IDrawMgr Class Reference

#include <IDrawMgr.h>

Inheritance diagram for IDrawMgr:

Classes
class	ClippingOrFilteringDisabler
struct	FilterInfo

Public Types
enum	{ kDefaultIID = IID_IDRAWMGR }

Public Member Functions
virtual void	BeginInterruptableDraw (DrawInterrupter *interruptChecker=nil)=0
virtual void	EndInterruptableDraw ()=0
virtual void	EnableInterruptableDraw (bool16 enable=kTrue)=0
virtual void	DisableInterruptableDraw ()=0
virtual bool16	IsDrawingInterruptable ()=0
virtual void	Abort ()=0
virtual bool16	DrawAtOnce (IGraphicsContext *gc, const UIDRef &thing, int32 flags)=0
virtual bool16	DrawIncrementallyUsingDrawbot (IGraphicsContext *gc, const UIDRef &thing, int32 flags, IDVPlatformOffscreen *srcOffscreen, dvaui::drawbot::Drawbot *dstDrawbot, SysRect updateBounds, int32 tickCount)=0
virtual void	BeginCullToViewRect (const PMRect &r)=0
virtual void	BeginCullToViewRegion (const SysRgn &rgn)=0
virtual bool16	EndLatestViewSpaceCulling ()=0
virtual SysRgn	GetViewCullRegion () const =0
virtual uint32	GetSpreadFilterCount () const =0
virtual uint32	BeginFilterToSpreadRect (const PMRect &r, const PMMatrix &m=PMMatrix(1., 0., 0., 1., 0., 0.), const PMMatrix &rest=PMMatrix(0., 0., 0., 0., 0., 0.))=0
virtual uint32	EndFilterToSpreadRect (PMRect *r=nil, PMMatrix *m=nil, PMMatrix *rest=nil)=0
virtual FilterInfo	GetNthSpreadFilter (uint32 which) const =0
virtual bool16	IsDrawAborted ()=0
virtual bool16	IsDrawClipped (IPMUnknown *thing, const PMMatrix *pb2view)=0
virtual bool16	BeginShape (IPMUnknown *theShape)=0
virtual void	EndShape (IPMUnknown *theShape)=0
virtual void	FlushOffscreenIfNecessary ()=0
virtual void	Disable (UID item, bool16 disable)=0
virtual bool16	IsItemDisabled (UID item) const =0
virtual bool16	WasDrawAborted () const =0
virtual void	ClearAborted ()=0
virtual void	IterateDrawOrder_ (const PMMatrix *xform, const UIDRef &thing, ICallback *callbackInfo, int32 flags)=0
void	IterateDrawOrder (const UIDRef &thing, ICallback *callbackInfo, int32 flags)
virtual bool16	DisableClippingOrFiltering ()=0
virtual void	EnableClippingOrFiltering ()=0
Public Member Functions inherited from IPMUnknown
virtual IPMUnknown *	QueryInterface (PMIID interfaceID) const =0
virtual void	AddRef () const =0
virtual void	Release () const =0

Detailed Description

The DrawMgr is a class that exists on each port and is used to set clipping areas as well as to initiate the drawing of any page element and its children. Optionally, this class can be used to iterate the draw order, calling a client provided callback routine for every page item in the hierarchy.

Member Enumeration Documentation

anonymous enum

default enum

Member Function Documentation

virtual void IDrawMgr::Abort ( )

pure virtual

Interrupts drawing, with the side effect that the current update area will be invalidated, causing an update/paint event to occur such that the drawing will start again in the future.

virtual void IDrawMgr::BeginCullToViewRect ( const PMRect &  r )

pure virtual

Set "clipping" region. Draw not called for items that fall outside the clip rect Beginning a new clip while a clip is already installed will push the new clip onto the draw mgr stack. The new clip does not union or intersect with the previous clip, it simply supercedes it. When endclip is called the clip is popped off the stack and the old clip takes over.

