From 40a0a995afd1f83181ac6fa482286749af31d23a Mon Sep 17 00:00:00 2001
From: Jelle Raaijmakers <jelle@gmta.nl>
Date: Sun, 24 Oct 2021 17:51:29 +0200
Subject: [PATCH] WindowServer: Prevent sending duplicate MousePackets when
 clicking

If a mouse button was clicked, `EventLoop::drain_mouse()` would always
send the last MousePacket state to the screen input - even if that
state is equivalent to the last state sent as part of the button logic.

By remembering if the state was already sent, we prevent sending that
state a second time saving some resources in the process.
---
 Userland/Services/WindowServer/EventLoop.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Userland/Services/WindowServer/EventLoop.cpp b/Userland/Services/WindowServer/EventLoop.cpp
index fc20cda1f2..b4b3eeee45 100644
--- a/Userland/Services/WindowServer/EventLoop.cpp
+++ b/Userland/Services/WindowServer/EventLoop.cpp
@@ -86,6 +86,8 @@ void EventLoop::drain_mouse()
     size_t npackets = nread / sizeof(MousePacket);
     if (!npackets)
         return;
+
+    bool state_is_sent = false;
     for (size_t i = 0; i < npackets; ++i) {
         auto& packet = packets[i];
         dbgln_if(WSMESSAGELOOP_DEBUG, "EventLoop: Mouse X {}, Y {}, Z {}, relative={}", packet.x, packet.y, packet.z, packet.is_relative);
@@ -99,11 +101,13 @@ void EventLoop::drain_mouse()
             state.y = packet.y;
         }
         state.z += packet.z;
+        state_is_sent = false;
 
         if (packet.buttons != state.buttons) {
             state.buttons = packet.buttons;
             dbgln_if(WSMESSAGELOOP_DEBUG, "EventLoop: Mouse Button Event");
             screen_input.on_receive_mouse_data(state);
+            state_is_sent = true;
             if (state.is_relative) {
                 state.x = 0;
                 state.y = 0;
@@ -111,6 +115,8 @@ void EventLoop::drain_mouse()
             }
         }
     }
+    if (state_is_sent)
+        return;
     if (state.is_relative && (state.x || state.y || state.z))
         screen_input.on_receive_mouse_data(state);
     if (!state.is_relative)