Defines the API for the editor which can be obtained by calling ITGUIParameter::edit(). More...

#include <IGUIParameter.h>

Public Member Functions
virtual tresult	commit (ParamType const &iValue)
	Shortcut method which calls `setValue(ParamType const &)` followed by `commit()`. More...

virtual tresult	setValue (ParamType const &iValue)=0
	Unconditionally sets the value of the parameter to the value provided. More...

virtual bool	updateValue (ParamType const &iValue)=0
	First check if the value provided (`iValue`) is different from the current value and if that is the case then updates it to the new value. More...

Public Member Functions inherited from IGUIParameter::Editor
virtual tresult	commit ()=0
	Commits all the changes applied to the parameter. More...

virtual tresult	rollback ()=0
	Rollback all the changes that were made to this parameter (since this editor was created). More...

virtual	~Editor ()=default
	Technically the destructor must only call `rollback()`, but due to the fact that it is a virtual method, it needs to be implemented by each subclass... More...

Detailed Description

template<typename T>
class pongasoft::VST::GUI::Params::ITGUIParameter< T >::ITEditor

Defines the API for the editor which can be obtained by calling ITGUIParameter::edit().

The editor is used in scenarios when you want to make multiple modifications to a parameter and then commit() or rollback() the set of changes. The typical use case is to create an editor on mouse down event in a view, modify the value on mouse move event and commit on mouse up event.

// Example
CMouseEventResult LCDDisplayView::onMouseDown(CPoint &where, const CButtonState &buttons)
{
  fLCDInputXEditor = fLCDInputXParameter.edit(computeLCDInputX(where));
  return kMouseEventHandled;
}
CMouseEventResult LCDDisplayView::onMouseMoved(CPoint &where, const CButtonState &buttons)
{
  if(fLCDInputXEditor)
  {
    fLCDInputXEditor->setValue(computeLCDInputX(where));
    return kMouseEventHandled;
  }
  return kMouseEventNotHandled;
}
CMouseEventResult LCDDisplayView::onMouseUp(CPoint &where, const CButtonState &buttons)
{
  if(fLCDInputXEditor)
  {
    fLCDInputXEditor->commit(computeLCDInputX(where));
    fLCDInputXEditor = nullptr;
    return kMouseEventHandled;
  }
  return kMouseEventNotHandled;
}
CMouseEventResult LCDDisplayView::onMouseCancel()
{
  if(fLCDInputXEditor)
  {
    fLCDInputXEditor->rollback();
    fLCDInputXEditor = nullptr;
    return kMouseEventHandled;
  }
  return kMouseEventNotHandled;
}

Member Function Documentation

◆ commit()

virtual tresult commit ( ParamType const & iValue )

inlinevirtual

Shortcut method which calls setValue(ParamType const &) followed by commit().

◆ setValue()

virtual tresult setValue ( ParamType const & iValue )

pure virtual

Unconditionally sets the value of the parameter to the value provided.

Parameters

iValue the value to set

Returns: kResultOk if successful

Implemented in DefaultEditorImpl< T >.

◆ updateValue()

virtual bool updateValue ( ParamType const & iValue )

pure virtual

First check if the value provided (iValue) is different from the current value and if that is the case then updates it to the new value.

Note: If the type T does not provide a way to compare the value, then this call will delegate to setValue(ParamType const &) and return true.

Parameters

iValue the value to update

Returns: true if the value was updated