haiku/src/servers/app/server/Layer.cpp

//------------------------------------------------------------------------------
//	Copyright (c) 2001-2002, OpenBeOS
//
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//	copy of this software and associated documentation files (the "Software"),
//	to deal in the Software without restriction, including without limitation
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//	and/or sell copies of the Software, and to permit persons to whom the
//	Software is furnished to do so, subject to the following conditions:
//
//	The above copyright notice and this permission notice shall be included in
//	all copies or substantial portions of the Software.
//
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//	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
//	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
//	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
//	FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
//	DEALINGS IN THE SOFTWARE.
//
//	File Name:		Layer.cpp
//	Author:			DarkWyrm <bpmagic@columbus.rr.com>
//	Description:	Class used for rendering to the frame buffer. One layer per 
//					view on screen and also for window decorators
//  
//------------------------------------------------------------------------------
#include <View.h>
#include <string.h>
#include <stdio.h>
#include "Layer.h"
#include "RectUtils.h"
#include "ServerWindow.h"
#include "PortLink.h"
#include "TokenHandler.h"

//#define DEBUG_LAYER

//! TokenHandler object used to provide IDs for all Layers and, thus, BViews
TokenHandler view_token_handler;

/*!
	\brief Constructor
	\param frame Size and placement of the Layer
	\param name Name of the layer
	\param resize Resizing flags as defined in View.h
	\param flags BView flags as defined in View.h
	\param win ServerWindow to which the Layer belongs
*/
Layer::Layer(BRect frame, const char *name, int32 resize, int32 flags,ServerWindow *win)
{
	// frame is in _parent layer's coordinates
	if(frame.IsValid())
		_frame=frame;
	else
		_frame.Set(0,0,5,5);

	_name=new BString(name);

	// Layer does not start out as a part of the tree
	_parent=NULL;
	_uppersibling=NULL;
	_lowersibling=NULL;
	_topchild=NULL;
	_bottomchild=NULL;

	_visible=new BRegion(Bounds());
	_full=new BRegion(Bounds());
	_invalid=new BRegion(Bounds());

	_serverwin=win;
	
	// We have view tokens to be able to identify BViews
	_view_token=view_token_handler.GetToken();

	_flags=flags;

	_hidecount=0;
	_is_dirty=false;
	_is_updating=false;

	_level=0;
	_layerdata=new LayerData;
#ifdef DEBUG_LAYER
printf("Layer: %s\n",name);
printf("\tFrame: (%.1f,%.1f,%.1f,%.1f)\n",frame.left,frame.top,frame.right,frame.bottom);
printf("\tWindow: %s\n",win?win->Title():"NULL");
#endif
}

//! Destructor frees all allocated heap space
Layer::~Layer(void)
{
#ifdef DEBUG_LAYER
printf("Layer: %s: ~Layer()\n",_name->String());
#endif
	if(_visible)
	{
		delete _visible;
		_visible=NULL;
	}
	if(_full)
	{
		delete _full;
		_full=NULL;
	}
	if(_invalid)
	{
		delete _invalid;
		_invalid=NULL;
	}
	if(_name)
	{
		delete _name;
		_name=NULL;
	}
	if(_layerdata)
	{
		delete _layerdata;
		_layerdata=NULL;
	}
}

/*!
	\brief Adds a child to the back of the a layer's child stack.
	\param layer The layer to add as a child
	\param before Add the child in front of this layer
	\param rebuild Flag to fully rebuild all visibility regions
*/
void Layer::AddChild(Layer *layer, Layer *before=NULL, bool rebuild)
{
#ifdef DEBUG_LAYER
printf("Layer: %s: Add Child (%s, %s, %s) - Incomplete\n",_name->String(),layer?layer->_name->String():"NULL",
	before?before->_name->String():"NULL",rebuild?"rebuild":"no rebuild");
#endif
	// TODO: Add before support

	if(layer->_parent!=NULL)
	{
		printf("ERROR: AddChild(): Layer already has a _parent\n");
		return;
	}
	layer->_parent=this;
	if(layer->_visible && layer->_hidecount==0 && _visible)
	{
		// Technically, we could safely take the address of ConvertToParent(BRegion)
		// but we don't just to avoid a compiler nag
		BRegion *reg=new BRegion(layer->ConvertToParent(layer->_visible));
		_visible->Exclude(reg);
		delete reg;
	}

