Method UpdateMouseMovingWindowNewFrame

Source/3rdParty/imgui/imgui.cpp:5286–5318

Handle mouse moving window Note: moving window with the navigation keys (Square + d-pad / Ctrl+Tab + Arrows) are processed in NavUpdateWindowing() FIXME: We don't have strong guarantee that g.MovingWindow stay synced with g.ActiveId == g.MovingWindow->MoveId. This is currently enforced by the fact that BeginDragDropSource() is setting all g.ActiveIdUsingXXXX flags to inhibit navigation inputs, but

// This is currently enforced by the fact that BeginDragDropSource() is setting all g.ActiveIdUsingXXXX flags to inhibit navigation inputs,
// but if we should more thoroughly test cases where g.ActiveId or g.MovingWindow gets changed and not the other.
void ImGui::UpdateMouseMovingWindowNewFrame()
{
    ImGuiContext& g = *GImGui;
    if (g.MovingWindow != NULL)
    {
        // We actually want to move the root window. g.MovingWindow == window we clicked on (could be a child window).
        // We track it to preserve Focus and so that generally ActiveIdWindow == MovingWindow and ActiveId == MovingWindow->MoveId for consistency.
        KeepAliveID(g.ActiveId);
        IM_ASSERT(g.MovingWindow && g.MovingWindow->RootWindow);
        ImGuiWindow* moving_window = g.MovingWindow->RootWindow;
        if (g.IO.MouseDown[0] && IsMousePosValid(&g.IO.MousePos))
        {
            ImVec2 pos = g.IO.MousePos - g.ActiveIdClickOffset;
            SetWindowPos(moving_window, pos, ImGuiCond_Always);
            FocusWindow(g.MovingWindow);
        }
        else
        {
            StopMouseMovingWindow();
            ClearActiveID();
        }
    }
    else
    {
        // When clicking/dragging from a window that has the _NoMove flag, we still set the ActiveId in order to prevent hovering others.
        if (g.ActiveIdWindow && g.ActiveIdWindow->MoveId == g.ActiveId)
        {
            KeepAliveID(g.ActiveId);
            if (!g.IO.MouseDown[0])
                ClearActiveID();
        }
    }
}

// Initiate focusing and moving window when clicking on empty space or title bar.
// Initiate focusing window when clicking on a disabled item.