Switch imgui to docking branch.

2025-03-20 07:40:02 +08:00 · 2020-05-03 13:16:17 +02:00
parent aa7851d1d7
commit c5f1128209
10 changed files with 7238 additions and 350 deletions
@@ -1,4 +1,4 @@
-// dear imgui, v1.76
+// dear imgui, v1.77 WIP
 // (widgets code)

 /*
@@ -480,13 +480,13 @@ bool ImGui::ButtonBehavior(const ImRect& bb, ImGuiID id, bool* out_hovered, bool
        flags |= ImGuiButtonFlags_PressedOnDefault_;

    ImGuiWindow* backup_hovered_window = g.HoveredWindow;
-    const bool flatten_hovered_children = (flags & ImGuiButtonFlags_FlattenChildren) && g.HoveredRootWindow == window;
+    const bool flatten_hovered_children = (flags & ImGuiButtonFlags_FlattenChildren) && g.HoveredRootWindow == window->RootWindow;
    if (flatten_hovered_children)
        g.HoveredWindow = window;

 #ifdef IMGUI_ENABLE_TEST_ENGINE
    if (id != 0 && window->DC.LastItemId != id)
-        ImGuiTestEngineHook_ItemAdd(&g, bb, id);
+        IMGUI_TEST_ENGINE_ITEM_ADD(bb, id);
 #endif

    bool pressed = false;
@@ -500,11 +500,13 @@ bool ImGui::ButtonBehavior(const ImRect& bb, ImGuiID id, bool* out_hovered, bool
    if (g.DragDropActive && (flags & ImGuiButtonFlags_PressedOnDragDropHold) && !(g.DragDropSourceFlags & ImGuiDragDropFlags_SourceNoHoldToOpenOthers))
        if (IsItemHovered(ImGuiHoveredFlags_AllowWhenBlockedByActiveItem))
        {
+            const float DRAG_DROP_HOLD_TIMER = 0.70f;
            hovered = true;
            SetHoveredID(id);
-            if (CalcTypematicRepeatAmount(g.HoveredIdTimer + 0.0001f - g.IO.DeltaTime, g.HoveredIdTimer + 0.0001f, 0.70f, 0.00f))
+            if (CalcTypematicRepeatAmount(g.HoveredIdTimer + 0.0001f - g.IO.DeltaTime, g.HoveredIdTimer + 0.0001f, DRAG_DROP_HOLD_TIMER, 0.00f))
            {
                pressed = true;
+                g.DragDropHoldJustPressedId = id;
                FocusWindow(window);
            }
        }
@@ -784,7 +786,8 @@ bool ImGui::CloseButton(ImGuiID id, const ImVec2& pos)//, float size)
    return pressed;
 }

-bool ImGui::CollapseButton(ImGuiID id, const ImVec2& pos)
+// The Collapse button also functions as a Dock Menu button.
+bool ImGui::CollapseButton(ImGuiID id, const ImVec2& pos, ImGuiDockNode* dock_node)
 {
    ImGuiContext& g = *GImGui;
    ImGuiWindow* window = g.CurrentWindow;
@@ -795,16 +798,22 @@ bool ImGui::CollapseButton(ImGuiID id, const ImVec2& pos)
    bool pressed = ButtonBehavior(bb, id, &hovered, &held, ImGuiButtonFlags_None);

    // Render
+    //bool is_dock_menu = (window->DockNodeAsHost && !window->Collapsed);
+    ImVec2 off = dock_node ? ImVec2(IM_FLOOR(-g.Style.ItemInnerSpacing.x * 0.5f) + 0.5f, 0.0f) : ImVec2(0.0f, 0.0f);
    ImU32 bg_col = GetColorU32((held && hovered) ? ImGuiCol_ButtonActive : hovered ? ImGuiCol_ButtonHovered : ImGuiCol_Button);
    ImU32 text_col = GetColorU32(ImGuiCol_Text);
    ImVec2 center = bb.GetCenter();
    if (hovered || held)
-        window->DrawList->AddCircleFilled(center/*+ ImVec2(0.0f, -0.5f)*/, g.FontSize * 0.5f + 1.0f, bg_col, 12);
-    RenderArrow(window->DrawList, bb.Min + g.Style.FramePadding, text_col, window->Collapsed ? ImGuiDir_Right : ImGuiDir_Down, 1.0f);
+        window->DrawList->AddCircleFilled(center + off + ImVec2(0,-0.5f), g.FontSize * 0.5f + 1.0f, bg_col, 12);
+
+    if (dock_node)
+        RenderArrowDockMenu(window->DrawList, bb.Min + g.Style.FramePadding, g.FontSize, text_col);
+    else
+        RenderArrow(window->DrawList, bb.Min + g.Style.FramePadding, text_col, window->Collapsed ? ImGuiDir_Right : ImGuiDir_Down, 1.0f);

