OpenPopup(): Added ImGuiPopupFlags_NoReopen. Nav, Menus: Fixed click on a BeginMenu() followed by right-arrow. (#1497, #1533)

  reopen

docs/CHANGELOG.txt

@@ -56,6 +56,13 @@ Other changes:
 - Nav: Fixed pressing Escape while in a child window with _NavFlattened flag. (#7237)
 - Nav: Improve handling of Alt key to toggle menu so that key ownership may be claimed on
   indiviudal left/right alt key without intefering with the other.
+- Nav, Menus: Fixed click on a BeginMenu() followed by right-arrow from making the child menu
+  reopen and flicker (using ImGuiPopupFlags_NoReopen).
+- OpenPopup(): Added ImGuiPopupFlags_NoReopen flag to specifically not close nd reopen a popup
+  when it is already open. (#1497, #1533)
+  (Note that this differs from specific handling we already have in place for the case of calling
+  OpenPopup() repeatedly every frame: we already didn't reopen in that specific situation, otherwise
+  the effect would be very disastrous in term of confusion, as reopening would steal focus).
 - Debug Tools: Metrics: Fixed debug break in SetShortcutRouting() not handling ImGuiMod_Shortcut redirect.
 - Debug Tools: Debug Log: Added "Input Routing" logging.
 - Debug Tools: Added "nop" to IM_DEBUG_BREAK macro on GCC to work around GDB bug (#7266) [@Peter0x44]

imgui.cpp

@@ -10773,16 +10773,22 @@ void ImGui::OpenPopupEx(ImGuiID id, ImGuiPopupFlags popup_flags)
     }
     else
     {
-        // Gently handle the user mistakenly calling OpenPopup() every frame. It is a programming mistake! However, if we were to run the regular code path, the ui
-        // would become completely unusable because the popup will always be in hidden-while-calculating-size state _while_ claiming focus. Which would be a very confusing
-        // situation for the programmer. Instead, we silently allow the popup to proceed, it will keep reappearing and the programming error will be more obvious to understand.
-        if (g.OpenPopupStack[current_stack_size].PopupId == id && g.OpenPopupStack[current_stack_size].OpenFrameCount == g.FrameCount - 1)
-        {
+        // Gently handle the user mistakenly calling OpenPopup() every frames: it is likely a programming mistake!
+        // However, if we were to run the regular code path, the ui would become completely unusable because the popup will always be
+        // in hidden-while-calculating-size state _while_ claiming focus. Which is extremely confusing situation for the programmer.
+        // Instead, for successive frames calls to OpenPopup(), we silently avoid reopening even if ImGuiPopupFlags_NoReopen is not specified.
+        bool keep_existing = false;
+        if (g.OpenPopupStack[current_stack_size].PopupId == id)
+            if ((g.OpenPopupStack[current_stack_size].OpenFrameCount == g.FrameCount - 1) || (popup_flags & ImGuiPopupFlags_NoReopen))
+                keep_existing = true;
+        if (keep_existing)
+        {
+            // No reopen
             g.OpenPopupStack[current_stack_size].OpenFrameCount = popup_ref.OpenFrameCount;
         }
         else
         {
-            // Close child popups if any, then flag popup for open/reopen
+            // Reopen: close child popups if any, then flag popup for open/reopen (set position, focus, init navigation)
             ClosePopupToLevel(current_stack_size, false);
             g.OpenPopupStack.push_back(popup_ref);
         }

imgui.h

@@ -24,7 +24,7 @@
 // Library Version
 // (Integer encoded as XYYZZ for use in #if preprocessor conditionals, e.g. '#if IMGUI_VERSION_NUM >= 12345')
 #define IMGUI_VERSION       "1.90.2 WIP"
-#define IMGUI_VERSION_NUM   19017
+#define IMGUI_VERSION_NUM   19018
 #define IMGUI_HAS_TABLE
 
