DropScriptDropType Class Reference

#include <idraganddrop.h>

Inheritance diagram for DropScriptDropType:

Public Member Functions
int	TypeCode ()
bool	IsDropType (int code)
DWORD	DropEffect ()
CoreExport BOOL	CompileDropScript (const MCHAR *filename)
CoreExport BOOL	RunDropScriptDragEnter (FPParams *params)
CoreExport BOOL	RunDropScriptDragOver (FPParams *params)
CoreExport BOOL	RunDropScriptDrop (FPParams *params)
CoreExport STDMETHODIMP	GetData (FORMATETC *pFormatetc, STGMEDIUM *pmedium)
CoreExport STDMETHODIMP	GetDataHere (FORMATETC *pFormatetc, STGMEDIUM *pmedium)
CoreExport STDMETHODIMP	QueryGetData (FORMATETC *pFormatetc)
void	InitDragDropCheck (MacroEntry *dropscript, LPARAM mousePt, WPARAM keyState, HWND hwnd)
bool	ReadyToDrag ()
Public Member Functions inherited from DropType
	DropType ()
virtual CoreExport	~DropType ()
virtual bool	Load (bool showProgress=true)
CoreExport STDMETHODIMP	QueryInterface (REFIID iid, void **ppvObject)
CoreExport	STDMETHODIMP_ (ULONG) AddRef(void)
CoreExport	STDMETHODIMP_ (ULONG) Release(void)
CoreExport STDMETHODIMP	GetData (FORMATETC *pFormatetc, STGMEDIUM *pmedium)
CoreExport STDMETHODIMP	GetDataHere (FORMATETC *pFormatetc, STGMEDIUM *pmedium)
CoreExport STDMETHODIMP	QueryGetData (FORMATETC *pFormatetc)
CoreExport STDMETHODIMP	GetCanonicalFormatEtc (FORMATETC *pFormatetcIn, FORMATETC *pFormatetcOut)
CoreExport STDMETHODIMP	SetData (FORMATETC *pFormatetc, STGMEDIUM *pmedium, BOOL fRelease)
CoreExport STDMETHODIMP	EnumFormatEtc (DWORD dwDirection, IEnumFORMATETC **ppenumFormatetc)
CoreExport STDMETHODIMP	DAdvise (FORMATETC *pFormatetc, DWORD advf, IAdviseSink *pAdvSink, DWORD *pdwConnection)
CoreExport STDMETHODIMP	DUnadvise (DWORD dwConnection)
CoreExport STDMETHODIMP	EnumDAdvise (IEnumSTATDATA **ppenumAdvise)
CoreExport STDMETHODIMP	QueryContinueDrag (BOOL fEscapePressed, DWORD grfKeyState)
CoreExport STDMETHODIMP	GiveFeedback (DWORD dwEffect)
virtual CoreExport void	InitDragDropCheck (LPARAM mousePt, WPARAM keyState, HWND hwnd)
virtual CoreExport void	CancelDragDropCheck ()
virtual CoreExport bool	DragDropCheck (LPARAM mousePt, WPARAM keyState, DWORD allowedEffects)

Static Public Attributes
static CoreExport MacroEntry *	current_dropscript
Static Public Attributes inherited from DropType
static CoreExport IDataObject *	current_dataobject

Additional Inherited Members
Static Public Member Functions inherited from DropType
static void	Init ()
Static Public Member Functions inherited from MaxHeapOperators
static UtilExport void *	operator new (size_t size)
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static UtilExport void *	operator new (size_t size, int block_type, const char *filename, int line)
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static UtilExport void *	operator new (size_t size, const std::nothrow_t &e, const char *filename, int line)
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static UtilExport void *	operator new[] (size_t size, const std::nothrow_t &e)
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static UtilExport void *	operator new[] (size_t size, const char *filename, int line)
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static UtilExport void *	operator new[] (size_t size, int block_type, const char *filename, int line)
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static UtilExport void *	operator new[] (size_t size, const std::nothrow_t &e, const char *filename, int line)
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static UtilExport void *	operator new[] (size_t size, unsigned long flags)
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static UtilExport void *	operator new[] (size_t size, const std::nothrow_t &e, unsigned long flags)
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static UtilExport void	operator delete (void *ptr, const char *filename, int line)
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static UtilExport void	operator delete (void *ptr, int block_type, const char *filename, int line)
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static UtilExport void	operator delete (void *ptr, unsigned long flags)
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static UtilExport void	operator delete[] (void *ptr)
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static UtilExport void	operator delete[] (void *ptr, const char *filename, int line)
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static UtilExport void *	aligned_malloc (size_t size, size_t alignment)
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static UtilExport void *	aligned_realloc (void *ptr, size_t size, size_t alignment)
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static UtilExport void	aligned_free (void *ptr)
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Static Protected Attributes inherited from DropType
static CoreExport IDragAndDropMgr *	dndMgr
static CoreExport bool	dragging
static CoreExport POINT	startPt
static CoreExport WPARAM	startKeyState
static CoreExport HWND	startWnd
static CoreExport bool	loaded

