ardour/libs/vst3/pluginterfaces/vst/ivstcontextmenu.h

//------------------------------------------------------------------------
// Project     : VST SDK
//
// Category    : Interfaces
// Filename    : pluginterfaces/vst/ivstcontextmenu.h
// Created by  : Steinberg, 10/2010
// Description : VST Context Menu Interfaces
//
//-----------------------------------------------------------------------------
// This file is part of a Steinberg SDK. It is subject to the license terms
// in the LICENSE file found in the top-level directory of this distribution
// and at www.steinberg.net/sdklicenses. 
// No part of the SDK, including this file, may be copied, modified, propagated,
// or distributed except according to the terms contained in the LICENSE file.
//-----------------------------------------------------------------------------

#pragma once

#include "pluginterfaces/base/funknown.h"
#include "vsttypes.h"

//------------------------------------------------------------------------
#include "pluginterfaces/base/falignpush.h"
//------------------------------------------------------------------------

namespace Steinberg {
class IPlugView;

namespace Vst {
class IContextMenu;

//------------------------------------------------------------------------
/** Extended Host callback interface IComponentHandler3 for an edit controller. 
\ingroup vstIHost vst350
- [host imp]
- [extends IComponentHandler]
- [released: 3.5.0]
- [optional]

A Plug-in can ask the host to create a context menu for a given exported Parameter ID or a generic context menu.\n

The host may pre-fill this context menu with specific items regarding the parameter ID like "Show automation for parameter",
"MIDI learn" etc...\n

The Plug-in can use the context menu in two ways :
- add its own items to the menu via the IContextMenu interface and call IContextMenu::popup(..) to pop-up it. See the \ref IContextMenuExample.
- extract the host menu items and add them to its own created context menu

\b Note: You can and should use this even if you don't add your own items to the menu as this is considered to be a big user value.

\sa IContextMenu
\sa IContextMenuTarget

\section IContextMenuExample Example
Adding Plug-in specific items to the context menu
\code
class PluginContextMenuTarget : public IContextMenuTarget, public FObject
{
public:
	PluginContextMenuTarget () {}

	virtual tresult PLUGIN_API executeMenuItem (int32 tag)
	{
		// this will be called if the user has executed one of the menu items of the Plug-in.
		// It won't be called for items of the host.
		switch (tag)
		{
			case 1: break;
			case 2: break;
		}
		return kResultTrue;
	}

	OBJ_METHODS(PluginContextMenuTarget, FObject)
	DEFINE_INTERFACES
		DEF_INTERFACE (IContextMenuTarget)
	END_DEFINE_INTERFACES (FObject)
	REFCOUNT_METHODS(FObject)
};

// The following is the code to create the context menu
void popupContextMenu (IComponentHandler* componentHandler, IPlugView* view, const ParamID* paramID, UCoord x, UCoord y)
{
	if (componentHandler == 0 || view == 0)
		return;
	FUnknownPtr<IComponentHandler3> handler (componentHandler);
	if (handler == 0)
		return;
	IContextMenu* menu = handler->createContextMenu (view, paramID);
	if (menu)
	{
		// here you can add your entries (optional)
		PluginContextMenuTarget* target = new PluginContextMenuTarget ();
		
		IContextMenu::Item item = {0};
		UString128 ("My Item 1").copyTo (item.name, 128);
		item.tag = 1;
		menu->addItem (item, target);

		UString128 ("My Item 2").copyTo (item.name, 128);
		item.tag = 2;
		menu->addItem (item, target);
		target->release ();
		//--end of adding new entries
		
		// here the the context menu will be pop-up (and it waits a user interaction)
		menu->popup (x, y);
		menu->release ();
	}
}
\endcode
*/
//------------------------------------------------------------------------
class IComponentHandler3 : public FUnknown
{
public:
	/** Creates a host context menu for a Plug-in:
		- If paramID is zero, the host may create a generic context menu.
		- The IPlugView object must be valid.
		- The return IContextMenu object needs to be released afterwards by the Plug-in.
	*/
	virtual IContextMenu* PLUGIN_API createContextMenu (IPlugView* plugView, const ParamID* paramID) = 0;
	//------------------------------------------------------------------------
	static const FUID iid;
};

DECLARE_CLASS_IID (IComponentHandler3, 0x69F11617, 0xD26B400D, 0xA4B6B964, 0x7B6EBBAB)
	
//------------------------------------------------------------------------
/** Context Menu Item Target Interface.
\ingroup vstIHost vstIPlug vst350
- [host imp]
- [plug imp]
- [released: 3.5.0]
- [optional]

A receiver of a menu item should implement this interface, which will be called after the user has selected
this menu item.

See IComponentHandler3 for more.
*/
//------------------------------------------------------------------------
class IContextMenuTarget : public FUnknown
{
public:
	/** Called when an menu item was executed. */
	virtual tresult PLUGIN_API executeMenuItem (int32 tag) = 0;
	//------------------------------------------------------------------------
	static const FUID iid;
};

DECLARE_CLASS_IID (IContextMenuTarget, 0x3CDF2E75, 0x85D34144, 0xBF86D36B, 0xD7C4894D)

//------------------------------------------------------------------------
/** IContextMenuItem is an entry element of the context menu. */
struct IContextMenuItem
{
	String128 name;									///< Name of the item
	int32 tag;										///< Identifier tag of the item
	int32 flags;									///< Flags of the item

	enum Flags {
		kIsSeparator	= 1 << 0,					///< Item is a separator
		kIsDisabled		= 1 << 1,					///< Item is disabled
		kIsChecked		= 1 << 2,					///< Item is checked
		kIsGroupStart	= 1 << 3 | kIsDisabled,		///< Item is a group start (like sub folder)
		kIsGroupEnd		= 1 << 4 | kIsSeparator,	///< Item is a group end
	};
};
//------------------------------------------------------------------------
/** Context Menu Interface.
\ingroup vstIHost vst350
- [host imp]
- [create with IComponentHandler3::createContextMenu(..)]
- [released: 3.5.0]
- [optional]

A context menu is composed of Item (entry). A Item is defined by a name, a tag, a flag
and a associated target (called when this item will be selected/executed). 
With IContextMenu the Plug-in can retrieve a Item, add a Item, remove a Item and pop-up the menu.

See IComponentHandler3 for more.
*/
//------------------------------------------------------------------------
class IContextMenu : public FUnknown
{
public:
	typedef IContextMenuItem Item;
	
	/** Gets the number of menu items. */
	virtual int32 PLUGIN_API getItemCount () = 0;

	/** Gets a menu item and its target (target could be not assigned). */
	virtual tresult PLUGIN_API getItem (int32 index, Item& item /*out*/, IContextMenuTarget** target /*out*/) = 0;

	/** Adds a menu item and its target. */
	virtual tresult PLUGIN_API addItem (const Item& item, IContextMenuTarget* target) = 0;

	/** Removes a menu item. */
	virtual tresult PLUGIN_API removeItem (const Item& item, IContextMenuTarget* target) = 0;

	/** Pop-ups the menu. Coordinates are relative to the top-left position of the Plug-ins view. */
	virtual tresult PLUGIN_API popup (UCoord x, UCoord y) = 0;

	//------------------------------------------------------------------------
	static const FUID iid;
};

DECLARE_CLASS_IID (IContextMenu, 0x2E93C863, 0x0C9C4588, 0x97DBECF5, 0xAD17817D)

//------------------------------------------------------------------------
} // namespace Vst
} // namespace Steinberg

//------------------------------------------------------------------------
#include "pluginterfaces/base/falignpop.h"
//------------------------------------------------------------------------