	// we need to change this to a loop for each _lowersibling of the layer
	if(_topchild!=NULL)
	{
		// we're adding to the back side of the stack??
		layer->_lowersibling=_topchild;
		
		// added layer will be at the bottom of the stack
		_topchild->_uppersibling=layer;
		for(Layer *lay=layer->_lowersibling; lay!=NULL; lay=lay->_lowersibling)
		{
			if(layer->_frame.Intersects(lay->_frame))
			{
				if(lay->_visible && lay->_hidecount==0)
				{
					// reg is what is _visible in the layer's _parent's coordinate system
					BRegion *reg=new BRegion(ConvertToParent(layer->_visible));
					// reg2 is the layer's _visible region in the sibling's coordinate system
					BRegion *reg2=new BRegion(lay->ConvertFromParent(reg));
					delete reg;
	
	//				layer->_lowersibling->_visible->Exclude(reg2);
					// lowersiblings occupy screen space _above_ a layer, so the layer itself
					// must remove from its _visible region 
					layer->_visible->Exclude(reg2);
					delete reg2;
				}
			}
		}
	}
	else
		_bottomchild=layer;
	_topchild=layer;
	layer->_level=_level+1;

	if(rebuild)
		RebuildRegions(true);
}

/*!
	\brief Removes a layer from the child stack
	\param layer The layer to remove
	\param rebuild Flag to rebuild all visibility regions
*/
void Layer::RemoveChild(Layer *layer, bool rebuild)
{
#ifdef DEBUG_LAYER
printf("Layer: %s: Remove Child (%s,%s)\n",_name->String(),layer?layer->_name->String():"NULL",
	rebuild?"rebuild":"no rebuild");
#endif
	if(layer->_parent==NULL)
	{
		printf("ERROR: RemoveChild(): Layer doesn't have a _parent\n");
		return;
	}
	if(layer->_parent!=this)
	{
		printf("ERROR: RemoveChild(): Layer is not a child of this layer\n");
		return;
	}

	if(_hidecount==0 && layer->_visible && layer->_parent->_visible)
	{
		BRegion *reg=new BRegion(ConvertToParent(_visible));
		layer->_parent->_visible->Include(reg);
		delete reg;
	}

	// Take care of _parent
	layer->_parent=NULL;
	if(_topchild==layer)
		_topchild=layer->_lowersibling;
	if(_bottomchild==layer)
		_bottomchild=layer->_uppersibling;

	// Take care of siblings
	if(layer->_uppersibling!=NULL)
		layer->_uppersibling->_lowersibling=layer->_lowersibling;
	if(layer->_lowersibling!=NULL)
		layer->_lowersibling->_uppersibling=layer->_uppersibling;
	layer->_uppersibling=NULL;
	layer->_lowersibling=NULL;

	if(rebuild)
		RebuildRegions(true);
}

/*!
	\brief Removes the layer from its parent's child stack
	\param rebuild Flag to rebuild visibility regions
*/
void Layer::RemoveSelf(bool rebuild)
{
#ifdef DEBUG_LAYER
printf("Layer: %s: RemoveSelf(%s)\n",_name->String(),rebuild?"rebuild":"no rebuild");
#endif
	// A Layer removes itself from the tree (duh)
	if(_parent==NULL)
	{
		printf("ERROR: RemoveSelf(): Layer doesn't have a _parent\n");
		return;
	}
	Layer *p=_parent;
	_parent->RemoveChild(this);
	
	if(rebuild)
		p->RebuildRegions(true);
}

/*!
	\brief Finds the first child at a given point.
	\param pt Point to look for a child
	\param recursive Flag to look for the bottom-most child
	\return non-NULL if found, NULL if not

	Find out which child gets hit if we click at a certain spot. Returns NULL
	if there are no _visible children or if the click does not hit a child layer
	If recursive==true, then it will continue to call until it reaches a layer
	which has no children, i.e. a layer that is at the top of its 'branch' in
	the layer tree
*/
Layer *Layer::GetChildAt(BPoint pt, bool recursive=false)
{
#ifdef DEBUG_LAYER
printf("Layer: %s: Get Child At (%.1f,%.1f)\n",_name->String(),pt.x,pt.y);
#endif
	Layer *child;
	if(recursive)
	{
		for(child=_bottomchild; child!=NULL; child=child->_uppersibling)
		{
			if(child->_bottomchild!=NULL)
				child->GetChildAt(pt,true);
			
			if(child->_hidecount>0)
				continue;
			
			if(child->_frame.Contains(pt))
				return child;
		}
	}
	else
	{
		for(child=_bottomchild; child!=NULL; child=child->_uppersibling)
		{
			if(child->_hidecount>0)
				continue;
			if(child->_frame.Contains(pt))
				return child;
		}
	}
	return NULL;
}

