Popups: Fix an edge case where programatically closing a popup while clicking on its empty space would attempt to focus it and close other popups. (#2880)

docs/CHANGELOG.txt

@@ -52,6 +52,8 @@ Other Changes:
   Set to 0.0f (default) to always make a close button appear on hover (same as Chrome, VS).
   Set to FLT_MAX to only display a close button when selected (merely hovering is not enough).
   Set to an intermediary value to toggle behavior based on width (same as Firefox).
+- Popups: Fix an edge case where programatically closing a popup while clicking on its empty space
+  would attempt to focus it and close other popups. (#2880)
 - Fix GetGlyphRangesKorean() end-range to end at 0xD7A3 (instead of 0xD79D). (#348, #3217) [@marukrap]
 - Metrics: Added a "Settings" section with some details about persistent ini settings.
 - Nav, Menus: Fix vertical wrap-around in menus or popups created with multiple appending calls to

imgui.cpp

@@ -3449,17 +3449,22 @@ void ImGui::UpdateMouseMovingWindowEndFrame()
     if (g.NavWindow && g.NavWindow->Appearing)
         return;
 
-    // Click to focus window and start moving (after we're done with all our widgets)
+    // Click on empty space to focus window and start moving (after we're done with all our widgets)
     if (g.IO.MouseClicked[0])
     {
-        if (g.HoveredRootWindow != NULL)
+        // Handle the edge case of a popup being closed while clicking in its empty space.
+        // If we try to focus it, FocusWindow() > ClosePopupsOverWindow() will accidentally close any parent popups because they are not linked together any more.
+        ImGuiWindow* root_window = g.HoveredRootWindow;
+        const bool is_closed_popup = root_window && (root_window->Flags & ImGuiWindowFlags_Popup) && !IsPopupOpenAtAnyLevel(root_window->PopupId);
+
+        if (root_window != NULL && !is_closed_popup)
         {
             StartMouseMovingWindow(g.HoveredWindow);
-            if (g.IO.ConfigWindowsMoveFromTitleBarOnly && !(g.HoveredRootWindow->Flags & ImGuiWindowFlags_NoTitleBar))
-                if (!g.HoveredRootWindow->TitleBarRect().Contains(g.IO.MouseClickedPos[0]))
+            if (g.IO.ConfigWindowsMoveFromTitleBarOnly && !(root_window->Flags & ImGuiWindowFlags_NoTitleBar))
+                if (!root_window->TitleBarRect().Contains(g.IO.MouseClickedPos[0]))
                     g.MovingWindow = NULL;
         }
-        else if (g.NavWindow != NULL && GetTopMostPopupModal() == NULL)
+        else if (root_window != NULL && g.NavWindow != NULL && GetTopMostPopupModal() == NULL)
         {
             // Clicking on void disable focus
             FocusWindow(NULL);
@@ -3700,7 +3705,7 @@ void ImGui::UpdateHoveredWindowAndCaptureFlags()
     for (int i = 0; i < IM_ARRAYSIZE(g.IO.MouseDown); i++)
     {
         if (g.IO.MouseClicked[i])
-            g.IO.MouseDownOwned[i] = (g.HoveredWindow != NULL) || (!g.OpenPopupStack.empty());
+            g.IO.MouseDownOwned[i] = (g.HoveredWindow != NULL) || (g.OpenPopupStack.Size > 0);
         mouse_any_down |= g.IO.MouseDown[i];
         if (g.IO.MouseDown[i])
             if (mouse_earliest_button_down == -1 || g.IO.MouseClickedTime[i] < g.IO.MouseClickedTime[mouse_earliest_button_down])
@@ -3718,7 +3723,7 @@ void ImGui::UpdateHoveredWindowAndCaptureFlags()
     if (g.WantCaptureMouseNextFrame != -1)
         g.IO.WantCaptureMouse = (g.WantCaptureMouseNextFrame != 0);
     else
-        g.IO.WantCaptureMouse = (mouse_avail_to_imgui && (g.HoveredWindow != NULL || mouse_any_down)) || (!g.OpenPopupStack.empty());
+        g.IO.WantCaptureMouse = (mouse_avail_to_imgui && (g.HoveredWindow != NULL || mouse_any_down)) || (g.OpenPopupStack.Size > 0);
 