Detailed Description

See also

Class DropType, Class DragAndDropHandler, Class FPParams, Class MacroEntry, DropTypes

Description:

This class is an intermediate base class for drop content that comes in the form of a dropScript. This is a special kind of macroScript that implements dropScript event handlers (see the DropScript documentation for details.) The prime subclass is DropScriptFileDropType which recognizes files of type .ds. The parsed data for this type is a single parsed macroScript, represented as a MacroEntrypointer. The DropScriptDropType class provides utility methods for compiling a .ds file into the current_dropscript slot and for running the drag and drop-associated handlers in the current dropScript.

The methods RunDropScriptDragEnter(FPParams* params), RunDropScriptDragOver(FPParams* params) and RunDropScriptDrop(FPParams* params) take care of the 'on droppable' handler in the current_dropscript, if supplied. The DragAndDropHandler::DragEnter call is usualy made once on initial entry to a registered drag and drop target window and DragAndDropHandler::DragOver is usually called as the mouse moves over this window. In both cases, the handler returns true or false to indicate whether the dropping dropScript will be accepted. If a handler is not supplied, the dropScript is always deemed droppable. If the handler returns false, the not-droppable cursor is shown.

The handler is called with a set of arguments, supplied by the DragAndDropHandler, that usually depends on the window currently under the mouse pointer. For example, over a viewport, the current mouse coordinates, scene node under the mouse, slot number in a list window, etc. By convention, the first argument is positional and always a window type name, such as "Viewport" or "MaterialEditor", and all the others are keyword arguments, since they will vary from window to window. They are delivered to the RunDropScriptXXX methods in a Function Publishing FPParam object, so that handler code needs to deal as little as possible with the MAXScript SDK. Here's an example code fragment from the default drop handler:

FPParams params (6,
TYPE_NAME, (vpwin ? _M("viewport") : _M("max")),
TYPE_KEYARG_MARKER,
TYPE_NAME, _M("node"),
TYPE_INODE, m_nodectx,
TYPE_NAME, _M("point"),
TYPE_POINT, &pt);
// run the dragEnter handler & set dropeffect based on result
if (dropScriptFileDropType.RunDropScriptDragEnter(&params))
     *pdwEffect = DROPEFFECT_COPY;
else
     *pdwEffect = DROPEFFECT_NONE;

In the above code, the handler is called with 3 actual arguments, one position and two keyword. They are loaded into the 'params' instance with the FPParams varargs constructor. The first is the positional window name, in this case either #viewport or #max, then comes a special TYPE_KEYARG_MARKER signalling that the following arguments are keyword. The keyword args are given in pairs, name then value, in this case node: and point:. See the Function Publishing system documentation for full details on using the FPParams class for passing parameter blocks. An example droppable handler might be as follows:

on droppable window node: do

return window == #viewport and superclassOf node == Shape

This handler effectively makes the dropScript droppable if the mouse is over a Shape object in a viewport window. Notice that the function only looks at the node: keyword argument in this definition; arguments delivered as keyword arguments can vary from call to call and the called function can choose to look at only subset of them.

Data Members:

public

static MacroEntry* current_dropscript;

Cache for current macroScript. See /MAXSDK/INCLUDE/iMacroScript.h for the MacroScript manager public API. There are also utility methods in DropScriptDropType that do all the necessary drag and drop compiling & running of macroScripts, so you only have to deal with the MacroScript manager for special processing.

Member Function Documentation

TypeCode()

int TypeCode ( )

inlinevirtual

Remarks

This method returns the typecode of the DropType.

Default Implementation:

{ return DROPSCRIPT_DROPTYPE; }

Implements DropType.

