From 1a661a61925b9ff59947be28ad4be95527079ea1 Mon Sep 17 00:00:00 2001 From: David Robillard Date: Sat, 26 Mar 2011 20:31:03 +0000 Subject: Clean up documentation. --- ext/ui.lv2/ui.h | 420 ++++++++++++++++++++++++++++-------------------------- ext/ui.lv2/ui.ttl | 68 ++++----- 2 files changed, 246 insertions(+), 242 deletions(-) diff --git a/ext/ui.lv2/ui.h b/ext/ui.lv2/ui.h index 82c14c0..599ed0e 100644 --- a/ext/ui.lv2/ui.h +++ b/ext/ui.lv2/ui.h @@ -2,7 +2,7 @@ * * In-process UI extension for LV2 * - * Copyright (C) 2006-2010 Lars Luthman + * Copyright (C) 2006-2011 Lars Luthman * * Based on lv2.h, which was * @@ -27,23 +27,24 @@ * ***********************************************************************/ -/** @file - This file specifies a C API for communication between an LV2 host and an - LV2 UI. The interface is similar to the one used for actual LV2 plugins. +/** + @file ui.h C API for the LV2 UI extension . + + This file specifies a C API for communication between an LV2 host and an + LV2 UI. The interface is similar to the one used for actual LV2 plugins. - The entry point is the function lv2ui_descriptor(). + The entry point is the function lv2ui_descriptor(). */ #ifndef LV2_UI_H #define LV2_UI_H - #include -/** The URI prefix for this extension. */ +/** The URI of this extension (note this is not the same as the prefix). */ #define LV2_UI_URI "http://lv2plug.in/ns/ext/ui" -/** The numerical index returned by LV2_UI_Host_Descriptor::port_index() for +/** The numerical ID returned by LV2_UI_Host_Descriptor::port_index() for invalid port symbols. */ #define LV2_UI_INVALID_PORT_INDEX ((uint32_t)-1) @@ -58,246 +59,255 @@ extern "C" { #endif - -/** A pointer to a widget or other type of UI handle. - The actual type is defined by the type of the UI defined in the RDF data. - All the functionality provided by this extension is toolkit - independent, the host only needs to pass the necessary callbacks and - display the widget, if possible. Plugins may have several UIs, in various - toolkits. */ +/** + A pointer to a widget or other type of UI. + The actual type is defined by the type of the UI defined in the RDF data. + All the functionality provided by this extension is toolkit independent, the + host only needs to pass the necessary callbacks and display the widget, if + possible. Plugins may have several UIs, in various toolkits. +*/ typedef void* LV2_UI_Widget; - -/** This handle indicates a particular instance of a UI. - It is valid to compare this to NULL (0 for C++) but otherwise the - host MUST not attempt to interpret it. The UI plugin may use it to - reference internal instance data. */ +/** + Handle for a particular instance of a UI. + It is valid to compare this to NULL (0 for C++) but otherwise the host MUST + NOT attempt to interpret it. The UI may use it to reference internal + instance data. +*/ typedef void* LV2_UI_Handle; - -/** An object of this type is passed to the UI's instantiate() function, - and the UI must in turn pass it as the first parameter to the callbacks - in LV2_UI_Host_Descriptor. The host may use it to reference internal data, - such as the plugin instance that the UI is associated with. The UI - MUST NOT interpret the value of an LV2_UI_Host_Handle in any way. */ +/** + Handle for host functions and data provided to a UI. + An object of this type is passed to the UI's instantiate() function, and the + UI must in turn pass it as the first parameter to the callbacks in + LV2_UI_Host_Descriptor. The host may use it to reference internal data, such + as the plugin instance that the UI is associated with. The UI MUST NOT + interpret the value of an LV2_UI_Host_Handle in any way. +*/ typedef void* LV2_UI_Host_Handle; +/** + Host-provided functions that the UI can use to control the plugin instance. + + A pointer to an object of this type is passed to the lv2ui_descriptor() + function. -/** This struct contains pointers to the host-provided functions that the - UI can use to control the plugin instance. A pointer to an object of this - type is passed to the lv2ui_descriptor() function. - - The host must provide non-NULL values for all the function pointers. + The host MUST provide non-NULL values for all the function pointers. */ typedef struct _LV2_UI_Host_Descriptor { - /** This is a function that the UI can use to send data to a plugin's - input ports. The @c buffer parameter must point to a block of data, - @c buffer_size bytes large. The contents of this buffer and what the - host should do with it depends on the value of the @c port_protocol - parameter. + /** + Send data to one of the plugin's input ports. + + The @a buffer parameter MUST point to a block of data @a buffer_size + bytes large. The contents of this buffer and what the host should do + with it depends on the value of the @a port_protocol parameter. - The @c port_protocol parameter should be a numeric ID for a - ui:PortProtocol. Numeric IDs for PortProtocols are retrieved using the - port_protocol_id() function. + The @a port_protocol parameter MUST be a numeric ID for a + ui:PortProtocol. Numeric IDs for PortProtocols are retrieved using the + port_protocol_id() function. - The @c buffer is only valid during the time of this function call, so if - the host wants to keep it for later use it has to copy the contents to an - internal buffer. + The @a buffer is only valid during the time of this function call, so if + the host wants to keep it for later use it has to copy the contents to an + internal