java.lang.Object
- org.eclipse.swt.graphics.Device

All Implemented Interfaces:

Drawable

Direct Known Subclasses:

Display, Printer
```
public abstract class Device
extends Object
implements Drawable
```
This class is the abstract superclass of all device objects, such as the Display device and the Printer device. Devices can have a graphics context (GC) created for them, and they can be drawn on by sending messages to the associated GC.

See Also:

Sample code and further information

Field Summary

Fields
Modifier and Type Field Description

protected static Device CurrentDevice

static boolean DEBUG

protected static Runnable DeviceFinder

Constructor Summary

Constructors
Constructor Description

Device()
Constructs a new instance of this class.

Device(DeviceData data)
Constructs a new instance of this class.

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method	Description
`protected void`	`checkDevice()`	Throws an `SWTException` if the receiver can not be accessed by the caller.
`protected void`	`create(DeviceData data)`	Creates the device in the operating system.
`protected void`	`destroy()`	Destroys the device in the operating system and releases the device's handle.
`void`	`dispose()`	Disposes of the operating system resources associated with the receiver.
`Rectangle`	`getBounds()`	Returns a rectangle describing the receiver's size and location.
`Rectangle`	`getClientArea()`	Returns a rectangle which describes the area of the receiver which is capable of displaying data.
`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.
`DeviceData`	`getDeviceData()`	Returns a `DeviceData` based on the receiver.
`protected int`	`getDeviceZoom()`	Gets the scaling factor from the device and calculates the zoom level.
`Point`	`getDPI()`	Returns a point whose x coordinate is the logical horizontal dots per inch of the display, and whose y coordinate is the logical vertical dots per inch of the display.
`FontData[]`	`getFontList(String faceName, boolean scalable)`	Returns `FontData` objects which describe the fonts that match the given arguments.
`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`.
`Font`	`getSystemFont()`	Returns a reasonable font for applications to use.
`boolean`	`getWarnings()`	Returns `true` if the underlying window system prints out warning messages on the console, and `setWarnings` had previously been called with `true`.
`protected void`	`init()`	Initializes any internal resources needed by the device.
`abstract void`	`internal_dispose_GC(long hDC, GCData data)`	Invokes platform specific functionality to dispose a GC handle.
`abstract long`	`internal_new_GC(GCData data)`	Invokes platform specific functionality to allocate a new GC handle.
`boolean`	`isDisposed()`	Returns `true` if the device has been disposed, and `false` otherwise.
`boolean`	`isTracking()`
`boolean`	`loadFont(String path)`	Loads the font specified by a file.
`protected void`	`release()`	Releases any internal resources back to the operating system and clears all fields except the device handle.
`void`	`setTracking(boolean tracking)`
`void`	`setWarnings(boolean warnings)`	If the underlying window system supports printing warning messages to the console, setting warnings to `false` prevents these messages from being printed.

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

Methods inherited from interface org.eclipse.swt.graphics.Drawable
isAutoScalable

- Field Detail
  - DEBUG
```
public static boolean DEBUG
```
  - CurrentDevice
```
protected static Device CurrentDevice
```
  - DeviceFinder
```
protected static Runnable DeviceFinder
```
- Constructor Detail
  - Device
```
public Device()
```
    Constructs a new instance of this class.
    You must dispose the device when it is no longer required.
    
    Since:
    
    3.1
    
    See Also:
    
    create(org.eclipse.swt.graphics.DeviceData), init()
  - Device
```
public Device(DeviceData data)
```
    Constructs a new instance of this class.
    You must dispose the device when it is no longer required.
    
