org.eclipse.swt.widgets.Display

All Implemented Interfaces:: Adaptable, Drawable

public class Display extends Device implements Adaptable

Instances of this class are responsible for managing the connection between SWT and the underlying operating system. Their most important function is to implement the SWT event loop in terms of the platform event model. They also provide various methods for accessing information about the operating system, and have overall control over the operating system resources which SWT allocates.

Applications which are built with SWT will almost always require only a single display. In particular, some platforms which SWT supports will not allow more than one active display. In other words, some platforms do not support creating a new display if one already exists that has not been sent the dispose() message.

In SWT, the thread which creates a Display instance is distinguished as the user-interface thread for that display.

The user-interface thread for a particular display has the following special attributes:

The event loop for that display must be run from the thread.
Some SWT API methods (notably, most of the public methods in Widget and its subclasses), may only be called from the thread. (To support multi-threaded user-interface applications, class Display provides inter-thread communication methods which allow threads other than the user-interface thread to request that it perform operations on their behalf.)
The thread is not allowed to construct other Displays until that display has been disposed. (Note that, this is in addition to the restriction mentioned above concerning platform support for multiple displays. Thus, the only way to have multiple simultaneously active displays, even on platforms which support it, is to have multiple threads.)

Enforcing these attributes allows SWT to be implemented directly on the underlying operating system's event model. This has numerous benefits including smaller footprint, better use of resources, safer memory management, clearer program logic, better performance, and fewer overall operating system threads required. The down side however, is that care must be taken (only) when constructing multi-threaded applications to use the inter-thread communication mechanisms which this class provides when required.

All SWT API methods which may only be called from the user-interface thread are distinguished in their documentation by indicating that they throw the "ERROR_THREAD_INVALID_ACCESS" SWT exception.

Styles:: (none)
Events:: Close, Dispose, Skin

IMPORTANT: This class is not intended to be subclassed.

Since:

1.0

See Also:

syncExec(java.lang.Runnable)
asyncExec(java.lang.Runnable)
wake()
readAndDispatch()
sleep()
Device.dispose()

Field Summary

Fields inherited from class org.eclipse.swt.graphics.Device
deviceLock
Constructor Summary

Constructors

Constructor

Description

Display()

Constructs a new instance of this class.
Method Summary

Modifier and Type

Method

Description

void

addFilter(int eventType, Listener listener)

Adds the listener to the collection of listeners who will be notified when an event of the given type occurs anywhere in a widget.

void

addListener(int eventType, Listener listener)

Adds the listener to the collection of listeners who will be notified when an event of the given type occurs.

void

asyncExec(Runnable runnable)

Causes the run() method of the runnable to be invoked by the user-interface thread at the next reasonable opportunity.

void

beep()

Causes the system hardware to emit a short sound (if it supports this capability).

protected void

checkDevice()

Throws an SWTException if the receiver can not be accessed by the caller.

void

close()

Requests that the connection between SWT and the underlying operating system be closed.

protected void

destroy()

Destroys the device .

void

disposeExec(Runnable runnable)

Causes the run() method of the runnable to be invoked by the user-interface thread just before the receiver is disposed.

static Display

findDisplay(Thread thread)

Returns the display which the given thread is the user-interface thread for, or null if the given thread is not a user-interface thread for any display.

Shell

getActiveShell()

Returns the currently active Shell, or null if no shell belonging to the currently running application is active.

<T> T

getAdapter(Class<T> adapter)

Returns an object which is an instance of the given class parameter associated with this object or null if no association exists.

static String

getAppName()

Returns the application name.

static String

getAppVersion()

Returns the application version.

Rectangle

getBounds()

Returns a rectangle describing the receiver's size and location.

static Display

getCurrent()

Returns the display which the currently running thread is the user-interface thread for, or null if the currently running thread is not a user-interface thread for any display.

Control

getCursorControl()

Returns the control which the on-screen pointer is currently over top of, or null if it is not currently over one of the controls built by the currently running application.

Point

getCursorLocation()

Returns the location of the on-screen pointer relative to the top left corner of the screen.

Object

getData()

Returns the application defined, display specific data associated with the receiver, or null if it has not been set.

Object

getData(String key)

Returns the application defined property of the receiver with the specified name, or null if it has not been set.

static Display

getDefault()

Returns the default display.

int

getDepth()

Returns the bit depth of the screen, which is the number of bits it takes to represent the number of unique colors that the screen is currently capable of displaying.

int

getDismissalAlignment()

Returns the button dismissal alignment, one of LEFT or RIGHT.

int

getDoubleClickTime()

Returns the longest duration, in milliseconds, between two mouse button clicks that will be considered a double click .