Parameters

r	IN specifies clipping rect

virtual void IDrawMgr::BeginCullToViewRegion ( const SysRgn &  rgn )

pure virtual

Set "clipping" region. Draw not called for items that fall outside the clip rect Beginning a new clip while a clip is already installed will push the new clip onto the draw mgr stack. The new clip does not union or intersect with the previous clip, it simply supercedes it. When endclip is called the clip is popped off the stack and the old clip takes over. Makes a copy of rgn.

Parameters

rgn	IN specifies clipping region

virtual uint32 IDrawMgr::BeginFilterToSpreadRect ( const PMRect &  r, const PMMatrix &  m = PMMatrix(1., 0., 0., 1., 0., 0.), const PMMatrix &  rest = PMMatrix(0., 0., 0., 0., 0., 0.)  )

pure virtual

A filter is a PMRect which specifies an area which must be intersected by a page item before it will be drawn. This filter does not affect how the page item is drawn (i.e. it does not clip). To clip the page item, use BeginClip.

Parameters

r	IN the filter rect

virtual void IDrawMgr::BeginInterruptableDraw ( DrawInterrupter *  interruptChecker = nil )

pure virtual

Sets an interrupt checker before drawing to a port. If this method is called before calling Draw(), then the interrupt checker will periodically (usually before each page item in the hierarchy is drawn) be called to see if the draw should be aborted.

Parameters

interruptChecker

IN the DrawInterrupter

virtual bool16 IDrawMgr::BeginShape ( IPMUnknown *  theShape )

pure virtual

Do not use, this method is called by the Draw Event Handler at the beginning of every IShape::Draw implementation.

Parameters

theShape

IN the shape being drawn

Returns

kTrue if the IShape implementation should not continue with the drawing of this page item

virtual void IDrawMgr::ClearAborted ( )

pure virtual

Clears flag if Draw was aborted during the last Begin/End Interruptable draw sequence.

virtual void IDrawMgr::Disable ( UID  item, bool16  disable  )

pure virtual

Disable an item. It is up to the page item to call back and ask if it is in fact disabled.

Parameters

item	IN UID of the page item to disable
disable	IN specifies whether to disable item

virtual bool16 IDrawMgr::DisableClippingOrFiltering ( )

pure virtual

Does a "global" disabling of any clipping or filtering. This method is useful for situations where a piece of content, such as a PageItem child or even Text content knows that it needs to draw but by the rules of the hierarchy it will get either clipped or filtered out.

Returns

kTrue if Clipping or Filtering was enabled, kFalse otherwise.

virtual void IDrawMgr::DisableInterruptableDraw ( )

pure virtual

Same as EnableInterruptableDraw(kFalse).

virtual bool16 IDrawMgr::DrawAtOnce ( IGraphicsContext *  gc, const UIDRef &  thing, int32  flags  )

pure virtual

Main entry point - if kFalse is returned, any loops (ie hierarchy loops) should immediately abort.

Parameters

gc	IN the graphics context. Contains info about the port.
thing	IN the page item to draw
flags	IN see IShape.h for the drawing flags

Returns

if kFalse, any loops (ie hierarchy loops) should immediately abort

virtual bool16 IDrawMgr::DrawIncrementallyUsingDrawbot ( IGraphicsContext *  gc, const UIDRef &  thing, int32  flags, IDVPlatformOffscreen *  srcOffscreen, dvaui::drawbot::Drawbot *  dstDrawbot, SysRect  updateBounds, int32  tickCount  )

pure virtual

Draw with timed updates to the screen. The client passes in a droverized platform offscreen and a pointer to the screen. Make sure the update bounds encompasses the entire region that will be painted by thing and its children. tickCount is the update interval. Too small and the screen is updated far too often. Too large and the benefit is minimal. Suggested value is 1/2 second (500 ticks).

