* int button = InputEvent.getMaskForButton(1);
*
* will have the same meaning as
*
* int button = InputEvent.getMaskForButton(MouseEvent.BUTTON1);
*
* because {@link MouseEvent#BUTTON1 MouseEvent.BUTTON1} equals to 1.
* If a mouse has three enabled buttons(see {@link java.awt.MouseInfo#getNumberOfButtons() MouseInfo.getNumberOfButtons()})
* then the values from the left column passed into the method will return
* corresponding values from the right column:
*
* button returned mask
* {@link MouseEvent#BUTTON1 BUTTON1} {@link MouseEvent#BUTTON1_DOWN_MASK BUTTON1_DOWN_MASK}
* {@link MouseEvent#BUTTON2 BUTTON2} {@link MouseEvent#BUTTON2_DOWN_MASK BUTTON2_DOWN_MASK}
* {@link MouseEvent#BUTTON3 BUTTON3} {@link MouseEvent#BUTTON3_DOWN_MASK 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 * {@link java.awt.MouseInfo#getNumberOfButtons() MouseInfo.getNumberOfButtons()}. * * @return a mask for an existing mouse button. * @throws IllegalArgumentException if {@code button} is less than zero or greater than the number * of button masks reserved for buttons * @since 1.7 * @see java.awt.MouseInfo#getNumberOfButtons() * @see Toolkit#areExtraMouseButtonsEnabled() * @see MouseEvent#getModifiers() * @see MouseEvent#getModifiersEx() */ public static int getMaskForButton(int button) { if (button <= 0 || button > BUTTON_DOWN_MASK.length) { throw new IllegalArgumentException("button doesn't exist " + button); } return BUTTON_DOWN_MASK[button - 1]; } // the constant below MUST be updated if any extra modifier // bits are to be added! // in fact, it is undesirable to add modifier bits // to the same field as this may break applications // see bug# 5066958 static final int FIRST_HIGH_BIT = 1 << 31; static final int JDK_1_3_MODIFIERS = SHIFT_DOWN_MASK - 1; static final int HIGH_MODIFIERS = ~( FIRST_HIGH_BIT - 1 ); /** * The input event's Time stamp in UTC format. The time stamp * indicates when the input event was created. * * @serial * @see #getWhen() */ long when; /** * The state of the modifier mask at the time the input * event was fired. * * @serial * @see #getModifiers() * @see #getModifiersEx() * @see java.awt.event.KeyEvent * @see java.awt.event.MouseEvent */ int modifiers; /* * A flag that indicates that this instance can be used to access * the system clipboard. */ private transient boolean canAccessSystemClipboard; static { /* ensure that the necessary native libraries are loaded */ NativeLibLoader.loadLibraries(); if (!GraphicsEnvironment.isHeadless()) { initIDs(); } AWTAccessor.setInputEventAccessor( new AWTAccessor.InputEventAccessor() { public int[] getButtonDownMasks() { return InputEvent.getButtonDownMasks(); } public boolean canAccessSystemClipboard(InputEvent event) { return event.canAccessSystemClipboard; } }); } /** * Initialize JNI field and method IDs for fields that may be accessed from C. */ private static native void initIDs(); /** * Constructs an InputEvent object with the specified source component, * modifiers, and type. *
This method throws an
* IllegalArgumentException if source
* is null.
*
* @param source the object where the event originated
* @param id the integer that identifies the event type.
* It is allowed to pass as parameter any value that
* allowed for some subclass of {@code InputEvent} class.
* Passing in the value different from those values result
* in unspecified behavior
* @param when a long int that gives the time the event occurred.
* Passing negative or zero value
* is not recommended
* @param modifiers a modifier mask describing the modifier keys and mouse
* buttons (for example, shift, ctrl, alt, and meta) that
* are down during the event.
* Only extended modifiers are allowed to be used as a
* value for this parameter (see the {@link InputEvent#getModifiersEx}
* class for the description of extended modifiers).
* Passing negative parameter
* is not recommended.
