Popups: Fix popups being closed by newly appearing windows. (ocornut#…

…4317)

* Popups/modals now remain open when new windows are created from within popup/modal begin stack.
* Modals are not closed when new window appears behind active modal.

docs/CHANGELOG.txt

@@ -172,6 +172,7 @@ Other Changes:
 - Backends: OSX: Use mach_absolute_time as CFAbsoluteTimeGetCurrent can jump backwards. (#4557, #4563) [@lfnoise]
 - Backends: All renderers: Normalize clipping rect handling across backends. (#4464)
 - Examples: Added SDL + SDL_Renderer example in "examples/example_sdl_sdlrenderer/" folder. (#3926) [@1bsyl]
+- Popups: Windows created from within a popup/modal will no longer close that popup/modal. (#4317) [@rokups]
 
 
 -----------------------------------------------------------------------

imgui.cpp

@@ -3895,7 +3895,7 @@ void ImGui::UpdateHoveredWindowAndCaptureFlags()
 
     // Modal windows prevents mouse from hovering behind them.
     ImGuiWindow* modal_window = GetTopMostPopupModal();
-    if (modal_window && g.HoveredWindow && !IsWindowChildOf(g.HoveredWindow->RootWindow, modal_window, true))
+    if (modal_window && g.HoveredWindow && !IsWindowChildOfBeginStack(g.HoveredWindow->RootWindow, modal_window))
         clear_hovered_windows = true;
 
     // Disabled mouse?
@@ -6126,7 +6126,10 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags)
         bool want_focus = false;
         if (window_just_activated_by_user && !(flags & ImGuiWindowFlags_NoFocusOnAppearing))
         {
-            if (flags & ImGuiWindowFlags_Popup)
+            ImGuiWindow* modal = GetTopMostPopupModal();
+            if (modal != NULL && !IsWindowChildOfBeginStack(window, modal))
+                want_focus = false;
+            else if (flags & ImGuiWindowFlags_Popup)
                 want_focus = true;
             else if ((flags & (ImGuiWindowFlags_ChildWindow | ImGuiWindowFlags_Tooltip)) == 0)
                 want_focus = true;
@@ -6765,6 +6768,19 @@ bool ImGui::IsWindowChildOf(ImGuiWindow* window, ImGuiWindow* potential_parent,
     return false;
 }
 
+bool ImGui::IsWindowChildOfBeginStack(ImGuiWindow* window, ImGuiWindow* potential_parent)
+{
+    if (window->RootWindow == potential_parent)
+        return true;
+    while (window != NULL)
+    {
+        if (window == potential_parent)
+            return true;
+        window = window->ParentWindowInBeginStack;
+    }
+    return false;
+}
+
 bool ImGui::IsWindowAbove(ImGuiWindow* potential_above, ImGuiWindow* potential_below)
 {
     ImGuiContext& g = *GImGui;
@@ -8437,7 +8453,7 @@ void ImGui::ClosePopupsOverWindow(ImGuiWindow* ref_window, bool restore_focus_to
             bool ref_window_is_descendent_of_popup = false;
             for (int n = popup_count_to_keep; n < g.OpenPopupStack.Size; n++)
                 if (ImGuiWindow* popup_window = g.OpenPopupStack[n].Window)
-                    if (popup_window->RootWindow == ref_window->RootWindow)
+                    if (IsWindowChildOfBeginStack(ref_window, popup_window))
                     {
                         ref_window_is_descendent_of_popup = true;
                         break;

imgui_internal.h

@@ -2415,6 +2415,7 @@ namespace ImGui
     IMGUI_API void          UpdateWindowParentAndRootLinks(ImGuiWindow* window, ImGuiWindowFlags flags, ImGuiWindow* parent_window);
     IMGUI_API ImVec2        CalcWindowNextAutoFitSize(ImGuiWindow* window);
     IMGUI_API bool          IsWindowChildOf(ImGuiWindow* window, ImGuiWindow* potential_parent, bool popup_hierarchy);
+    IMGUI_API bool          IsWindowChildOfBeginStack(ImGuiWindow* window, ImGuiWindow* potential_parent);
     IMGUI_API bool          IsWindowAbove(ImGuiWindow* potential_above, ImGuiWindow* potential_below);
     IMGUI_API bool          IsWindowNavFocusable(ImGuiWindow* window);
     IMGUI_API void          SetWindowPos(ImGuiWindow* window, const ImVec2& pos, ImGuiCond cond = 0);