param edit gesture API

src/format/clap/host.rs

@@ -1,5 +1,10 @@
-use crate::plugin::HostInner;
+use crate::host::HostInner;
+use crate::params::{ParamId, ParamValue};
 
 pub struct ClapHost {}
 
-impl HostInner for ClapHost {}
+impl HostInner for ClapHost {
+    fn begin_gesture(&self, id: ParamId) {}
+    fn end_gesture(&self, id: ParamId) {}
+    fn set_param(&self, id: ParamId, value: ParamValue) {}
+}

src/format/clap/instance.rs

@@ -14,8 +14,9 @@ use crate::buffers::{BufferData, BufferType, Buffers};
 use crate::bus::{BusDir, Format};
 use crate::editor::Editor;
 use crate::events::{Data, Event, Events};
+use crate::host::Host;
 use crate::params::{ParamId, ParamInfo, ParamValue};
-use crate::plugin::{Host, Plugin, PluginInfo};
+use crate::plugin::{Plugin, PluginInfo};
 use crate::process::{Config, Processor};
 use crate::sync::params::ParamValues;
 use crate::util::{copy_cstring, slice_from_raw_parts_checked, DisplayParam};

src/format/vst3/component.rs

@@ -13,8 +13,9 @@ use super::view::View;
 use crate::bus::{BusDir, Format, Layout};
 use crate::editor::Editor;
 use crate::events::{Data, Event, Events};
+use crate::host::Host;
 use crate::params::ParamId;
-use crate::plugin::{Host, Plugin, PluginInfo};
+use crate::plugin::{Plugin, PluginInfo};
 use crate::process::{Config, Processor};
 use crate::sync::params::ParamValues;
 use crate::util::{slice_from_raw_parts_checked, DisplayParam};

src/format/vst3/host.rs

@@ -1,5 +1,10 @@
-use crate::plugin::HostInner;
+use crate::host::HostInner;
+use crate::params::{ParamId, ParamValue};
 
 pub struct Vst3Host {}
 
-impl HostInner for Vst3Host {}
+impl HostInner for Vst3Host {
+    fn begin_gesture(&self, id: ParamId) {}
+    fn end_gesture(&self, id: ParamId) {}
+    fn set_param(&self, id: ParamId, value: ParamValue) {}
+}

src/host.rs

@@ -0,0 +1,46 @@
+use std::sync::Arc;
+
+use crate::params::{ParamId, ParamInfo, ParamValue};
+
+pub trait HostInner {
+    fn begin_gesture(&self, id: ParamId);
+    fn end_gesture(&self, id: ParamId);
+    fn set_param(&self, id: ParamId, value: ParamValue);
+}
+
+#[derive(Clone)]
+pub struct Host {
+    inner: Arc<dyn HostInner + Send + Sync>,
+}
+
+impl Host {
+    pub fn from_inner(inner: Arc<dyn HostInner + Send + Sync>) -> Host {
+        Host { inner }
+    }
+
+    pub fn edit_param(&self, id: ParamId) -> Gesture {
+        self.inner.begin_gesture(id);
+
+        Gesture {
+            inner: Arc::clone(&self.inner),
+            id,
+        }
+    }
+}
+
+pub struct Gesture {
+    inner: Arc<dyn HostInner + Send + Sync>,
+    id: ParamId,
+}
+
+impl Gesture {
+    pub fn set_value(&self, value: ParamValue) {
+        self.inner.set_param(self.id, value);
+    }
+}
+
+impl Drop for Gesture {
+    fn drop(&mut self) {
+        self.inner.end_gesture(self.id);
+    }
+}

src/lib.rs

@@ -3,6 +3,7 @@ pub mod bus;
 pub mod editor;
 pub mod events;
 pub mod format;
+pub mod host;
 pub mod params;
 pub mod plugin;
 pub mod process;

src/plugin.rs

@@ -1,8 +1,8 @@
 use std::io::{self, Read, Write};
-use std::sync::Arc;
 
 use crate::bus::{BusInfo, Layout};
 use crate::editor::{Editor, Parent};
+use crate::host::Host;
 use crate::params::{ParamId, ParamInfo, ParamValue};
 use crate::process::{Config, Processor};
 
@@ -34,19 +34,6 @@ impl Default for PluginInfo {
     }
 }
 
-pub trait HostInner {}
-
-#[derive(Clone)]
-pub struct Host {
-    _inner: Arc<dyn HostInner>,
-}
-
-impl Host {
-    pub fn from_inner(inner: Arc<dyn HostInner>) -> Host {
-        Host { _inner: inner }
-    }
-}
-
 pub trait Plugin: Send + Sized + 'static {
     type Processor: Processor;
     type Editor: Editor;