    // Switch to moving the window after mouse is moved beyond the initial drag threshold
    if (IsItemActive() && IsMouseDragging(0))
-        StartMouseMovingWindow(window);
+        StartMouseMovingWindowOrNode(window, dock_node, true);

    return pressed;
 }
@@ -1132,6 +1141,7 @@ bool ImGui::RadioButton(const char* label, bool active)
    if (label_size.x > 0.0f)
        RenderText(ImVec2(check_bb.Max.x + style.ItemInnerSpacing.x, check_bb.Min.y + style.FramePadding.y), label);

+    IMGUI_TEST_ENGINE_ITEM_INFO(id, label, window->DC.ItemFlags);
    return pressed;
 }

@@ -4192,7 +4202,10 @@ bool ImGui::InputTextEx(const char* label, const char* hint, char* buf, int buf_

            // Notify OS of text input position for advanced IME (-1 x offset so that Windows IME can cover our cursor. Bit of an extra nicety.)
            if (!is_readonly)
-                g.PlatformImePos = ImVec2(cursor_screen_pos.x - 1.0f, cursor_screen_pos.y - g.FontSize);
+            {
+                g.PlatformImePos = ImVec2(cursor_screen_pos.x - 1, cursor_screen_pos.y - g.FontSize);
+                g.PlatformImePosViewport = window->Viewport;
+            }
        }
    }
    else
@@ -5360,10 +5373,11 @@ bool ImGui::TreeNodeBehavior(ImGuiID id, ImGuiTreeNodeFlags flags, const char* l
    // It is rather standard that arrow click react on Down rather than Up and we'd be tempted to make it the default
    // (by removing the _OpenOnArrow test below), however this would have a perhaps surprising effect on CollapsingHeader()?
    // So right now we are making this optional. May evolve later.
+    // We set ImGuiButtonFlags_PressedOnClickRelease on OpenOnDoubleClick because we want the item to be active on the initial MouseDown in order for drag and drop to work.
    if (is_mouse_x_over_arrow && (flags & ImGuiTreeNodeFlags_OpenOnArrow))
        button_flags |= ImGuiButtonFlags_PressedOnClick;
    else if (flags & ImGuiTreeNodeFlags_OpenOnDoubleClick)
-        button_flags |= ImGuiButtonFlags_PressedOnDoubleClick;
+        button_flags |= ImGuiButtonFlags_PressedOnClickRelease | ImGuiButtonFlags_PressedOnDoubleClick;
    else
        button_flags |= ImGuiButtonFlags_PressedOnClickRelease;

@@ -5375,7 +5389,7 @@ bool ImGui::TreeNodeBehavior(ImGuiID id, ImGuiTreeNodeFlags flags, const char* l
    bool toggled = false;
    if (!is_leaf)
    {
-        if (pressed)
+        if (pressed && g.DragDropHoldJustPressedId != id)
        {
            if ((flags & (ImGuiTreeNodeFlags_OpenOnArrow | ImGuiTreeNodeFlags_OpenOnDoubleClick)) == 0 || (g.NavActivateId == id))
                toggled = true;
@@ -5383,8 +5397,12 @@ bool ImGui::TreeNodeBehavior(ImGuiID id, ImGuiTreeNodeFlags flags, const char* l
                toggled |= is_mouse_x_over_arrow && !g.NavDisableMouseHover; // Lightweight equivalent of IsMouseHoveringRect() since ButtonBehavior() already did the job
            if ((flags & ImGuiTreeNodeFlags_OpenOnDoubleClick) && g.IO.MouseDoubleClicked[0])
                toggled = true;
-            if (g.DragDropActive && is_open) // When using Drag and Drop "hold to open" we keep the node highlighted after opening, but never close it again.
-                toggled = false;
+        }
+        else if (pressed && g.DragDropHoldJustPressedId == id)
+        {
+            IM_ASSERT(button_flags & ImGuiButtonFlags_PressedOnDragDropHold);
+            if (!is_open) // When using Drag and Drop "hold to open" we keep the node highlighted after opening, but never close it again.
+                toggled = true;
        }

