From 03ffd08ebbbe4b46978229bd17e25931699c5f59 Mon Sep 17 00:00:00 2001
From: Thomas Linford <tlinford@users.noreply.github.com>
Date: Sat, 30 Apr 2022 18:46:17 +0200
Subject: [PATCH] fix(mouse): improve mouse event reporting (#1329)

* fix: do not rebroadcast mouse press events
* fix: do not send generated mouse hold events to applications
* begin selecting only if click is on terminal pane
---
 zellij-client/src/stdin_handler.rs | 37 +++++++++++++-----------------
 zellij-server/src/tab/mod.rs       | 16 +++++++++++--
 2 files changed, 30 insertions(+), 23 deletions(-)

diff --git a/zellij-client/src/stdin_handler.rs b/zellij-client/src/stdin_handler.rs
index d8321463..e6794ded 100644
--- a/zellij-client/src/stdin_handler.rs
+++ b/zellij-client/src/stdin_handler.rs
@@ -1,9 +1,7 @@
 use crate::os_input_output::ClientOsApi;
 use crate::InputInstruction;
 use zellij_utils::channels::SenderWithContext;
-use zellij_utils::input::mouse::{MouseButton, MouseEvent};
-
-use zellij_utils::termwiz::input::{InputEvent, InputParser};
+use zellij_utils::termwiz::input::{InputEvent, InputParser, MouseButtons};
 
 pub(crate) fn stdin_loop(
     os_input: Box<dyn ClientOsApi>,
@@ -17,8 +15,7 @@ pub(crate) fn stdin_loop(
         current_buffer.append(&mut buf.to_vec());
         let maybe_more = false; // read_from_stdin should (hopefully) always empty the STDIN buffer completely
         let parse_input_event = |input_event: InputEvent| {
-            holding_mouse = should_hold_mouse(input_event.clone());
-            if holding_mouse {
+            if holding_mouse && is_mouse_press_or_hold(&input_event) {
                 let mut poller = os_input.stdin_poller();
                 loop {
                     let ready = poller.ready();
@@ -32,29 +29,27 @@ pub(crate) fn stdin_loop(
                         ))
                         .unwrap();
                 }
-            } else {
-                send_input_instructions
-                    .send(InputInstruction::KeyEvent(
-                        input_event,
-                        current_buffer.drain(..).collect(),
-                    ))
-                    .unwrap();
             }
+
+            holding_mouse = is_mouse_press_or_hold(&input_event);
+
+            send_input_instructions
+                .send(InputInstruction::KeyEvent(
+                    input_event,
+                    current_buffer.drain(..).collect(),
+                ))
+                .unwrap();
         };
         input_parser.parse(&buf, parse_input_event, maybe_more);
     }
 }
 
-fn should_hold_mouse(input_event: InputEvent) -> bool {
+fn is_mouse_press_or_hold(input_event: &InputEvent) -> bool {
     if let InputEvent::Mouse(mouse_event) = input_event {
-        let mouse_event = zellij_utils::input::mouse::MouseEvent::from(mouse_event);
-        if let MouseEvent::Press(button, _point) = mouse_event {
-            match button {
-                MouseButton::Left | MouseButton::Right => {
-                    return true;
-                }
-                _ => {}
-            }
+        if mouse_event.mouse_buttons.contains(MouseButtons::LEFT)
+            || mouse_event.mouse_buttons.contains(MouseButtons::RIGHT)
+        {
+            return true;
         }
     }
     false
diff --git a/zellij-server/src/tab/mod.rs b/zellij-server/src/tab/mod.rs
index 18eb99f3..9f9d4d4e 100644
--- a/zellij-server/src/tab/mod.rs
+++ b/zellij-server/src/tab/mod.rs
@@ -90,6 +90,7 @@ pub(crate) struct Tab {
     // it seems that optimization is possible using `active_panes`
     focus_pane_id: Option<PaneId>,
     copy_on_select: bool,
+    last_mouse_hold_position: Option<Position>,
     terminal_emulator_colors: Rc<RefCell<Palette>>,
 }
 
@@ -354,6 +355,7 @@ impl Tab {
             clipboard_provider,
             focus_pane_id: None,
             copy_on_select: copy_options.copy_on_select,
+            last_mouse_hold_position: None,
             terminal_emulator_colors,
         }
     }
@@ -1547,7 +1549,7 @@ impl Tab {
                     relative_position.line.0 + 1
                 );
                 self.write_to_active_terminal(mouse_event.into_bytes(), client_id);
-            } else {
+            } else if let PaneId::Terminal(_) = pane.pid() {
                 pane.start_selection(&relative_position, client_id);
                 self.selecting_with_mouse = true;
             }
@@ -1588,6 +1590,8 @@ impl Tab {
         }
     }
     pub fn handle_mouse_release(&mut self, position: &Position, client_id: ClientId) {
+        self.last_mouse_hold_position = None;
+
         if self.floating_panes.panes_are_visible()
             && self.floating_panes.pane_is_being_moved_with_mouse()
         {
@@ -1629,6 +1633,14 @@ impl Tab {
         }
     }
     pub fn handle_mouse_hold(&mut self, position_on_screen: &Position, client_id: ClientId) {
+        // determine if event is repeated to enable smooth scrolling
+        let is_repeated = if let Some(last_position) = self.last_mouse_hold_position {
+            position_on_screen == &last_position
+        } else {
+            false
+        };
+        self.last_mouse_hold_position = Some(*position_on_screen);
+
         let search_selectable = true;
 
         if self.floating_panes.panes_are_visible()
@@ -1646,7 +1658,7 @@ impl Tab {
 
         if let Some(active_pane) = active_pane {
             let relative_position = active_pane.relative_position(position_on_screen);
-            if active_pane.mouse_mode() {
+            if active_pane.mouse_mode() && !is_repeated {
                 // ensure that coordinates are valid
                 let col = (relative_position.column.0 + 1)
                     .max(1)