buffer. - @param host_handle The LV2_UI_Host_Handle that was passed to the UI's - instantiate() function. - @param port_index The index of the port that the data should be written - to, as returned by port_index(). - @param buffer_size The size of the data pointer to by @c buffer, in - bytes. - @param port_protocol The numeric ID for the Port Protocol to use, - as returned by port_protocol_id(). - */ - void (*write_port)(LV2_UI_Host_Handle host_handle, - uint32_t port_index, - uint32_t buffer_size, - uint32_t port_protocol, - void const* buffer); + @param host_handle The @a host_handle that was passed to the UI's + instantiate() function. + @param port_index The index of the port that the data should be written + to, as returned by port_index(). + @param buffer_size The size of the data pointed to by @a buffer, in + bytes. + @param port_protocol The numeric ID of the Port Protocol to use, + as returned by port_protocol_id(). + */ + void (*write_port)(LV2_UI_Host_Handle host_handle, + uint32_t port_index, + uint32_t buffer_size, + uint32_t port_protocol, + void const* buffer); - /** Returns a numerical index for a port. This index is used when writing - data to ports using write_port() and whe receiving data using - port_event(). If @c port_symbol is not a valid port symbol for @c plugin - the host it MUST return LV2_UI_INVALID_PORT_INDEX. + /** + Return the numerical index for a port. + This index is used when writing data to ports using write_port() and whe + receiving data using port_event(). If @a port_symbol is not a valid port + symbol for @a plugin the host it MUST return + LV2_UI_INVALID_PORT_INDEX. For performance reasons it may be a good idea + to cache port indices in the UI at instantiation time. - @param host_handle The LV2_UI_Host_Handle that was passed to the UI's - instantiate() function. - @param port_symbol A port symbol, as defined in the RDF data for - the plugin. - */ - uint32_t (*port_index)(LV2_UI_Host_Handle host_handle, - char const* port_symbol); + @param host_handle The LV2_UI_Host_Handle that was passed to the UI's + instantiate() function. + @param port_symbol The port's symbol, as defined in the RDF data for + the plugin. + */ + uint32_t (*port_index)(LV2_UI_Host_Handle host_handle, + char const* port_symbol); - /** This function is used by the UI, typically at instantiation, to get - the numeric IDs that are mapped to certain ui:PortProtocols (see - ui.ttl for details). If the host does not support the given - ui:PortProtocol it MUST return LV2_UI_INVALID_PORT_PROTOCOL_ID. - - As a special case, when @c port_protocol_uri is LV2_UI_FLOAT_CONTROL_URI - and ui:floatControl is listed as a required Feature for the UI, this - function MUST return 0. The UI may assume this and skip the call. + /** + This function is used by the UI, typically at instantiation, to get + the numeric IDs that are mapped to certain ui:PortProtocols (see + ui.ttl for details). If the host does not support the given + ui:PortProtocol it MUST return LV2_UI_INVALID_PORT_PROTOCOL_ID. + + As a special case, when @a port_protocol_uri is LV2_UI_FLOAT_CONTROL_URI + and ui:floatControl is listed as a required Feature for the UI, this + function MUST return 0. The UI may assume this and skip the call. - @param host_handle The LV2_UI_Host_Handle that was passed to the UI's - instantiate() function. - @param port_protocol_uri The URI of the ui:PortProtocol. - */ - uint32_t (*port_protocol_id)(LV2_UI_Host_Handle host_handle, - char const* port_protocol_uri); + @param host_handle The @a host_handle that was passed to the UI's + instantiate() function. + @param port_protocol_uri The URI of the ui:PortProtocol. + */ + uint32_t (*port_protocol_id)(LV2_UI_Host_Handle host_handle, + char const* port_protocol_uri); - /** Add a port subscription. This means that the host will call the UI's - port_event() function when the port value changes (as defined by - the PortProtocol). + /** + Subscribe to updates for a port. + This means that the host will call the UI's port_event() function when + the port value changes (as defined by the PortProtocol). - Calling this function with the same @c port_index and @c port_protocol - as an already active subscription has no effect. + Calling this function with the same @a port_index and @a port_protocol + as an already active subscription has no effect. - @param host_handle The LV2_UI_Host_Handle that was passed to the UI's - instantiate() function. - @param port_index The index for the port, as returned by port_index(). - @param port_protocol The numeric ID for the PortProtocol, as - returned by port_protocol_id. - */ - void (*add_port_subscription)(LV2_UI_Host_Handle host_handle, - uint32_t port_index, - uint32_t port_protocol); - - /** Remove a port subscription that has been added previously using - add_port_subscription, i.e. tell the host to stop calling port_event() - when the port value changes. + @param host_handle The @a host_handle that was passed to the UI's + instantiate() function. + @param port_index The index of the port, as returned by port_index(). + @param port_protocol The numeric ID of the PortProtocol, as + returned by port_protocol_id(). + */ + void (*add_port_subscription)(LV2_UI_Host_Handle host_handle, + uint32_t port_index, + uint32_t port_protocol); + + /** + Unsubscribe to updates for a port. + This means that the host will cease calling calling port_event() when + the port value changes. - Calling this function with a @c port_index and @c port_protocol