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/* -*- Mode: C ; c-basic-offset: 2 -*- */
/*****************************************************************************
*
* This work is in public domain.
*
* This file is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*
* Author of this extension is Nedko Arnaudov <nedko@arnaudov.name>
*
* Several people helped improving the extension:
* * Krzysztof Foltman <wdev@foltman.com>
* * Dave Robillard <dave@drobilla.net>
*
* If you have questions ask in the #lv2 or #lad channel,
* FreeNode IRC network or use the lv2 mailing list.
*
*****************************************************************************/
#ifndef LV2_PROGRESS_H__F576843C_CA13_49C3_9BF9_CFF3A15AD18C__INCLUDED
#define LV2_PROGRESS_H__F576843C_CA13_49C3_9BF9_CFF3A15AD18C__INCLUDED
/**
* @file lv2_progress.h
* @brief LV2 progress notification extension definition
*
* @par Purpose and scope
* The purpose of this extension is to prevent thread (often the main one)
* freeze for plugins doing intensive computations during instantiation.
* Host may want to display progress bar of some sort and if it is using
* GUI toolkit event loop, to dispatch queued events.
*
* @par
* Using this extension for reporting progress of other lengthy operations
* is possible and encouraged but not subject of this extension alone.
* It is probably not good idea to call progress callback from plugin created
* thread nor it is good idea to call it from a LV2 audio class function.
* Any extension that wants to work in conjuction with progress extension
* must define thread context semantics for calling the progress callback.
*
* @par Plugin instantiation progress usage
* Plugin calls the host provided callback on regular basis during
* instantiation. One second between calls is good target. Everything between
* half second and two seconds should provide enough motion so user does
* not get "the thing froze" impression.
*/
#ifdef __cplusplus
extern "C" {
#endif
#if 0
} /* Adjust editor indent */
#endif
/** URI for the plugin progress feature */
#define LV2_PROGRESS_URI "http://lv2plug.in/ns/dev/progress"
/** @brief host feature structure */
struct lv2_progress
{
/** to be supplied as first parameter of progress() callback */
void * context;
/**
* This function is called by plugin to notify host about progress of a
* lengthy operation.
*
* @param context Host context
* @param progress Progress, from 0.0 to 100.0
* @param message Optional (may be NULL) string describing current operation.
* If called once with non-NULL message, subsequent calls will NULL message
* mean that host will reuse the previous message.
*/
void (*progress)(void * context, float progress, const char * message);
};
#if 0
{ /* Adjust editor indent */
#endif
#ifdef __cplusplus
} /* extern "C" */
#endif
#endif /* #ifndef LV2_PROGRESS_H__F576843C_CA13_49C3_9BF9_CFF3A15AD18C__INCLUDED */
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