    Parameters:
    
    data - the DeviceData which describes the receiver
    
    See Also:
    
    create(org.eclipse.swt.graphics.DeviceData), init(), DeviceData
- Method Detail
  - isTracking
```
public boolean isTracking()
```
    Throws:
    
    SWTException -
    
    ERROR_DEVICE_DISPOSED - if the receiver has been disposed
    
    Since:
    
    3.115
  - setTracking
```
public void setTracking(boolean tracking)
```
    Throws:
    
    SWTException -
    
    ERROR_DEVICE_DISPOSED - if the receiver has been disposed
    
    Since:
    
    3.115
  - checkDevice
```
protected void checkDevice()
```
    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.
    Throws:
    
    SWTException -
    
    ERROR_WIDGET_DISPOSED - if the receiver has been disposed
  - create
```
protected void create(DeviceData data)
```
    Creates the device in the operating system. If the device does not have a handle, this method may do nothing depending on the device.
    This method is called before init.
    Subclasses are supposed to reimplement this method and not call the super implementation.
    
    Parameters:
    
    data - the DeviceData which describes the receiver
    
    See Also:
    
    init()
  - destroy
```
protected void destroy()
```
    Destroys the device in the operating system and releases the device's handle. 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.
    
    See Also:
    
    dispose(), release()
  - dispose
```
public void dispose()
```
    Disposes of the operating system resources associated with the receiver. After this method has been invoked, the receiver will answer true when sent the message isDisposed().
    
    See Also:
    
    release(), destroy(), checkDevice()
  - getBounds
```
public Rectangle getBounds()
```
    Returns a rectangle describing the receiver's size and location.
    Returns:
    
    the bounding rectangle
    
    Throws:
    
    SWTException -
    
    ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  - getDeviceData
```
public DeviceData getDeviceData()
```
    Returns a DeviceData based on the receiver. Modifications made to this DeviceData will not affect the receiver.
    Returns:
    
    a DeviceData containing the device's data and attributes
    
    Throws:
    
    SWTException -
    
    ERROR_DEVICE_DISPOSED - if the receiver has been disposed
    
    See Also:
    
    DeviceData
  - getClientArea
```
public Rectangle getClientArea()
```
    Returns a rectangle which describes the area of the receiver which is capable of displaying data.
    Returns:
    
    the client area
    
    Throws:
    
    SWTException -
    
    ERROR_DEVICE_DISPOSED - if the receiver has been disposed
    
    See Also:
    
    getBounds()
  - getDepth
```
public 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. This number will typically be one of 1, 8, 15, 16, 24 or 32.
    Returns:
    
    the depth of the screen
    
    Throws:
    
    SWTException -
    
    ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  - getDPI
```
public Point getDPI()
```
    Returns a point whose x coordinate is the logical horizontal dots per inch of the display, and whose y coordinate is the logical vertical dots per inch of the display.
    Returns:
    
    the horizontal and vertical DPI
    
    Throws:
    
    SWTException -
    
    ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  - getFontList
```
public FontData[] getFontList(String faceName,
                              boolean scalable)
```
    Returns FontData objects which describe the fonts that match the given arguments. If the faceName is null, all fonts will be returned.
    Parameters:
    
    faceName - the name of the font to look for, or null
    
    scalable - if true only scalable fonts are returned, otherwise only non-scalable fonts are returned.
    
    Returns:
    
    the matching font data
    
    Throws:
    
    SWTException -
    
    ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  - getSystemColor
```
public 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. 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 freed because it was allocated by the system, not the application.
    Parameters:
    
    id - the color constant
    
    Returns:
    
    the matching color
    
    Throws:
    
    SWTException -
    
    ERROR_DEVICE_DISPOSED - if the receiver has been disposed
    
    See Also:
    
    SWT
  - getSystemFont
```
public Font getSystemFont()
```
    Returns a reasonable font for applications to use. On some platforms, this will match the "default font" or "system font" if such can be found. This font should not be freed because it was allocated by the system, not the application.
    Typically, applications which want the default look should simply not set the font on the widgets they create. Widgets are always created with the correct default font for the class of user-interface component they represent.
    Returns:
    
    a font
    
    Throws:
    
    SWTException -
    
    ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  - getWarnings
```
public boolean getWarnings()
```
    Returns true if the underlying window system prints out warning messages on the console, and setWarnings had previously been called with true.
    Returns:
    
    trueif warnings are being handled, and false otherwise
    
    Throws:
    
    SWTException -
    
    ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  - init
```
protected void init()
```
    Initializes any internal resources needed by the device.
    This method is called after create.
    If subclasses reimplement this method, they must call the super implementation.
    