        if (g.NavId == id && g.NavMoveRequest && g.NavMoveDir == ImGuiDir_Left && is_open)
@@ -5485,7 +5503,8 @@ void ImGui::TreePush(const void* ptr_id)

 void ImGui::TreePushOverrideID(ImGuiID id)
 {
-    ImGuiWindow* window = GetCurrentWindow();
+    ImGuiContext& g = *GImGui;
+    ImGuiWindow* window = g.CurrentWindow;
    Indent();
    window->DC.TreeDepth++;
    window->IDStack.push_back(id);
@@ -6167,18 +6186,39 @@ void ImGui::EndMenuBar()
    window->DC.MenuBarAppending = false;
 }

-// For the main menu bar, which cannot be moved, we honor g.Style.DisplaySafeAreaPadding to ensure text can be visible on a TV set.
 bool ImGui::BeginMainMenuBar()
 {
    ImGuiContext& g = *GImGui;
+    ImGuiViewportP* viewport = g.Viewports[0];
+    ImGuiWindow* menu_bar_window = FindWindowByName("##MainMenuBar");
+
+    // For the main menu bar, which cannot be moved, we honor g.Style.DisplaySafeAreaPadding to ensure text can be visible on a TV set.
    g.NextWindowData.MenuBarOffsetMinVal = ImVec2(g.Style.DisplaySafeAreaPadding.x, ImMax(g.Style.DisplaySafeAreaPadding.y - g.Style.FramePadding.y, 0.0f));
-    SetNextWindowPos(ImVec2(0.0f, 0.0f));
-    SetNextWindowSize(ImVec2(g.IO.DisplaySize.x, g.NextWindowData.MenuBarOffsetMinVal.y + g.FontBaseSize + g.Style.FramePadding.y));
+
+    // Get our rectangle at the top of the work area
+    if (menu_bar_window == NULL || menu_bar_window->BeginCount == 0)
+    {
+        // Set window position
+        // We don't attempt to calculate our height ahead, as it depends on the per-viewport font size. However menu-bar will affect the minimum window size so we'll get the right height.
+        ImVec2 menu_bar_pos = viewport->Pos + viewport->CurrWorkOffsetMin;
+        ImVec2 menu_bar_size = ImVec2(viewport->Size.x - viewport->CurrWorkOffsetMin.x + viewport->CurrWorkOffsetMax.x, 1.0f);
+        SetNextWindowPos(menu_bar_pos);
+        SetNextWindowSize(menu_bar_size);
+    }
+
+    // Create window
+    SetNextWindowViewport(viewport->ID); // Enforce viewport so we don't create our own viewport when ImGuiConfigFlags_ViewportsNoMerge is set.
    PushStyleVar(ImGuiStyleVar_WindowRounding, 0.0f);
-    PushStyleVar(ImGuiStyleVar_WindowMinSize, ImVec2(0, 0));
-    ImGuiWindowFlags window_flags = ImGuiWindowFlags_NoTitleBar | ImGuiWindowFlags_NoResize | ImGuiWindowFlags_NoMove | ImGuiWindowFlags_NoScrollbar | ImGuiWindowFlags_NoSavedSettings | ImGuiWindowFlags_MenuBar;
+    PushStyleVar(ImGuiStyleVar_WindowMinSize, ImVec2(0, 0));    // Lift normal size constraint, however the presence of a menu-bar will give us the minimum height we want.
+    ImGuiWindowFlags window_flags = ImGuiWindowFlags_NoDocking | ImGuiWindowFlags_NoTitleBar | ImGuiWindowFlags_NoResize | ImGuiWindowFlags_NoMove | ImGuiWindowFlags_NoScrollbar | ImGuiWindowFlags_NoSavedSettings | ImGuiWindowFlags_MenuBar;
    bool is_open = Begin("##MainMenuBar", NULL, window_flags) && BeginMenuBar();
    PopStyleVar(2);
+
+    // Report our size into work area (for next frame) using actual window size
+    menu_bar_window = GetCurrentWindow();
+    if (menu_bar_window->BeginCount == 1)
+        viewport->CurrWorkOffsetMin.y += menu_bar_window->Size.y;
+
    g.NextWindowData.MenuBarOffsetMinVal = ImVec2(0.0f, 0.0f);
    if (!is_open)
    {
@@ -6451,6 +6491,7 @@ bool ImGui::MenuItem(const char* label, const char* shortcut, bool* p_selected,
 // - TabBarCalcTabID() [Internal]
 // - TabBarCalcMaxTabWidth() [Internal]
 // - TabBarFindTabById() [Internal]
+// - TabBarAddTab() [Internal]
 // - TabBarRemoveTab() [Internal]
 // - TabBarCloseTab() [Internal]
 // - TabBarScrollClamp()v
@@ -6518,10 +6559,10 @@ bool    ImGui::BeginTabBar(const char* str_id, ImGuiTabBarFlags flags)
    ImGuiTabBar* tab_bar = g.TabBars.GetOrAddByKey(id);
    ImRect tab_bar_bb = ImRect(window->DC.CursorPos.x, window->DC.CursorPos.y, window->WorkRect.Max.x, window->DC.CursorPos.y + g.FontSize + g.Style.FramePadding.y * 2);
    tab_bar->ID = id;
-    return BeginTabBarEx(tab_bar, tab_bar_bb, flags | ImGuiTabBarFlags_IsFocused);
+    return BeginTabBarEx(tab_bar, tab_bar_bb, flags | ImGuiTabBarFlags_IsFocused, NULL);
 }

