Internals: Docking: More fixes to make DockNodeBeginAmendTabBar() viable (probably some issues left)

imgui.cpp

@@ -6747,7 +6747,7 @@ void ImGui::End()
     IM_ASSERT(g.CurrentWindowStack.Size > 0);
 
     // Error checking: verify that user doesn't directly call End() on a child window.
-    if ((window->Flags & ImGuiWindowFlags_ChildWindow) && !window->DockIsActive)
+    if ((window->Flags & ImGuiWindowFlags_ChildWindow) && !(window->Flags & ImGuiWindowFlags_DockNodeHost) && !window->DockIsActive)
         IM_ASSERT_USER_ERROR(g.WithinEndChild, "Must call EndChild() and not End()!");
 
     // Close anything that is open
@@ -12705,7 +12705,7 @@ static void ImGui::DockNodeMoveWindows(ImGuiDockNode* dst_node, ImGuiDockNode* s
     IM_ASSERT(src_node && dst_node && dst_node != src_node);
     ImGuiTabBar* src_tab_bar = src_node->TabBar;
     if (src_tab_bar != NULL)
-        IM_ASSERT(src_node->Windows.Size == src_node->TabBar->Tabs.Size);
+        IM_ASSERT(src_node->Windows.Size <= src_node->TabBar->Tabs.Size);
 
     // If the dst_node is empty we can just move the entire tab bar (to preserve selection, scrolling, etc.)
     bool move_tab_bar = (src_tab_bar != NULL) && (dst_node->TabBar == NULL);
@@ -12717,10 +12717,13 @@ static void ImGui::DockNodeMoveWindows(ImGuiDockNode* dst_node, ImGuiDockNode* s
 
     for (int n = 0; n < src_node->Windows.Size; n++)
     {
-        ImGuiWindow* window = src_tab_bar ? src_tab_bar->Tabs[n].Window : src_node->Windows[n];
-        window->DockNode = NULL;
-        window->DockIsActive = false;
-        DockNodeAddWindow(dst_node, window, move_tab_bar ? false : true);
+        // DockNode's TabBar may have non-window Tabs manually appended by user
+        if (ImGuiWindow* window = src_tab_bar ? src_tab_bar->Tabs[n].Window : src_node->Windows[n])
+        {
+            window->DockNode = NULL;
+            window->DockIsActive = false;
+            DockNodeAddWindow(dst_node, window, move_tab_bar ? false : true);
+        }
     }
     src_node->Windows.clear();
 
@@ -13233,9 +13236,9 @@ static ImGuiID ImGui::DockNodeUpdateWindowMenu(ImGuiDockNode* node, ImGuiTabBar*
             for (int tab_n = 0; tab_n < tab_bar->Tabs.Size; tab_n++)
             {
                 ImGuiTabItem* tab = &tab_bar->Tabs[tab_n];
-                if (tab->Window == NULL)
+                if (tab->Flags & ImGuiTabItemFlags_Button)
                     continue;
-                if (Selectable(tab->Window->Name, tab->ID == tab_bar->SelectedTabId))
+                if (Selectable(tab_bar->GetTabName(tab), tab->ID == tab_bar->SelectedTabId))
                     ret_tab_id = tab->ID;
                 SameLine();
                 Text("   ");
@@ -13251,6 +13254,8 @@ bool ImGui::DockNodeBeginAmendTabBar(ImGuiDockNode* node)
 {
     if (node->TabBar == NULL || node->HostWindow == NULL)
         return false;
+    if (node->SharedFlags & ImGuiDockNodeFlags_KeepAliveOnly)
+        return false;
     Begin(node->HostWindow->Name);
     PushOverrideID(node->ID);
     bool ret = BeginTabBarEx(node->TabBar, node->TabBar->BarRect, node->TabBar->Flags, node);
@@ -13484,7 +13489,7 @@ static void ImGui::DockNodeUpdateTabBar(ImGuiDockNode* node, ImGuiWindow* host_w
 
             // Forward moving request to selected window
             if (ImGuiTabItem* tab = TabBarFindTabByID(tab_bar, tab_bar->SelectedTabId))
-                StartMouseMovingWindowOrNode(tab->Window, node, false);
+                StartMouseMovingWindowOrNode(tab->Window ? tab->Window : node->HostWindow, node, false);
         }
     }
 