Point

getDPI()

Returns a point whose x coordinate is the horizontal dots per inch of the display, and whose y coordinate is the vertical dots per inch of the display.

Control

getFocusControl()

Returns the control which currently has keyboard focus, or null if keyboard events are not currently going to any of the controls built by the currently running application.

boolean

getHighContrast()

Returns true when the high contrast mode is enabled.

Menu

getMenuBar()

Returns the single instance of the application menu bar or null when there is no application menu bar for the platform.

Monitor[]

getMonitors()

Returns an array of monitors attached to the device.

Monitor

getPrimaryMonitor()

Returns the primary monitor for that device.

Shell[]

getShells()

Returns a (possibly empty) array containing all shells which have not been disposed and have the receiver as their display.

Synchronizer

getSynchronizer()

Gets the synchronizer used by the display.

Thread

getSyncThread()

Returns the thread that has invoked syncExec or null if no such runnable is currently being invoked by the user-interface thread.

Color

getSystemColor(int id)

Returns the matching standard color for the given constant, which should be one of the color constants specified in class SWT.

Cursor

getSystemCursor(int id)

Returns the matching standard platform cursor for the given constant, which should be one of the cursor constants specified in class SWT.

Image

getSystemImage(int id)

Returns the matching standard platform image for the given constant, which should be one of the icon constants specified in class SWT.

Menu

getSystemMenu()

Returns the single instance of the system-provided menu for the application.

TaskBar

getSystemTaskBar()

Returns the single instance of the system taskBar or null when there is no system taskBar available for the platform.

Tray

getSystemTray()

Returns the single instance of the system tray or null when there is no system tray available for the platform.

Thread

getThread()

Returns the user-interface thread for the receiver.

boolean

getTouchEnabled()

Returns true if a touch-aware input device is attached to the system, enabled, and ready for use.

Point

map(Control from, Control to, int x, int y)

Maps a point from one coordinate system to another.

Rectangle

map(Control from, Control to, int x, int y, int width, int height)

Maps a point from one coordinate system to another.

Point

map(Control from, Control to, Point point)

Maps a point from one coordinate system to another.

Rectangle

map(Control from, Control to, Rectangle rectangle)

Maps a point from one coordinate system to another.

boolean

readAndDispatch()

Reads an event from the event queue, dispatches it appropriately, and returns true if there is potentially more work to do, or false if the caller can sleep until another event is placed on the event queue.

protected void

release()

Releases any internal resources .

void

removeFilter(int eventType, Listener listener)

Removes the listener from the collection of listeners who will be notified when an event of the given type occurs anywhere in a widget.

void

removeListener(int eventType, Listener listener)

Removes the listener from the collection of listeners who will be notified when an event of the given type occurs.

static void

setAppName(String name)

Sets the application name to the argument.

static void

setAppVersion(String version)

Sets the application version to the argument.

void

setData(Object data)

Sets the application defined, display specific data associated with the receiver, to the argument.

void

setData(String key, Object value)

Sets the application defined property of the receiver with the specified name to the given argument.

void

setSynchronizer(Synchronizer synchronizer)

Sets the synchronizer used by the display to be the argument, which can not be null.

boolean

sleep()

Causes the user-interface thread to sleep (that is, to be put in a state where it does not consume CPU cycles) until an event is received or it is otherwise awakened.

void

syncExec(Runnable runnable)

Causes the run() method of the runnable to be invoked by the user-interface thread at the next reasonable opportunity.

void

timerExec(int milliseconds, Runnable runnable)

Causes the run() method of the runnable to be invoked by the user-interface thread after the specified number of milliseconds have elapsed.

void

update()

Forces all outstanding paint requests for the display to be processed before this method returns.

void

wake()

Notifies the client to send a request in order to wake up a sleeping UI thread and to perform pending UI updates.

protected void

wakeThread()

Methods inherited from class org.eclipse.swt.graphics.Device
dispose, getClientArea, getFontList, getSystemFont, isDisposed

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details
- Display
  
  public Display()
  
  Constructs a new instance of this class.
  Note: The resulting display is marked as the current display. If this is the first display which has been constructed since the application started, it is also marked as the default display.
  Throws:
  
  SWTException -
  
  ERROR_THREAD_INVALID_ACCESS - if called from a thread that already created an existing display
  
  ERROR_INVALID_SUBCLASS - if this class is not an allowed subclass
  
  See Also:
  
  getCurrent()
  
  getDefault()
  
  Widget.checkSubclass()
  
  Shell
Method Details
- getCurrent
  
  public static Display getCurrent()
  
  Returns the display which the currently running thread is the user-interface thread for, or null if the currently running thread is not a user-interface thread for any display.
  
