Merge pull request #147 from k0kubun/reimagine-modifiers

Replace modifier: true with virtual_modifiers

README.md

@@ -21,6 +21,7 @@
 * Automatically remap newly connected devices by starting xremap with `--watch`.
 * Support [Emacs-like key remapping](example/emacs.yml), including the mark mode.
 * Trigger commands on key press/release events.
+* Use a non-modifier key as a virtual modifier key.
 
 ## Installation
 
@@ -155,9 +156,6 @@ modmap:
     remap: # Required
       # Replace a key with another
       KEY_XXX: KEY_YYY # Required
-      # Make it a logical modifier key
-      KEY_XXX:
-        modifier: true # Required
       # Dispatch different keys depending on whether you hold it or press it alone
       KEY_XXX:
         held: KEY_YYY # Required
@@ -231,7 +229,7 @@ You can use multiple prefixes like `C-M-Shift-a`.
 You may also suffix them with `_L` or `_R` (case-insensitive) so that
 remapping is triggered only on a left or right modifier, e.g. `Ctrl_L-a`.
 
-If you set `modifier: true` in `modmap`, you can use it in the `MOD1-` part too.
+If you use `virtual_modifiers` explained below, you can use it in the `MOD1-` part too.
 
 ### application
 
@@ -278,6 +276,21 @@ swaymsg -t get_tree
 
 Locate `app_id` in the output.
 
+### virtual\_modifiers
+
+You can declare keys that should act like a modifier.
+
+```
+virtual_modifiers:
+  - CapsLock
+keymap:
+  - remap:
+      CapsLock-i: Up
+      CapsLock-j: Left
+      CapsLock-k: Down
+      CapsLock-l: Right
+```
+
 ## License
 
 `xremap` is available as open source under the terms of the [MIT License](https://opensource.org/licenses/MIT).

src/config/key_action.rs

@@ -12,16 +12,10 @@ use super::action::{Action, Actions};
 pub enum KeyAction {
     #[serde(deserialize_with = "deserialize_key")]
     Key(Key),
-    ModifierKey(ModifierKey),
     MultiPurposeKey(MultiPurposeKey),
     PressReleaseKey(PressReleaseKey),
 }
 
-#[derive(Clone, Debug, Deserialize)]
-pub struct ModifierKey {
-    pub modifier: bool,
-}
-
 #[serde_as]
 #[derive(Clone, Debug, Deserialize)]
 pub struct MultiPurposeKey {

src/config/mod.rs

@@ -16,10 +16,13 @@ use evdev::Key;
 use keymap::Keymap;
 use modmap::Modmap;
 use nix::sys::inotify::{AddWatchFlags, InitFlags, Inotify};
-use serde::Deserialize;
+use serde::{Deserialize, Deserializer};
 use std::{collections::HashMap, error, fs, path::Path, time::SystemTime};
 
-use self::keymap::{build_keymap_table, KeymapEntry};
+use self::{
+    key::parse_key,
+    keymap::{build_keymap_table, KeymapEntry},
+};
 
 #[derive(Debug, Deserialize)]
 #[serde(deny_unknown_fields)]
@@ -31,6 +34,8 @@ pub struct Config {
     pub keymap: Vec<Keymap>,
     #[serde(default = "default_mode")]
     pub default_mode: String,
+    #[serde(deserialize_with = "deserialize_virtual_modifiers", default = "Vec::new")]
+    pub virtual_modifiers: Vec<Key>,
 
     // Internals
     #[serde(skip)]
@@ -69,3 +74,15 @@ pub fn config_watcher(watch: bool, file: &Path) -> anyhow::Result<Option<Inotify
 fn default_mode() -> String {
     "default".to_string()
 }
+
+fn deserialize_virtual_modifiers<'de, D>(deserializer: D) -> Result<Vec<Key>, D::Error>
+where
+    D: Deserializer<'de>,
+{
+    let key_strs = Vec::<String>::deserialize(deserializer)?;
+    let mut keys: Vec<Key> = vec![];
+    for key_str in key_strs {
+        keys.push(parse_key(&key_str).map_err(serde::de::Error::custom)?);
+    }
+    return Ok(keys);
+}

src/config/tests.rs

@@ -66,6 +66,14 @@ fn test_modmap_multi_purpose_key() {
     "})
 }
 
+#[test]
+fn test_virtual_modifiers() {
+    assert_parse(indoc! {"
+    virtual_modifiers:
+      - CapsLock
+    "})
+}
+
 #[test]
 fn test_modmap_press_release_key() {
     assert_parse(indoc! {r#"

src/event_handler.rs

@@ -1,7 +1,7 @@
 use crate::client::{build_client, WMClient};
 use crate::config::action::Action;
 use crate::config::application::Application;
-use crate::config::key_action::{KeyAction, ModifierKey, MultiPurposeKey, PressReleaseKey};
+use crate::config::key_action::{KeyAction, MultiPurposeKey, PressReleaseKey};
 use crate::config::key_press::{KeyPress, Modifier};
 use crate::config::keymap::{build_override_table, OverrideEntry};
 use crate::config::remap::Remap;
@@ -85,7 +85,10 @@ impl EventHandler {
 
         // Apply keymap
         for (key, value) in key_values.into_iter() {
-            if MODIFIER_KEYS.contains(&key.code()) {
+            if config.virtual_modifiers.contains(&key) {
+                self.update_modifier(key, value);
+                continue;
+            } else if MODIFIER_KEYS.contains(&key.code()) {
                 self.update_modifier(key, value);
             } else if is_pressed(value) {
                 if self.escape_next_key {
@@ -162,17 +165,6 @@ impl EventHandler {
     ) -> Result<Vec<(Key, i32)>, Box<dyn Error>> {
         let keys = match key_action {
             KeyAction::Key(modmap_key) => vec![(modmap_key, value)],
-            KeyAction::ModifierKey(ModifierKey { modifier }) => {
-                if modifier {
-                    if value == PRESS {
-                        self.modifiers.insert(key);
-                    } else if value == RELEASE {
-                        self.modifiers.remove(&key);
-                    }
-                }
-                // Process this key only in xremap
-                vec![]
-            }
             KeyAction::MultiPurposeKey(MultiPurposeKey {
                 held,
                 alone,