haiku/src/servers/app/CursorHandler.cpp

//------------------------------------------------------------------------------
//	Copyright (c) 2001-2002, Haiku, Inc.
//
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//	to deal in the Software without restriction, including without limitation
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//	The above copyright notice and this permission notice shall be included in
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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
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//	FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
//	DEALINGS IN THE SOFTWARE.
//
//	File Name:		CursorHandler.cpp
//	Author:			DarkWyrm <bpmagic@columbus.rr.com>
//	Description:	class for handling cursor display for DisplayDriver
//  
//------------------------------------------------------------------------------
#include "CursorHandler.h"
#include "DisplayDriver.h"
#include "RectUtils.h"

CursorHandler::CursorHandler(DisplayDriver *driver)
 : 	fDriver(driver),
	fOldPosition(0,0,0,0),
	fPosition(0,0,0,0),
	fCursorPos(0,0),
	fSavedData(NULL),
	fCursor(NULL),
	fHideLevel(0),
	fDrawData(),
	fDriverHidden(false),
	fIsObscured(false),
	fValidSaveData(false)
{
}

//! Frees any memory used for saving screen data
CursorHandler::~CursorHandler(void)
{
	delete fSavedData;
}

/*!
	\brief Tests to see if the passed rectangle intersects the cursor's current position
	\param r The rectangle to test against
	\return true if r intersects the cursor's current screen footprint
*/
bool CursorHandler::IntersectsCursor(const BRect &r)
{
	return TestRectIntersection(r, fPosition);
}

void CursorHandler::SetCursor(ServerCursor *cursor)
{
	// we may start empty, but we will never need to stay that way
	if(!cursor)
		return;
	
	Hide();
	
	if(fSavedData && cursor->Bounds()!=fSavedData->Bounds())
	{
		delete fSavedData;
		fSavedData=NULL;
	}
	
	if(!fSavedData)
		fSavedData=new UtilityBitmap(cursor);
	
	fCursor=cursor;
	
	// We change the position rectangles to reflect the new cursor, compensating for the
	// new cursor's hotspot.
	fPosition=cursor->Bounds().OffsetToCopy(fCursorPos.x-fCursor->GetHotSpot().x,
		fCursorPos.y-fCursor->GetHotSpot().y);
	fOldPosition=fPosition;
	
	Show();
}

/*!
	\brief Moves the cursor to the specified place on screen
	\param pt The new cursor location
	
	This function fails if asked to move the cursor outside the screen boundaries
*/
void CursorHandler::MoveTo(BPoint pt)
{
	pt.x = max_c(pt.x, 0.0);
	pt.y = max_c(pt.y, 0.0);
	pt.x = min_c(pt.x, fDriver->DisplayMode()->virtual_width - 1);
	pt.y = min_c(pt.y, fDriver->DisplayMode()->virtual_height - 1);

	if (fCursorPos != pt) {
	
		fCursorPos=pt;

		if (!fSavedData)
			debugger("NULL savedata\n");

		fDriver->CopyBitmap(fSavedData,fSavedData->Bounds(),fOldPosition,&fDrawData);
		fPosition.OffsetTo(fCursorPos.x-fCursor->GetHotSpot().x,
				fCursorPos.y-fCursor->GetHotSpot().y);
		fDriver->CopyToBitmap(fSavedData,fPosition);
		
		fDrawData.draw_mode=B_OP_ALPHA;
		fDriver->CopyBitmap(fCursor,fCursor->Bounds(),fPosition,&fDrawData);
		fDrawData.draw_mode=B_OP_COPY;
		
		fDriver->Invalidate(fOldPosition);
		fOldPosition=fPosition;
		
		fDriver->Invalidate(fPosition);
	}
}

//! Shows the cursor. Unlike BView, calls are not cumulative
void CursorHandler::Show(void)
{
	// This call is pretty simple -- save the area underneath the cursor and draw the thing
	
	if (fHideLevel == 0)
		return;
	
	fIsObscured = false;
	fHideLevel--;
	
	if (fHideLevel > 0)
		return;
	
	fOldPosition = fPosition;
	
	if (!fCursor)
		return;
	
	fValidSaveData = true;
	
	if (!fSavedData)
		fSavedData = new UtilityBitmap(fCursor->Bounds(),
									   (color_space)fDriver->DisplayMode()->space, 0);
	
	fDriver->CopyToBitmap(fSavedData, fPosition);
	
	// Draw the data to the buffer
	fDrawData.draw_mode = B_OP_ALPHA;
	fDriver->CopyBitmap(fCursor, fCursor->Bounds(), fPosition, &fDrawData);
	fDrawData.draw_mode = B_OP_COPY;
	fDriver->Invalidate(fPosition);
}

//! Hides the cursor. Unlike BView, calls are not cumulative
void CursorHandler::Hide(void)
{
	fHideLevel++;
	
	// TODO: find out what the behavior is if a Hide is called on an obscured cursor
	
	// For now, we will change the state from obscured to hidden and leave it at that
	if(fIsObscured)
	{
		fIsObscured=false;
		return;
	}
	
	if(fHideLevel>1)
		return;
	
	if(!fCursor)
		return;
	
	if(!fSavedData)
		fSavedData=new UtilityBitmap(fCursor);
	
	fDriver->CopyBitmap(fSavedData,fSavedData->Bounds(),fOldPosition,&fDrawData);
	fDriver->Invalidate(fPosition);
}

//! Hides the cursor until the next MoveTo call. Unlike BView, calls are not cumulative
void CursorHandler::Obscure(void)
{
	if(IsObscured())
		return;
	
	fIsObscured=true;
	
	// TODO: find out what the behavior is if an Obscure is called on a hidden cursor
	
	// For now, we will change the state from obscured to hidden and leave it at that
	if(fHideLevel>0)
	{
		fHideLevel=0;
		return;
	}
	
	fDriver->CopyBitmap(fSavedData,fSavedData->Bounds(),fOldPosition,&fDrawData);
	fDriver->Invalidate(fPosition);
}

void CursorHandler::DriverHide(void)
{
	if(fDriverHidden)
		return;
		
	fDriverHidden=true;
	
	if(!fCursor)
		return;
	
	if(!fSavedData)
		fSavedData=new UtilityBitmap(fCursor);
	
	fDriver->CopyBitmap(fSavedData,fSavedData->Bounds(),fOldPosition,&fDrawData);
	fDriver->Invalidate(fPosition);
}

void CursorHandler::DriverShow(void)
{
	if(!fDriverHidden)
		return;
	
	fDriverHidden=false;
	
	fOldPosition=fPosition;
	
	if(!fCursor)
		return;
	
	fValidSaveData=true;
	
	if(!fSavedData)
		fSavedData=new UtilityBitmap(fCursor->Bounds(),(color_space)fDriver->DisplayMode()->space,0);
	
	fDriver->CopyToBitmap(fSavedData,fPosition);
	
	// Draw the data to the buffer
	fDrawData.draw_mode=B_OP_ALPHA;
	fDriver->CopyBitmap(fCursor,fCursor->Bounds(),fPosition,&fDrawData);
	fDrawData.draw_mode=B_OP_COPY;
	fDriver->Invalidate(fPosition);
}