Parameters

gc	IN the graphics context. Contains info about the port.
thing	IN the page item to draw
flags	IN see IShape.h for the drawing flags
srcOffscreen	IN a pointer to the droverized offscreen we are drawing to
dstDrawbot	IN a pointer to the destination drawbot we are drawing to
updateBounds	IN the area of the port or offscreen we are updating
tickCount	IN how frequently to update the port using the srcOffscreen

Returns

kTrue if drawing was successful

virtual void IDrawMgr::EnableClippingOrFiltering ( )

pure virtual

Re-enables clipping or filtering disabled by a call to the previous method.

virtual void IDrawMgr::EnableInterruptableDraw ( bool16  enable = kTrue )

pure virtual

Enables/disables the ability to interrupt drawing. When enabled, BeginInterruptableDraw() has no effect. Useful in some tracking situations.

Parameters

enable

IN whether to enable drawing interrupt

virtual uint32 IDrawMgr::EndFilterToSpreadRect ( PMRect *  r = nil, PMMatrix *  m = nil, PMMatrix *  rest = nil  )

pure virtual

End the current filter.

virtual void IDrawMgr::EndInterruptableDraw ( )

pure virtual

Removes the interrupt checker set by BeginInterruptableDraw.

virtual bool16 IDrawMgr::EndLatestViewSpaceCulling ( )

pure virtual

Removes the current clipping from the stack.

Returns

kTrue if there are still clips on the draw mgr stack, kFalse otherwise

virtual void IDrawMgr::EndShape ( IPMUnknown *  theShape )

pure virtual

Do not use, this method is called by the Draw Event Handler at the end of every IShape::Draw implementation. Every call to BeginShape should be paired with a call to EndShape, even if the drawing was aborted.

Parameters

theShape

IN the shape being drawn

virtual void IDrawMgr::FlushOffscreenIfNecessary ( )

pure virtual

IsDrawAborted flushes the offscreen to the screen every few seconds. Sometimes, you want to flush the offscreen, but you don't want to set the aborted flag, even if the user has done something to abort. This will accomplish that. You can call it alot, it will only have an effect every few seconds or so, just like IsDrawAborted.

virtual SysRgn IDrawMgr::GetViewCullRegion ( ) const

pure virtual

Returns a copy of the current clipping region. If there is no clipping region, then nil is returned. Caller is responsible for disposing of the result if non-nil.

Returns

SysRgn of the current clipping region

virtual bool16 IDrawMgr::IsDrawAborted ( )

pure virtual

Do not use, use ProcessEvent() with the kAbortCheckMessage event to check for interruption.

virtual bool16 IDrawMgr::IsDrawClipped ( IPMUnknown *  thing, const PMMatrix *  pb2view  )

pure virtual

Do not use, use ProcessEvent() with the kFilterCheckMessage event to check for clipping.

virtual bool16 IDrawMgr::IsDrawingInterruptable ( )

pure virtual

Used to determine whether or not interruptable drawing has been disabled via a call to EnableInterruptableDraw() or DisableInterruptableDraw().

Returns

kTrue if interrupts are allowed, kFalse if interrupts have been disabled

virtual bool16 IDrawMgr::IsItemDisabled ( UID  item ) const

pure virtual

Returns whether page item is disabled.

Parameters

item	UID of the page item

virtual void IDrawMgr::IterateDrawOrder_ ( const PMMatrix *  xform, const UIDRef &  thing, ICallback *  callbackInfo, int32  flags  )

pure virtual

To walk the display hierarchy in the same order as Draw, use this. the transform matrix is passed instead of a graphics context (which may not exist); callees can modify the transform for their own purposes (e.g. master pages will concatenate a translation).

Parameters

xform	IN specifies transform matrix.
thing	IN UIDRef of the shape to iterate from.
callbackInfo	IN the ICallback interface to use to for callback.
flags	IN see IShape.h for the drawing flags

virtual bool16 IDrawMgr::WasDrawAborted ( ) const

pure virtual

Returns whether draw was aborted or not during the last Begin/End Interruptable draw sequence. The flag is cleared either by a successful Begin/End Interruptable draw or by calling ClearAborted()

Returns

kTrue if the draw was aborted, kFalse otherwise.