Docking: added ImGuiDockNodeFlags_DockedWindowsInFocusRoute to configure a dock node to automatically set ParentWindowForFocusRoute on its docked windows. (#6798, #2637, #456)

docs/CHANGELOG.txt

@@ -58,6 +58,9 @@ Docking+Viewports Branch:
 - Added ImGuiWindowClass::FocusRouteParentWindowId as a way to connect the focus route between
   a tool window to a parent document window, so that Shortcuts in the documents are routed when the
   tool is focused (regardless of whether the tool is docked or in a floating viewport, etc.) (#6798)
+- Added ImGuiDockNodeFlags_DockedWindowsInFocusRoute to automatically make a dockspace connect
+  the focus route of its docked window. This is provided a convenience in case you have windows
+  where a connection is not explicit. (#6798)
 
 
 -----------------------------------------------------------------------

imgui.cpp

@@ -6844,6 +6844,9 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
         // There's little point to expose a flag to set this: because the interesting cases won't be using parent_window_in_stack,
         // Use for e.g. linking a tool window in a standalone viewport to a document window, regardless of their Begin() stack parenting. (#6798)
         window->ParentWindowForFocusRoute = (window->RootWindow != window) ? parent_window_in_stack : NULL;
+        if (window->ParentWindowForFocusRoute == NULL && window->DockNode != NULL)
+            if (window->DockNode->MergedFlags & ImGuiDockNodeFlags_DockedWindowsInFocusRoute)
+                window->ParentWindowForFocusRoute = window->DockNode->HostWindow;
 
         // Override with SetNextWindowClass() field or direct call to SetWindowParentWindowForFocusRoute()
         if (window->WindowClass.FocusRouteParentWindowId != 0)
@@ -20380,6 +20383,7 @@ static void DebugNodeDockNodeFlags(ImGuiDockNodeFlags* p_flags, const char* labe
     CheckboxFlags("HiddenTabBar", p_flags, ImGuiDockNodeFlags_HiddenTabBar);
     CheckboxFlags("NoWindowMenuButton", p_flags, ImGuiDockNodeFlags_NoWindowMenuButton);
     CheckboxFlags("NoCloseButton", p_flags, ImGuiDockNodeFlags_NoCloseButton);
+    CheckboxFlags("DockedWindowsInFocusRoute", p_flags, ImGuiDockNodeFlags_DockedWindowsInFocusRoute);
     CheckboxFlags("NoDocking", p_flags, ImGuiDockNodeFlags_NoDocking); // Multiple flags
     CheckboxFlags("NoDockingSplit", p_flags, ImGuiDockNodeFlags_NoDockingSplit);
     CheckboxFlags("NoDockingSplitOther", p_flags, ImGuiDockNodeFlags_NoDockingSplitOther);

imgui_internal.h

@@ -1723,6 +1723,7 @@ enum ImGuiDockNodeFlagsPrivate_
     ImGuiDockNodeFlags_NoCloseButton            = 1 << 15,  // Saved // Disable close button
     ImGuiDockNodeFlags_NoResizeX                = 1 << 16,  //       //
     ImGuiDockNodeFlags_NoResizeY                = 1 << 17,  //       //
+    ImGuiDockNodeFlags_DockedWindowsInFocusRoute= 1 << 18,  //       // Any docked window will be automatically be focus-route chained (window->ParentWindowForFocusRoute set to this) so Shortcut() in this window can run when any docked window is focused.
     // Disable docking/undocking actions in this dockspace or individual node (existing docked nodes will be preserved)
     // Those are not exposed in public because the desirable sharing/inheriting/copy-flag-on-split behaviors are quite difficult to design and understand.
     // The two public flags ImGuiDockNodeFlags_NoDockingOverCentralNode/ImGuiDockNodeFlags_NoDockingSplit don't have those issues.