@@ -13500,10 +13505,11 @@ static void ImGui::DockNodeUpdateTabBar(ImGuiDockNode* node, ImGuiWindow* host_w
     // Apply navigation focus
     if (focus_tab_id != 0)
         if (ImGuiTabItem* tab = TabBarFindTabByID(tab_bar, focus_tab_id))
-        {
-            FocusWindow(tab->Window);
-            NavInitWindow(tab->Window, false);
-        }
+            if (tab->Window)
+            {
+                FocusWindow(tab->Window);
+                NavInitWindow(tab->Window, false);
+            }
 
     EndTabBar();
     PopID();
@@ -13819,25 +13825,29 @@ static void ImGui::DockNodePreviewDockRender(ImGuiWindow* host_window, ImGuiDock
 
         // Draw tab shape/label preview (payload may be a loose window or a host window carrying multiple tabbed windows)
         if (root_payload->DockNodeAsHost)
-            IM_ASSERT(root_payload->DockNodeAsHost->Windows.Size == root_payload->DockNodeAsHost->TabBar->Tabs.Size);
-        const int payload_count = root_payload->DockNodeAsHost ? root_payload->DockNodeAsHost->TabBar->Tabs.Size : 1;
+            IM_ASSERT(root_payload->DockNodeAsHost->Windows.Size <= root_payload->DockNodeAsHost->TabBar->Tabs.Size);
+        ImGuiTabBar* tab_bar_with_payload = root_payload->DockNodeAsHost ? root_payload->DockNodeAsHost->TabBar : NULL;
+        const int payload_count = tab_bar_with_payload ? tab_bar_with_payload->Tabs.Size : 1;
         for (int payload_n = 0; payload_n < payload_count; payload_n++)
         {
-            // Calculate the tab bounding box for each payload window
-            ImGuiWindow* payload = root_payload->DockNodeAsHost ? root_payload->DockNodeAsHost->TabBar->Tabs[payload_n].Window : root_payload;
-            if (!DockNodeIsDropAllowedOne(payload, host_window))
+            // DockNode's TabBar may have non-window Tabs manually appended by user
+            ImGuiWindow* payload_window = tab_bar_with_payload ? tab_bar_with_payload->Tabs[payload_n].Window : root_payload;
+            if (tab_bar_with_payload && payload_window == NULL)
+                continue;
+            if (!DockNodeIsDropAllowedOne(payload_window, host_window))
                 continue;
 
-            ImVec2 tab_size = TabItemCalcSize(payload->Name, payload->HasCloseButton);
+            // Calculate the tab bounding box for each payload window
+            ImVec2 tab_size = TabItemCalcSize(payload_window->Name, payload_window->HasCloseButton);
             ImRect tab_bb(tab_pos.x, tab_pos.y, tab_pos.x + tab_size.x, tab_pos.y + tab_size.y);
             tab_pos.x += tab_size.x + g.Style.ItemInnerSpacing.x;
             for (int overlay_n = 0; overlay_n < overlay_draw_lists_count; overlay_n++)
             {
-                ImGuiTabItemFlags tab_flags = ImGuiTabItemFlags_Preview | ((payload->Flags & ImGuiWindowFlags_UnsavedDocument) ? ImGuiTabItemFlags_UnsavedDocument : 0);
+                ImGuiTabItemFlags tab_flags = ImGuiTabItemFlags_Preview | ((payload_window->Flags & ImGuiWindowFlags_UnsavedDocument) ? ImGuiTabItemFlags_UnsavedDocument : 0);
                 if (!tab_bar_rect.Contains(tab_bb))
                     overlay_draw_lists[overlay_n]->PushClipRect(tab_bar_rect.Min, tab_bar_rect.Max);
                 TabItemBackground(overlay_draw_lists[overlay_n], tab_bb, tab_flags, overlay_col_tabs);
-                TabItemLabelAndCloseButton(overlay_draw_lists[overlay_n], tab_bb, tab_flags, g.Style.FramePadding, payload->Name, 0, 0, false);
+                TabItemLabelAndCloseButton(overlay_draw_lists[overlay_n], tab_bb, tab_flags, g.Style.FramePadding, payload_window->Name, 0, 0, false);
                 if (!tab_bar_rect.Contains(tab_bb))
                     overlay_draw_lists[overlay_n]->PopClipRect();
             }
@@ -14358,10 +14368,8 @@ void ImGui::DockSpace(ImGuiID id, const ImVec2& size_arg, ImGuiDockNodeFlags fla
     // Update the node
     DockNodeUpdate(node);
 
