Module java.desktop

Class InputEvent

All Implemented Interfaces:
Serializable
Direct Known Subclasses:
KeyEvent, MouseEvent

public abstract class InputEvent
extends ComponentEvent
The root event class for all component-level input events. Input events are delivered to listeners before they are processed normally by the source where they originated. This allows listeners and component subclasses to "consume" the event so that the source will not process them in their default manner. For example, consuming mousePressed events on a Button component will prevent the Button from being activated.
Since:
1.1
See Also:
KeyEvent, KeyAdapter, MouseEvent, MouseAdapter, MouseMotionAdapter, Serialized Form
  • Field Details

  • Method Details

    • getMaskForButton

      public static int getMaskForButton​(int button)
      A method to obtain a mask for any existing mouse button. The returned mask may be used for different purposes. Following are some of them:
      Parameters:
      button - is a number to represent a button starting from 1. For example,
       int button = InputEvent.getMaskForButton(1);
       
      will have the same meaning as
       int button = InputEvent.getMaskForButton(MouseEvent.BUTTON1);
       
      because MouseEvent.BUTTON1 equals to 1. If a mouse has three enabled buttons(see MouseInfo.getNumberOfButtons()) then the values from the left column passed into the method will return corresponding values from the right column:
          button    returned mask
          BUTTON1  BUTTON1_DOWN_MASK
          BUTTON2  BUTTON2_DOWN_MASK
          BUTTON3  BUTTON3_DOWN_MASK
       
      If a mouse has more than three enabled buttons then more values are admissible (4, 5, etc.). There is no assigned constants for these extended buttons. The button masks for the extra buttons returned by this method have no assigned names like the first three button masks.

      This method has the following implementation restriction. It returns masks for a limited number of buttons only. The maximum number is implementation dependent and may vary. This limit is defined by the relevant number of buttons that may hypothetically exist on the mouse but it is greater than the MouseInfo.getNumberOfButtons().

      Returns:
      a mask for an existing mouse button.
      Throws:
      IllegalArgumentException - if button is less than zero or greater than the number of button masks reserved for buttons
      Since:
      1.7
      See Also:
      MouseInfo.getNumberOfButtons(), Toolkit.areExtraMouseButtonsEnabled(), getModifiers(), getModifiersEx()
    • isShiftDown

      public boolean isShiftDown()
      Returns whether or not the Shift modifier is down on this event.
      Returns:
      whether or not the Shift modifier is down on this event
    • isControlDown

      public boolean isControlDown()
      Returns whether or not the Control modifier is down on this event.
      Returns:
      whether or not the Control modifier is down on this event
    • isMetaDown

      public boolean isMetaDown()
      Returns whether or not the Meta modifier is down on this event.
      Returns:
      whether or not the Meta modifier is down on this event
    • isAltDown

      public boolean isAltDown()
      Returns whether or not the Alt modifier is down on this event.
      Returns:
      whether or not the Alt modifier is down on this event
    • isAltGraphDown

      public boolean isAltGraphDown()
      Returns whether or not the AltGraph modifier is down on this event.
      Returns:
      whether or not the AltGraph modifier is down on this event
    • getWhen

      public long getWhen()
      Returns the difference in milliseconds between the timestamp of when this event occurred and midnight, January 1, 1970 UTC.
      Returns:
      the difference in milliseconds between the timestamp and midnight, January 1, 1970 UTC
    • getModifiers

      @Deprecated(since="9") public int getModifiers()
      Deprecated.
      It is recommended that extended modifier keys and getModifiersEx() be used instead
      Returns the modifier mask for this event.
      Returns:
      the modifier mask for this event
    • getModifiersEx

      public int getModifiersEx()
      Returns the extended modifier mask for this event.

      Extended modifiers are the modifiers that ends with the _DOWN_MASK suffix, such as ALT_DOWN_MASK, BUTTON1_DOWN_MASK, and others.

      Extended modifiers represent the state of all modal keys, such as ALT, CTRL, META, and the mouse buttons just after the event occurred.

      For example, if the user presses button 1 followed by button 2, and then releases them in the same order, the following sequence of events is generated:

          MOUSE_PRESSED:  BUTTON1_DOWN_MASK
          MOUSE_PRESSED:  BUTTON1_DOWN_MASK | BUTTON2_DOWN_MASK
          MOUSE_RELEASED: BUTTON2_DOWN_MASK
          MOUSE_CLICKED:  BUTTON2_DOWN_MASK
          MOUSE_RELEASED:
          MOUSE_CLICKED:
       

      It is not recommended to compare the return value of this method using == because new modifiers can be added in the future. For example, the appropriate way to check that SHIFT and BUTTON1 are down, but CTRL is up is demonstrated by the following code:

          int onmask = SHIFT_DOWN_MASK | BUTTON1_DOWN_MASK;
          int offmask = CTRL_DOWN_MASK;
          if ((event.getModifiersEx() & (onmask | offmask)) == onmask) {
              ...
          }
       
      The above code will work even if new modifiers are added.

      Returns:
      the extended modifier mask for this event
      Since:
      1.4
    • consume

      public void consume()
      Consumes this event so that it will not be processed in the default manner by the source which originated it.
      Overrides:
      consume in class AWTEvent
    • isConsumed

      public boolean isConsumed()
      Returns whether or not this event has been consumed.
      Overrides:
      isConsumed in class AWTEvent
      Returns:
      whether or not this event has been consumed
      See Also:
      consume()
    • getModifiersExText

      public static String getModifiersExText​(int modifiers)
      Returns a String describing the extended modifier keys and mouse buttons, such as "Shift", "Button1", or "Ctrl+Shift". These strings can be localized by changing the awt.properties file.

      Note that passing negative parameter is incorrect, and will cause the returning an unspecified string. Zero parameter means that no modifiers were passed and will cause the returning an empty string.

      Parameters:
      modifiers - a modifier mask describing the extended modifier keys and mouse buttons for the event
      Returns:
      a text description of the combination of extended modifier keys and mouse buttons that were held down during the event.
      Since:
      1.4