/*!
	\brief Returns the size of the layer
	\return the size of the layer
*/
BRect Layer::Bounds(void)
{
	return _frame.OffsetToCopy(0,0);
}

/*!
	\brief Returns the layer's size and position in its parent coordinates
	\return The layer's size and position in its parent coordinates
*/
BRect Layer::Frame(void)
{
	return _frame;
}

/*!
	\brief recursively deletes all children (and grandchildren, etc) of the layer

	This is mostly used for server shutdown or deleting a workspace
*/
void Layer::PruneTree(void)
{
#ifdef DEBUG_LAYER
printf("Layer: %s: Prune Tree\n",_name->String());
#endif
	Layer *lay,*nextlay;

	lay=_topchild;
	_topchild=NULL;
	
	while(lay!=NULL)
	{
		if(lay->_topchild!=NULL)
		{
			lay->PruneTree();
		}
		nextlay=lay->_lowersibling;
		lay->_lowersibling=NULL;
		delete lay;
		lay=nextlay;
	}
	// Man, this thing is short. Elegant, ain't it? :P
}

/*!
	\brief Finds a layer based on its token ID
	\return non-NULL if found, NULL if not
*/
Layer *Layer::FindLayer(int32 token)
{
#ifdef DEBUG_LAYER
printf("Layer: %s: Find Layer (%ld)\n",_name->String(),token);
#endif
	// recursive search for a layer based on its view token
	Layer *lay, *trylay;

	// Search child layers first
	for(lay=_topchild; lay!=NULL; lay=lay->_lowersibling)
	{
		if(lay->_view_token==token)
			return lay;
	}
	
	// Hmmm... not in this layer's children. Try lower descendants
	for(lay=_topchild; lay!=NULL; lay=lay->_lowersibling)
	{
		trylay=lay->FindLayer(token);
		if(trylay)
			return trylay;
	}
	
	// Well, we got this far in the function, so apparently there is no match to be found
	return NULL;
}

/*!
	\brief Sets a region as invalid and, thus, needing to be drawn
	\param The region to invalidate
	
	All children of the layer also receive this call, so only 1 Invalidate call is 
	needed to set a section as invalid on the screen.
*/
void Layer::Invalidate(BRegion region)
{
#ifdef DEBUG_LAYER
printf("Layer: %s: Invalidate(BRegion)\n",_name->String());
region.PrintToStream();
#endif
	int32 i;
	BRect r;

	// See if the region intersects with our current area
	if(region.Intersects(Bounds()) && _hidecount==0)
	{
		BRegion clippedreg(region);
		clippedreg.IntersectWith(_visible);
		if(clippedreg.CountRects()>0)
		{
			_is_dirty=true;
			if(_invalid)
				_invalid->Include(&clippedreg);
			else
				_invalid=new BRegion(clippedreg);
		}		
	}
	
	BRegion *reg;
	for(Layer *lay=_topchild;lay!=NULL; lay=lay->_lowersibling)
	{
		if(lay->_hidecount==0)
		{	
			reg=new BRegion(lay->ConvertFromParent(&region));
	
			for(i=0;i<reg->CountRects();i++)
			{
				r=reg->RectAt(i);
				if(_frame.Intersects(r))
					lay->Invalidate(r);
			}
	
			delete reg;
		}
	}
}

/*!
	\brief Sets a rectangle as invalid and, thus, needing to be drawn
	\param The rectangle to invalidate
	
