Class: TScrollCoordinator

Declaration: ScrollCoordinator.h

Taxonomy Categories:

Member Functions:

Interface Category:

API.

Inherits From:

MCollectible

Inherited By:

TStandardScrollCoordinator

Purpose:

TScrollCoordinator is an abstract class used by TScrollingView to determine the transformation associated with common scroll operations. In a vertical line scroll, for example, the TScrollingView queries the TScrollCoordinator to determine how far to scroll.

Instantiation:

TScrollCoordinator is an abstract class and should not be instantiated.

Deriving Classes:

Derive classes from TScrollCoordinator to provide client specified scrolling behavior.

Concurrency:

Not multithread safe.

Resource Use:

No special requirements.

Other Considerations:

None.

Member Function: TScrollCoordinator::~TScrollCoordinator

virtual ~ TScrollCoordinator ()

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: TScrollCoordinator::operator>>=

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

Interface Category:

API.

Purpose:

Stream-out operator.

Calling Context:

Called to stream out data.

Parameters:

TStream & -The destination stream.

Return Value:

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

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TScrollCoordinator::operator<<=

virtual TStream & operator <<= (TStream &)

Interface Category:

API.

Purpose:

Stream-in operator.

Calling Context:

Called to stream in data.

Parameters:

TStream & -The source stream.

Return Value:

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

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TScrollCoordinator::GetVerticalUnitScrollEffect

virtual TGPoint GetVerticalUnitScrollEffect (signed long lines, const TView & scrolledView, const TGRect & clippedRect)

Interface Category:

API.

Purpose:

Returns the size currently used as the vertical scroll unit.

Calling Context:

Call this function directly to obtain the size of the vertical scroll unit.

Parameters:

signed long lines -A multiplier to apply to the size of one unit scroll. Typically it is set to 1, but can be set higher for multi-line scrolling.
const TView & scrolledView -The view being scrolled.
const TGRect & clippedRect -The TScrollingView's clipping rectangle.

Return Value:

Returns the size currently used as the vertical scroll unit.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

Deriving classes must implement this member function.

Member Function: TScrollCoordinator::GetHorizontalUnitScrollEffect

virtual TGPoint GetHorizontalUnitScrollEffect (signed long lines, const TView & scrolledView, const TGRect & clippedRect)

Interface Category:

API.

Purpose:

Returns the size currently used as the horizontal scroll unit.

Calling Context:

Call this function directly to obtain the size of the horizontal scroll unit.

Parameters:

signed long lines -A multiplier to apply to the size of one unit scroll. Typically it is set to 1, but can be set higher for multi-line scrolling.
const TView & scrolledView -The view being scrolled.
const TGRect & clippedRect -The TScrollingView's clipping rectangle.

Return Value:

Returns the size currently used as the horizontal scroll unit.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

Deriving classes must implement this member function.

Member Function: TScrollCoordinator::GetVerticalPagingScrollEffect

virtual TGPoint GetVerticalPagingScrollEffect (signed long pages, const TView & scrolledView, const TGRect & clippedRect)

Interface Category:

API.

Purpose:

Returns the size of the vertical page scroll. Vertical page scrolls are caused by a click in a scroll bar's trough.

Calling Context:

Call this function directly to obtain the size of the vertical page scroll.

Parameters:

signed long pages -A multiplier to apply to the size of one unit scroll. Typically it is set to 1, but can be set higher for multipage scrolling.
const TView & scrolledView -The view being scrolled.
const TGRect & clippedRect -The TScrollingView's clipping rectangle.

Return Value:

Returns the size of the vertical page scroll.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

Deriving classes must implement this member function.

Member Function: TScrollCoordinator::GetHorizontalPagingScrollEffect

virtual TGPoint GetHorizontalPagingScrollEffect (signed long pages, const TView & scrolledView, const TGRect & clippedRect)

Interface Category:

API.

Purpose:

Returns the size of the horizontal page scroll. Horizontal page scrolls are caused by a click in a scroll bar's trough.

Calling Context:

Call this function directly to obtain the size of the horizontal page scroll.

Parameters:

signed long pages -A multiplier to apply to the size of one unit scroll. Typically it is set to 1, but can be set higher for multipage scrolling.
const TView & scrolledView -The view being scrolled.
const TGRect & clippedRect -The TScrollingView's clipping rectangle.

Return Value:

Returns the size of the horizontal page scroll.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

Deriving classes must implement this member function.

Member Function: TScrollCoordinator::GetHomeScrollEffect

virtual TGPoint GetHomeScrollEffect (const TView & viewToScroll, const TGRect & clippedRect)

Interface Category:

API.

Purpose:

Returns the effect necessary to return the view to the home position.

Calling Context:

Call this function directly to obtain the effect necessary to scroll the view to the home position.

Parameters:

const TView & viewToScroll -The view being scrolled.
const TGRect & clippedRect -The TScrollingView's clipping rectangle.

Return Value:

Returns the the effect necessary to return the view to the home position.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TScrollCoordinator::GetEndScrollEffect

virtual TGPoint GetEndScrollEffect (const TView & viewToScroll, const TGRect & clippedRect)

Interface Category:

API.

Purpose:

Returns the the effect necessary to return the view to the end position.

Calling Context:

Call this function directly to obtain the effect necessary to scroll the view to the end position.

Parameters:

const TView & viewToScroll -The view being scrolled.
const TGRect & clippedRect -The TScrollingView's clipping rectangle.

Return Value:

Returns the the effect necessary to return the view to the end position.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TScrollCoordinator::TScrollCoordinator

TScrollCoordinator ()
TScrollCoordinator (const TScrollCoordinator &)

Interface Category:

API.

Purpose:

Default constructor.
Copy constructor.

Calling Context:

Called to create a TScrollCoordinator object suitable for streaming into.
Called to copy an object.

Parameters:

Takes no parameters.
const TScrollCoordinator & -The object to be copied.

Return Value:

None.

Exceptions:

Throws no exceptions, passes all exceptions through.

Concurrency:

Not multithread safe.

Other Considerations:

None.

Member Function: TScrollCoordinator::operator=

TScrollCoordinator & operator =(const TScrollCoordinator &)

Interface Category:

API.

Purpose:

Assignment operator.

Calling Context:

Called when an object is assigned to another compatible object.

Parameters:

const TScrollCoordinator & -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.

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