that - does not define an active port subscription has no effect. + Calling this function with a @a port_index and @a port_protocol that + does not refer to an active port subscription has no effect. - @param host_handle The LV2_UI_Host_Handle that was passed to the UI's - instantiate() function. - @param port_index The index for the port, as returned by port_index(). - @param port_protocol The numeric ID for the PortProtocol, as - returned by port_protocol_id. - */ - void (*remove_port_subscription)(LV2_UI_Host_Handle host_handle, - uint32_t port_index, - uint32_t port_protocol); + @param host_handle The @a host_handle that was passed to the UI's + instantiate() function. + @param port_index The index of the port, as returned by port_index(). + @param port_protocol The numeric ID of the PortProtocol, as + returned by port_protocol_id(). + */ + void (*remove_port_subscription)(LV2_UI_Host_Handle host_handle, + uint32_t port_index, + uint32_t port_protocol); } LV2_UI_Host_Descriptor; - - -/** This struct contains the implementation of an UI. A pointer to an - object of this type is returned by the lv2ui_descriptor() function. +/** + This struct contains the implementation of an UI. A pointer to an + object of this type is returned by the lv2ui_descriptor() function. */ typedef struct _LV2_UI_Descriptor { - /** The URI for this UI (not for the plugin it controls). */ - char const* URI; + /** + The URI for this UI (not for the plugin it controls). + */ + char const* URI; - /** Create a new UI object and return a handle to it. This function works - similarly to the instantiate() member in LV2_Descriptor. - - @param descriptor The descriptor for the UI that you want to instantiate. - @param plugin_uri The URI of the plugin that this UI will control. - @param bundle_path The path to the bundle containing the RDF data file - that references this shared object file, including the - trailing '/'. - @param host_descriptor A pointer to an object that contains function - pointers that the UI instance should use to - control the plugin instance. This pointer MUST - be valid until cleanup() is called for this UI - instance. - @param host_handle A handle that the host may use to reference internal - data. It should be passed as the first parameter - to the function pointers in @c host_descriptor, and - MUST NOT be interpreted in any other way by the UI. - @param features A NULL-terminated array of LV2_Feature pointers. The - host must pass all feature URIs that it and the UI - supports and any additional data, just like in the - LV2 plugin instantiate() function. Note that UI - features and plugin features are NOT necessarily the - same, they just share the same data structure - this - will probably not be the same array as the one the - plugin host passes to a plugin. - */ - LV2_UI_Handle (*instantiate)(struct _LV2_UI_Descriptor const* descriptor, - char const* plugin_uri, - char const* bundle_path, - LV2_UI_Host_Descriptor const* host_descriptor, - LV2_UI_Host_Handle host_handle, - LV2_Feature const* const* features); - - /** Return the widget pointer for the UI object. This MUST return the - same value during the entire lifetime of the UI object. - */ - LV2_UI_Widget (*get_widget)(LV2_UI_Handle ui); - - /** Destroy the UI object and the associated widget. The host must not try - to access the widget after calling this function. - */ - void (*cleanup)(LV2_UI_Handle ui); + /** + Create a new UI object and return a handle to it. This function works + similarly to the instantiate() member in LV2_Descriptor. + + @param descriptor The descriptor for the UI to instantiate. + + @param plugin_uri The URI of the plugin that this UI will control. + + @param bundle_path The path to the bundle containing the RDF data that + references this shared object file, with trailing separator (e.g. '/'). + + @param host_descriptor A pointer to an object that contains function + pointers that the UI instance should use to control the plugin + instance. This pointer MUST be valid until cleanup() is called for this + UI instance. + + @param host_handle A handle that the host may use to reference internal + data. It MUST be passed as the first parameter to the function + pointers in @a host_descriptor, and MUST NOT be interpreted in any other + way by the UI. + + @param features A NULL-terminated array of LV2_Feature pointers. The + host must pass all feature URIs that it and the UI supports and any + additional data, just like in the LV2 plugin instantiate() + function. Note that UI features and plugin features are NOT necessarily + the same; @a features will probably not be the same array as the one the + plugin host passes to a plugin. + */ + LV2_UI_Handle (*instantiate)(struct _LV2_UI_Descriptor const* descriptor, + char const* plugin_uri, + char const* bundle_path, + LV2_UI_Host_Descriptor const* host_descriptor, + LV2_UI_Host_Handle host_handle, + LV2_Feature const* const* features); + + /** + Return the widget pointer for the UI object. + This MUST return the same value during the entire lifetime of the UI + object. + */ + LV2_UI_Widget (*get_widget)(LV2_UI_Handle ui); + + /** + Destroy the UI object and the associated widget. + The host must not try to access the widget after calling this function. + */ + void (*cleanup)(LV2_UI_Handle ui); - /** This is called by the host when something happens at a plugin port that - a subscription has been added for using - LV2_UI_Host_Descriptor::add_port_subscription(). + /** + Notify