Class: TCanvasPolygon

Declaration: CanvasPolygon.h

Taxonomy Categories:

Member Functions:

Interface Category:

API.

Inherits From:

MCanvasGraphic

Inherited By:

None.

Purpose:

A polygon canvas graphic.

Instantiation:

Allocate on the heap or the stack.

Deriving Classes:

Intended to be used as is but can also be derived.

Concurrency:

Not multithread safe.

Resource Use:

No special requirements.

Member Function: TCanvasPolygon::TCanvasPolygon

Interface Category:

API.

Purpose:

Constructor for creating new canvas polygons.
Copy constructor.
Default constructor.

Calling Context:

Called to create a new canvas polygon.
Called to copy an object.
Called by the stream-in operators and constructors of derived classes.

Parameters:

const TGPolygon & -A polygon geometry.
const TCanvasPolygon & -Another canvas polygon.
Takes no parameters.

Return Value:

None.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TCanvasPolygon::~TCanvasPolygon

virtual ~ TCanvasPolygon ()

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:

Not multithread safe.

Other Considerations:

None.

Member Function: TCanvasPolygon::operator=

TCanvasPolygon & operator =(const TCanvasPolygon &)

Interface Category:

API.

Purpose:

Assignment operator.

Calling Context:

Called when an object is assigned to another compatible object.

Parameters:

const TCanvasPolygon & -The object to be copied.

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: TCanvasPolygon::operator>>=

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

Interface Category:

API.

Purpose:

Stream-out operator.

Calling Context:

Called to stream out data.

Parameters:

TStream & -The stream the object is streamed out to.

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: TCanvasPolygon::operator<<=

virtual TStream & operator <<= (TStream &)

Interface Category:

API.

Purpose:

Stream-in operator.

Calling Context:

Called to stream in data.

Parameters:

TStream & -The stream the object is streamed in from.

Return Value:

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

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TCanvasPolygon::HandleDraw

virtual void HandleDraw (TGrafPort &) const

Interface Category:

API.

Purpose:

Draws the graphic's untransformed geometry.

Calling Context:

Called by MCanvasGraphic::Draw, which links the graphic's transform and bundle to the port before calling HandleDraw.

Parameters:

TGrafPort & -The port to draw into.

Return Value:

None.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TCanvasPolygon::HandleGetBounds

virtual TGRect HandleGetBounds () const

Interface Category:

API.

Purpose:

Returns the bounding rectangle of the untransformed geometry.

Calling Context:

Called by MCanvasGraphic::GetGeometricBounds and MCanvasGraphic::GetLooseFitBounds, which apply the graphic's transform to the returned bounds and expand it as required by the graphic's bundle.

Parameters:

Takes no parameters.

Return Value:

TGRect -The graphic's untransformed geometric bounds.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TCanvasPolygon::HandleHit

virtual bool HandleHit (const TGPoint &) const

Interface Category:

API.

Purpose:

Detects the intersection of the point with the graphic's untransformed geometry.

Calling Context:

Called by MCanvasGraphic::Hit, which provides a point that has been untransformed by the graphic's transform.

Parameters:

const TGPoint & -The point to detect a hit against.

Return Value:

Returns true if the point intersects ( hits ) the graphic's untransformed geometry.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TCanvasPolygon::GetParametric

bool GetParametric (const TGPoint &, GCoordinate & u) const

Interface Category:

API.

Purpose:

Identifies the canvas polygonÕs vertex closest to the specified point. The point must be within 10 pixels of a vertex to succeed.

Calling Context:

Called by clients to edit the canvas polygon after it is created.

Parameters:

const TGPoint & -A point.
GCoordinate & u -The closest parametric to the point is returned.

Return Value:

Returns true if a parametric was identified.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

Use in conjunction with DragPolygonTo.

Member Function: TCanvasPolygon::DragPolygonTo

void DragPolygonTo (GCoordinate u, const TGPoint &)

Interface Category:

API.

Purpose:

Changes a specified parametric of the canvas polygon.

Calling Context:

Called by clients to edit the canvas polygon after it is created.

Parameters:

GCoordinate u -The parametric to change.
const TGPoint & -The new vertex for the parametric.

Return Value:

None.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

Use in conjunction with GetParametric.

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