Method DockContextBindNodeToWindow

imgui_tiny_app/imgui/imgui.cpp:21105–21146

}

static ImGuiDockNode* ImGui::DockContextBindNodeToWindow(ImGuiContext* ctx, ImGuiWindow* window)
{
    ImGuiContext& g = *ctx;
    ImGuiDockNode* node = DockContextFindNodeByID(ctx, window->DockId);
    IM_ASSERT(window->DockNode == NULL);

    // We should not be docking into a split node (SetWindowDock should avoid this)
    if (node && node->IsSplitNode())
    {
        DockContextProcessUndockWindow(ctx, window);
        return NULL;
    }

    // Create node
    if (node == NULL)
    {
        node = DockContextAddNode(ctx, window->DockId);
        node->AuthorityForPos = node->AuthorityForSize = node->AuthorityForViewport = ImGuiDataAuthority_Window;
        node->LastFrameAlive = g.FrameCount;
    }

    // If the node just turned visible and is part of a hierarchy, it doesn't have a Size assigned by DockNodeTreeUpdatePosSize() yet,
    // so we're forcing a Pos/Size update from the first ancestor that is already visible (often it will be the root node).
    // If we don't do this, the window will be assigned a zero-size on its first frame, which won't ideally warm up the layout.
    // This is a little wonky because we don't normally update the Pos/Size of visible node mid-frame.
    if (!node->IsVisible)
    {
        ImGuiDockNode* ancestor_node = node;
        while (!ancestor_node->IsVisible && ancestor_node->ParentNode)
            ancestor_node = ancestor_node->ParentNode;
        IM_ASSERT(ancestor_node->Size.x > 0.0f && ancestor_node->Size.y > 0.0f);
        DockNodeUpdateHasCentralNodeChild(DockNodeGetRootNode(ancestor_node));
        DockNodeTreeUpdatePosSize(ancestor_node, ancestor_node->Pos, ancestor_node->Size, node);
    }

    // Add window to node
    bool node_was_visible = node->IsVisible;
    DockNodeAddWindow(node, window, true);
    node->IsVisible = node_was_visible; // Don't mark visible right away (so DockContextEndFrame() doesn't render it, maybe other side effects? will see)
    IM_ASSERT(node == window->DockNode);
    return node;
}

static void StoreDockStyleForWindow(ImGuiWindow* window)
{