Class Device
- All Implemented Interfaces:
- Drawable
- Direct Known Subclasses:
- Display
This class is not intended to be directly used by clients.
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Field SummaryFields
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Constructor SummaryConstructors
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Method SummaryModifier and TypeMethodDescriptionprotected voidThrows anSWTExceptionif the receiver can not be accessed by the caller.protected voiddestroy()Destroys the device .voiddispose()Disposes of the operating system resources associated with the receiver.Returns a rectangle describing the receiver's size and location.Returns a rectangle which describes the area of the receiver which is capable of displaying data.intgetDepth()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.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.FontData[]getFontList(String faceName, boolean scalable) ReturnsFontDataobjects which describe the fonts that match the given arguments.getSystemColor(int id) Returns the matching standard color for the given constant, which should be one of the color constants specified in classSWT.Returns a reasonable font for applications to use.booleanReturnstrueif the device has been disposed, andfalseotherwise.protected voidrelease()Releases any internal resources .
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Field Details- 
deviceLockprotected final SerializableLock deviceLock
 
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Constructor Details- 
Devicepublic Device()
 
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Method Details- 
getSystemColorReturns the matching standard color for the given constant, which should be one of the color constants specified in classSWT. 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.- Parameters:
- id- the color constant
- Returns:
- the matching color
- 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:
 
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getSystemFontReturns 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 free'd 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_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver
- ERROR_DEVICE_DISPOSED - if the receiver has been disposed
 
 
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getFontListReturnsFontDataobjects which describe the fonts that match the given arguments. If thefaceNameis 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
 
- Since:
- 1.3
 
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getClientAreaReturns 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
 
- Since:
- 1.2
- See Also:
 
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getDepthpublic 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
 
- Since:
- 1.3
 
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getDPIReturns 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.- Returns:
- the horizontal and vertical DPI
- Throws:
- SWTException-- ERROR_DEVICE_DISPOSED - if the receiver has been disposed
 
- Since:
- 1.3
 
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getBoundsReturns a rectangle describing the receiver's size and location.- Returns:
- the bounding rectangle
- Throws:
- SWTException-- ERROR_DEVICE_DISPOSED - if the receiver has been disposed
 
- Since:
- 1.2
 
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disposepublic void dispose()Disposes of the operating system resources associated with the receiver. After this method has been invoked, the receiver will answertruewhen sent the messageisDisposed().- See Also:
 
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isDisposedpublic boolean isDisposed()Returnstrueif the device has been disposed, andfalseotherwise.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:
- truewhen the device is disposed and- falseotherwise
 
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releaseprotected void release()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 This method is called beforerelease. 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 bydestroy.destroy.If subclasses reimplement this method, they must call the superimplementation.
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destroyprotected void destroy()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 superimplementation.
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checkDeviceprotected void checkDevice()Throws anSWTExceptionif 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()anddispose()) on a device that has had itsdispose()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
 
 
 
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