Class: TSystemLayer

Declaration: SystemWindow.h

Taxonomy Categories:

Member Functions:

TSystemLayer
~TSystemLayer
SetName
GetName
SetClipArea
RemoveClipArea
GetChildLayerFromName
GetLayerFromName
GetSurrogate
GetContainedLayerables
GetClipArea

Interface Category:

API.

Inherits From:

TSystemLayerable

Inherited By:

None.

Purpose:

TSystemLayer, which derives from TSystemLayerable, provides the protocol for a real layer. Creating a TSystemLayer object creates a new layer. Likewise, deleting the TSystemLayer object deletes the layer. Keep in mind that TSystemLayer cannot be copied or streamed.

Instantiation:

Allocate on the heap or the stack.

Deriving Classes:

You do not normally derive from this class. Instead derive from TSystemLayerable.

Concurrency:

Multithread safe.

Resource Use:

No special requirements.

Member Function: TSystemLayer::TSystemLayer

TSystemLayer (const TAbstractLayerableReference & relativeToWindow, bool isVisible =true, const TText & layerName =TStandardText ( kDefaultLayerNameLength ), EWindowPosition itsPosition =kBehind)
TSystemLayer (const TSystemLayerable & relativeToWindow, bool isVisible =true, const TText & layerName =TStandardText ( kDefaultLayerNameLength ), EWindowPosition itsPosition =kBehind)
TSystemLayer (EWindowPosition itsPosition, bool isVisible =true, const TText & layerName =TStandardText ( kDefaultLayerNameLength ))
TSystemLayer (const TSystemLayerSurrogate & inLayer, EWindowPosition itsPosition, bool isVisible =true, const TText & layerName =TStandardText ( kDefaultLayerNameLength ))

Interface Category:

API.

Purpose:

Creates a layer behind a window or layer.
Creates a layer behind a window or layer.
Creates a layer in the root layer.
Creates a layer in another layer.

Calling Context:

Called to create a layer behind a layerable in its layer.
Called to create a layer behind a layerable in its layer.
Called to create a layer in the root layer.
Called to create a layer in another layer.

Parameters:

const TAbstractLayerableReference & relativeToWindow- Reference to a layerable to create new layer behind.
bool isVisible =true -New layer is initially visible.
const TText & layerName =TStandardText ( kDefaultLayerNameLength ) -New layer's name.
EWindowPosition itsPosition =kBehind -The new layer is placed behind the others.
const TSystemLayerable & relativeToWindow- Layerable to create new layer behind.
bool isVisible =true -New layer is initially visible.
const TText & layerName =TStandardText ( kDefaultLayerNameLength ) -New layer's name.
EWindowPosition itsPosition =kBehind -The new layer is placed behind the others.
EWindowPosition itsPosition -Create above or behind other layerables.
bool isVisible =true -New layer is initially visible.
const TText & layerName =TStandardText ( kDefaultLayerNameLength ) -New layer's name.
const TSystemLayerSurrogate & inLayer -Layer to create new layer in.
EWindowPosition itsPosition -Create above or behind other layerables.
bool isVisible =true -New layer is initially visible.
const TText & layerName =TStandardText ( kDefaultLayerNameLength ) -New layer's name.

Return Value:

None.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Multithread safe.

Other Considerations:

None.

Member Function: TSystemLayer::~TSystemLayer

~ TSystemLayer ()

Interface Category:

API.

Purpose:

Destructor.

Calling Context:

Called to destroy an object.

Parameters:

Takes no parameters.

Return Value:

None.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Multithread safe.

Other Considerations:

Any child layers/windows will be reparented to the parent layer for this layer and a notification will be sent.

Member Function: TSystemLayer::SetName

void SetName (const TText & layerName)

Interface Category:

API.

Purpose:

Sets the name of the layer.

Calling Context:

Called to change the name of the layer.

Parameters:

const TText & layerName -The new name.

Return Value:

None.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Multithread safe.

Other Considerations:

None.

Member Function: TSystemLayer::GetName

void GetName (TStandardText & layerName) const

Interface Category:

API.

Purpose:

Gets the layer's name.

Calling Context:

Called to get the name of the layer.

Parameters:

TStandardText & layerName -Returned name.

Return Value:

None.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Multithread safe.

Other Considerations:

None.

Member Function: TSystemLayer::SetClipArea

void SetClipArea (const TGArea & clipTo)

Interface Category:

API.

Purpose:

Sets the clip area of the layer.

Calling Context:

Called to cause the layer to clip contained windows to an area.

Parameters:

const TGArea & clipTo -A reference to the clip area.

Return Value:

None.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Multithread safe.

Other Considerations:

None.

Member Function: TSystemLayer::RemoveClipArea

void RemoveClipArea ()

Interface Category:

API.

Purpose:

Stops clipping.

Calling Context:

Called to stop the layer from clipping contained windows.

Parameters:

Takes no parameters.

Return Value:

None.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Multithread safe.

Other Considerations:

None.

Member Function: TSystemLayer::GetChildLayerFromName

bool GetChildLayerFromName (const TText & theName, TLayerableReference & theLayer)

Interface Category:

API.

Purpose:

Gets a child layer by name.

Calling Context:

Called when the client needs a named layer that is descended from this one.

Parameters:

const TText & theName -The name of the layer to search for.
TLayerableReference & theLayer -Returned layer.

Return Value:

Returns true if a layer with theName is found.

Exceptions:

Throws a TSystemWindowException(kOtherLayerableNonexistant) exception if the named layer does not exist.

Concurrency:

Multithread safe.

Other Considerations:

None.

Member Function: TSystemLayer::GetLayerFromName

static bool GetLayerFromName (const TText & theName, TLayerableReference & theLayer)

Interface Category:

API.

Purpose:

Gets a layer by name.

Calling Context:

Called when the client needs the first like-named layer.

Parameters:

const TText & theName -The name to search for.
TLayerableReference & theLayer -Returned layer.

Return Value:

Returns true if a layer with theName is found.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Multithread safe.

Other Considerations:

None.

Member Function: TSystemLayer::GetSurrogate

virtual const TLayerableSurrogate & GetSurrogate () const
virtual TLayerableSurrogate & GetSurrogate ()

Interface Category:

API.

Purpose:

Gets a const TLayerableSurrogate.
Gets a reference to TLayerableSurrogate.

Calling Context:

Called to return the const object.
Called to return a reference to the object.

Parameters:

Takes no parameters.
Takes no parameters.

Return Value:

Returns either the left-side const TLayerableSurrogate or a reference to TLayerableSurrogate.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Multithread safe.

Other Considerations:

None.

Member Function: TSystemLayer::GetContainedLayerables

void GetContainedLayerables (TDequeOf < TLayerableReference > & dequeToFill) const

Interface Category:

API.

Purpose:

Gets the list of windows and/or layers contained by this window or layer.

Calling Context:

Call this function directly.

Parameters:

TDequeOf < TLayerableReference > & dequeToFill -The list of contained layers or windows that is filled in by the function.

Return Value:

None.

Exceptions:

Throws a TSystemWindowException(kOtherLayerableNonexistant) exception if no other layers exist.

Concurrency:

Multithread safe.

Other Considerations:

None.

Member Function: TSystemLayer::GetClipArea

void GetClipArea (TGArea & clipTo) const

Interface Category:

API.

Purpose:

Gets the clip area for the layer.

Calling Context:

Call this function directly.

Parameters:

TGArea & clipTo -A reference to the clip area for the layer, which is returned by the function.

Return Value:

None.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Multithread safe.

Other Considerations:

None.

Click the icon to mail questions or corrections about this material to Taligent personnel.