FxCustomParameterActionAPI

Introduction

Defines the methods the host application provides to support a custom parameter view.

Discussion

Because custom-parameter views may get user events at any time, this protocol provides methods to prepare the host application for parameter changes or other actions at arbitrary times.

NOTE: It is NOT safe to set or get parameter values at arbitrary times outside of a startAction:/endAction: pair. For example, when a custom-parameter view receives a keyDown event, it may want to change its parameter value. It would then call the following sequence:

id <FxCustomParameterActionAPI> actionAPI = [apiManager apiForProtocol:FxCustomParameterActionAPI];
id <FxParameterSettingAPI> settingAPI = [apiManager apiForProtocol:FxParameterSettingAPI];
double time = [actionAPI currentTime];
  
[actionAPI startAction:self];
[settingAPI setCustomParameterValue:myObject toParm:myParameterID];
[actionAPI endAction:self];

Methods

-currentTime

Returns the current time, expressed in canonical frames.

-endAction:

Tells the host application that the plug-in is done accessing parameters.

-startAction:

Prepares the host to access parameters.

Returns the current time, expressed in canonical frames.

- (double)currentTime; 

Return Value

The current time, expressed as a floating-point frame number, in canonical frames.

Discussion

This is useful when a custom parameter view needs to set a parameter value in response to a user event. Depending on the host application, the time value may be relative to the start of the timeline or to the start of the clip. See the header file FxPlug/FxHostCapabilities.h

Tells the host application that the plug-in is done accessing parameters.

- (void)endAction:(id)sender; 

Parameters

sender

The view class that implements this protocol. Typically passed as self.

Prepares the host to access parameters.

- (void)startAction:(id)sender;

Parameters

sender

The view class that implements this protocol. Typically passed as self.

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Last Updated: 2008-06-05