  Returns:
  
  the current display
- getDefault
  
  public static Display getDefault()
  
  Returns the default display. One is created if it did not already exist.
  Note: In RWT, a new display is only created if the calling thread is the user-interface thread.
  
  Returns:
  
  the default display
- getBounds
  
  public Rectangle getBounds()
  
  Returns a rectangle describing the receiver's size and location.
  Overrides:
  
  getBounds in class Device
  
  Returns:
  
  the bounding rectangle
  
  Throws:
  
  SWTException -
  
  ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
- getDPI
  
  public Point getDPI()
  
  Description copied from class: Device
  
  Returns a point whose x coordinate is the horizontal dots per inch of the display, and whose y coordinate is the vertical dots per inch of the display.
  
  Overrides:
  
  getDPI in class Device
  
  Returns:
  
  the horizontal and vertical DPI
- getDepth
  
  public int getDepth()
  
  Description copied from class: Device
  
  Returns the bit depth of the screen, which is the number of bits it takes to represent the number of unique colors that the screen is currently capable of displaying. This number will typically be one of 1, 8, 15, 16, 24 or 32.
  
  Overrides:
  
  getDepth in class Device
  
  Returns:
  
  the depth of the screen
- getFocusControl
  
  public Control getFocusControl()
  
  Returns the control which currently has keyboard focus, or null if keyboard events are not currently going to any of the controls built by the currently running application.
  Returns:
  
  the control under the cursor
  
  Throws:
  
  SWTException -
  
  ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
- map
  
  public Point map(Control from, Control to, Point point)
  
  Maps a point from one coordinate system to another. When the control is null, coordinates are mapped to the display.
  NOTE: On right-to-left platforms where the coordinate systems are mirrored, special care needs to be taken when mapping coordinates from one control to another to ensure the result is correctly mirrored. Mapping a point that is the origin of a rectangle and then adding the width and height is not equivalent to mapping the rectangle. When one control is mirrored and the other is not, adding the width and height to a point that was mapped causes the rectangle to extend in the wrong direction. Mapping the entire rectangle instead of just one point causes both the origin and the corner of the rectangle to be mapped.
  Parameters:
  
  from - the source Control or null
  
  to - the destination Control or null
  
  point - to be mapped
  
  Returns:
  
  point with mapped coordinates
  
  Throws:
  
  IllegalArgumentException -
  
  ERROR_NULL_ARGUMENT - if the point is null
  
  ERROR_INVALID_ARGUMENT - if the Control from or the Control to have been disposed
  
  SWTException -
  
  ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
- map
  
  public Point map(Control from, Control to, int x, int y)
  
  Maps a point from one coordinate system to another. When the control is null, coordinates are mapped to the display.
  NOTE: On right-to-left platforms where the coordinate systems are mirrored, special care needs to be taken when mapping coordinates from one control to another to ensure the result is correctly mirrored. Mapping a point that is the origin of a rectangle and then adding the width and height is not equivalent to mapping the rectangle. When one control is mirrored and the other is not, adding the width and height to a point that was mapped causes the rectangle to extend in the wrong direction. Mapping the entire rectangle instead of just one point causes both the origin and the corner of the rectangle to be mapped.
  Parameters:
  
  from - the source Control or null
  
  to - the destination Control or null
  
  x - coordinates to be mapped
  
  y - coordinates to be mapped
  
  Returns:
  
  point with mapped coordinates
  
  Throws:
  
  IllegalArgumentException -
  
  ERROR_INVALID_ARGUMENT - if the Control from or the Control to have been disposed
  
  SWTException -
  
  ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
- map
  
  public Rectangle map(Control from, Control to, Rectangle rectangle)
  
  Maps a point from one coordinate system to another. When the control is null, coordinates are mapped to the display.
  NOTE: On right-to-left platforms where the coordinate systems are mirrored, special care needs to be taken when mapping coordinates from one control to another to ensure the result is correctly mirrored. Mapping a point that is the origin of a rectangle and then adding the width and height is not equivalent to mapping the rectangle. When one control is mirrored and the other is not, adding the width and height to a point that was mapped causes the rectangle to extend in the wrong direction. Mapping the entire rectangle instead of just one point causes both the origin and the corner of the rectangle to be mapped.
  Parameters:
  
  from - the source Control or null
  
  to - the destination Control or null
  
  rectangle - to be mapped
  
  Returns:
  
  rectangle with mapped coordinates
  
  Throws:
  
  IllegalArgumentException -
  
  ERROR_NULL_ARGUMENT - if the rectangle is null
  
  ERROR_INVALID_ARGUMENT - if the Control from or the Control to have been disposed
  
  SWTException -
  
  ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
- map
  
  public Rectangle map(Control from, Control to, int x, int y, int width, int height)
  