-bool    ImGui::BeginTabBarEx(ImGuiTabBar* tab_bar, const ImRect& tab_bar_bb, ImGuiTabBarFlags flags)
+bool    ImGui::BeginTabBarEx(ImGuiTabBar* tab_bar, const ImRect& tab_bar_bb, ImGuiTabBarFlags flags, ImGuiDockNode* dock_node)
 {
    ImGuiContext& g = *GImGui;
    ImGuiWindow* window = g.CurrentWindow;
@@ -6538,7 +6579,7 @@ bool    ImGui::BeginTabBarEx(ImGuiTabBar* tab_bar, const ImRect& tab_bar_bb, ImG
    if (tab_bar->CurrFrameVisible == g.FrameCount)
    {
        //IMGUI_DEBUG_LOG("BeginTabBarEx already called this frame\n", g.FrameCount);
-        IM_ASSERT(0);
+        //IM_ASSERT(0);
        return true;
    }

@@ -6565,6 +6606,13 @@ bool    ImGui::BeginTabBarEx(ImGuiTabBar* tab_bar, const ImRect& tab_bar_bb, ImG
    // Draw separator
    const ImU32 col = GetColorU32((flags & ImGuiTabBarFlags_IsFocused) ? ImGuiCol_TabActive : ImGuiCol_TabUnfocusedActive);
    const float y = tab_bar->BarRect.Max.y - 1.0f;
+    if (dock_node != NULL)
+    {
+        const float separator_min_x = dock_node->Pos.x + window->WindowBorderSize;
+        const float separator_max_x = dock_node->Pos.x + dock_node->Size.x - window->WindowBorderSize;
+        window->DrawList->AddLine(ImVec2(separator_min_x, y), ImVec2(separator_max_x, y), col, 1.0f);
+    }
+    else
    {
        const float separator_min_x = tab_bar->BarRect.Min.x - IM_FLOOR(window->WindowPadding.x * 0.5f);
        const float separator_max_x = tab_bar->BarRect.Max.x + IM_FLOOR(window->WindowPadding.x * 0.5f);
@@ -6685,7 +6733,7 @@ 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->Flags & ImGuiTabItemFlags_NoCloseButton) ? false : true;
+        const bool has_close_button = tab->Window ? tab->Window->HasCloseButton : ((tab->Flags & ImGuiTabItemFlags_NoCloseButton) == 0);
        tab->ContentWidth = TabItemCalcSize(tab_name, has_close_button).x;

        width_total_contents += (tab_n > 0 ? g.Style.ItemInnerSpacing.x : 0.0f) + tab->ContentWidth;
@@ -6749,6 +6797,10 @@ static void ImGui::TabBarLayout(ImGuiTabBar* tab_bar)
    tab_bar->VisibleTabId = tab_bar->SelectedTabId;
    tab_bar->VisibleTabWasSubmitted = false;

