Class: TDisplayDeviceHandle

Declaration: DisplayDeviceHandle.h

Taxonomy Categories:

Member Functions:

Interface Category:

API.

Inherits From:

MCollectible, MRemoteCaller

Inherited By:

TVideoDeviceHandle

Purpose:

TDisplayDeviceHandle is an abstract base class that defines the behavior of video device derived classes. Instantiations of TDisplayDeviceHandle derived classes are meant to act as implicit surrogates of the TDisplayDeviceDrivers that act directly on the hardware. Derived classes must override all of the member functions declared in this base class!

Instantiation:

Allocate on the heap or the stack.

Deriving Classes:

Derive a class from TDisplayDeviceHandle to add more specific functionality needed by a different display device. For example, TVideoDeviceHandle is a derived class that inherits all of the TDisplayDeviceHandle member function calls. In addition, it adds functionality for video-specific devices. In this example, the derived class overrides the CreateScreen function in order to create a special video screen for the device.

Concurrency:

Not multithread safe.

Resource Use:

No special requirements.

Member Function: TDisplayDeviceHandle::CreateScreen

virtual MScreen * CreateScreen ()

Interface Category:

API.

Purpose:

Returns a pointer to the appropriate screen device. The Window server or Video Device server calls this to get the screen device that has the characteristics of the DisplayDeviceHandle type.The screen device is created using the configuration of the DisplayDeviceHandle as well as the current world bounds setting for the screen device layout.

Calling Context:

Called by the Window server or Video Device server to start the Graphics system.

Parameters:

Return Value:

Returns the appropriate MScreen subtype.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TDisplayDeviceHandle::GetScreenHeight

virtual GCoordinate GetScreenHeight () const

Interface Category:

API.

Purpose:

Returns the height of the screen polymorphically.

Calling Context:

Called internally to obtain information used to create the screen device.

Parameters:

Return Value:

Returns the GCoordinate value for the height of the screen in pixels.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TDisplayDeviceHandle::GetScreenWidth

virtual GCoordinate GetScreenWidth () const

Interface Category:

API.

Purpose:

Returns the width of the screen polymorphically.

Calling Context:

Called internally to obtain information used to create the screen device.

Parameters:

Return Value:

Returns the GCoordinate value for the width of the screen in pixels.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TDisplayDeviceHandle::TDisplayDeviceHandle

  1. TDisplayDeviceHandle ()
  2. TDisplayDeviceHandle (const TDisplayDeviceHandle &)

Interface Category:

API.

Purpose:

  1. Default constructor.
  2. Copy constructor.

Calling Context:

  1. Called by the stream-in operators
  2. Called to copy an object.

Parameters:

Return Value:

None.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TDisplayDeviceHandle::operator=

TDisplayDeviceHandle & operator =(const TDisplayDeviceHandle &)

Interface Category:

API.

Purpose:

Assignment operator.

Calling Context:

Called when an object is assigned to another compatible object.

Parameters:

Return Value:

A non-const reference to the left-hand side object.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TDisplayDeviceHandle::operator>>=

virtual TStream & operator >>=(TStream & towhere) const

Interface Category:

API.

Purpose:

Stream-out operator.

Calling Context:

Called to stream out data.

Parameters:

Return Value:

Returns a reference to the stream the object streams itself out to.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TDisplayDeviceHandle::operator<<=

virtual TStream & operator <<= (TStream & towhere)

Interface Category:

API.

Purpose:

Stream-in operator.

Calling Context:

Called to stream in data.

Parameters:

Return Value:

Returns a reference to the stream the object streams itself in to.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TDisplayDeviceHandle::GetWorldBoundsOffset

virtual TGPoint GetWorldBoundsOffset () const

Interface Category:

API.

Purpose:

Gets the position in world coordinates.

Calling Context:

Called during system configuration.

Parameters:

Return Value:

Returns a TGPoint with an x and y offset position.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TDisplayDeviceHandle::~TDisplayDeviceHandle

virtual ~ TDisplayDeviceHandle ()

Interface Category:

API.

Purpose:

Destructor.

Calling Context:

Called to destroy an object.

Parameters:

Return Value:

None.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.
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