Focus: start moving modal check into FocusWindow(), add ImGuiFocusRequestFlags_UnlessBelowModal (currently opt-in, should try to make opt-out). (#6357, #4317)

imgui.cpp

@@ -1056,7 +1056,6 @@ static void             RenderWindowDecorations(ImGuiWindow* window, const ImRec
 static void             RenderWindowTitleBarContents(ImGuiWindow* window, const ImRect& title_bar_rect, const char* name, bool* p_open);
 static void             RenderDimmedBackgroundBehindWindow(ImGuiWindow* window, ImU32 col);
 static void             RenderDimmedBackgrounds();
-static ImGuiWindow*     FindBlockingModal(ImGuiWindow* window);
 
 // Viewports
 static void             UpdateViewportsNewFrame();
@@ -3911,7 +3910,7 @@ bool ImGui::IsWindowContentHoverable(ImGuiWindow* window, ImGuiHoveredFlags flag
 
                 // Inhibit hover unless the window is within the stack of our modal/popup
                 if (want_inhibit)
-                    if (!ImGui::IsWindowWithinBeginStackOf(window->RootWindow, focused_root_window))
+                    if (!IsWindowWithinBeginStackOf(window->RootWindow, focused_root_window))
                         return false;
             }
     return true;
@@ -4296,10 +4295,10 @@ void ImGui::UpdateMouseMovingWindowEndFrame()
             if (g.HoveredIdDisabled)
                 g.MovingWindow = NULL;
         }
-        else if (root_window == NULL && g.NavWindow != NULL && GetTopMostPopupModal() == NULL)
+        else if (root_window == NULL && g.NavWindow != NULL)
         {
             // Clicking on void disable focus
-            FocusWindow(NULL);
+            FocusWindow(NULL, ImGuiFocusRequestFlags_UnlessBelowModal);
         }
     }
 
@@ -4624,7 +4623,7 @@ void ImGui::NewFrame()
 
     // Closing the focused window restore focus to the first active root window in descending z-order
     if (g.NavWindow && !g.NavWindow->WasActive)
-        FocusTopMostWindowUnderOne(NULL, NULL, NULL);
+        FocusTopMostWindowUnderOne(NULL, NULL, NULL, ImGuiFocusRequestFlags_None);
 
     // No window should be open at the beginning of the frame.
     // But in order to allow the user to call NewFrame() multiple times without calling Render(), we are doing an explicit clear.
@@ -6077,7 +6076,7 @@ void ImGui::UpdateWindowParentAndRootLinks(ImGuiWindow* window, ImGuiWindowFlags
 //      - Window        //                  .. returns Modal2
 //          - Window    //                  .. returns Modal2
 //          - Modal2    //                  .. returns Modal2
-static ImGuiWindow* ImGui::FindBlockingModal(ImGuiWindow* window)
+ImGuiWindow* ImGui::FindBlockingModal(ImGuiWindow* window)
 {
     ImGuiContext& g = *GImGui;
     if (g.OpenPopupStack.Size <= 0)
@@ -6091,6 +6090,8 @@ static ImGuiWindow* ImGui::FindBlockingModal(ImGuiWindow* window)
             continue;
         if (!popup_window->Active && !popup_window->WasActive)      // Check WasActive, because this code may run before popup renders on current frame, also check Active to handle newly created windows.
             continue;
+        if (window == NULL)                                         // FindBlockingModal(NULL) test for if FocusWindow(NULL) is naturally possible via a mouse click.
+            return popup_window;
         if (IsWindowWithinBeginStackOf(window, popup_window))       // Window is rendered over last modal, no render order change needed.
             break;
         for (ImGuiWindow* parent = popup_window->ParentWindowInBeginStack->RootWindow; parent != NULL; parent = parent->ParentWindowInBeginStack->RootWindow)
@@ -6928,10 +6929,19 @@ int ImGui::FindWindowDisplayIndex(ImGuiWindow* window)
 }
 