	All children of the layer also receive this call, so only 1 Invalidate call is 
	needed to set a section as invalid on the screen.
*/
void Layer::Invalidate(BRect rect)
{
#ifdef DEBUG_LAYER
printf("Layer: %s: Invalidate(%.1f,%.1f,%.1f,%.1f)\n",_name->String(),rect.left,rect.top,rect.right,
	rect.bottom);
#endif
	// Make our own section dirty and pass it on to any children, if necessary....
	// YES, WE ARE SHARING DIRT! Mudpies anyone? :D
	if(TestRectIntersection(Frame(),rect))
	{
		// Clip the rectangle to the _visible region of the layer
		if(TestRegionIntersection(_visible,rect))
		{
			BRegion reg(*_visible);
			IntersectRegionWith(&reg,rect);
			if(reg.CountRects()>0)
			{
				_is_dirty=true;
				if(_invalid)
					_invalid->Include(&reg);
				else
					_invalid=new BRegion(reg);
			}
			else
			{
			}
		}
		else
		{
		}
	}	
	for(Layer *lay=_topchild;lay!=NULL; lay=lay->_lowersibling)
		lay->Invalidate(lay->ConvertFromParent(rect));
}

/*!
	\brief Ask the layer's BView to draw itself
	\param r The area that needs to be drawn
*/
void Layer::RequestDraw(const BRect &r)
{
#ifdef DEBUG_LAYER
printf("Layer: %s: RequestDraw(%.1f,%.1f,%.1f,%.1f) - unimplemented\n",
	_name->String(),r.left,r.top,r.right,r.bottom);
#endif
	// TODO: Implement and fix
/*	if(_visible==NULL || _hidecount>0)
		return;

	if(_serverwin)
	{
		if(_invalid==NULL)
			_invalid=new BRegion(*_visible);
		_serverwin->RequestDraw(_invalid->Frame());
		delete _invalid;
		_invalid=NULL;
	}

	_is_dirty=false;
	for(Layer *lay=_topchild; lay!=NULL; lay=lay->_lowersibling)
	{
		if(lay->IsDirty())
			lay->RequestDraw();
	}
*/
}

void Layer::RequestDraw(void)
{
	RequestDraw(Bounds());
}

/*!
	\brief Determines whether the layer needs to be redrawn
	\return True if the layer needs to be redrawn, false if not
*/
bool Layer::IsDirty(void) const
{
	return (!_invalid)?true:false;
}

//! Show the layer. Operates just like the BView call with the same name
void Layer::Show(void)
{
#ifdef DEBUG_LAYER
printf("Layer: %s: Show\n",_name->String());
#endif
	if(_hidecount==0)
		return;

	_hidecount--;
	if(_hidecount==0)
	{
		BRegion *reg=new BRegion(ConvertToParent(_visible));
		_parent->_visible->Exclude(reg);
		delete reg;
		_is_dirty=true;
	}
	
	Layer *child;
	for(child=_topchild; child!=NULL; child=child->_lowersibling)
		child->Show();
}

//! Hide the layer. Operates just like the BView call with the same name
void Layer::Hide(void)
{
#ifdef DEBUG_LAYER
printf("Layer: %s: Hide\n",_name->String());
#endif
	if(_hidecount==0)
	{
		BRegion *reg=new BRegion(ConvertToParent(_visible));
		_parent->_visible->Include(reg);
		delete reg;
		_parent->_is_dirty=true;
		_is_dirty=true;
	}
	_hidecount++;
	
	Layer *child;
	for(child=_topchild; child!=NULL; child=child->_lowersibling)
		child->Hide();
}

/*!
	\brief Determines whether the layer is hidden or not
	\return true if hidden, false if not.
*/
bool Layer::IsHidden(void)
{
	return (_hidecount==0)?false:true;
}

/*!
	\brief Counts the number of children the layer has
	\return the number of children the layer has, not including grandchildren
*/
uint32 Layer::CountChildren(void)
{
	uint32 i=0;
	Layer *lay=_topchild;
	while(lay!=NULL)
	{
		lay=lay->_lowersibling;
		i++;
	}
	return i;
}

/*!
	\brief Moves a layer in its parent coordinate space
	\param x X offset
	\param y Y offset
*/
void Layer::MoveBy(float x, float y)
{
#ifdef DEBUG_LAYER
printf("Layer: %s: Move By (%.1f,%.1f)\n",_name->String(),x,y);
#endif
	BRect oldframe(_frame);
	_frame.OffsetBy(x,y);

	if(_parent)
	{
		if(_parent->_invalid==NULL)
			_parent->_invalid=new BRegion(oldframe);
		else
			_parent->_invalid->Include(oldframe);
	}

//	for(Layer *lay=_topchild; lay!=NULL; lay=lay->_lowersibling)
//		lay->MoveBy(x,y);
//	Invalidate(Frame());
}

