Return error instead of panicing when we get a parameter event with an invalid ID

Author: ilmai

examples/gain-plugin/src/plugin.rs

@@ -4,7 +4,7 @@ use std::io::{Read, Write};
 use std::rc::Rc;
 
 use plinth_plugin::error::Error;
-use plinth_plugin::{export_clap, export_vst3, Event, Host, HostInfo, Parameters, Plugin, ProcessorConfig};
+use plinth_plugin::{Event, Host, HostInfo, Parameters, Plugin, ProcessorConfig, export_clap, export_vst3, tracing};
 use plinth_plugin::clap::ClapPlugin;
 use plinth_plugin::vst3::Vst3Plugin;
 
@@ -38,7 +38,12 @@ impl Plugin for GainPlugin {
     }
 
     fn process_event(&mut self, event: &Event) {
-        self.parameters.process_event(event);
+        match self.parameters.process_event(event) {
+            Ok(_) => {},
+            Err(e) => {
+                tracing::error!("Error processing event: {e:?}");
+            },
+        }
     }
 
     fn create_processor(&self, _config: ProcessorConfig) -> Self::Processor {

examples/gain-plugin/src/processor.rs

@@ -1,4 +1,4 @@
-use plinth_plugin::{plinth_core::signals::signal::{Signal, SignalMut}, Event, FloatParameter, Parameters, ProcessState, Processor, Transport};
+use plinth_plugin::{Event, FloatParameter, Parameters, ProcessState, Processor, Transport, plinth_core::signals::signal::{Signal, SignalMut}, tracing};
 
 use crate::parameters::{GainParameter, GainParameters};
 
@@ -30,7 +30,12 @@ impl Processor for GainPluginProcessor {
         events: impl Iterator<Item = Event>
     ) -> ProcessState {
         for event in events {
-            self.parameters.process_event(&event);
+            match self.parameters.process_event(&event) {
+                Ok(_) => {},
+                Err(e) => {
+                    tracing::error!("Error processing event: {e:?}");
+                },
+            }
         }
 
         let gain_db = self.parameters.value::<FloatParameter>(GainParameter::Gain);
@@ -40,14 +45,19 @@ impl Processor for GainPluginProcessor {
             for sample in channel.iter_mut() {
                 *sample *= gain;
             }
-        }        
+        }
 
         ProcessState::Normal
     }
 
     fn process_events(&mut self, events: impl Iterator<Item = Event>) {
         for event in events {
-            self.parameters.process_event(&event);
+            match self.parameters.process_event(&event) {
+                Ok(_) => {},
+                Err(e) => {
+                    tracing::error!("Error processing event: {e:?}");
+                },
+            }
         }
     }
 }

plinth-plugin/src/parameters.rs

@@ -50,20 +50,28 @@ pub trait Parameters {
         self.typed::<T>(id).unwrap().modulated_plain()
     }
 
-    fn process_event(&self, event: &Event) {
+    fn process_event(&self, event: &Event) -> Result<(), Error> {
         match event {
             Event::ParameterValue { id, value, .. } => {
-                let parameter = self.get(*id).unwrap_or_else(|| panic!("Tried to get parameter with id {id} but it doesn't exist"));
+                let Some(parameter) = self.get(*id) else {
+                    return Err(Error::ParameterIdError(*id));
+                };
+
                 parameter.set_normalized_value(*value).unwrap();
             },
 
             Event::ParameterModulation { id, amount, .. } => {
-                let parameter = self.get(*id).unwrap_or_else(|| panic!("Tried to get parameter with id {id} but it doesn't exist"));
+                let Some(parameter) = self.get(*id) else {
+                    return Err(Error::ParameterIdError(*id));
+                };
+
                 parameter.set_normalized_modulation(*amount);
             },
 
             _ => {},
         }
+
+        Ok(())
     }
 
     fn reset(&self) {