From 6d68db3bdc7743a4c51403bfb9ba111f9edd0900 Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <m@mitchellh.com>
Date: Fri, 27 Sep 2024 14:18:33 -0700
Subject: [PATCH] core: only extend selection on mouse if click interval is
 exceeded

Previously, once we had one click registered, shift+click would always
go into selection extend mode. This is not the behavior we want, since
we want shift+double/triple click to work in alternate screens.

This commit changes the behavior so that we only extend the selection
after the multi-click interval has passed.

I see a lot of opportunity to improve this whole callback much more but
I don't want to risk introducing new bugs since this is a hard to test
area, so I'm going to leave it for now.
---
 src/Surface.zig | 28 +++++++++++++++++++++++-----
 1 file changed, 23 insertions(+), 5 deletions(-)

diff --git a/src/Surface.zig b/src/Surface.zig
index 298b7eabd..e8bbb885f 100644
--- a/src/Surface.zig
+++ b/src/Surface.zig
@@ -2476,15 +2476,33 @@ pub fn mouseButtonCallback(
         if (mods.shift and
             self.mouse.left_click_count > 0 and
             !shift_capture)
-        {
+        extend_selection: {
             // We split this conditional out on its own because this is the
             // only one that requires a renderer mutex grab which is VERY
             // expensive because it could block all our threads.
-            if (self.hasSelection()) {
-                const pos = try self.rt_surface.getCursorPos();
-                try self.cursorPosCallback(pos, null);
-                return true;
+            if (!self.hasSelection()) break :extend_selection;
+
+            // If we are within the interval that the click would register
+            // an increment then we do not extend the selection.
+            if (std.time.Instant.now()) |now| {
+                const since = now.since(self.mouse.left_click_time);
+                if (since <= self.config.mouse_interval) {
+                    // Click interval very short, we may be increasing
+                    // click counts so we don't extend the selection.
+                    break :extend_selection;
+                }
+            } else |err| {
+                // This is a weird behavior, I think either behavior is actually
+                // fine. This failure should be exceptionally rare anyways.
+                // My thinking here is that we can't be sure if we should extend
+                // the selection or not so we just don't.
+                log.warn("failed to get time, not extending selection err={}", .{err});
+                break :extend_selection;
             }
+
+            const pos = try self.rt_surface.getCursorPos();
+            try self.cursorPosCallback(pos, null);
+            return true;
         }
     }