Add support for configuring clipboard used for mouse yank

Adds mouse_yank_clipboard configuration option under the
editor section:

[editor]
mouse-yank-clipboard = "system" / "primary" (default "primary")

This affects the following actions:
- Selecting text with mouse will yank to configured clipboard
- Pasting with middle mouse button will use configured clipboard
- Replacing selected text with ALT+middle mouse button will use
  configured clipboard

Without this option Helix will fallback to current behavior of using
the primary clipboard for the above mentioned actions.

book/src/editor.md

@@ -24,6 +24,7 @@
 |--|--|---------|
 | `scrolloff` | Number of lines of padding around the edge of the screen when scrolling | `5` |
 | `mouse` | Enable mouse mode | `true` |
+| `mouse-yank-register` | Which register to use for mouse yanks. | `*` |
 | `middle-click-paste` | Middle click paste support | `true` |
 | `scroll-lines` | Number of lines to scroll per scroll wheel step | `3` |
 | `shell` | Shell to use when running external commands | Unix: `["sh", "-c"]`<br/>Windows: `["cmd", "/C"]` |

helix-term/src/commands.rs

@@ -4174,7 +4174,7 @@ fn yank_joined_to_primary_clipboard(cx: &mut Context) {
     exit_select_mode(cx);
 }
 
-fn yank_primary_selection_impl(editor: &mut Editor, register: char) {
+pub(crate) fn yank_main_selection_to_register(editor: &mut Editor, register: char) {
     let (view, doc) = current!(editor);
     let text = doc.text().slice(..);
 
@@ -4187,17 +4187,17 @@ fn yank_primary_selection_impl(editor: &mut Editor, register: char) {
 }
 
 fn yank_main_selection_to_clipboard(cx: &mut Context) {
-    yank_primary_selection_impl(cx.editor, '+');
+    yank_main_selection_to_register(cx.editor, '+');
     exit_select_mode(cx);
 }
 
 fn yank_main_selection_to_primary_clipboard(cx: &mut Context) {
-    yank_primary_selection_impl(cx.editor, '*');
+    yank_main_selection_to_register(cx.editor, '*');
     exit_select_mode(cx);
 }
 
 #[derive(Copy, Clone)]
-enum Paste {
+pub(crate) enum Paste {
     Before,
     After,
     Cursor,
@@ -4314,11 +4314,11 @@ fn paste_primary_clipboard_before(cx: &mut Context) {
 }
 
 fn replace_with_yanked(cx: &mut Context) {
-    replace_with_yanked_impl(cx.editor, cx.register.unwrap_or('"'), cx.count());
+    replace_selections_with_register(cx.editor, cx.register.unwrap_or('"'), cx.count());
     exit_select_mode(cx);
 }
 
-fn replace_with_yanked_impl(editor: &mut Editor, register: char, count: usize) {
+pub(crate) fn replace_selections_with_register(editor: &mut Editor, register: char, count: usize) {
     let Some(values) = editor
         .registers
         .read(register, editor)
@@ -4355,16 +4355,16 @@ fn replace_with_yanked_impl(editor: &mut Editor, register: char, count: usize) {
 }
 
 fn replace_selections_with_clipboard(cx: &mut Context) {
-    replace_with_yanked_impl(cx.editor, '+', cx.count());
+    replace_selections_with_register(cx.editor, '+', cx.count());
     exit_select_mode(cx);
 }
 
 fn replace_selections_with_primary_clipboard(cx: &mut Context) {
-    replace_with_yanked_impl(cx.editor, '*', cx.count());
+    replace_selections_with_register(cx.editor, '*', cx.count());
     exit_select_mode(cx);
 }
 
-fn paste(editor: &mut Editor, register: char, pos: Paste, count: usize) {
+pub(crate) fn paste(editor: &mut Editor, register: char, pos: Paste, count: usize) {
     let Some(values) = editor.registers.read(register, editor) else {
         return;
     };

helix-term/src/commands/typed.rs

@@ -918,7 +918,7 @@ fn yank_main_selection_to_clipboard(
         return Ok(());
     }
 
-    yank_primary_selection_impl(cx.editor, '+');
+    yank_main_selection_to_register(cx.editor, '+');
     Ok(())
 }
 
@@ -966,7 +966,7 @@ fn yank_main_selection_to_primary_clipboard(
         return Ok(());
     }
 
-    yank_primary_selection_impl(cx.editor, '*');
+    yank_main_selection_to_register(cx.editor, '*');
     Ok(())
 }
 
@@ -1047,7 +1047,7 @@ fn replace_selections_with_clipboard(
         return Ok(());
     }
 
-    replace_with_yanked_impl(cx.editor, '+', 1);
+    replace_selections_with_register(cx.editor, '+', 1);
     Ok(())
 }
 
@@ -1060,7 +1060,7 @@ fn replace_selections_with_primary_clipboard(
         return Ok(());
     }
 
-    replace_with_yanked_impl(cx.editor, '*', 1);
+    replace_selections_with_register(cx.editor, '*', 1);
     Ok(())
 }
 

helix-term/src/ui/editor.rs

@@ -1251,8 +1251,10 @@ impl EditorView {
                 };
 
                 if should_yank {
-                    commands::MappableCommand::yank_main_selection_to_primary_clipboard
+                    commands::yank_main_selection_to_register(
-                        .execute(cxt);
+                        cxt.editor,
+                        config.mouse_yank_register,
+                    );
                     EventResult::Consumed(None)
                 } else {
                     EventResult::Ignored(None)
@@ -1292,8 +1294,11 @@ impl EditorView {
                 }
 
                 if modifiers == KeyModifiers::ALT {
-                    commands::MappableCommand::replace_selections_with_primary_clipboard
+                    commands::replace_selections_with_register(
-                        .execute(cxt);
+                        cxt.editor,
+                        config.mouse_yank_register,
+                        cxt.count(),
+                    );
 
                     return EventResult::Consumed(None);
                 }
@@ -1302,7 +1307,13 @@ impl EditorView {
                     let doc = doc_mut!(editor, &view!(editor, view_id).doc);
                     doc.set_selection(view_id, Selection::point(pos));
                     cxt.editor.focus(view_id);
-                    commands::MappableCommand::paste_primary_clipboard_before.execute(cxt);
+
+                    commands::paste(
+                        cxt.editor,
+                        config.mouse_yank_register,
+                        commands::Paste::Before,
+                        cxt.count(),
+                    );
 
                     return EventResult::Consumed(None);
                 }

helix-view/src/editor.rs

@@ -249,6 +249,8 @@ pub struct Config {
     pub scroll_lines: isize,
     /// Mouse support. Defaults to true.
     pub mouse: bool,
+    /// Which register to use for mouse yank.
+    pub mouse_yank_register: char,
     /// Shell to use for shell commands. Defaults to ["cmd", "/C"] on Windows and ["sh", "-c"] otherwise.
     pub shell: Vec<String>,
     /// Line number mode.
@@ -932,6 +934,7 @@ impl Default for Config {
             scrolloff: 5,
             scroll_lines: 3,
             mouse: true,
+            mouse_yank_register: '*',
             shell: if cfg!(windows) {
                 vec!["cmd".to_owned(), "/C".to_owned()]
             } else {