+    // CTRL+TAB can override visible tab temporarily
+    if (g.NavWindowingTarget != NULL && g.NavWindowingTarget->DockNode && g.NavWindowingTarget->DockNode->TabBar == tab_bar)
+        tab_bar->VisibleTabId = scroll_track_selected_tab_id = g.NavWindowingTarget->ID;
+
    // Update scrolling
    if (scroll_track_selected_tab_id)
        if (ImGuiTabItem* scroll_track_selected_tab = TabBarFindTabByID(tab_bar, scroll_track_selected_tab_id))
@@ -6805,6 +6857,38 @@ ImGuiTabItem* ImGui::TabBarFindTabByID(ImGuiTabBar* tab_bar, ImGuiID tab_id)
    return NULL;
 }

+// FIXME: See references to #2304 in TODO.txt
+ImGuiTabItem* ImGui::TabBarFindMostRecentlySelectedTabForActiveWindow(ImGuiTabBar* tab_bar)
+{
+    ImGuiTabItem* most_recently_selected_tab = NULL;
+    for (int tab_n = 0; tab_n < tab_bar->Tabs.Size; tab_n++)
+    {
+        ImGuiTabItem* tab = &tab_bar->Tabs[tab_n];
+        if (most_recently_selected_tab == NULL || most_recently_selected_tab->LastFrameSelected < tab->LastFrameSelected)
+            if (tab->Window && tab->Window->WasActive)
+                most_recently_selected_tab = tab;
+    }
+    return most_recently_selected_tab;
+}
+
+// The purpose of this call is to register tab in advance so we can control their order at the time they appear.
+// Otherwise calling this is unnecessary as tabs are appending as needed by the BeginTabItem() function.
+void ImGui::TabBarAddTab(ImGuiTabBar* tab_bar, ImGuiTabItemFlags tab_flags, ImGuiWindow* window)
+{
+    ImGuiContext& g = *GImGui;
+    IM_ASSERT(TabBarFindTabByID(tab_bar, window->ID) == NULL);
+    IM_ASSERT(g.CurrentTabBar != tab_bar);  // Can't work while the tab bar is active as our tab doesn't have an X offset yet, in theory we could/should test something like (tab_bar->CurrFrameVisible < g.FrameCount) but we'd need to solve why triggers the commented early-out assert in BeginTabBarEx() (probably dock node going from implicit to explicit in same frame)
+
+    ImGuiTabItem new_tab;
+    new_tab.ID = window->ID;
+    new_tab.Flags = tab_flags;
+    new_tab.LastFrameVisible = tab_bar->CurrFrameVisible;   // Required so BeginTabBar() doesn't ditch the tab
+    if (new_tab.LastFrameVisible == -1)
+        new_tab.LastFrameVisible = g.FrameCount - 1;
+    new_tab.Window = window;                                // Required so tab bar layout can compute the tab width before tab submission
+    tab_bar->Tabs.push_back(new_tab);
+}
+
 // The *TabId fields be already set by the docking system _before_ the actual TabItem was created, so we clear them regardless.
 void ImGui::TabBarRemoveTab(ImGuiTabBar* tab_bar, ImGuiID tab_id)
 {
@@ -6980,7 +7064,7 @@ bool    ImGui::BeginTabItem(const char* label, bool* p_open, ImGuiTabItemFlags f
        IM_ASSERT_USER_ERROR(tab_bar, "BeginTabItem() Needs to be called between BeginTabBar() and EndTabBar()!");
        return false;
    }
-    bool ret = TabItemEx(tab_bar, label, p_open, flags);
+    bool ret = TabItemEx(tab_bar, label, p_open, flags, NULL);
    if (ret && !(flags & ImGuiTabItemFlags_NoPushId))
    {
        ImGuiTabItem* tab = &tab_bar->Tabs[tab_bar->LastTabItemIdx];
@@ -7008,7 +7092,7 @@ void    ImGui::EndTabItem()
        window->IDStack.pop_back();
 }

-bool    ImGui::TabItemEx(ImGuiTabBar* tab_bar, const char* label, bool* p_open, ImGuiTabItemFlags flags)
+bool    ImGui::TabItemEx(ImGuiTabBar* tab_bar, const char* label, bool* p_open, ImGuiTabItemFlags flags, ImGuiWindow* docked_window)
 {
    // Layout whole tab bar if not already done
    if (tab_bar->WantLayout)
@@ -7023,6 +7107,7 @@ bool    ImGui::TabItemEx(ImGuiTabBar* tab_bar, const char* label, bool* p_open,
    const ImGuiID id = TabBarCalcTabID(tab_bar, label);