    See Also:
    
    create(org.eclipse.swt.graphics.DeviceData)
  - internal_new_GC
```
public abstract long internal_new_GC(GCData data)
```
    Invokes platform specific functionality to allocate a new GC handle.
    IMPORTANT: This method is not part of the public API for Device. It is marked public only so that it can be shared within the packages provided by SWT. It is not available on all platforms, and should never be called from application code.
    
    Specified by:
    
    internal_new_GC in interface Drawable
    
    Parameters:
    
    data - the platform specific GC data
    
    Returns:
    
    the platform specific GC handle
    
    Restriction:
    
    This method is not intended to be referenced by clients.
  - internal_dispose_GC
```
public abstract void internal_dispose_GC(long hDC,
                                         GCData data)
```
    Invokes platform specific functionality to dispose a GC handle.
    IMPORTANT: This method is not part of the public API for Device. It is marked public only so that it can be shared within the packages provided by SWT. It is not available on all platforms, and should never be called from application code.
    
    Specified by:
    
    internal_dispose_GC in interface Drawable
    
    Parameters:
    
    hDC - the platform specific GC handle
    
    data - the platform specific GC data
    
    Restriction:
    
    This method is not intended to be referenced by clients.
  - isDisposed
```
public boolean isDisposed()
```
    Returns true if the device has been disposed, and false otherwise.
    This method gets the dispose state for the device. When a device has been disposed, it is an error to invoke any other method using the device.
    
    Returns:
    
    true when the device is disposed and false otherwise
  - loadFont
```
public boolean loadFont(String path)
```
    Loads the font specified by a file. The font will be present in the list of fonts available to the application.
    Parameters:
    
    path - the font file path
    
    Returns:
    
    whether the font was successfully loaded
    
    Throws:
    
    SWTException -
    
    ERROR_NULL_ARGUMENT - if path is null
    
    ERROR_DEVICE_DISPOSED - if the receiver has been disposed
    
    Since:
    
    3.3
    
    See Also:
    
    Font
  - release
```
protected void release()
```
    Releases any internal resources back to the operating system and clears all fields except the device handle.
    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.
    
    See Also:
    
    dispose(), destroy()
  - setWarnings
```
public void setWarnings(boolean warnings)
```
    If the underlying window system supports printing warning messages to the console, setting warnings to false prevents these messages from being printed. If the argument is true then message printing is not blocked.
    Parameters:
    
    warnings - trueif warnings should be printed, and false otherwise
    
    Throws:
    
    SWTException -
    
    ERROR_DEVICE_DISPOSED - if the receiver has been disposed
  - getDeviceZoom
```
protected int getDeviceZoom()
```
    Gets the scaling factor from the device and calculates the zoom level.
    
    Returns:
    
    zoom in percentage
    
    Since:
    
    3.105
    
    Restriction:
    
    This method is not intended to be referenced by clients.
    
    Restriction:
    
    This method is not intended to be re-implemented or extended by clients.

Modifier and Type	Field	Description
`protected static Device`	`CurrentDevice`
`static boolean`	`DEBUG`
`protected static Runnable`	`DeviceFinder`

Constructor	Description
`Device()`	Constructs a new instance of this class.
`Device(DeviceData data)`	Constructs a new instance of this class.

Class Device

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface org.eclipse.swt.graphics.Drawable

Field Detail

DEBUG

CurrentDevice

DeviceFinder

Constructor Detail

Device

Device

Method Detail

isTracking

setTracking

checkDevice

create

destroy

dispose

getBounds

getDeviceData

getClientArea

getDepth

getDPI

getFontList

getSystemColor

getSystemFont

getWarnings

init

internal_new_GC

internal_dispose_GC

isDisposed

loadFont

release

setWarnings

getDeviceZoom