) GDK_VISUAL_DIRECT_COLOR, GDK_VISUAL_TRUE_COLOR, GDK_VISUAL_PSEUDO_COLOR, GDK_VISUAL_STATIC_COLOR, GDK_VISUAL_GRAYSCALE, then GDK_VISUAL_STATIC_GRAY.
Constructor & Destructor Documentation
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virtual |
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protected |
Member Function Documentation
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static |
Get the visual with the most available colors for the default GDK screen.
The return value should not be freed.
- Returns:
- Best visual.
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static |
Get the best visual with depth depth for the default GDK screen.
Color visuals and visuals with mutable colormaps are preferred over grayscale or fixed-colormap visuals. The return value should not be freed. 0
may be returned if no visual supports depth.
- Parameters:
-
depth A bit depth.
- Returns:
- Best visual for the given depth.
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static |
Get the best visual of the given visual_type for the default GDK screen.
Visuals with higher color depths are considered better. The return value should not be freed. 0
may be returned if no visual has type visual_type.
- Parameters:
-
visual_type A visual type.
- Returns:
- Best visual of the given type.
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static |
Combines get_best_with_depth() and get_best_with_type().
- Parameters:
-
depth A bit depth. visual_type A visual type.
- Returns:
- Best visual with both depth and visual_type, or
0
if none.
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static |
Get the best available depth for the default GDK screen.
"Best" means "largest," i.e. 32 preferred over 24 preferred over 8 bits per pixel.
- Returns:
- Best available depth.
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static |
Return the best available visual type for the default GDK screen.
- Returns:
- Best visual type.
int Gdk::Visual::get_bits_per_rgb | ( | ) | const |
Returns the number of significant bits per red, green and blue value.
- Returns:
- The number of significant bits per color value for visual.
void Gdk::Visual::get_blue_pixel_details | ( | guint32 & | mask, |
int & | shift, | ||
int & | precision | ||
) | const |
Obtains values that are needed to calculate blue pixel values in TrueColor and DirectColor.
The "mask" is the significant bits within the pixel. The "shift" is the number of bits left we must shift a primary for it to be in position (according to the "mask"). Finally, "precision" refers to how much precision the pixel value contains for a particular primary.
- Parameters:
-
mask A pointer to a #guint32 to be filled in, or 0
.shift A pointer to a int
to be filled in, or0
.precision A pointer to a int
to be filled in, or0
.
ByteOrder Gdk::Visual::get_byte_order | ( | ) |
Returns the byte order of this visual.
- Returns:
- A Gdk::ByteOrder stating the byte order of visual.
int Gdk::Visual::get_colormap_size | ( | ) | const |
Returns the size of a colormap for this visual.
- Returns:
- The size of a colormap that is suitable for visual.
int Gdk::Visual::get_depth | ( | ) | const |
void Gdk::Visual::get_green_pixel_details | ( | guint32 & | mask, |
int & | shift, | ||
int & | precision | ||
) | const |
Obtains values that are needed to calculate green pixel values in TrueColor and DirectColor.
The "mask" is the significant bits within the pixel. The "shift" is the number of bits left we must shift a primary for it to be in position (according to the "mask"). Finally, "precision" refers to how much precision the pixel value contains for a particular primary.
- Parameters:
-
mask A pointer to a #guint32 to be filled in, or 0
.shift A pointer to a int
to be filled in, or0
.precision A pointer to a int
to be filled in, or0
.
void Gdk::Visual::get_red_pixel_details | ( | guint32 & | mask, |
int & | shift, | ||
int & | precision | ||
) | const |
Obtains values that are needed to calculate red pixel values in TrueColor and DirectColor.
The "mask" is the significant bits within the pixel. The "shift" is the number of bits left we must shift a primary for it to be in position (according to the "mask"). Finally, "precision" refers to how much precision the pixel value contains for a particular primary.
- Parameters:
-
mask A pointer to a #guint32 to be filled in, or 0
.shift A pointer to a int
to be filled in, or0
.precision A pointer to a int
to be filled in, or0
.
Glib::RefPtr<Screen> Gdk::Visual::get_screen | ( | ) |
Gets the screen to which this visual belongs.
- Returns:
- The screen to which this visual belongs.
Glib::RefPtr<const Screen> Gdk::Visual::get_screen | ( | ) | const |
Gets the screen to which this visual belongs.
- Returns:
- The screen to which this visual belongs.
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static |
Get the system's default visual for the default GDK screen.
This is the visual for the root window of the display. The return value should not be freed.
- Returns:
- System visual.
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Get the GType for this class, for use with the underlying GObject type system.
VisualType Gdk::Visual::get_visual_type | ( | ) | const |
Returns the type of visual this is (PseudoColor, TrueColor, etc).
- Returns:
- A Gdk::VisualType stating the type of visual.
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inline |
Provides access to the underlying C GObject.
Reimplemented from Glib::Object.
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inline |
Provides access to the underlying C GObject.
Reimplemented from Glib::Object.
GdkVisual* Gdk::Visual::gobj_copy | ( | ) |
Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs.
Friends And Related Function Documentation
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related |
A Glib::wrap() method for this object.
- Parameters:
-
object The C instance. take_copy False if the result should take ownership of the C instance. True if it should take a new copy or ref.
- Returns:
- A C++ instance that wraps this C instance.
The documentation for this class was generated from the following file:
- gdkmm/visual.h