    // If the user called us with *p_open == false, we early out and don't render. We make a dummy call to ItemAdd() so that attempts to use a contextual popup menu with an implicit ID won't use an older ID.
+    IMGUI_TEST_ENGINE_ITEM_INFO(id, label, window->DC.LastItemStatusFlags);
    if (p_open && !*p_open)
    {
        PushItemFlag(ImGuiItemFlags_NoNav | ImGuiItemFlags_NoNavDefaultFocus, true);
@@ -7059,10 +7144,20 @@ bool    ImGui::TabItemEx(ImGuiTabBar* tab_bar, const char* label, bool* p_open,
    const bool tab_appearing = (tab->LastFrameVisible + 1 < g.FrameCount);
    tab->LastFrameVisible = g.FrameCount;
    tab->Flags = flags;
+    tab->Window = docked_window;

    // Append name with zero-terminator
-    tab->NameOffset = tab_bar->TabsNames.size();
-    tab_bar->TabsNames.append(label, label + strlen(label) + 1);
+    if (tab_bar->Flags & ImGuiTabBarFlags_DockNode)
+    {
+        IM_ASSERT(tab->Window != NULL);
+        tab->NameOffset = -1;
+    }
+    else
+    {
+        IM_ASSERT(tab->Window == NULL);
+        tab->NameOffset = tab_bar->TabsNames.size();
+        tab_bar->TabsNames.append(label, label + strlen(label) + 1); // Append name _with_ the zero-terminator.
+    }

    // If we are not reorderable, always reset offset based on submission order.
    // (We already handled layout and sizing using the previous known order, but sizing is not affected by order!)
@@ -7085,7 +7180,7 @@ bool    ImGui::TabItemEx(ImGuiTabBar* tab_bar, const char* label, bool* p_open,
        tab_bar->VisibleTabWasSubmitted = true;

    // On the very first frame of a tab bar we let first tab contents be visible to minimize appearing glitches
-    if (!tab_contents_visible && tab_bar->SelectedTabId == 0 && tab_bar_appearing)
+    if (!tab_contents_visible && tab_bar->SelectedTabId == 0 && tab_bar_appearing && docked_window == NULL)
        if (tab_bar->Tabs.Size == 1 && !(tab_bar->Flags & ImGuiTabBarFlags_AutoSelectNewTabs))
            tab_contents_visible = true;

@@ -7128,7 +7223,7 @@ bool    ImGui::TabItemEx(ImGuiTabBar* tab_bar, const char* label, bool* p_open,

    // Click to Select a tab
    ImGuiButtonFlags button_flags = (ImGuiButtonFlags_PressedOnClick | ImGuiButtonFlags_AllowItemOverlap);
-    if (g.DragDropActive)
+    if (g.DragDropActive && !g.DragDropPayload.IsDataType(IMGUI_PAYLOAD_TYPE_WINDOW))
        button_flags |= ImGuiButtonFlags_PressedOnDragDropHold;
    bool hovered, held;
    bool pressed = ButtonBehavior(bb, id, &hovered, &held, button_flags);
@@ -7140,23 +7235,66 @@ bool    ImGui::TabItemEx(ImGuiTabBar* tab_bar, const char* label, bool* p_open,
    if (!held)
        SetItemAllowOverlap();