* Zero value means that no modifiers were passed
* @throws IllegalArgumentException if source is null
* @see #getSource()
* @see #getID()
* @see #getWhen()
* @see #getModifiers()
*/
InputEvent(Component source, int id, long when, int modifiers) {
super(source, id);
this.when = when;
this.modifiers = modifiers;
canAccessSystemClipboard = canAccessSystemClipboard();
}
private boolean canAccessSystemClipboard() {
boolean b = false;
if (!GraphicsEnvironment.isHeadless()) {
SecurityManager sm = System.getSecurityManager();
if (sm != null) {
try {
sm.checkPermission(AWTPermissions.ACCESS_CLIPBOARD_PERMISSION);
b = true;
} catch (SecurityException se) {
if (logger.isLoggable(PlatformLogger.Level.FINE)) {
logger.fine("InputEvent.canAccessSystemClipboard() got SecurityException ", se);
}
}
} else {
b = true;
}
}
return b;
}
/**
* Returns whether or not the Shift modifier is down on this event.
* @return whether or not the Shift modifier is down on this event
*/
public boolean isShiftDown() {
return (modifiers & SHIFT_MASK) != 0;
}
/**
* Returns whether or not the Control modifier is down on this event.
* @return whether or not the Control modifier is down on this event
*/
public boolean isControlDown() {
return (modifiers & CTRL_MASK) != 0;
}
/**
* Returns whether or not the Meta modifier is down on this event.
* @return whether or not the Meta modifier is down on this event
*/
public boolean isMetaDown() {
return (modifiers & META_MASK) != 0;
}
/**
* Returns whether or not the Alt modifier is down on this event.
* @return whether or not the Alt modifier is down on this event
*/
public boolean isAltDown() {
return (modifiers & ALT_MASK) != 0;
}
/**
* Returns whether or not the AltGraph modifier is down on this event.
* @return whether or not the AltGraph modifier is down on this event
*/
public boolean isAltGraphDown() {
return (modifiers & ALT_GRAPH_MASK) != 0;
}
/**
* Returns the difference in milliseconds between the timestamp of when this event occurred and
* midnight, January 1, 1970 UTC.
* @return the difference in milliseconds between the timestamp and midnight, January 1, 1970 UTC
*/
public long getWhen() {
return when;
}
/**
* Returns the modifier mask for this event.
* @return the modifier mask for this event
*/
public int getModifiers() {
return modifiers & (JDK_1_3_MODIFIERS | HIGH_MODIFIERS);
}
/**
* 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.
*
* @return the extended modifier mask for this event
* @since 1.4
*/
public int getModifiersEx() {
return modifiers & ~JDK_1_3_MODIFIERS;
}
/**
* Consumes this event so that it will not be processed
* in the default manner by the source which originated it.
*/
public void consume() {
consumed = true;
}
/**
* Returns whether or not this event has been consumed.
* @return whether or not this event has been consumed
* @see #consume
*/
public boolean isConsumed() {
return consumed;
}
// state serialization compatibility with JDK 1.1
static final long serialVersionUID = -2482525981698309786L;
/**
* 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. * * @return a String describing the extended modifier keys and * mouse buttons * * @param modifiers a modifier mask describing the extended * modifier keys and mouse buttons for the event * @return a text description of the combination of extended * modifier keys and mouse buttons that were held down * during the event. * @since 1.4 */ public static String getModifiersExText(int modifiers) { StringBuilder buf = new StringBuilder(); if ((modifiers & InputEvent.META_DOWN_MASK) != 0) { buf.append(Toolkit.getProperty("AWT.meta", "Meta")); buf.append("+"); } if ((modifiers & InputEvent.CTRL_DOWN_MASK) != 0) { buf.append(Toolkit.getProperty("AWT.control", "Ctrl")); buf.append("+"); } if ((modifiers & InputEvent.ALT_DOWN_MASK) != 0) { buf.append(Toolkit.getProperty("AWT.alt", "Alt")); buf.append("+"); } if ((modifiers & InputEvent.SHIFT_DOWN_MASK) != 0) { buf.append(Toolkit.getProperty("AWT.shift", "Shift")); buf.append("+"); } if ((modifiers & InputEvent.ALT_GRAPH_DOWN_MASK) != 0) { buf.append(Toolkit.getProperty("AWT.altGraph", "Alt Graph")); buf.append("+"); } int buttonNumber = 1; for (int mask : InputEvent.BUTTON_DOWN_MASK){ if ((modifiers & mask) != 0) { buf.append(Toolkit.getProperty("AWT.button"+buttonNumber, "Button"+buttonNumber)); buf.append("+"); } buttonNumber++; } if (buf.length() > 0) { buf.setLength(buf.length()-1); // remove trailing '+' } return buf.toString(); } }