Java Reference
In-Depth Information
if(colorA.getRGB() == colorB.getRGB())
// Do something....
This compares the two integer RGB values for equality.
System Colors
The package java.awt defines the class SystemColor as a subclass of the Color class. The
SystemColor class encapsulates the standard system colors used for displaying various components.
The class contains definitions for 24 public final static variables of type SystemColor that
specify the standard system colors used by the operating system for a range of GUI components. For
example, the system colors for a window are referenced by:
WINDOW
Defines the background color for a window.
WINDOW _ TEXT
Defines the text color for a window.
WINDOW _ BORDER
Defines the border color for a window.
You can find the others covering colors used for menus, captions, controls, and so on, if you need them,
by looking at the documentation for the SystemColor class.
If you want to compare a SystemColor value with a Color object you have created, then you must
use the getRGB() method in the comparison. This is because the SystemColor class stores the colors
internally in a way that makes use of the fields it inherits from the Color class differently from a
normal Color object. For example, to see whether colorA corresponds to the system background
color for a window you would write:
if(colorA.getRGB() == SystemColor.WINDOW.getRGB())
// colorA is the window background color...
Creating Cursors
An object of the Cursor class represents a mouse cursor. The Cursor class contains a range of final
static constants that specify standard cursor types. You use these to select or create a particular
cursor. The standard cursor types are:
DEFAULT _ CURSOR
N _ RESIZE _ CURSOR
NE _ RESIZE _ CURSOR
CROSSHAIR _ CURSOR
S _ RESIZE _ CURSOR
NW _ RESIZE _ CURSOR
WAIT _ CURSOR
E _ RESIZE _ CURSOR
SE _ RESIZE _ CURSOR
TEXT _ CURSOR
W _ RESIZE _ CURSOR
SW _ RESIZE _ CURSOR
HAND _ CURSOR
MOVE _ CURSOR
The resize cursors are the ones you see when resizing a window by dragging its boundaries. Note that
these are not like the Color constants, which are Color objects - these constants are of type int , not
type Cursor , and are intended to be used as arguments to a constructor.
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