IInfoListener Class Reference

Channel context interface: Vst::IInfoListener. More...

#include <ivstchannelcontextinfo.h>

Inheritance diagram for IInfoListener:

Public Member Functions
virtual tresult	setChannelContextInfos (IAttributeList *list)=0
	Receive the channel context infos from host.
Public Member Functions inherited from FUnknown
virtual tresult	queryInterface (const TUID _iid, void **obj)=0
virtual uint32	addRef ()=0
virtual uint32	release ()=0

Static Public Attributes
static const FUID	iid
Static Public Attributes inherited from FUnknown
static const FUID	iid

Detailed Description

Channel context interface: Vst::IInfoListener.

• [plug imp]
• [extends IEditController]
• [released: 3.6.5]
• [optional]

Allows the host to inform the plug-in about the context in which the plug-in is instantiated, mainly channel based info (color, name, index,...). Index can be defined inside a namespace (for example, index start from 1 to N for Type Input/Output Channel (Index namespace) and index start from 1 to M for Type Audio Channel).
As soon as the plug-in provides this IInfoListener interface, the host will call setChannelContextInfos for each change occurring to this channel (new name, new color, new indexation,...)

Example

//------------------------------------------------------------------------
tresult PLUGIN_API MyPlugin::setChannelContextInfos (IAttributeList* list)
{
    if (list)
    {
        // optional we can ask for the Channel Name Length
        int64 length;
        if (list->getInt (ChannelContext::kChannelNameLengthKey, length) == kResultTrue)
        {
            ...
        }
        
        // get the Channel Name where we, as plug-in, are instantiated
        String128 name;
        if (list->getString (ChannelContext::kChannelNameKey, name, sizeof (name)) == kResultTrue)
        {
            ...
        }

        // get the Channel UID
        if (list->getString (ChannelContext::kChannelUIDKey, name, sizeof (name)) == kResultTrue)
        {
            ...
        }
        
        // get Channel Index
        int64 index;
        if (list->getInt (ChannelContext::kChannelIndexKey, index) == kResultTrue)
        {
            ...
        }
        
        // get the Channel Color
        int64 color;
        if (list->getInt (ChannelContext::kChannelColorKey, color) == kResultTrue)
        {
            uint32 channelColor = (uint32)color;
            String str;
            str.printf ("%x%x%x%x", ChannelContext::GetAlpha (channelColor),
            ChannelContext::GetRed (channelColor),
            ChannelContext::GetGreen (channelColor),
            ChannelContext::GetBlue (channelColor));
            String128 string128;
            Steinberg::UString (string128, 128).fromAscii (str);
            ...
        }

        // get Channel Index Namespace Order of the current used index namespace
        if (list->getInt (ChannelContext::kChannelIndexNamespaceOrderKey, index) == kResultTrue)
        {
            ...
        }
    
        // get the channel Index Namespace Length
        if (list->getInt (ChannelContext::kChannelIndexNamespaceLengthKey, length) == kResultTrue)
        {
            ...
        }
        
        // get the channel Index Namespace
        String128 namespaceName;
        if (list->getString (ChannelContext::kChannelIndexNamespaceKey, namespaceName, sizeof (namespaceName)) == kResultTrue)
        {
            ...
        }

        // get plug-in Channel Location
        int64 location;
        if (list->getInt (ChannelContext::kChannelPluginLocationKey, location) == kResultTrue)
        {
            String128 string128;
            switch (location)
            {
                case ChannelContext::kPreVolumeFader:
                    Steinberg::UString (string128, 128).fromAscii ("PreVolFader");
                break;
                case ChannelContext::kPostVolumeFader:
                    Steinberg::UString (string128, 128).fromAscii ("PostVolFader");
                break;
                case ChannelContext::kUsedAsPanner:
                    Steinberg::UString (string128, 128).fromAscii ("UsedAsPanner");
                break;
                default: Steinberg::UString (string128, 128).fromAscii ("unknown!");
                break;
            }
        }
        
        // do not forget to call addRef () if you want to keep this list
    }
}

Member Function Documentation

virtual tresult setChannelContextInfos ( IAttributeList *  list )

pure virtual

Receive the channel context infos from host.

Member Data Documentation

const FUID iid

static