 // Moving window to front of display and set focus (which happens to be back of our sorted list)
-void ImGui::FocusWindow(ImGuiWindow* window)
+void ImGui::FocusWindow(ImGuiWindow* window, ImGuiFocusRequestFlags flags)
 {
     ImGuiContext& g = *GImGui;
 
+    // Modal check?
+    if (flags & ImGuiFocusRequestFlags_UnlessBelowModal)
+        if (ImGuiWindow* blocking_modal = FindBlockingModal(window))
+        {
+            IMGUI_DEBUG_LOG_FOCUS("[focus] FocusWindow(\"%s\", UnlessBelowModal): prevented by \"%s\".\n", window ? window->Name : "<NULL>", blocking_modal->Name);
+            return;
+        }
+
+    // Apply focus
     if (g.NavWindow != window)
     {
         SetNavWindow(window);
@@ -6968,7 +6978,7 @@ void ImGui::FocusWindow(ImGuiWindow* window)
         BringWindowToDisplayFront(display_front_window);
 }
 
-void ImGui::FocusTopMostWindowUnderOne(ImGuiWindow* under_this_window, ImGuiWindow* ignore_window, ImGuiViewport* filter_viewport)
+void ImGui::FocusTopMostWindowUnderOne(ImGuiWindow* under_this_window, ImGuiWindow* ignore_window, ImGuiViewport* filter_viewport, ImGuiFocusRequestFlags flags)
 {
     ImGuiContext& g = *GImGui;
     IM_UNUSED(filter_viewport); // Unused in master branch.
@@ -6994,11 +7004,11 @@ void ImGui::FocusTopMostWindowUnderOne(ImGuiWindow* under_this_window, ImGuiWind
         if ((window->Flags & (ImGuiWindowFlags_NoMouseInputs | ImGuiWindowFlags_NoNavInputs)) != (ImGuiWindowFlags_NoMouseInputs | ImGuiWindowFlags_NoNavInputs))
         {
             ImGuiWindow* focus_window = NavRestoreLastChildNavWindow(window);
-            FocusWindow(focus_window);
+            FocusWindow(focus_window, flags);
             return;
         }
     }
-    FocusWindow(NULL);
+    FocusWindow(NULL, flags);
 }
 
 // Important: this alone doesn't alter current ImDrawList state. This is called by PushFont/PopFont only.
@@ -10101,6 +10111,7 @@ bool ImGui::IsPopupOpen(const char* str_id, ImGuiPopupFlags popup_flags)
     return IsPopupOpen(id, popup_flags);
 }
 
+// FIXME: In principle we should converge toward replacing calls to GetTopMostPopupModal() + IsWindowWithinBeginStackOf() with calls to FindBlockingModal()
 ImGuiWindow* ImGui::GetTopMostPopupModal()
 {
     ImGuiContext& g = *GImGui;
@@ -10263,7 +10274,7 @@ void ImGui::ClosePopupToLevel(int remaining, bool restore_focus_to_window_under_
         if (focus_window && !focus_window->WasActive && popup_window)
         {
             // Fallback
-            FocusTopMostWindowUnderOne(popup_window, NULL, NULL);
+            FocusTopMostWindowUnderOne(popup_window, NULL, NULL, ImGuiFocusRequestFlags_None);
         }
         else
         {

imgui_internal.h

@@ -164,6 +164,7 @@ typedef int ImGuiLayoutType;            // -> enum ImGuiLayoutType_         // E
 // Flags
 typedef int ImGuiActivateFlags;         // -> enum ImGuiActivateFlags_      // Flags: for navigation/focus function (will be for ActivateItem() later)
 typedef int ImGuiDebugLogFlags;         // -> enum ImGuiDebugLogFlags_      // Flags: for ShowDebugLogWindow(), g.DebugLogFlags
+typedef int ImGuiFocusRequestFlags;     // -> enum ImGuiFocusRequestFlags_  // Flags: for FocusWindow();
 typedef int ImGuiInputFlags;            // -> enum ImGuiInputFlags_         // Flags: for IsKeyPressed(), IsMouseClicked(), SetKeyOwner(), SetItemKeyOwner() etc.
 typedef int ImGuiItemFlags;             // -> enum ImGuiItemFlags_          // Flags: for PushItemFlag(), g.LastItemData.InFlags
 typedef int ImGuiItemStatusFlags;       // -> enum ImGuiItemStatusFlags_    // Flags: for g.LastItemData.StatusFlags
@@ -906,6 +907,15 @@ enum ImGuiSeparatorFlags_
     ImGuiSeparatorFlags_SpanAllColumns          = 1 << 2,
 };
 