the UI that something has happened to a subscribed port. + + This is called by the host when something happens at a plugin port that + has been subscribed to using + LV2_UI_Host_Descriptor::add_port_subscription(). - The @c buffer is only valid during the time of this function call, so if - the UI wants to keep it for later use it has to copy the contents to an - internal buffer. + The @a buffer is only valid during the time of this function call, so if + the UI wants to keep it for later use it has to copy the contents to an + internal buffer. - @param ui A handle for the UI object. - @param port_index The index of the port for which something has - happened as returned by - LV2_UI_Host_Descriptor::port_index(). - @param buffer_size The size of the data buffer in bytes. - @param port_protocol The format of the data buffer, as returned by - LV2_UI_Host_Descriptor::port_protocol_id(). - @param buffer A pointer to the data buffer. - */ - void (*port_event)(LV2_UI_Handle ui, - uint32_t port_index, - uint32_t buffer_size, - uint32_t port_protocol, - void const* buffer); + @param ui A handle for the UI object. + @param port_index The index of the port that has changed, as returned by + LV2_UI_Host_Descriptor::port_index(). + @param buffer_size The size of the data buffer in bytes. + @param port_protocol The format of the data buffer, as returned by + LV2_UI_Host_Descriptor::port_protocol_id(). + @param buffer A pointer to the data buffer. + */ + void (*port_event)(LV2_UI_Handle ui, + uint32_t port_index, + uint32_t buffer_size, + uint32_t port_protocol, + void const* buffer); - /** Returns a data structure associated with an extension URI, for example - a struct containing additional function pointers. Avoid returning - function pointers directly since standard C++ has no valid way of - casting a void* to a function pointer. This member may be set to NULL - if the UI is not interested in supporting any extensions. This is similar - to the extension_data() member in LV2_Descriptor. - */ - void const* (*extension_data)(char const* uri); + /** + Return a data structure associated with an extension URI. -} LV2_UI_Descriptor; + This facility can be used by extensions to extend the LV2_UI_Descriptor + API. This function adheres to the same rules as + LV2_Descriptor::extension_data, except it applies to UIs rather than + plugins. + */ + void const* (*extension_data)(char const* uri); +} LV2_UI_Descriptor; +/** + Prototype for UI accessor function. -/** A plugin UI programmer must include a function called "lv2ui_descriptor" - with the following function prototype within the shared object - file. This function will have C-style linkage (if you are using - C++ this is taken care of by the 'extern "C"' clause at the top of - the file). This function will be accessed by the UI host using the - @c dlsym() function and called to get a LV2_UI_UIDescriptor for the - wanted plugin. - - Just like lv2_descriptor(), this function takes an index parameter. The - index should only be used for enumeration and not as any sort of ID number - - the host should just iterate from 0 and upwards until the function returns - NULL or a descriptor with an URI matching the one the host is looking for. + This function follows the same rules as lv2_desciprotr(), except it applies + to UIs rather than plugins. */ LV2_UI_Descriptor const* lv2ui_descriptor(uint32_t index); - -/** This is the type of the lv2ui_descriptor() function. */ +/** + Type of the lv2ui_descriptor() function in a UI library. +*/ typedef LV2_UI_Descriptor const* (*LV2_UI_DescriptorFunction)(uint32_t index); - - #ifdef __cplusplus } #endif - -#endif +#endif /* LV2_UI_H */ diff --git a/ext/ui.lv2/ui.ttl b/ext/ui.lv2/ui.ttl index 00f4f4b..fdd9ed6 100644 --- a/ext/ui.lv2/ui.ttl +++ b/ext/ui.lv2/ui.ttl @@ -1,8 +1,7 @@ -# In-process UI extension -# +# LV2 UI Extension # Copyright (C) 2010-2011 Lars Luthman # -# based on lv2.ttl, which is +# Based on lv2.ttl, which is # Copyright (C) 2006-2008 Steve Harris, David Robillard # # This extension should be considered a replacement for the earlier @@ -29,7 +28,7 @@ # ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR # OTHER DEALINGS IN THE SOFTWARE. -@prefix ui: . +@prefix ui: . @prefix lv2: . @prefix rdf: . @prefix rdfs: . @@ -38,7 +37,7 @@ a lv2:Specification ; doap:license ; - doap:name "LV2 in-process UI" ; + doap:name "LV2 UI" ; doap:release [ doap:revision "0.1" ; doap:created "2011-03-26" @@ -53,48 +52,43 @@ plugins. The UIs are code that reside in shared object files in an LV2 bundle and are referenced in the RDF data using the triples 
-  @prefix ui: <http://lv2plug.in/ns/ext/ui#> .
-  <http://my.pluginui>  a             ui-gtk:GtkUI ;
-                        lv2:appliesTo <http://my.plugin> ;
-                        ui:binary     <myui.so> .
+  @prefix ui:     <http://lv2plug.in/ns/ext/ui#> .
+  @prefix ui-gtk: <http://lv2plug.in/ns/ext/ui-gtk#> .
+  <http://example.org/my-ui>  a             ui-gtk:GtkUI ;
+                              lv2:appliesTo <http://example.org/my-plugin> ;
+                              ui:binary     <my-ui.so> .
-where <http://my.plugin> is the URI of the plugin, -<http://my.pluginui> is -the URI of the plugin UI and <myui.so> is the relative URI -to the shared -object file. While it is possible to have the plugin UI and the plugin in -the same shared object file it is probably a good idea to keep them -separate so that hosts that don't want UIs don't have to load the UI code. -