-    g.WithinEndChild = true;
     End();
     ItemSize(size);
-    g.WithinEndChild = false;
 }
 
 // Tips: Use with ImGuiDockNodeFlags_PassthruCentralNode!
@@ -15881,7 +15889,8 @@ void ImGui::ShowMetricsWindow(bool* p_open)
             for (int tab_n = 0; tab_n < ImMin(tab_bar->Tabs.Size, 3); tab_n++)
             {
                 ImGuiTabItem* tab = &tab_bar->Tabs[tab_n];
-                p += ImFormatString(p, buf_end - p, "%s'%s'", tab_n > 0 ? ", " : "", (tab->Window || tab->NameOffset != -1) ? tab_bar->GetTabName(tab) : "???");
+                p += ImFormatString(p, buf_end - p, "%s'%s'",
+                    tab_n > 0 ? ", " : "", (tab->Window || tab->NameOffset != -1) ? tab_bar->GetTabName(tab) : "???");
             }
             p += ImFormatString(p, buf_end - p, (tab_bar->Tabs.Size > 3) ? " ... }" : " } ");
             if (!is_active) { PushStyleColor(ImGuiCol_Text, GetStyleColorVec4(ImGuiCol_TextDisabled)); }
@@ -15902,7 +15911,8 @@ void ImGui::ShowMetricsWindow(bool* p_open)
                     ImGui::PushID(tab);
                     if (ImGui::SmallButton("<")) { TabBarQueueReorder(tab_bar, tab, -1); } ImGui::SameLine(0, 2);
                     if (ImGui::SmallButton(">")) { TabBarQueueReorder(tab_bar, tab, +1); } ImGui::SameLine();
-                    ImGui::Text("%02d%c Tab 0x%08X '%s' Offset: %.1f, Width: %.1f/%.1f", tab_n, (tab->ID == tab_bar->SelectedTabId) ? '*' : ' ', tab->ID, (tab->Window || tab->NameOffset != -1) ? tab_bar->GetTabName(tab) : "???", tab->Offset, tab->Width, tab->ContentWidth);
+                    ImGui::Text("%02d%c Tab 0x%08X '%s' Offset: %.1f, Width: %.1f/%.1f",
+                        tab_n, (tab->ID == tab_bar->SelectedTabId) ? '*' : ' ', tab->ID, (tab->Window || tab->NameOffset != -1) ? tab_bar->GetTabName(tab) : "???", tab->Offset, tab->Width, tab->ContentWidth);
                     ImGui::PopID();
                 }
                 ImGui::TreePop();

imgui_widgets.cpp

@@ -7099,7 +7099,7 @@ static void ImGui::TabBarLayout(ImGuiTabBar* tab_bar)
         // Additionally, when using TabBarAddTab() to manipulate tab bar order we occasionally insert new tabs that don't have a width yet,
         // and we cannot wait for the next BeginTabItem() call. We cannot compute this width within TabBarAddTab() because font size depends on the active window.
         const char* tab_name = tab_bar->GetTabName(tab);
-        const bool has_close_button = tab->Window ? tab->Window->HasCloseButton : ((tab->Flags & ImGuiTabItemFlags_NoCloseButton) == 0);
+        const bool has_close_button = (tab->Flags & ImGuiTabItemFlags_NoCloseButton) == 0;
         tab->ContentWidth = TabItemCalcSize(tab_name, has_close_button).x;
 
         int section_n = (tab->Flags & ImGuiTabItemFlags_Leading) ? 0 : (tab->Flags & ImGuiTabItemFlags_Trailing) ? 2 : 1;
@@ -7524,7 +7524,7 @@ bool    ImGui::BeginTabItem(const char* label, bool* p_open, ImGuiTabItemFlags f
         IM_ASSERT_USER_ERROR(tab_bar, "Needs to be called between BeginTabBar() and EndTabBar()!");
         return false;
     }
-    IM_ASSERT(!(flags & ImGuiTabItemFlags_Button)); // BeginTabItem() Can't be used with button flags, use TabItemButton() instead!
+    IM_ASSERT((flags & ImGuiTabItemFlags_Button) == 0);             // BeginTabItem() Can't be used with button flags, use TabItemButton() instead!
 
     bool ret = TabItemEx(tab_bar, label, p_open, flags, NULL);
     if (ret && !(flags & ImGuiTabItemFlags_NoPushId))