PF_EventExtra

この構造体は、現在のイベントのコンテキスト情報を提供します。 After Effects は、Entry Point 関数の追加パラメーターでこの構造体へのポインターを渡します。

PF_EventUnion (PF_EventExtra で送信) はイベントの種類によって異なり、そのイベントに固有の情報が含まれます。

Member	Purpose
`contextH`	Handle to the `PF_Context`. This drawing context is used with the Drawbot suites for drawing, and also for the UI Callbacks.
`e_type`	Which event is occurring.
`u`	A PF_EventUnion containing information specific to the event.
`effect_win`	A `PF_EffectWindowInfo` about the event if it occurs within the effects window. Otherwise, as of After Effects 5.0, effect_win can be replaced by a `PF_WindowUnion`. This struct contains both a `PF_EffectWindowInfo` and an `PF_ItemWindowInfo`, which (for now) is simply the port rectangle for the item window. Replacement only occurs if `PF_USE_NEW_WINDOW_UNION` was defined during compilation; otherwise, it will continue to be just a `PF_EffectWindowInfo`.
`cbs`	Pointer to UI Callbacks, which are needed to translate points between layer, composition, and screen coordinate systems.
`evt_in_flags`	Event Input Flags. This currently contains only one value, `PF_EI_DONT_DRAW`, which you should check before drawing!
`evt_out_flags`	One or more of the following, combined with a bitwise OR operation: - `PF_EO_NONE` - `PF_EO_HANDLED_EVENT` tells After Effects you’ve handled the event. - `PF_EO_ALWAYS_UPDATE` forces After Effects to rerender the composite in response to every click or drag; this is the same behavior generated by ‘alt-scrubbing’ the parameter value. - `PF_EO_NEVER_UPDATE` prevents After Effects from rerendering the composite until the user stops clicking and dragging. - `PF_EO_UPDATE_NOW` tells After Effects to update the view immediately after the event returns after calling `PF_InvalidateRect`

PF_Context

PF_Context details the event’s UI context.

Member	Purpose
`magic`	Do not change.
`w_type`	The window type. If you have Custom Comp and ECW UIs in the same plug-in, this is the way to differentiate between them (what kind of masochist are you, anyway?). - `PF_Window_COMP`, - `PF_Window_LAYER`, - `PF_Window_EFFECT`
`reserved_flt`	Do not change.
`plugin_state[4]`	An array of 4 `A_longs` which the plug-in can use to store state information for a given context.
`reserved_drawref`	A `DRAWBOT_DrawRef` for use with the Drawbot suites.
`*reserved_paneP`	Do not change.

PF_EffectWindowInfo

If an event occurs in the ECP, an PF_EffectWindowInfo is sent in PF_EventExtra.

Member	Purpose
`index`	This indicates which parameter in the effect window is being affected. The controls are numbered from 0 to the number of controls minus 1.
`area`	This indicates if the control title (`PF_EA_PARAM_TITLE`) or the control itself (`PF_EA_CONTROL`) are being affected. The title is the area still visible when the parameter’s topic (“twirly”) is spun up.
`current_frame`	A PF_Rect indicating the full frame of the area occupied by the control.
`param_title_frame`	A PF_Rect indicating the title area of the control.
`horiz_offset`	A horizontal offset from the left side of the title area in which to draw into the title.