+where http://example.org/my-plugin is the URI of the plugin, +http://example.org/my-ui is the URI of the plugin UI and +my-ui.so is the relative URI to the shared object file. While it +is possible to have the plugin UI and the plugin in the same shared object file +it is probably a good idea to keep them separate so that hosts that don't want +UIs don't have to load the UI code.

A UI MUST specify its class in the RDF data and the class MUST be a proper -subclass of ui:UI, in this case ui-gtk:GtkUI. The class defines what type the UI -is, e.g. what graphics toolkit it uses. There are no UI classes defined in -this extension, those are specified separately (and anyone can define their -own). -

+subclass of ui:UI, in this case ui-gtk:GtkUI. The class defines what type the +UI is, e.g. what graphics toolkit it uses. There are no UI classes defined in +this extension, those are specified separately (and anyone can define their +own).

It's entirely possible to have multiple UIs for the same plugin, or to have -the UI for a plugin in a different bundle from the actual plugin - this -way people other than the plugin author can write plugin UIs independently -without editing the original plugin bundle. It is also possible to have one -UI that works with several different plugins. -

+the UI for a plugin in a different bundle from the actual plugin - this way +people other than the plugin author can write plugin UIs independently without +editing the original plugin bundle. It is also possible to have one UI that +works with several different plugins.

UIs should also be written in such a way that the host may load several instances of an UI, or different UIs, and use them with the same plugin -instance. -

+instance.

Note that the process that loads the shared object file containing the UI -code and the process that loads the shared object file containing the -actual plugin implementation do not have to be the same. There are many -valid reasons for having the plugin and the UI in different processes, or -even on different machines. This means that you can not use singletons -and global variables and expect them to refer to the same objects in the -UI and the actual plugin. The function callback interface defined in the -header lv2_ui.h is all you can expect to work. -

+code and the process that loads the shared object file containing the actual +plugin implementation do not have to be the same. There are many valid reasons +for having the plugin and the UI in different processes, or even on different +machines. This means that you can not use singletons and global +variables and expect them to refer to the same objects in the UI and the actual +plugin. The function callback interface defined in the header ui.h is all you +can expect to work.

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