  Maps a point from one coordinate system to another. When the control is null, coordinates are mapped to the display.
  NOTE: On right-to-left platforms where the coordinate systems are mirrored, special care needs to be taken when mapping coordinates from one control to another to ensure the result is correctly mirrored. Mapping a point that is the origin of a rectangle and then adding the width and height is not equivalent to mapping the rectangle. When one control is mirrored and the other is not, adding the width and height to a point that was mapped causes the rectangle to extend in the wrong direction. Mapping the entire rectangle instead of just one point causes both the origin and the corner of the rectangle to be mapped.
  Parameters:
  
  from - the source Control or null
  
  to - the destination Control or null
  
  x - coordinates to be mapped
  
  y - coordinates to be mapped
  
  width - coordinates to be mapped
  
  height - coordinates to be mapped
  
  Returns:
  
  rectangle with mapped coordinates
  
  Throws:
  
  IllegalArgumentException -
  
  ERROR_INVALID_ARGUMENT - if the Control from or the Control to have been disposed
  
  SWTException -
  
  ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
- addListener
  
  public void addListener(int eventType, Listener listener)
  
  Adds the listener to the collection of listeners who will be notified when an event of the given type occurs. The event type is one of the event constants defined in class SWT. When the event does occur in the display, the listener is notified by sending it the handleEvent() message.
  Parameters:
  
  eventType - the type of event to listen for
  
  listener - the listener which should be notified when the event occurs
  
  Throws:
  
  IllegalArgumentException -
  
  ERROR_NULL_ARGUMENT - if the listener is null
  
  SWTException -
  
  ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  
  Since:
  
  1.3
  
  See Also:
  
  Listener
  
  SWT
  
  removeListener(int, org.eclipse.swt.widgets.Listener)
- removeListener
  
  public void removeListener(int eventType, Listener listener)
  
  Removes the listener from the collection of listeners who will be notified when an event of the given type occurs. The event type is one of the event constants defined in class SWT.
  Parameters:
  
  eventType - the type of event to listen for
  
  listener - the listener which should no longer be notified
  
  Throws:
  
  IllegalArgumentException -
  
  ERROR_NULL_ARGUMENT - if the listener is null
  
  SWTException -
  
  ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  
  Since:
  
  1.3
  
  See Also:
  
  Listener
  
  SWT
  
  addListener(int, org.eclipse.swt.widgets.Listener)
- disposeExec
  
  public void disposeExec(Runnable runnable)
  
  Causes the run() method of the runnable to be invoked by the user-interface thread just before the receiver is disposed. Specifying a null runnable is ignored.
  Parameters:
  
  runnable - code to run at dispose time.
  
  Throws:
  
  SWTException -
  
  ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
- close
  
  public void close()
  
  Requests that the connection between SWT and the underlying operating system be closed.
  Throws:
  
  SWTException -
  
  ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  
  Since:
  
  1.3
  
  See Also:
  
  Device.dispose()
- release
  
  protected void release()
  
  Description copied from class: Device
  
  Releases any internal resources .
  When a device is destroyed, resources that were acquired on behalf of the programmer need to be returned to the operating system. For example, if the device allocated a font to be used as the system font, this font would be freed in release. Also,to assist the garbage collector and minimize the amount of memory that is not reclaimed when the programmer keeps a reference to a disposed device, all fields except the handle are zero'd. The handle is needed by destroy.
  This method is called before destroy.
  If subclasses reimplement this method, they must call the super implementation.
  Overrides:
  
  release in class Device
  
  See Also:
  
  Device.dispose()
  
  Device.destroy()
- destroy
  
  protected void destroy()
  
  Description copied from class: Device
  
  Destroys the device . If the device does not have a handle, this method may do nothing depending on the device.
  This method is called after release.
  Subclasses are supposed to reimplement this method and not call the super implementation.
  Overrides:
  
  destroy in class Device
  
  See Also:
  
  Device.dispose()
  
  Device.release()
- getAdapter
  
  public <T> T getAdapter(Class<T> adapter)
  
  Description copied from interface: Adaptable
  
  Returns an object which is an instance of the given class parameter associated with this object or null if no association exists.
  
  Specified by:
  
  getAdapter in interface Adaptable
  
  Parameters:
  
  adapter - the lookup class
  
  Returns:
  
  an object that can be cast to the given class or null if there is no adapter associated with the given class.
- getShells
  
  public Shell[] getShells()
  
  Returns a (possibly empty) array containing all shells which have not been disposed and have the receiver as their display.
  Returns:
  
  the receiver's shells
  
  Throws:
  
  SWTException -
  
  ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
- getActiveShell
  
  public Shell getActiveShell()
  
  Returns the currently active Shell, or null if no shell belonging to the currently running application is active.
  Returns:
  
  the active shell or null
  
  Throws:
  
  SWTException -
  
  ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
- getThread
  
  public Thread getThread()
  
  Returns the user-interface thread for the receiver. Note that the user-interface thread may change per user-request.
  Returns:
  
  the receiver's user-interface thread or null if there's no current user-request executed that belongs to the display.
  
