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[3.5.0] Context Menu

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Introduction

Extended host callback interface for an edit controller: Vst::IComponentHandler3

A plug-in can ask the host to create a context menu for a given exported parameter ID or a generic context menu. The host may pre-fill this context menu with specific items regarding the parameter ID like "Show automation for parameter", "MIDI learn" etc... 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 create the pop-up. See below for an example of how to use it.
  • extract the host menu items and add them to a context menu created by the plug-in.

Note
It is recommended to use this context menu interface, even if you do not add your own items to the menu as this is considered to be a big user value.

See also IContextMenu, IContextMenuTarget

Examples

From the host perspective

For example, Cubase adds its owned entries in the context menu opened with right-click on an exported parameter when the plug-in uses createContextMenu. The plug-in itself, in this example, only adds the "Open UIDescription Editor" entry.

Note
Plug-ins using VSTGUI automatically have this context menu feature.

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Context menu with Cubase

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Here an example of what Bitwig is doing with context menus.

From the plug-in perspective

Adding plug-in specific items to the context menu:

//------------------------------------------------------------------------
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 ();
    }
}