Cursor

Introduced in Java 1.1, the Cursor class provides the different cursors that can be associated with a Component. Previously, cursors could only be associated with a whole Frame. Now any component can use fancy cursors when the user is interacting with the system.

To change the cursor, a component calls its setCursor() method; its argument is a Cursor object, which is defined by this class.

NOTE:

There is still no way to assign a user-defined cursor to a Component. You are restricted to the 14 predefined cursors.

Cursor Constants

The following is a list of Cursor constants. The cursors corresponding to the constants are shown in Figure 5.6.

public final static int DEFAULT_CURSOR
public final static int CROSSHAIR_CURSOR
public final static int TEXT_CURSOR
public final static int WAIT_CURSOR
public final static int HAND_CURSOR
public final static int MOVE_CURSOR
public final static int N_RESIZE_CURSOR
public final static int S_RESIZE_CURSOR
public final static int E_RESIZE_CURSOR
public final static int W_RESIZE_CURSOR
public final static int NE_RESIZE_CURSOR
public final static int NW_RESIZE_CURSOR
public final static int SE_RESIZE_CURSOR
public final static int SW_RESIZE_CURSOR

Figure 5.6: Standard Java cursors

Cursor Methods

• public Cursor (int type)
• The sole constructor creates a Cursor of the specified type. type must be one of the Cursor class constants. If type is not one of the class constants, the constructor throws the run-time exception IllegalArgumentException.

  This constructor exists primarily to support object serialization; you don't need to call it in your code. It is more efficient to call getPredefinedCursor(), discussed later in this section.

• public int getType()
• The getType() method returns the cursor type. The value returned is one of the class constants.
• static public Cursor getPredefinedCursor(int type)
• The getPredefinedCursor() method returns the predefined Cursor of the given type. If type is not one of the class constants, this method throws the run-time exception IllegalArgumentException. This method checks what Cursor objects already exist and gives you a reference to a preexisting Cursor if it can find one with the appropriate type. Otherwise, it creates a new Cursor for you. This is more efficient than calling the Cursor constructor whenever you need one.
• static public Cursor getDefaultCursor()
• The getDefaultCursor() method returns the predefined Cursor for the DEFAULT_CURSOR type.