  Throws:
  
  SWTException -
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
- findDisplay
  
  public static Display findDisplay(Thread thread)
  
  Returns the display which the given thread is the user-interface thread for, or null if the given thread is not a user-interface thread for any display. Specifying null as the thread will return null for the display.
  
  Parameters:
  
  thread - the user-interface thread
  
  Returns:
  
  the display for the given thread
- setSynchronizer
  
  public void setSynchronizer(Synchronizer synchronizer)
  
  Sets the synchronizer used by the display to be the argument, which can not be null.
  Parameters:
  
  synchronizer - the new synchronizer for the display (must not be null)
  
  Throws:
  
  IllegalArgumentException -
  
  ERROR_NULL_ARGUMENT - if the synchronizer is null
  
  SWTException -
  
  ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  
  ERROR_FAILED_EXEC - if an exception occurred while running an inter-thread message
  
  Since:
  
  1.3
- getSynchronizer
  
  public Synchronizer getSynchronizer()
  
  Gets the synchronizer used by the display.
  Returns:
  
  the receiver's synchronizer
  
  Throws:
  
  SWTException -
  
  ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  
  Since:
  
  1.3
- getSyncThread
  
  public Thread getSyncThread()
  
  Returns the thread that has invoked syncExec or null if no such runnable is currently being invoked by the user-interface thread.
  Note: If a runnable invoked by asyncExec is currently running, this method will return null.
  Returns:
  
  the receiver's sync-interface thread
  
  Throws:
  
  SWTException -
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  
  Since:
  
  1.3
- asyncExec
  
  public void asyncExec(Runnable runnable)
  
  Causes the run() method of the runnable to be invoked by the user-interface thread at the next reasonable opportunity. Note that the user-interface thread may change per user-request. The caller of this method continues to run in parallel, and is not notified when the runnable has completed. Specifying null as the runnable simply wakes the user-interface thread when run.
  Note that at the time the runnable is invoked, widgets that have the receiver as their display may have been disposed. Therefore, it is necessary to check for this case inside the runnable before accessing the widget.
  Parameters:
  
  runnable - code to run on the user-interface thread or null
  
  Throws:
  
  SWTException -
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  
  See Also:
  
  syncExec(java.lang.Runnable)
- syncExec
  
  public void syncExec(Runnable runnable)
  
  Causes the run() method of the runnable to be invoked by the user-interface thread at the next reasonable opportunity. Note that the user-interface thread may change per user-request. The thread which calls this method is suspended until the runnable completes. Specifying null as the runnable simply wakes the user-interface thread.
  Note that at the time the runnable is invoked, widgets that have the receiver as their display may have been disposed. Therefore, it is necessary to check for this case inside the runnable before accessing the widget.
  Parameters:
  
  runnable - code to run on the user-interface thread or null
  
  Throws:
  
  SWTException -
  
  ERROR_FAILED_EXEC - if an exception occured when executing the runnable
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  
  See Also:
  
  asyncExec(java.lang.Runnable)
- timerExec
  
  public void timerExec(int milliseconds, Runnable runnable)
  
  Causes the run() method of the runnable to be invoked by the user-interface thread after the specified number of milliseconds have elapsed. If milliseconds is less than zero, the runnable is not executed.
  Note that at the time the runnable is invoked, widgets that have the receiver as their display may have been disposed. Therefore, it is necessary to check for this case inside the runnable before accessing the widget.
  Parameters:
  
  milliseconds - the delay before running the runnable
  
  runnable - code to run on the user-interface thread
  
  Throws:
  
  IllegalArgumentException -
  
  ERROR_NULL_ARGUMENT - if the runnable is null
  
  SWTException -
  
  ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  
  Since:
  
  1.2
  
  See Also:
  
  asyncExec(java.lang.Runnable)
- readAndDispatch
  
  public boolean readAndDispatch()
  
  Reads an event from the event queue, dispatches it appropriately, and returns true if there is potentially more work to do, or false if the caller can sleep until another event is placed on the event queue.
  In addition to checking the system event queue, this method also checks if any inter-thread messages (created by syncExec() or asyncExec()) are waiting to be processed, and if so handles them before returning.
  Returns:
  
  false if the caller can sleep upon return from this method
  
  Throws:
  
  SWTException -
  
  ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  
  ERROR_FAILED_EXEC - if an exception occurred while running an inter-thread message
  
  Since:
  
  1.1
  
  See Also:
  
  sleep()
  
  wake()
- sleep
  
  public boolean sleep()
  
  Causes the user-interface thread to sleep (that is, to be put in a state where it does not consume CPU cycles) until an event is received or it is otherwise awakened.
  Returns:
  
  true if an event requiring dispatching was placed on the queue.
  
