DropType Class Reference

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#include <idraganddrop.h>

Inheritance diagram for DropType:

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Class Description

See also:

Class DropClipFormat, Class FileDropType, Class DropScriptDropType, DropTypes.

Description:

This is the base class for droppable content types. Distinguished instances of subclasses represent different types of drop content, such as a file distinguished by file suffix or a scene object The active DropClipFormat parses dropped IDataObject into one of these dropped types, filling its data members with appropriate guff from the data object.

Each DropClipFormat can encompass multiple possible types of dropped data. For example, the iDrop package can drop max files, image files, script files, etc. The DropClipFormat classes parse raw dropped clipboard data into one of the DropType family of classes. These contain recognizer predicates, extracted data from the current drop, and utilities for working with the data, such as URL downloads, script compile & execution, etc. Custom drop-types can be created by subclassing one of the DropType base classes. The built-in DropTypes are listed in DropTypes.

Data Members:

protected:

static IDragAndDropMgr* dndMgr;

Cached pointer to the drag and drop manager.

static bool dragging;

The drop source state.

static POINT startPt;

The drag and drop starting point.

static WPARAM startKeyState;

They starting state of the keyboard.

static HWND startWnd;

The handle to the starting window.

static bool loaded;

Flags if the current packages is already downloaded.

static IDataObject* current_dataobject;

Currently dropping IDataObject. Filled in by the low-level DragEnter() code.

Public Member Functions
	DropType ()
virtual CoreExport	~DropType ()
virtual int	TypeCode ()=0
virtual bool	IsDropType (int code)
virtual bool	Load (bool showProgress=true)
virtual DWORD	DropEffect ()
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)
virtual CoreExport bool	ReadyToDrag ()
Static Public Member Functions
static void	Init ()
Static Public Attributes
static CoreExport IDataObject *	current_dataobject
Static Protected Attributes
static CoreExport IDragAndDropMgr *	dndMgr
static CoreExport bool	dragging
static CoreExport POINT	startPt
static CoreExport WPARAM	startKeyState
static CoreExport HWND	startWnd
static CoreExport bool	loaded

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Constructor & Destructor Documentation

DropType

(

)

[inline]

Remarks:

Constructor.

{ if (dndMgr == NULL) dndMgr = GetDragAndDropMgr(); }

virtual CoreExport ~DropType

(

)

[virtual]

Remarks:

Destructor.

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Member Function Documentation

static void Init

(

)

[inline, static]

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Remarks:

This method clears the currently-parsed drop data.

Default Implementation:

{ current_dataobject = NULL; loaded = false; }

Reimplemented in FileDropType.

{ current_dataobject = NULL; loaded = false; }

virtual int TypeCode

(

)

[pure virtual]

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Remarks:

This method returns the typecode of the DropType.

Implemented in FileDropType, DropScriptDropType, SceneFileDropType, ImageFileDropType, ImportFileDropType, ScriptFileDropType, DropScriptFileDropType, MSZipPackageFileDropType, BitmapDropType, and PathConfigDropType.

virtual bool IsDropType

(

int

code

)

[inline, virtual]

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Remarks:

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

Each DropType subclass is given a unique integer code that can be used for type-testing, switching, etc. The TypeCode() method must be implemented to return this code and isDropType() to test against the given code (this is provided to that intermediate DropType base classes with codes can effectively support superclass testing). The codes for the built-in DropTypes are given by the following defined symbols which are listed in DropTypes.

Parameters:

int code

The DropType code.

Default Implementation:

{ return code == TypeCode(); }

Reimplemented in FileDropType, and DropScriptDropType.

{ return code == TypeCode(); }

virtual bool Load

(

bool

showProgress = true

)

[inline, virtual]

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Remarks:

Subclasses should implement this method if they need to perform any droptype-specific loading prior to clipformat data use. For example, the URL package types all download any web-resident files in this method. Control any implemented progress dialog with the showProgress parameter.

Parameters:

bool showProgress = true

The download progress dialog can be displayed by passing true.

Default Implementation:

{ return true; }

Reimplemented in FileDropType, DropScriptFileDropType, and MSZipPackageFileDropType.

{ return true; }

virtual DWORD DropEffect

(

)

[inline, virtual]

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Remarks:

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

Default Implementation:

{ return DROPEFFECT_MOVE; }

Reimplemented in DropScriptDropType.

{ return DROPEFFECT_MOVE; }

CoreExport STDMETHODIMP QueryInterface	(	REFIID	iid,
		void **	ppvObject
	)

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CoreExport STDMETHODIMP_

(

ULONG

)

[inline]

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{ return 1; }

CoreExport STDMETHODIMP_

(

ULONG

)

[inline]

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{ return 1; }

CoreExport STDMETHODIMP GetData	(	FORMATETC *	pFormatetc,
		STGMEDIUM *	pmedium
	)		[inline]

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Reimplemented in FileDropType, and DropScriptDropType.

{ return E_UNEXPECTED; }

CoreExport STDMETHODIMP GetDataHere	(	FORMATETC *	pFormatetc,
		STGMEDIUM *	pmedium
	)		[inline]

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Reimplemented in FileDropType, and DropScriptDropType.

{ return E_UNEXPECTED; }

CoreExport STDMETHODIMP QueryGetData

(

FORMATETC *

pFormatetc

)

[inline]

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Reimplemented in FileDropType, and DropScriptDropType.

{ return E_UNEXPECTED; }

CoreExport STDMETHODIMP GetCanonicalFormatEtc	(	FORMATETC *	pFormatetcIn,
		FORMATETC *	pFormatetcOut
	)

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CoreExport STDMETHODIMP SetData	(	FORMATETC *	pFormatetc,
		STGMEDIUM *	pmedium,
		BOOL	fRelease
	)

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CoreExport STDMETHODIMP EnumFormatEtc	(	DWORD	dwDirection,
		IEnumFORMATETC **	ppenumFormatetc
	)

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CoreExport STDMETHODIMP DAdvise	(	FORMATETC *	pFormatetc,
		DWORD	advf,
		IAdviseSink *	pAdvSink,
		DWORD *	pdwConnection
	)

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CoreExport STDMETHODIMP DUnadvise

(

DWORD

dwConnection

)

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CoreExport STDMETHODIMP EnumDAdvise

(

IEnumSTATDATA **

ppenumAdvise

)

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CoreExport STDMETHODIMP QueryContinueDrag	(	BOOL	fEscapePressed,
		DWORD	grfKeyState
	)

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CoreExport STDMETHODIMP GiveFeedback

(

DWORD

dwEffect

)

[inline]

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{ return DRAGDROP_S_USEDEFAULTCURSORS; }

virtual CoreExport void InitDragDropCheck	(	LPARAM	mousePt,
		WPARAM	keyState,
		HWND	hwnd
	)		[virtual]

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virtual CoreExport void CancelDragDropCheck

(

)

[virtual]

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virtual CoreExport bool DragDropCheck	(	LPARAM	mousePt,
		WPARAM	keyState,
		DWORD	allowedEffects
	)		[virtual]

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virtual CoreExport bool ReadyToDrag

(

)

[inline, virtual]

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Reimplemented in DropScriptDropType.

{ return false; }

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Member Data Documentation

CoreExport IDragAndDropMgr* dndMgr [static, protected]

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CoreExport bool dragging [static, protected]

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CoreExport POINT startPt [static, protected]

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CoreExport WPARAM startKeyState [static, protected]

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CoreExport HWND startWnd [static, protected]

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CoreExport bool loaded [static, protected]

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CoreExport IDataObject* current_dataobject [static]

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