/*!
	\brief Resizes the layer.
	\param x X offset
	\param y Y offset
	
	This resizes the layer itself and resizes any children based on their resize
	flags.
*/
void Layer::ResizeBy(float x, float y)
{
#ifdef DEBUG_LAYER
printf("Layer: %s: Rezize By (%.1f,%.1f) - Incomplete\n",_name->String(),x,y);
#endif
	// TODO: Implement and test child resizing based on flags
	
	BRect oldframe=_frame;
	_frame.right+=x;
	_frame.bottom+=y;

//	for(Layer *lay=_topchild; lay!=NULL; lay=lay->_lowersibling)
//		lay->ResizeBy(x,y);

	if(_parent)
		_parent->RebuildRegions(true);
	else
		RebuildRegions(true);
	if(x<0 || y<0)
		_parent->Invalidate(oldframe);
}

/*!
	\brief Rebuilds visibility regions
	\param include_children Flag to rebuild all children and subchildren
*/
void Layer::RebuildRegions(bool include_children=true)
{
#ifdef DEBUG_LAYER
printf("Layer: %s: Rebuild Regions (%s)\n",_name->String(),include_children?"include children":
"no child inclusion");
#endif
	BRegion *reg,*reg2;
	if(_full)
		_full->Include(Bounds());
	else
		_full=new BRegion(Bounds());

	if(_visible)
		_visible->Include(Bounds());
	else
		_visible=new BRegion(Bounds());

	// Remove child footprints from _visible region
	for(Layer *childlay=_topchild; childlay!=NULL; childlay=childlay->_lowersibling)
	{
		if(childlay->_visible && childlay->_hidecount==0)
		{
			// reg is what is _visible in the layer's _parent's coordinate system
			reg=new BRegion(ConvertToParent(_visible));
			// reg2 is the layer's _visible region in the sibling's coordinate system
			reg2=new BRegion(childlay->ConvertFromParent(reg));
			delete reg;

			// lowersiblings occupy screen space _above_ a layer, so the layer itself
			// must remove from its _visible region 
			_visible->Exclude(reg2);
			delete reg2;
		}
	}

	// Remove _lowersibling footprints, which are on top of the layer on screen
	for(Layer *siblay=_lowersibling; siblay!=NULL; siblay=siblay->_lowersibling)
	{
		if(_frame.Intersects(siblay->_frame))
		{
			if(siblay->_visible && siblay->_hidecount==0)
			{
				// reg is what is _visible in the layer's _parent's coordinate system
				reg=new BRegion(ConvertToParent(_visible));
				// reg2 is the layer's _visible region in the sibling's coordinate system
				reg2=new BRegion(siblay->ConvertFromParent(reg));
				delete reg;

				// lowersiblings occupy screen space _above_ a layer, so the layer itself
				// must remove from its _visible region 
				_visible->Exclude(reg2);
				delete reg2;
			}
		}
	}

	if(include_children)
	{
		for(Layer *lay=_topchild; lay!=NULL; lay=lay->_lowersibling)
		{
			if(lay->_topchild)
				lay->RebuildRegions(true);
		}
	}
}

//! Prints all relevant layer data to stdout
void Layer::PrintToStream(void)
{
	printf("-----------\nLayer %s\n",_name->String());
	if(_parent)
		printf("Parent: %s (%p)\n",_parent->_name->String(), _parent);
	else
		printf("Parent: NULL\n");
	if(_uppersibling)
		printf("Upper sibling: %s (%p)\n",_uppersibling->_name->String(), _uppersibling);
	else
		printf("Upper sibling: NULL\n");
	if(_lowersibling)
		printf("Lower sibling: %s (%p)\n",_lowersibling->_name->String(), _lowersibling);
	else
		printf("Lower sibling: NULL\n");
	if(_topchild)
		printf("Top child: %s (%p)\n",_topchild->_name->String(), _topchild);
	else
		printf("Top child: NULL\n");
	if(_bottomchild)
		printf("Bottom child: %s (%p)\n",_bottomchild->_name->String(), _bottomchild);
	else
		printf("Bottom child: NULL\n");
	printf("Frame: "); _frame.PrintToStream();
	printf("Token: %ld\nLevel: %ld\n",_view_token, _level);
	printf("Hide count: %u\n",_hidecount);
	if(_invalid)
	{
		printf("Invalid Areas: "); _invalid->PrintToStream();
	}
	else
		printf("Invalid Areas: NULL\n");
	if(_visible)
	{
		printf("Visible Areas: "); _visible->PrintToStream();
	}
	else
		printf("Visible Areas: NULL\n");
	printf("Is updating = %s\n",(_is_updating)?"yes":"no");
}