  Throws:
  
  SWTException -
  
  ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  
  Since:
  
  1.1
  
  See Also:
  
  wake()
- wake
  
  public void wake()
  
  Notifies the client to send a request in order to wake up a sleeping UI thread and to perform pending UI updates. Note that this method may be called from any thread.
  Note that this method has no effect unless a ServerPushSession is active.
  Throws:
  
  SWTException -
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
- wakeThread
  
  protected void wakeThread()
- getSystemTray
  
  public Tray getSystemTray()
  
  Returns the single instance of the system tray or null when there is no system tray available for the platform.
  Returns:
  
  the system tray or null
  
  Throws:
  
  SWTException -
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  
  Since:
  
  1.4
- getMenuBar
  
  public Menu getMenuBar()
  
  Returns the single instance of the application menu bar or null when there is no application menu bar for the platform.
  Returns:
  
  the application menu bar or null
  
  Throws:
  
  SWTException -
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  
  Since:
  
  1.4
- getSystemTaskBar
  
  public TaskBar getSystemTaskBar()
  
  Returns the single instance of the system taskBar or null when there is no system taskBar available for the platform.
  Returns:
  
  the system taskBar or null
  
  Throws:
  
  SWTException -
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  
  Since:
  
  1.4
- getSystemMenu
  
  public Menu getSystemMenu()
  
  Returns the single instance of the system-provided menu for the application. On platforms where no menu is provided for the application this method returns null.
  Returns:
  
  the system menu or null
  
  Throws:
  
  SWTException -
  
  ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  
  Since:
  
  1.4
- getSystemColor
  
  public Color getSystemColor(int id)
  
  Description copied from class: Device
  
  Returns the matching standard color for the given constant, which should be one of the color constants specified in class SWT. Any value other than one of the SWT color constants which is passed in will result in the color black. This color should not be free'd because it was allocated by the system, not the application.
  Overrides:
  
  getSystemColor in class Device
  
  Parameters:
  
  id - the color constant
  
  Returns:
  
  the matching color
  
  See Also:
  
  SWT
- getSystemImage
  
  public Image getSystemImage(int id)
  
  Returns the matching standard platform image for the given constant, which should be one of the icon constants specified in class SWT. This image should not be free'd because it was allocated by the system, not the application. A value of null will be returned either if the supplied constant is not an SWT icon constant or if the platform does not define an image that corresponds to the constant.
  Parameters:
  
  id - the SWT icon constant
  
  Returns:
  
  the corresponding image or null
  
  Throws:
  
  SWTException -
  
  ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  
  See Also:
  
  SWT.ICON_ERROR
  
  SWT.ICON_INFORMATION
  
  SWT.ICON_QUESTION
  
  SWT.ICON_WARNING
  
  SWT.ICON_WORKING
- getSystemCursor
  
  public Cursor getSystemCursor(int id)
  
  Returns the matching standard platform cursor for the given constant, which should be one of the cursor constants specified in class SWT. This cursor should not be free'd because it was allocated by the system, not the application. A value of null will be returned if the supplied constant is not an SWT cursor constant.
  Parameters:
  
  id - the SWT cursor constant
  
  Returns:
  
  the corresponding cursor or null
  
  Throws:
  
  SWTException -
  
  ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  
  Since:
  
  1.3
  
  See Also:
  
  SWT.CURSOR_ARROW
  
  SWT.CURSOR_WAIT
  
  SWT.CURSOR_CROSS
  
  SWT.CURSOR_HELP
  
  SWT.CURSOR_SIZEALL
  
  SWT.CURSOR_SIZENS
  
  SWT.CURSOR_SIZEWE
  
  SWT.CURSOR_SIZEN
  
  SWT.CURSOR_SIZES
  
  SWT.CURSOR_SIZEE
  
  SWT.CURSOR_SIZEW
  
  SWT.CURSOR_SIZENE
  
  SWT.CURSOR_SIZESE
  
  SWT.CURSOR_SIZESW
  
  SWT.CURSOR_SIZENW
  
  SWT.CURSOR_IBEAM
  
  SWT.CURSOR_HAND
- getDoubleClickTime
  
  public int getDoubleClickTime()
  
  Returns the longest duration, in milliseconds, between two mouse button clicks that will be considered a double click .
  Returns:
  
  the double click time
  
  Throws:
  
  SWTException -
  
  ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  
  Since:
  
