IShAction Struct Reference
[Shell Interfaces]

Interface for basic Actions. All actions should implement these functions. More...

Inheritance diagram for IShAction:

List of all members.

Public Member Functions
virtual MCCOMErr MCCOMAPI	Do ()=0
virtual MCCOMErr MCCOMAPI	Undo ()=0
virtual MCCOMErr MCCOMAPI	Redo ()=0
virtual boolean MCCOMAPI	WillCauseChange ()=0
virtual boolean MCCOMAPI	CanUndo ()=0
virtual void MCCOMAPI	GetPartToRedraw (IMFPart **outPart, int32 stage)=0
virtual MCCOMErr MCCOMAPI	GetName (TMCString &name)=0
virtual boolean MCCOMAPI	NeedsToPrepareMenus (void)=0

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Detailed Description

Interface for basic Actions. All actions should implement these functions.

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Member Function Documentation

virtual boolean MCCOMAPI IShAction::CanUndo (   )  [pure virtual]

Returns true if the action is undoable. If CanUndo() returns false, Undo() and Redo() should return MC_E_NOTIMPL and do nothing. Returns: true if the action is undoable.

virtual MCCOMErr MCCOMAPI IShAction::Do (   )  [pure virtual]

Function called to actually perform the action. Note: As the constructor of the action is not protected by the exception mechanism, no memory allocations (ie 'pointer = new ...') should be used there. Only initializations (like 'pointer = NULL;') should be made in the constructor. The allocations should be made here in Do().

virtual MCCOMErr MCCOMAPI IShAction::GetName (  TMCString &  name  )  [pure virtual]

Return the name to display in the undo/redo list. Note: Do not use hardcoded strings inside the code, use strings from resources instead. Parameters: name  The name of the action

virtual void MCCOMAPI IShAction::GetPartToRedraw (  IMFPart **  outPart, int32  stage )  [pure virtual]

Gives the action the opportunity to tell the Shell that the returned part should be redrawn after Do/Undo/Redo. Return NULL in outPart if no redraw is needed. Parameters: outPart  Returns a pointer to the part that needs to be redrawn after the action runs. stage  Allows you to specify what stage to query for part redraw. kShDoAction, kShUndoAction, kShRedoAction

virtual boolean MCCOMAPI IShAction::NeedsToPrepareMenus (  void   )  [pure virtual]

Returns: true if execution of the action (Do() or Undo() or Redo()) should cause the menus to be prepared (ie if contents of the menus need to be enabled/disabled)

virtual MCCOMErr MCCOMAPI IShAction::Redo (   )  [pure virtual]

Called to Redo the action. This can often simply call Do().

virtual MCCOMErr MCCOMAPI IShAction::Undo (   )  [pure virtual]

Called to undo the action. Note: When undone, an action must restore the database to EXACTLY the same state it was in before Do() was called. This means that if a pointer is cloned, the action must store the original pointer in Do() and apply its modifications to the clone. Then, when Undo() is called, the action simply replaces the cloned and modified pointer with the original, unmodified one.

virtual boolean MCCOMAPI IShAction::WillCauseChange (   )  [pure virtual]

Returns: true if the action will modify the database.

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The documentation for this struct was generated from the following file:

• IShUtilities.h

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