//! Prints hierarchy data to stdout
void Layer::PrintNode(void)
{
	printf("-----------\nLayer %s\n",_name->String());
	if(_parent)
		printf("Parent: %s (%p)\n",_parent->_name->String(), _parent);
	else
		printf("Parent: NULL\n");
	if(_uppersibling)
		printf("Upper sibling: %s (%p)\n",_uppersibling->_name->String(), _uppersibling);
	else
		printf("Upper sibling: NULL\n");
	if(_lowersibling)
		printf("Lower sibling: %s (%p)\n",_lowersibling->_name->String(), _lowersibling);
	else
		printf("Lower sibling: NULL\n");
	if(_topchild)
		printf("Top child: %s (%p)\n",_topchild->_name->String(), _topchild);
	else
		printf("Top child: NULL\n");
	if(_bottomchild)
		printf("Bottom child: %s (%p)\n",_bottomchild->_name->String(), _bottomchild);
	else
		printf("Bottom child: NULL\n");
	if(_visible)
	{
		printf("Visible Areas: "); _visible->PrintToStream();
	}
	else
		printf("Visible Areas: NULL\n");
}

/*!
	\brief Converts the rectangle to the layer's parent coordinates
	\param the rectangle to convert
	\return the converted rectangle
*/
BRect Layer::ConvertToParent(BRect rect)
{
	return (rect.OffsetByCopy(_frame.LeftTop()));
}

/*!
	\brief Converts the region to the layer's parent coordinates
	\param the region to convert
	\return the converted region
*/
BRegion Layer::ConvertToParent(BRegion *reg)
{
	BRegion newreg;
	for(int32 i=0; i<reg->CountRects();i++)
		newreg.Include(ConvertToParent(reg->RectAt(i)));
	return BRegion(newreg);
}

/*!
	\brief Converts the rectangle from the layer's parent coordinates
	\param the rectangle to convert
	\return the converted rectangle
*/
BRect Layer::ConvertFromParent(BRect rect)
{
	return (rect.OffsetByCopy(_frame.left*-1,_frame.top*-1));
}

/*!
	\brief Converts the region from the layer's parent coordinates
	\param the region to convert
	\return the converted region
*/
BRegion Layer::ConvertFromParent(BRegion *reg)
{
	BRegion newreg;
	for(int32 i=0; i<reg->CountRects();i++)
		newreg.Include(ConvertFromParent(reg->RectAt(i)));
	return BRegion(newreg);
}

/*!
	\brief Converts the region to screen coordinates
	\param the region to convert
	\return the converted region
*/
BRegion Layer::ConvertToTop(BRegion *reg)
{
	BRegion newreg;
	for(int32 i=0; i<reg->CountRects();i++)
		newreg.Include(ConvertToTop(reg->RectAt(i)));
	return BRegion(newreg);
}

/*!
	\brief Converts the rectangle to screen coordinates
	\param the rectangle to convert
	\return the converted rectangle
*/
BRect Layer::ConvertToTop(BRect rect)
{
	if (_parent!=NULL)
		return(_parent->ConvertToTop(rect.OffsetByCopy(_frame.LeftTop())) );
	else
		return(rect);
}

/*!
	\brief Converts the region from screen coordinates
	\param the region to convert
	\return the converted region
*/
BRegion Layer::ConvertFromTop(BRegion *reg)
{
	BRegion newreg;
	for(int32 i=0; i<reg->CountRects();i++)
		newreg.Include(ConvertFromTop(reg->RectAt(i)));
	return BRegion(newreg);
}

/*!
	\brief Converts the rectangle from screen coordinates
	\param the rectangle to convert
	\return the converted rectangle
*/
BRect Layer::ConvertFromTop(BRect rect)
{
	if (_parent!=NULL)
		return(_parent->ConvertFromTop(rect.OffsetByCopy(_frame.LeftTop().x*-1,
			_frame.LeftTop().y*-1)) );
	else
		return(rect);
}