  1.2
- getCursorControl
  
  public Control getCursorControl()
  
  Returns the control which the on-screen pointer is currently over top of, or null if it is not currently over one of the controls built by the currently running application.
  Returns:
  
  the control under the cursor or null
  
  Throws:
  
  SWTException -
  
  ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  
  Since:
  
  1.3
- getDismissalAlignment
  
  public int getDismissalAlignment()
  
  Returns the button dismissal alignment, one of LEFT or RIGHT. The button dismissal alignment is the ordering that should be used when positioning the default dismissal button for a dialog. For example, in a dialog that contains an OK and CANCEL button, on platforms where the button dismissal alignment is LEFT, the button ordering should be OK/CANCEL. When button dismissal alignment is RIGHT, the button ordering should be CANCEL/OK.
  Returns:
  
  the button dismissal order
  
  Throws:
  
  SWTException -
  
  ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  
  Since:
  
  1.3
- getHighContrast
  
  public boolean getHighContrast()
  
  Returns true when the high contrast mode is enabled. Otherwise, false is returned.
  Note: This operation is a hint and is not supported on platforms that do not have this concept.
  Returns:
  
  the high contrast mode
  
  Throws:
  
  SWTException -
  
  ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  
  Since:
  
  1.3
- getCursorLocation
  
  public Point getCursorLocation()
  
  Returns the location of the on-screen pointer relative to the top left corner of the screen.
  Returns:
  
  the cursor location
  
  Throws:
  
  SWTException -
  
  ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  
  Since:
  
  1.3
- addFilter
  
  public void addFilter(int eventType, Listener listener)
  
  Adds the listener to the collection of listeners who will be notified when an event of the given type occurs anywhere in a widget. The event type is one of the event constants defined in class SWT. When the event does occur, the listener is notified by sending it the handleEvent() message.
  Setting the type of an event to SWT.None from within the handleEvent() method can be used to change the event type and stop subsequent Java listeners from running. Because event filters run before other listeners, event filters can both block other listeners and set arbitrary fields within an event. For this reason, event filters are both powerful and dangerous. They should generally be avoided for performance, debugging and code maintenance reasons.
  
  NOTE: In RAP, only events that have a matching listener registered on the event's source widget are processed on the server. One exception are key events, for which a whitelist can be define using RWT#ACTIVE_KEYS.
  Parameters:
  
  eventType - the type of event to listen for
  
  listener - the listener which should be notified when the event occurs
  
  Throws:
  
  IllegalArgumentException -
  
  ERROR_NULL_ARGUMENT - if the listener is null
  
  SWTException -
  
  ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  
  See Also:
  
  Listener
  
  SWT
  
  removeFilter(int, org.eclipse.swt.widgets.Listener)
  
  removeListener(int, org.eclipse.swt.widgets.Listener)
- removeFilter
  
  public void removeFilter(int eventType, Listener listener)
  
  Removes the listener from the collection of listeners who will be notified when an event of the given type occurs anywhere in a widget. The event type is one of the event constants defined in class SWT.
  Parameters:
  
  eventType - the type of event to listen for
  
  listener - the listener which should no longer be notified when the event occurs
  
  Throws:
  
  IllegalArgumentException -
  
  ERROR_NULL_ARGUMENT - if the listener is null
  
  SWTException -
  
  ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
  
  See Also:
  
  Listener
  
  SWT
  
  addFilter(int, org.eclipse.swt.widgets.Listener)
  
  addListener(int, org.eclipse.swt.widgets.Listener)
- getData
  
  public Object getData()
  
  Returns the application defined, display specific data associated with the receiver, or null if it has not been set. The display specific data is a single, unnamed field that is stored with every display.
  Applications may put arbitrary objects in this field. If the object stored in the display specific data needs to be notified when the display is disposed of, it is the application's responsibility to provide a disposeExec() handler which does so.
  Returns:
  
  the display specific data
  
  Throws:
  
  SWTException -
  
  ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  
  Since:
  
  1.2
  
  See Also:
  
  setData(Object)
  
  disposeExec(Runnable)
- setData
  
  public void setData(Object data)
  
  Sets the application defined, display specific data associated with the receiver, to the argument. The display specific data is a single, unnamed field that is stored with every display.
  Applications may put arbitrary objects in this field. If the object stored in the display specific data needs to be notified when the display is disposed of, it is the application's responsibility provide a disposeExec() handler which does so.
  Parameters:
  
  data - the new display specific data
  
  Throws:
  
  SWTException -
  
  ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  
  Since:
  
  1.2
  
  See Also:
  
  getData()
  
  disposeExec(Runnable)
- setData
  
  public void setData(String key, Object value)
  
