Device

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 <a href="http://www.eclipse.org/swt/">Sample code and further information</a>

abstract

class Device : Drawable {

void* xDisplay;

GtkWidget* shellHandle;

bool DEBUG;

bool debugging;

bool tracking;

Exception[] errors;

Object[] objects;

Object trackingLock;

GdkColor*[] gdkColors;

int[] colorRefCount;

bool disposed;

String[] log_domains;

int[] handler_ids;

int warningLevel;

int function(void*) mXIOErrorHandler;

int function(void*, XErrorEvent*) mXErrorHandler;

ptrdiff_t XErrorProc;

ptrdiff_t XIOErrorProc;

ptrdiff_t XNullErrorProc;

ptrdiff_t XNullIOErrorProc;

Device[] Devices;

Color COLOR_BLACK;

Color COLOR_DARK_RED;

Color COLOR_DARK_GREEN;

Color COLOR_DARK_YELLOW;

Color COLOR_DARK_BLUE;

Color COLOR_DARK_MAGENTA;

Color COLOR_DARK_CYAN;

Color COLOR_GRAY;

Color COLOR_DARK_GRAY;

Color COLOR_RED;

Color COLOR_GREEN;

Color COLOR_YELLOW;

Color COLOR_BLUE;

Color COLOR_MAGENTA;

Color COLOR_CYAN;

Color COLOR_WHITE;

Font systemFont;

PangoTabArray* emptyTab;

bool useXRender;

bool CAIRO_LOADED;

Device CurrentDevice;

Runnable DeviceFinder;

this();

this(DeviceData data);

void checkDevice();

void create(DeviceData data);

void dispose();

void destroy();

Rectangle getBounds();

DeviceData getDeviceData();

Rectangle getClientArea();

int getDepth();

Point getDPI();

FontData[] getFontList(String faceName, bool scalable);

Color getSystemColor(int id);

Font getSystemFont();

bool getWarnings();

void init_();

GdkGC* internal_new_GC(GCData data);

void internal_dispose_GC(GdkGC* handle, GCData data);

bool isDisposed();

bool loadFont(String path);

void release();

void setWarnings(bool warnings);

}

Constructors

this this(): Constructs a new instance of this class. You must dispose the device when it is no longer required.
this this(DeviceData data): Constructs a new instance of this class. You must dispose the device when it is no longer required.

Members

Functions

checkDevice void checkDevice(): Throws an <code>SWTException</code> 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 <code>isDisposed()</code> and <code>dispose()</code>) on a device that has had its <code>dispose()</code> method called. In future releases of SWT, there may be more or fewer error checks and exceptions may be thrown for different reasons.
create 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 <code>init</code>. Subclasses are supposed to reimplement this method and not call the <code>super</code> implementation.
destroy 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 <code>release</code>. Subclasses are supposed to reimplement this method and not call the <code>super</code> implementation.
dispose void dispose(): Disposes of the operating system resources associated with the receiver. After this method has been invoked, the receiver will answer <code>true</code> when sent the message <code>isDisposed()</code>.
getBounds Rectangle getBounds(): Returns a rectangle describing the receiver's size and location.
getClientArea Rectangle getClientArea(): Returns a rectangle which describes the area of the receiver which is capable of displaying data.
getDPI 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.
getDepth 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.
getDeviceData DeviceData getDeviceData(): Returns a <code>DeviceData</code> based on the receiver. Modifications made to this <code>DeviceData</code> will not affect the receiver.
getFontList FontData[] getFontList(String faceName, bool scalable): Returns <code>FontData</code> objects which describe the fonts that match the given arguments. If the <code>faceName</code> is null, all fonts will be returned.
getSystemColor Color getSystemColor(int id): Returns the matching standard color for the given constant, which should be one of the color constants specified in class <code>SWT</code>. 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.
getSystemFont 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.
getWarnings bool getWarnings(): Returns <code>true</code> if the underlying window system prints out warning messages on the console, and <code>setWarnings</code> had previously been called with <code>true</code>.
init_ void init_(): Initializes any internal resources needed by the device. This method is called after <code>create</code>. If subclasses reimplement this method, they must call the <code>super</code> implementation.
internal_dispose_GC void internal_dispose_GC(GdkGC* handle, GCData data): Invokes platform specific functionality to dispose a GC handle. IMPORTANT: This method is not part of the public API for <code>Device</code>. 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.
internal_new_GC GdkGC* 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 <code>Device</code>. 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.
isDisposed bool isDisposed(): Returns <code>true</code> if the device has been disposed, and <code>false</code> 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.
loadFont bool loadFont(String path): Loads the font specified by a file. The font will be present in the list of fonts available to the application.
release 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 <code>release</code>. 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 <code>destroy</code>. This method is called before <code>destroy</code>. If subclasses reimplement this method, they must call the <code>super</code> implementation.
setWarnings void setWarnings(bool warnings): If the underlying window system supports printing warning messages to the console, setting warnings to <code>false</code> prevents these messages from being printed. If the argument is <code>true</code> then message printing is not blocked.

Variables

xDisplay void* xDisplay;: the handle to the X Display (Warning: This field is platform dependent) IMPORTANT: This field is not part of the SWT public API. It is marked protected only so that it can be shared within the packages provided by SWT. It is not available on all platforms and should never be accessed from application code.

Inherited Members

From Drawable

internal_new_GC GdkGC* 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 <code>Drawable</code>. 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.
internal_dispose_GC void internal_dispose_GC(GdkGC* handle, GCData data): Invokes platform specific functionality to dispose a GC handle. IMPORTANT: This method is not part of the public API for <code>Drawable</code>. 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.