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Diffstat (limited to 'ext/ui.lv2/ui.h')
| -rw-r--r-- | ext/ui.lv2/ui.h | 303 |
1 files changed, 303 insertions, 0 deletions
diff --git a/ext/ui.lv2/ui.h b/ext/ui.lv2/ui.h new file mode 100644 index 0000000..ac54256 --- /dev/null +++ b/ext/ui.lv2/ui.h @@ -0,0 +1,303 @@ +/************************************************************************
+ *
+ * In-process UI extension for LV2
+ *
+ * Copyright (C) 2006-2010 Lars Luthman <mail@larsluthman.net>
+ *
+ * Based on lv2.h, which was
+ *
+ * Copyright (C) 2000-2002 Richard W.E. Furse, Paul Barton-Davis,
+ * Stefan Westerfeld
+ * Copyright (C) 2006 Steve Harris, Dave Robillard.
+ *
+ * This header is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation; either version 2.1 of the License,
+ * or (at your option) any later version.
+ *
+ * This header 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. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301
+ * USA.
+ *
+ ***********************************************************************/
+
+/** @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.
+
+ The entry point is the function lv2ui_descriptor().
+*/
+
+#ifndef LV2_UI_H
+#define LV2_UI_H
+
+
+#include <lv2.h>
+
+/** The URI prefix for this extension. */
+#define LV2_UI_URI "http://lv2plug.in/ns/ext/ui"
+
+/** The numerical index returned by LV2_UI_Host_Descriptor::port_index() for
+ invalid port symbols. */
+#define LV2_UI_INVALID_PORT_INDEX ((uint32_t)-1)
+
+/** The numerical ID returned by LV2_UI_Host_Descriptor::port_protocol_id() for
+ invalid or unsupported PortProtocols. */
+#define LV2_UI_INVALID_PORT_PROTOCOL_ID ((uint32_t)-1)
+
+/** The full URI for the ui:floatControl PortProtocol. */
+#define LV2_UI_FLOAT_CONTROL_URI "http://lv2plug.in/ns/ext/ui#floatControl"
+
+#ifdef __cplusplus
+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. */
+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. */
+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. */
+typedef void* LV2_UI_Host_Handle;
+
+
+/** 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.
+*/
+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.
+
+ 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 @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.
+
+ @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);
+
+ /** 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.
+
+ @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);
+
+ /** 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.
+
+ @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);
+
+ /** 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).
+
+ Calling this function with the same @c port_index and @c 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.
+
+ Calling this function with a @c port_index and @c port_protocol that
+ does not define 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);
+
+} 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.
+*/
+typedef struct _LV2_UI_Descriptor {
+
+ /** 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);
+
+ /** 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().
+
+ 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.
+
+ @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);
+
+ /** 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);
+
+} LV2_UI_Descriptor;
+
+
+
+/** 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.
+*/
+LV2_UI_Descriptor const* lv2ui_descriptor(uint32_t index);
+
+
+/** This is the type of the lv2ui_descriptor() function. */
+typedef LV2_UI_Descriptor const* (*LV2_UI_DescriptorFunction)(uint32_t index);
+
+
+
+#ifdef __cplusplus
+}
+#endif
+
+
+#endif
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