  Sets the application defined property of the receiver with the specified name to the given argument.
  Applications may have associated arbitrary objects with the receiver in this fashion. If the objects stored in the properties need to be notified when the display is disposed of, it is the application's responsibility provide a disposeExec() handler which does so.
  Parameters:
  
  key - the name of the property
  
  value - the new value for the property
  
  Throws:
  
  IllegalArgumentException -
  
  ERROR_NULL_ARGUMENT - if the key is null
  
  SWTException -
  
  ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  
  Since:
  
  1.2
  
  See Also:
  
  getData(String)
  
  disposeExec(Runnable)
- getData
  
  public Object getData(String key)
  
  Returns the application defined property of the receiver with the specified name, or null if it has not been set.
  Applications may have associated arbitrary objects with the receiver in this fashion. If the objects stored in the properties need to be notified when the display is disposed of, it is the application's responsibility to provide a disposeExec() handler which does so.
  Parameters:
  
  key - the name of the property
  
  Returns:
  
  the value of the property or null if it has not been set
  
  Throws:
  
  IllegalArgumentException -
  
  ERROR_NULL_ARGUMENT - if the key is null
  
  SWTException -
  
  ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  
  Since:
  
  1.2
  
  See Also:
  
  setData(String, Object)
  
  disposeExec(Runnable)
- getMonitors
  
  public Monitor[] getMonitors()
  
  Returns an array of monitors attached to the device.
  
  Returns:
  
  the array of monitors
  
  Since:
  
  1.2
- getPrimaryMonitor
  
  public Monitor getPrimaryMonitor()
  
  Returns the primary monitor for that device.
  
  Returns:
  
  the primary monitor
  
  Since:
  
  1.2
- getAppName
  
  public static String getAppName()
  
  Returns the application name.
  Returns:
  
  the application name
  
  Since:
  
  1.3
  
  See Also:
  
  setAppName(String)
- getAppVersion
  
  public static String getAppVersion()
  
  Returns the application version.
  Returns:
  
  the application version
  
  Since:
  
  1.3
  
  See Also:
  
  setAppVersion(String)
- setAppName
  
  public static void setAppName(String name)
  
  Sets the application name to the argument.
  Specifying null for the name clears it.
  
  Parameters:
  
  name - the new app name or null
  
  Since:
  
  1.3
- setAppVersion
  
  public static void setAppVersion(String version)
  
  Sets the application version to the argument.
  
  Parameters:
  
  version - the new app version
  
  Since:
  
  1.3
- update
  
  public void update()
  
  Forces all outstanding paint requests for the display to be processed before this method returns.
  Throws:
  
  SWTException -
  
  ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  
  Since:
  
  1.3
  
  See Also:
  
  Control.update()
- beep
  
  public void beep()
  
  Causes the system hardware to emit a short sound (if it supports this capability).
  Throws:
  
  SWTException -
  
  ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
  
  ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  
  Since:
  
  1.3
- getTouchEnabled
  
  public boolean getTouchEnabled()
  
  Returns true if a touch-aware input device is attached to the system, enabled, and ready for use.
  
  Since:
  
  1.4
- checkDevice
  
  protected void checkDevice()
  
  Description copied from class: Device
  
  Throws an SWTException if the receiver can not be accessed by the caller. This may include both checks on the state of the receiver and more generally on the entire execution context. This method should be called by device implementors to enforce the standard SWT invariants.
  Currently, it is an error to invoke any method (other than isDisposed() and dispose()) on a device that has had its dispose() method called.
  In future releases of SWT, there may be more or fewer error checks and exceptions may be thrown for different reasons.
  
  Overrides:
  
  checkDevice in class Device

Class Display

Field Summary

Fields inherited from class org.eclipse.swt.graphics.Device

Constructor Summary

Method Summary

Methods inherited from class org.eclipse.swt.graphics.Device

Methods inherited from class java.lang.Object

Constructor Details

Display

Method Details

getCurrent

getDefault

getBounds

getDPI

getDepth

getFocusControl

map

map

map

map

addListener

removeListener

disposeExec

close

release

destroy

getAdapter

getShells

getActiveShell

getThread

findDisplay

setSynchronizer

getSynchronizer

getSyncThread

asyncExec

syncExec

timerExec

readAndDispatch

sleep

wake

wakeThread

getSystemTray

getMenuBar

getSystemTaskBar

getSystemMenu

getSystemColor

getSystemImage

getSystemCursor

getDoubleClickTime

getCursorControl

getDismissalAlignment

getHighContrast

getCursorLocation

addFilter

removeFilter

getData

setData

setData

getData

getMonitors

getPrimaryMonitor

getAppName

getAppVersion

setAppName

setAppVersion

update

beep

getTouchEnabled

checkDevice