From 653b2dc676d50619db166073678fcf00d2e76604 Mon Sep 17 00:00:00 2001
From: Thorsten Ball <mrnugget@gmail.com>
Date: Fri, 8 Nov 2024 16:53:39 +0100
Subject: [PATCH] project panel: Stop flickering border when preview tabs
 disabled (#20417)

PR #20154 changed the project panel to focus the editor on click in case
preview tabs are disabled.

That lead to a flickering behavior: on mouse-down the border of the
still-selected entry in the project panel would flash, only to disappear
as soon as the entry was opened and editor focused.

This change fixes it by manually keeping track of the mouse-down state,
because we couldn't find a better solution that allows us to simply not
show the border while a "click" is going on.

Release Notes:

- Fixed project panel entries flickering the border when user clicks on
another entry to open it (when preview tabs are disabled.)

Co-authored-by: Piotr <piotr@zed.dev>
---
 crates/project_panel/src/project_panel.rs | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/crates/project_panel/src/project_panel.rs b/crates/project_panel/src/project_panel.rs
index 0129be5f19..d8ad0c58a5 100644
--- a/crates/project_panel/src/project_panel.rs
+++ b/crates/project_panel/src/project_panel.rs
@@ -91,6 +91,9 @@ pub struct ProjectPanel {
     horizontal_scrollbar_state: ScrollbarState,
     hide_scrollbar_task: Option<Task<()>>,
     max_width_item_index: Option<usize>,
+    // We keep track of the mouse down state on entries so we don't flash the UI
+    // in case a user clicks to open a file.
+    mouse_down: bool,
 }
 
 #[derive(Clone, Debug)]
@@ -338,6 +341,7 @@ impl ProjectPanel {
                     .parent_view(cx.view()),
                 max_width_item_index: None,
                 scroll_handle,
+                mouse_down: false,
             };
             this.update_visible_entries(None, cx);
 
@@ -2582,12 +2586,21 @@ impl ProjectPanel {
                 this.hover_scroll_task.take();
                 this.drag_onto(selections, entry_id, kind.is_file(), cx);
             }))
+            .on_mouse_down(
+                MouseButton::Left,
+                cx.listener(move |this, _, cx| {
+                    this.mouse_down = true;
+                    cx.propagate();
+                }),
+            )
             .on_click(cx.listener(move |this, event: &gpui::ClickEvent, cx| {
                 if event.down.button == MouseButton::Right || event.down.first_mouse || show_editor
                 {
                     return;
                 }
-
+                if event.down.button == MouseButton::Left {
+                    this.mouse_down = false;
+                }
                 cx.stop_propagation();
 
                 if let Some(selection) = this.selection.filter(|_| event.down.modifiers.shift) {
@@ -2767,7 +2780,7 @@ impl ProjectPanel {
                     .border_color(colors.ghost_element_selected)
             })
             .when(
-                is_active && self.focus_handle.contains_focused(cx),
+                !self.mouse_down && is_active && self.focus_handle.contains_focused(cx),
                 |this| this.border_color(Color::Selected.color(cx)),
             )
     }