feat(config): introduce clipboard threshold option

espanso-config/src/config/mod.rs

@@ -32,6 +32,7 @@ pub trait Config: Send {
   fn label(&self) -> &str;
   fn match_paths(&self) -> &[String];
   fn backend(&self) -> Backend;
+  fn clipboard_threshold(&self) -> usize;
 
   fn is_match(&self, app: &AppProperties) -> bool;
 }

espanso-config/src/config/parse/mod.rs

@@ -28,6 +28,7 @@ pub(crate) struct ParsedConfig {
   pub label: Option<String>,
 
   pub backend: Option<String>,
+  pub clipboard_threshold: Option<usize>,
 
   // Includes
   pub includes: Option<Vec<String>>,

espanso-config/src/config/parse/yaml.rs

@@ -33,6 +33,9 @@ pub(crate) struct YAMLConfig {
   #[serde(default)]
   pub backend: Option<String>,
 
+  #[serde(default)]
+  pub clipboard_threshold: Option<usize>,
+
   #[serde(default)]
   pub includes: Option<Vec<String>>,
 
@@ -82,6 +85,7 @@ impl TryFrom<YAMLConfig> for ParsedConfig {
     Ok(Self {
       label: yaml_config.label,
       backend: yaml_config.backend,
+      clipboard_threshold: yaml_config.clipboard_threshold,
       use_standard_includes: yaml_config.use_standard_includes,
       includes: yaml_config.includes,
       extra_includes: yaml_config.extra_includes,
@@ -107,6 +111,7 @@ mod tests {
       r#"
     label: "test"
     backend: clipboard
+    clipboard_threshold: 200
       
     use_standard_includes: true
     includes: ["test1"]
@@ -129,6 +134,7 @@ mod tests {
         label: Some("test".to_string()),
 
         backend: Some("clipboard".to_string()),
+        clipboard_threshold: Some(200),
 
         use_standard_includes: Some(true),
         includes: Some(vec!["test1".to_string()]),

espanso-config/src/config/resolve.rs

@@ -128,6 +128,10 @@ impl Config for ResolvedConfig {
       }
     }
   }
+
+  fn clipboard_threshold(&self) -> usize {
+    self.parsed.clipboard_threshold.unwrap_or(100)
+  }
 }
 
 impl ResolvedConfig {
@@ -185,6 +189,7 @@ impl ResolvedConfig {
       // Fields
       label,
       backend,
+      clipboard_threshold,
       includes,
       excludes,
       extra_includes,

espanso-config/src/config/store.rs

@@ -161,6 +161,10 @@ mod tests {
     fn backend(&self) -> crate::config::Backend {
       unimplemented!()
     }
+    
+    fn clipboard_threshold(&self) -> usize {
+      unimplemented!()
+    }
   }
 
   #[test]

espanso-config/src/legacy/config.rs

@@ -378,34 +378,9 @@ impl LegacyConfig {
 pub enum BackendType {
   Inject,
   Clipboard,
-
-  // On Linux systems there is a long standing issue with text injection (which
-  // in general is better than Clipboard copy/pasting) that prevents certain
-  // apps from correctly handling special characters (such as emojis or accented letters)
-  // when injected. For this reason, espanso initially defaulted on the Clipboard
-  // backend on Linux, as it was the most reliable (working in 99% of cases),
-  // even though it was less efficient and with a few inconveniences (for example, the
-  // previous clipboard content being overwritten).
-  // The Auto backend tries to take it a step further, by automatically determining
-  // when an injection is possible (only ascii characters in the replacement), and falling
-  // back to the Clipboard backend otherwise.
-  // Should only be used on Linux systems.
   Auto,
 }
 impl Default for BackendType {
-  // The default backend varies based on the operating system.
-  // On Windows and macOS, the Inject backend is working great and should
-  // be preferred as it doesn't override the clipboard.
-  // On the other hand, on linux it has many problems due to the bugs
-  // of the libxdo used. For this reason, Clipboard will be the default
-  // backend on Linux from version v0.3.0
-
-  #[cfg(not(target_os = "linux"))]
-  fn default() -> Self {
-    BackendType::Inject
-  }
-
-  #[cfg(target_os = "linux")]
   fn default() -> Self {
     BackendType::Auto
   }

espanso-config/src/legacy/mod.rs

@@ -252,6 +252,10 @@ impl Config for LegacyInteropConfig {
     // All the filters that have been specified must be true to define a match
     is_exec_match && is_title_match && is_class_match
   }
+
+  fn clipboard_threshold(&self) -> usize {
+    100
+  }
 }
 
 struct LegacyMatchGroup {