-    // Drag and drop: re-order tabs
-    if (held && !tab_appearing && IsMouseDragging(0))
+    // Drag and drop a single floating window node moves it
+    ImGuiDockNode* node = docked_window ? docked_window->DockNode : NULL;
+    const bool single_floating_window_node = node && node->IsFloatingNode() && (node->Windows.Size == 1);
+    if (held && single_floating_window_node && IsMouseDragging(0, 0.0f))
    {
-        if (!g.DragDropActive && (tab_bar->Flags & ImGuiTabBarFlags_Reorderable))
+        // Move
+        StartMouseMovingWindow(docked_window);
+    }
+    else if (held && !tab_appearing && IsMouseDragging(0))
+    {
+        // Drag and drop: re-order tabs
+        float drag_distance_from_edge_x = 0.0f;
+        if (!g.DragDropActive && ((tab_bar->Flags & ImGuiTabBarFlags_Reorderable) || (docked_window != NULL)))
        {
            // While moving a tab it will jump on the other side of the mouse, so we also test for MouseDelta.x
            if (g.IO.MouseDelta.x < 0.0f && g.IO.MousePos.x < bb.Min.x)
            {
+                drag_distance_from_edge_x = bb.Min.x - g.IO.MousePos.x;
                if (tab_bar->Flags & ImGuiTabBarFlags_Reorderable)
                    TabBarQueueChangeTabOrder(tab_bar, tab, -1);
            }
            else if (g.IO.MouseDelta.x > 0.0f && g.IO.MousePos.x > bb.Max.x)
            {
+                drag_distance_from_edge_x = g.IO.MousePos.x - bb.Max.x;
                if (tab_bar->Flags & ImGuiTabBarFlags_Reorderable)
                    TabBarQueueChangeTabOrder(tab_bar, tab, +1);
            }
        }
+
+        // Extract a Dockable window out of it's tab bar
+        if (docked_window != NULL && !(docked_window->Flags & ImGuiWindowFlags_NoMove))
+        {
+            // We use a variable threshold to distinguish dragging tabs within a tab bar and extracting them out of the tab bar
+            bool undocking_tab = (g.DragDropActive && g.DragDropPayload.SourceId == id);
+
+            if (!undocking_tab) //&& (!g.IO.ConfigDockingWithShift || g.IO.KeyShift)
+            {
+                float threshold_base = g.FontSize;
+                //float threshold_base = g.IO.ConfigDockingWithShift ? g.FontSize * 0.5f : g.FontSize;
+                float threshold_x = (threshold_base * 2.2f);
+                float threshold_y = (threshold_base * 1.5f) + ImClamp((ImFabs(g.IO.MouseDragMaxDistanceAbs[0].x) - threshold_base * 2.0f) * 0.20f, 0.0f, threshold_base * 4.0f);
+                //GetForegroundDrawList()->AddRect(ImVec2(bb.Min.x - threshold_x, bb.Min.y - threshold_y), ImVec2(bb.Max.x + threshold_x, bb.Max.y + threshold_y), IM_COL32_WHITE); // [DEBUG]
+
+                float distance_from_edge_y = ImMax(bb.Min.y - g.IO.MousePos.y, g.IO.MousePos.y - bb.Max.y);
+                if (distance_from_edge_y >= threshold_y)
+                    undocking_tab = true;
+                else if (drag_distance_from_edge_x > threshold_x)
+                    if ((tab_bar->ReorderRequestDir < 0 && tab_bar->GetTabOrder(tab) == 0) || (tab_bar->ReorderRequestDir > 0 && tab_bar->GetTabOrder(tab) == tab_bar->Tabs.Size - 1))
+                        undocking_tab = true;
+            }
+
+            if (undocking_tab)
+            {
+                // Undock
+                DockContextQueueUndockWindow(&g, docked_window);
+                g.MovingWindow = docked_window;
+                g.ActiveId = g.MovingWindow->MoveId;
+                g.ActiveIdClickOffset -= g.MovingWindow->Pos - bb.Min;
+            }
+        }
    }

 #if 0
@@ -7219,6 +7357,16 @@ void    ImGui::SetTabItemClosed(const char* label)
        ImGuiID tab_id = TabBarCalcTabID(tab_bar, label);
        TabBarRemoveTab(tab_bar, tab_id);
    }
+    else if (ImGuiWindow* window = FindWindowByName(label))
+    {
+        if (window->DockIsActive)
+            if (ImGuiDockNode* node = window->DockNode)
+            {
+                ImGuiID tab_id = TabBarCalcTabID(node->TabBar, label);
+                TabBarRemoveTab(node->TabBar, tab_id);
+                window->DockTabWantClose = true;
+            }
+    }
 }

 ImVec2 ImGui::TabItemCalcSize(const char* label, bool has_close_button)
@@ -7242,7 +7390,7 @@ void ImGui::TabItemBackground(ImDrawList* draw_list, const ImRect& bb, ImGuiTabI
    IM_ASSERT(width > 0.0f);
    const float rounding = ImMax(0.0f, ImMin(g.Style.TabRounding, width * 0.5f - 1.0f));
    const float y1 = bb.Min.y + 1.0f;
-    const float y2 = bb.Max.y - 1.0f;
+    const float y2 = bb.Max.y + ((flags & ImGuiTabItemFlags_Preview) ? 0.0f : -1.0f);
    draw_list->PathLineTo(ImVec2(bb.Min.x, y2));
    draw_list->PathArcToFast(ImVec2(bb.Min.x + rounding, y1 + rounding), rounding, 6, 9);
    draw_list->PathArcToFast(ImVec2(bb.Max.x - rounding, y1 + rounding), rounding, 9, 12);