+// Flags for FocusWindow(). This is not called ImGuiFocusFlags to avoid confusion with public-facing ImGuiFocusedFlags.
+// FIXME: Once we finishing replacing more uses of GetTopMostPopupModal()+IsWindowWithinBeginStackOf()
+// and FindBlockingModal() with this, we may want to change the flag to be opt-out instead of opt-in.
+enum ImGuiFocusRequestFlags_
+{
+    ImGuiFocusRequestFlags_None                 = 0,
+    ImGuiFocusRequestFlags_UnlessBelowModal     = 1 << 0,   // Do not set focus if the window is below a modal.
+};
+
 enum ImGuiTextFlags_
 {
     ImGuiTextFlags_None                         = 0,
@@ -2751,8 +2761,8 @@ namespace ImGui
     inline ImRect           WindowRectRelToAbs(ImGuiWindow* window, const ImRect& r) { ImVec2 off = window->DC.CursorStartPos; return ImRect(r.Min.x + off.x, r.Min.y + off.y, r.Max.x + off.x, r.Max.y + off.y); }
 
     // Windows: Display Order and Focus Order
-    IMGUI_API void          FocusWindow(ImGuiWindow* window);
+    IMGUI_API void          FocusWindow(ImGuiWindow* window, ImGuiFocusRequestFlags flags = 0);
-    IMGUI_API void          FocusTopMostWindowUnderOne(ImGuiWindow* under_this_window, ImGuiWindow* ignore_window, ImGuiViewport* filter_viewport);
+    IMGUI_API void          FocusTopMostWindowUnderOne(ImGuiWindow* under_this_window, ImGuiWindow* ignore_window, ImGuiViewport* filter_viewport, ImGuiFocusRequestFlags flags);
     IMGUI_API void          BringWindowToFocusFront(ImGuiWindow* window);
     IMGUI_API void          BringWindowToDisplayFront(ImGuiWindow* window);
     IMGUI_API void          BringWindowToDisplayBack(ImGuiWindow* window);
@@ -2872,6 +2882,7 @@ namespace ImGui
     IMGUI_API ImRect        GetPopupAllowedExtentRect(ImGuiWindow* window);
     IMGUI_API ImGuiWindow*  GetTopMostPopupModal();
     IMGUI_API ImGuiWindow*  GetTopMostAndVisiblePopupModal();
+    IMGUI_API ImGuiWindow*  FindBlockingModal(ImGuiWindow* window);
     IMGUI_API ImVec2        FindBestWindowPosForPopup(ImGuiWindow* window);
     IMGUI_API ImVec2        FindBestWindowPosForPopupEx(const ImVec2& ref_pos, const ImVec2& size, ImGuiDir* last_dir, const ImRect& r_outer, const ImRect& r_avoid, ImGuiPopupPositionPolicy policy);
 

imgui_widgets.cpp

@@ -7084,7 +7084,7 @@ void ImGui::EndMainMenuBar()
     // FIXME: With this strategy we won't be able to restore a NULL focus.
     ImGuiContext& g = *GImGui;
     if (g.CurrentWindow == g.NavWindow && g.NavLayer == ImGuiNavLayer_Main && !g.NavAnyRequest)
-        FocusTopMostWindowUnderOne(g.NavWindow, NULL, NULL);
+        FocusTopMostWindowUnderOne(g.NavWindow, NULL, NULL, ImGuiFocusRequestFlags_UnlessBelowModal);
 
     End();
 }