Fix: Keep the top bar's controls where they take clicks when the appbar folds

rivet/platform/windows/src/row_watch.rs

@@ -216,6 +216,7 @@ pub const FEATURES: &[&str] = &[
     "split-grid-3",
     "split-grid-4",
     "bar-layout",
+    "bar-folded",
     "mini-pop-out",
     "mini-move",
     "mini-return",

rivet/runtime/windows/src/features/address_bar.rs

@@ -692,14 +692,22 @@ pub(crate) unsafe fn with_field_pixels<R>(
     })
 }
 
-unsafe fn part_at(window: HWND, point: POINT) -> Option<Part> {
+/// The control of the top bar under a client pixel. The window's hit test asks it too, so the bar
+/// takes the clicks of its controls wherever the browser would put its own title bar.
+pub(crate) unsafe fn part_at(window: HWND, point: POINT) -> Option<Part> {
     let [x, y, width] = place(window)?;
     let f = factor(window);
     let (px, py) = (point.x as f32 / f - x, point.y as f32 / f - y);
+    part_in(width, in_pane(window), dev_reserve(window), px, py)
+}
+
+/// The control of a bar `width` DIPs wide at `px`, `py` DIPs from its top left corner, from the
+/// same places the bar is painted at.
+pub(crate) fn part_in(width: f32, pane: bool, reserve: f32, px: f32, py: f32) -> Option<Part> {
     if py < 0.0 || py >= ROW_HEIGHT as f32 {
         return None;
     }
-    let parts = parts_reserving(width, in_pane(window), dev_reserve(window));
+    let parts = parts_reserving(width, pane, reserve);
     // The chip lies inside the address, so it is looked for first.
     parts
         .iter()
@@ -1709,6 +1717,27 @@ pub(crate) fn caret(window: HWND) -> Option<RECT> {
 mod tests {
     use super::*;
 
+    #[test]
+    fn fr12_each_control_answers_where_it_is_painted_shown_and_folded() {
+        // A bar beside the shown appbar and the wider bar of a folded one, as the browser lays
+        // the panel out for each.
+        for width in [1156.0, 1422.0] {
+            for (part, at, w) in parts_reserving(width, false, 0.0) {
+                if part == Part::Chip {
+                    continue;
+                }
+                let middle = at + w / 2.0;
+                assert_eq!(
+                    part_in(width, false, 0.0, middle, ROW_HEIGHT as f32 / 2.0),
+                    Some(part),
+                    "{part:?} of a {width} DIP bar"
+                );
+            }
+            assert_eq!(part_in(width, false, 0.0, 10.0, -1.0), None);
+            assert_eq!(part_in(width, false, 0.0, 10.0, ROW_HEIGHT as f32), None);
+        }
+    }
+
     #[test]
     fn nfr2_one_key_asks_the_browser_once_and_rivets_own_completion_never() {
         // A key down and up leave the text alone, so only the character asks.

rivet/runtime/windows/src/frame.rs

@@ -3460,9 +3460,19 @@ fn panel_moved(window: HWND) {
                 }
             }
         });
+        // The top bar is the panel's first row, so it moves with the panel. It is painted after
+        // this layout, never inside it, and until then its old place would show where the bar no
+        // longer takes clicks, as after the appbar folds.
+        PostMessageW(window, bar_moved_message(), 0, 0);
     }
 }
 
+const BAR_MOVED_MESSAGE: &str = "Rivet.BarMoved";
+
+fn bar_moved_message() -> u32 {
+    unsafe { RegisterWindowMessageW(wide(BAR_MOVED_MESSAGE).as_ptr()) }
+}
+
 /// The thickness of the visible window border along the top edge. A maximized window has none.
 unsafe fn top_border(window: HWND) -> i32 {
     if IsZoomed(window) != 0 {
@@ -3589,6 +3599,11 @@ unsafe fn hit_test(window: HWND, lparam: LPARAM) -> StripHit {
         && row_hit(window, point).is_none()
         && crate::dev_bar::hit(window, point).is_none()
     {
+        // The bar's controls are Rivet's, at the places it painted them, whatever the browser's
+        // own hit test would say of its title bar there.
+        if crate::features::address_bar::part_at(window, point).is_some() {
+            return StripHit::Client;
+        }
         let mut client: RECT = std::mem::zeroed();
         GetClientRect(window, &mut client);
         // The panel starts one gap below the client area's top edge, so the row is measured from it.
@@ -3767,6 +3782,10 @@ unsafe fn handle(window: HWND, message: u32, wparam: WPARAM, lparam: LPARAM) ->
         toggle_appbar(window);
         return 0;
     }
+    if message == bar_moved_message() && attached(window) {
+        update_top_bar(window);
+        return 0;
+    }
     // Rivet's top bar takes the pointer over it and, while its address is edited, the keyboard and
     // the input method.
     if attached(window) && !menu_open(window) && !tab_dragging(window) && !dragging(window) {
@@ -4145,6 +4164,7 @@ unsafe fn handle(window: HWND, message: u32, wparam: WPARAM, lparam: LPARAM) ->
             StripHit::Top => HTTOP as LRESULT,
             StripHit::TopLeft => HTTOPLEFT as LRESULT,
             StripHit::Appbar | StripHit::Resizer => APPBAR_HIT as LRESULT,
+            StripHit::Client => 1, // HTCLIENT
             StripHit::Minimize => HTMINBUTTON as LRESULT,
             StripHit::Maximize => HTMAXBUTTON as LRESULT,
             StripHit::Close => HTCLOSE as LRESULT,

