AOO410/main/svx/inc/svx/e3dsceneupdater.hxx

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#ifndef _E3D_SCENEUPDATER_HXX
#define _E3D_SCENEUPDATER_HXX

#include <svx/svxdllapi.h>

//////////////////////////////////////////////////////////////////////////////
// predeclarations

class SdrObject;
class E3dScene;
namespace drawinglayer { namespace geometry {
    class ViewInformation3D;
}}

//////////////////////////////////////////////////////////////////////////////
// This class is a helper to encapsulate 3D object changes which shall change the 
// scene's 2D geometry. E.g. when moving one 3D object in a scene, the visualisation
// would not change since the scene's 2D attributes are defined by it's 2D object 
// transformation and the changed content would be projected to the same 2D bounds
// as before. To reflect the fact that the 2D positions may 'change' for the user's
// imagination, it is necessary to calculate a new 2D object transformation of the scene
// (the SnapRect) using the old 3D transformation stack and the eventually changed
// 3D content and tu use it. This is only wanted if changes to the scene's
// content are intended to change the scene's 2D geometry attributes

class SVX_DLLPUBLIC E3DModifySceneSnapRectUpdater
{
	// the scene which may be changed. This gets set to the outmost scene
	// of the to-be-changed 3D object when the scene has a 3d transformation
	// stack at construction time. In all other cases it's set to zero and
	// no action needs to be taken
	E3dScene*									mpScene;

	// the 3d transformation stack at the time of construction, valid when
	// mpScene is not zero
	drawinglayer::geometry::ViewInformation3D*	mpViewInformation3D;

public:
	// the constructor evaluates and sets the members at construction time
	E3DModifySceneSnapRectUpdater(const SdrObject* pObject);

	// the destructor will take action if mpScene is not zero and modify the
	// 2D geomeztry of the target scene
	~E3DModifySceneSnapRectUpdater();
};

#endif			// _E3D_SCENEUPDATER_HXX