     // Update io.WantCaptureKeyboard for the user application (true = dispatch keyboard info to imgui, false = dispatch keyboard info to Dear ImGui + app)
     if (g.WantCaptureKeyboardNextFrame != -1)
@@ -7610,6 +7615,15 @@ bool ImGui::IsPopupOpen(const char* str_id)
     return g.OpenPopupStack.Size > g.BeginPopupStack.Size && g.OpenPopupStack[g.BeginPopupStack.Size].PopupId == g.CurrentWindow->GetID(str_id);
 }
 
+bool ImGui::IsPopupOpenAtAnyLevel(ImGuiID id)
+{
+    ImGuiContext& g = *GImGui;
+    for (int n = 0; n < g.OpenPopupStack.Size; n++)
+        if (g.OpenPopupStack[n].PopupId == id)
+            return true;
+    return false;
+}
+
 ImGuiWindow* ImGui::GetTopMostPopupModal()
 {
     ImGuiContext& g = *GImGui;
@@ -7661,8 +7675,8 @@ void ImGui::OpenPopupEx(ImGuiID id)
         else
         {
             // Close child popups if any, then flag popup for open/reopen
-            g.OpenPopupStack.resize(current_stack_size + 1);
-            g.OpenPopupStack[current_stack_size] = popup_ref;
+            ClosePopupToLevel(current_stack_size, false);
+            g.OpenPopupStack.push_back(popup_ref);
         }
 
         // When reopening a popup we first refocus its parent, otherwise if its parent is itself a popup it would get closed by ClosePopupsOverWindow().
@@ -7675,7 +7689,7 @@ void ImGui::OpenPopupEx(ImGuiID id)
 void ImGui::ClosePopupsOverWindow(ImGuiWindow* ref_window, bool restore_focus_to_window_under_popup)
 {
     ImGuiContext& g = *GImGui;
-    if (g.OpenPopupStack.empty())
+    if (g.OpenPopupStack.Size == 0)
         return;
 
     // When popups are stacked, clicking on a lower level popups puts focus back to it and close popups above it.
@@ -7714,6 +7728,8 @@ void ImGui::ClosePopupToLevel(int remaining, bool restore_focus_to_window_under_
 {
     ImGuiContext& g = *GImGui;
     IM_ASSERT(remaining >= 0 && remaining < g.OpenPopupStack.Size);
+
+    // Trim open popup stack
     ImGuiWindow* focus_window = g.OpenPopupStack[remaining].SourceWindow;
     ImGuiWindow* popup_window = g.OpenPopupStack[remaining].Window;
     g.OpenPopupStack.resize(remaining);

imgui_internal.h

@@ -1581,7 +1581,7 @@ struct IMGUI_API ImGuiWindow
     bool                    WantCollapseToggle;
     bool                    SkipItems;                          // Set when items can safely be all clipped (e.g. window not visible or collapsed)
     bool                    Appearing;                          // Set during the frame where the window is appearing (or re-appearing)
-    bool                    Hidden;                             // Do not display (== (HiddenFrames*** > 0))
+    bool                    Hidden;                             // Do not display (== HiddenFrames*** > 0)
     bool                    IsFallbackWindow;                   // Set on the "Debug##Default" window.
     bool                    HasCloseButton;                     // Set when the window has a close button (p_open != NULL)
     signed char             ResizeBorderHeld;                   // Current border being held for resize (-1: none, otherwise 0-3)
@@ -1853,6 +1853,7 @@ namespace ImGui
     IMGUI_API void          ClosePopupToLevel(int remaining, bool restore_focus_to_window_under_popup);
     IMGUI_API void          ClosePopupsOverWindow(ImGuiWindow* ref_window, bool restore_focus_to_window_under_popup);
     IMGUI_API bool          IsPopupOpen(ImGuiID id); // Test for id at current popup stack level (currently begin-ed into); this doesn't scan the whole popup stack!
+    IMGUI_API bool          IsPopupOpenAtAnyLevel(ImGuiID id);
     IMGUI_API bool          BeginPopupEx(ImGuiID id, ImGuiWindowFlags extra_flags);
     IMGUI_API void          BeginTooltipEx(ImGuiWindowFlags extra_flags, ImGuiTooltipFlags tooltip_flags);
     IMGUI_API ImGuiWindow*  GetTopMostPopupModal();