rivet/runtime/windows/src/lib.rs

@@ -189,6 +189,9 @@ enum StripHit {
     Resizer,
     /// Belongs to the appbar's own content.
     Appbar,
+    /// A control of Rivet's top bar, which takes its clicks in the client area.
+    #[cfg_attr(not(windows), allow(dead_code))]
+    Client,
     /// The caption buttons, which Windows needs by name for Snap Layouts.
     #[cfg_attr(not(windows), allow(dead_code))]
     Minimize,

scripts/tests/windows-features.ps1

@@ -16,7 +16,7 @@
 # rows run only when no other run is active (windows-test-safety.ps1).
 param(
   [string[]]$Browsers = @('chrome', 'edge', 'whale', 'brave', 'samsung'),
-  [string[]]$Features = @('split', 'sidebar', 'newtab', 'space', 'split-start', 'split-menu', 'split-menu-start', 'split-drag', 'split-drag-start', 'split-shortcut', 'split-one-tab', 'split-maximised', 'split-space', 'split-click', 'split-rows', 'split-drop-top', 'split-drop-bottom', 'split-grid-3', 'split-grid-4', 'bar-layout', 'mini-pop-out', 'mini-move', 'mini-return', 'mini-close', 'tab-sections', 'tab-close-select', 'tab-reopen', 'tab-archive', 'ctrl-t-setting', 'link-new-tab', 'command-bar', 'link-preview', 'rivet-settings', 'link-rules', 'address-suggest', 'appbar-width', 'appbar-peek', 'open-link-running', 'open-link-start', 'credentials-browser', 'credentials-system', 'view-click', 'view-click-other', 'view-keys', 'view-ime', 'tab-moves', 'first-frame', 'fullscreen-sidebar', 'taskbar-identity', 'taskbar-relaunch', 'sidebar-scale-monitor', 'split-panel-look', 'sidebar-floats', 'sidebar-open-button', 'dev-row', 'address-editing', 'security-chip', 'permission-bubble', 'password-bubble', 'typing-keeps-active', 'cli-control', 'cli-input', 'cli-hidden'),
+  [string[]]$Features = @('split', 'sidebar', 'newtab', 'space', 'split-start', 'split-menu', 'split-menu-start', 'split-drag', 'split-drag-start', 'split-shortcut', 'split-one-tab', 'split-maximised', 'split-space', 'split-click', 'split-rows', 'split-drop-top', 'split-drop-bottom', 'split-grid-3', 'split-grid-4', 'bar-layout', 'bar-folded', 'mini-pop-out', 'mini-move', 'mini-return', 'mini-close', 'tab-sections', 'tab-close-select', 'tab-reopen', 'tab-archive', 'ctrl-t-setting', 'link-new-tab', 'command-bar', 'link-preview', 'rivet-settings', 'link-rules', 'address-suggest', 'appbar-width', 'appbar-peek', 'open-link-running', 'open-link-start', 'credentials-browser', 'credentials-system', 'view-click', 'view-click-other', 'view-keys', 'view-ime', 'tab-moves', 'first-frame', 'fullscreen-sidebar', 'taskbar-identity', 'taskbar-relaunch', 'sidebar-scale-monitor', 'split-panel-look', 'sidebar-floats', 'sidebar-open-button', 'dev-row', 'address-editing', 'security-chip', 'permission-bubble', 'password-bubble', 'typing-keeps-active', 'cli-control', 'cli-input', 'cli-hidden'),
   [string]$OutDir,
   [switch]$NoBuild,
   # A browser build outside its usual folder, such as one a row job downloaded. Needs one -Browsers.