Nav: Fixed an issue with losing focus on docked windows when pressing Alt while keyboard navigation is disabled. (#4547, #4439)

docs/CHANGELOG.txt

@@ -152,6 +152,8 @@ Docking+Viewports Branch:
   docking hierarchy. Added ImGuiFocusedFlags_DockHierarchy flag to consider docking hierarchy in the test.
 - IsWindowHovered: Fixed using ImGuiHoveredFlags_ChildWindows (without _RootWindow) from leaking the
   docking hierarchy. Added ImGuiHoveredFlags_DockHierarchy flag to consider docking hierarchy in the test.
+- Nav: Fixed an issue with losing focus on docked windows when pressing Alt while keyboard navigation
+  is disabled. (#4547, #4439) [@PathogenDavid]
 - Docking: Improved resizing system so that non-central zone are better at keeping their fixed size.
   The algorithm is still not handling the repartition of size idealy for nested sibling, but it got better.
 - Docking: Fixed settings load issue when mouse wheeling. (#4310)

imgui.cpp

@@ -10413,8 +10413,9 @@ static void ImGui::NavUpdateWindowing()
     }
 
     // Start CTRL-TAB or Square+L/R window selection
-    bool start_windowing_with_gamepad = allow_windowing && !g.NavWindowingTarget && IsNavInputTest(ImGuiNavInput_Menu, ImGuiInputReadMode_Pressed);
-    bool start_windowing_with_keyboard = allow_windowing && !g.NavWindowingTarget && io.KeyCtrl && IsKeyPressedMap(ImGuiKey_Tab) && (io.ConfigFlags & ImGuiConfigFlags_NavEnableKeyboard);
+    const bool nav_keyboard_active = (io.ConfigFlags & ImGuiConfigFlags_NavEnableKeyboard) != 0;
+    const bool start_windowing_with_gamepad = allow_windowing && !g.NavWindowingTarget && IsNavInputTest(ImGuiNavInput_Menu, ImGuiInputReadMode_Pressed);
+    const bool start_windowing_with_keyboard = allow_windowing && !g.NavWindowingTarget && nav_keyboard_active && io.KeyCtrl && IsKeyPressedMap(ImGuiKey_Tab);
     if (start_windowing_with_gamepad || start_windowing_with_keyboard)
         if (ImGuiWindow* window = g.NavWindow ? g.NavWindow : FindWindowNavFocusable(g.WindowsFocusOrder.Size - 1, -INT_MAX, -1))
         {
@@ -10465,7 +10466,7 @@ static void ImGui::NavUpdateWindowing()
     // Keyboard: Press and Release ALT to toggle menu layer
     // - Testing that only Alt is tested prevents Alt+Shift or AltGR from toggling menu layer.
     // - AltGR is normally Alt+Ctrl but we can't reliably detect it (not all backends/systems/layout emit it as Alt+Ctrl). But even on keyboards without AltGR we don't want Alt+Ctrl to open menu anyway.
-    if (io.KeyMods == ImGuiKeyModFlags_Alt && (io.KeyModsPrev & ImGuiKeyModFlags_Alt) == 0)
+    if (nav_keyboard_active && io.KeyMods == ImGuiKeyModFlags_Alt && (io.KeyModsPrev & ImGuiKeyModFlags_Alt) == 0)
     {
         g.NavWindowingToggleLayer = true;
         g.NavInputSource = ImGuiInputSource_Keyboard;