 /*
@@ -1122,10 +1122,12 @@ enum ImGuiPopupFlags_
     ImGuiPopupFlags_MouseButtonMiddle       = 2,        // For BeginPopupContext*(): open on Middle Mouse release. Guaranteed to always be == 2 (same as ImGuiMouseButton_Middle)
     ImGuiPopupFlags_MouseButtonMask_        = 0x1F,
     ImGuiPopupFlags_MouseButtonDefault_     = 1,
-    ImGuiPopupFlags_NoOpenOverExistingPopup = 1 << 5,   // For OpenPopup*(), BeginPopupContext*(): don't open if there's already a popup at the same level of the popup stack
-    ImGuiPopupFlags_NoOpenOverItems         = 1 << 6,   // For BeginPopupContextWindow(): don't return true when hovering items, only when hovering empty space
-    ImGuiPopupFlags_AnyPopupId              = 1 << 7,   // For IsPopupOpen(): ignore the ImGuiID parameter and test for any popup.
-    ImGuiPopupFlags_AnyPopupLevel           = 1 << 8,   // For IsPopupOpen(): search/test at any level of the popup stack (default test in the current level)
+    ImGuiPopupFlags_NoReopen                = 1 << 5,   // For OpenPopup*(), BeginPopupContext*(): don't reopen same popup if already open (won't reposition, won't reinitialize navigation)
+    //ImGuiPopupFlags_NoReopenAlwaysNavInit = 1 << 6,   // For OpenPopup*(), BeginPopupContext*(): focus and initialize navigation even when not reopening.
+    ImGuiPopupFlags_NoOpenOverExistingPopup = 1 << 7,   // For OpenPopup*(), BeginPopupContext*(): don't open if there's already a popup at the same level of the popup stack
+    ImGuiPopupFlags_NoOpenOverItems         = 1 << 8,   // For BeginPopupContextWindow(): don't return true when hovering items, only when hovering empty space
+    ImGuiPopupFlags_AnyPopupId              = 1 << 10,  // For IsPopupOpen(): ignore the ImGuiID parameter and test for any popup.
+    ImGuiPopupFlags_AnyPopupLevel           = 1 << 11,  // For IsPopupOpen(): search/test at any level of the popup stack (default test in the current level)
     ImGuiPopupFlags_AnyPopup                = ImGuiPopupFlags_AnyPopupId | ImGuiPopupFlags_AnyPopupLevel,
 };
 

imgui_widgets.cpp

@@ -7518,6 +7518,7 @@ bool ImGui::BeginMenuEx(const char* label, const char* icon, bool enabled)
         PopItemFlag();
 
     bool want_open = false;
+    bool want_open_nav_init = false;
     bool want_close = false;
     if (window->DC.LayoutType == ImGuiLayoutType_Vertical) // (window->Flags & (ImGuiWindowFlags_Popup|ImGuiWindowFlags_ChildMenu))
     {
@@ -7560,8 +7561,9 @@ bool ImGui::BeginMenuEx(const char* label, const char* icon, bool enabled)
             want_open = true;
         if (g.NavId == id && g.NavMoveDir == ImGuiDir_Right) // Nav-Right to open
         {
-            want_open = true;
+            want_open = want_open_nav_init = true;
             NavMoveRequestCancel();
+            NavRestoreHighlightAfterMove();
         }
     }
     else
@@ -7593,13 +7595,13 @@ bool ImGui::BeginMenuEx(const char* label, const char* icon, bool enabled)
 
     if (want_open && !menu_is_open && g.OpenPopupStack.Size > g.BeginPopupStack.Size)
     {
-        // Don't reopen/recycle same menu level in the same frame, first close the other menu and yield for a frame.
+        // Don't reopen/recycle same menu level in the same frame if it is a different menu ID, first close the other menu and yield for a frame.
         OpenPopup(label);
     }
     else if (want_open)
     {
         menu_is_open = true;
-        OpenPopup(label);
+        OpenPopup(label, ImGuiPopupFlags_NoReopen);// | (want_open_nav_init ? ImGuiPopupFlags_NoReopenAlwaysNavInit : 0));
     }
 
     if (menu_is_open)
@@ -7611,6 +7613,14 @@ bool ImGui::BeginMenuEx(const char* label, const char* icon, bool enabled)
         PopStyleVar();
         if (menu_is_open)
         {
+            // Implement what ImGuiPopupFlags_NoReopenAlwaysNavInit would do:
+            // Perform an init request in the case the popup was already open (via a previous mouse hover)
+            if (want_open && want_open_nav_init && !g.NavInitRequest)
+            {
+                FocusWindow(g.CurrentWindow, ImGuiFocusRequestFlags_UnlessBelowModal);
+                NavInitWindow(g.CurrentWindow, false);
+            }
+
             // Restore LastItemData so IsItemXXXX functions can work after BeginMenu()/EndMenu()
             // (This fixes using IsItemClicked() and IsItemHovered(), but IsItemHovered() also relies on its support for ImGuiItemFlags_NoWindowHoverableCheck)
             g.LastItemData = last_item_in_parent;