Reimplemented in MSZipPackageFileDropType, and DropScriptFileDropType.

{ return DROPSCRIPT_DROPTYPE; }

IsDropType()

bool IsDropType ( int  code )

inlinevirtual

Remarks

This method returns TRUE if the DropType is of the specified DropType code, otherwise FALSE.

Parameters:

int code

The DropType code.

Default Implementation:

{ return code == TypeCode() || code == DROPSCRIPT_DROPTYPE; }

Reimplemented from DropType.

{ return code == TypeCode() || code == DROPSCRIPT_DROPTYPE; }

DropEffect()

DWORD DropEffect ( )

inlinevirtual

Remarks

This method returns the dropeffect currently supported by the accepted dropping type.

Default Implementation:

{ return DROPEFFECT_MOVE; }

The following methods provide assistance for developing custom drag-and-drop handlers that want to accept dropScripts. They work on the shared current_dropscript static data member in DropScriptDropType.

Reimplemented from DropType.

{ return DROPEFFECT_MOVE; }

CompileDropScript()

CoreExport BOOL CompileDropScript

(

const MCHAR *

filename

)

Remarks

This method parses the given file, looking for a single macroScript definition. If successful, interns the macroScript and places its corresponding MacroEntry* in the current_dropscript static data member. Note that if there is more code than just a single macroScript in the file, only the last macroScript definition is taken; the other code is NOT executed, so you cannot include auxiliary global functions and other prep code in the file. These should be inside the body of the macroScript, as local data and functions.

Parameters:

MCHAR* filename

The filename of the script.

Returns

TRUE if successfully compiled, otherwise FALSE.

RunDropScriptDragEnter()

CoreExport BOOL RunDropScriptDragEnter

(

FPParams *

params

)

Remarks

This methods takes care of the 'on droppable' handler in the current_dropscript, if supplied. If the handler returns false, the not-droppable cursor is shown.

Parameters:

FPParams* params

The set of arguments for the handler.

Returns

TRUE if droppable script will be accepted, otherwise FALSE.

RunDropScriptDragOver()

CoreExport BOOL RunDropScriptDragOver

(

FPParams *

params

)

Remarks

This methods takes care of the 'on droppable' handler in the current_dropscript, if supplied, during the process of dragging contents over the drop target. If the handler returns false, the not-droppable cursor is shown.

Parameters:

FPParams* params

The set of arguments for the handler.

Returns

TRUE if droppable script will be accepted, otherwise FALSE.

RunDropScriptDrop()

CoreExport BOOL RunDropScriptDrop

(

FPParams *

params

)

Remarks

This methods takes care of the 'on droppable' handler in the current_dropscript, if supplied and handles the parsing of the dropped script. If the handler returns false, the not-droppable cursor is shown.

Parameters:

FPParams* params

The set of arguments for the handler.

Returns

TRUE if droppable script will be accepted, otherwise FALSE.

GetData()

CoreExport STDMETHODIMP GetData	(	FORMATETC *	pFormatetc,
		STGMEDIUM *	pmedium
	)

GetDataHere()

CoreExport STDMETHODIMP GetDataHere	(	FORMATETC *	pFormatetc,
		STGMEDIUM *	pmedium
	)

QueryGetData()

CoreExport STDMETHODIMP QueryGetData

(

FORMATETC *

pFormatetc

)

InitDragDropCheck()

void InitDragDropCheck ( MacroEntry *  dropscript, LPARAM  mousePt, WPARAM  keyState, HWND  hwnd  )

inline

Remarks

This method will initialize a drag and drop check.

Parameters:

MacroEntry* dropscript

The drop script macro entry.

LPARAM mousePt

The initial mouse cursor position.

WPARAM keyState

They initial state of the keyboard.

HWND hwnd

The handle to the initial start window.

   {
      DropType::InitDragDropCheck(mousePt, keyState, hwnd);
      current_dropscript = dropscript;
   }

ReadyToDrag()

bool ReadyToDrag ( )

inlinevirtual

Remarks

This method returns TRUE if the system is ready to drag, otherwise FALSE.

Default Implementation:

{ return current_dropscript != NULL; }

Reimplemented from DropType.

{ return current_dropscript != NULL; }

Member Data Documentation

current_dropscript

CoreExport MacroEntry* current_dropscript

static