Setting min/max on map view while Panning using CartoType

Question

I am working with the .NET CartoType SDK on Windows.

How can I restrict panning?

In the "Windows Maps" app I am able to pan outside of the map boundaries. I would like to prevent this.

The C# demo program supplied with CartoType contains this code to pan the map in response to a mouse drag event, and I've added the code starting with the comment "clamp view to extent of map", but the map is still panned too far. The aim is to prevent any edge of the display going beyond the edge of the map.

private void Form1_MouseMove(object sender, MouseEventArgs e)
    {
        if (e.Button == MouseButtons.Left)
        {
            m_map_drag_offset_x = e.X - m_map_drag_anchor_x;
            m_map_drag_offset_y = e.Y - m_map_drag_anchor_y;

            if (m_graphics_acceleration)
            {
                m_framework.Pan(-m_map_drag_offset_x, -m_map_drag_offset_y);
                m_map_drag_offset_x = 0;
                m_map_drag_offset_y = 0;
                m_map_drag_anchor_x = e.X;
                m_map_drag_anchor_y = e.Y;

                // clamp view to extent of map
                var state = m_framework.GetViewState();
                var map_extent = new CartoType.Rect();
                m_framework.GetMapExtent(map_extent, CartoType.CoordType.Degree);
                var x = state.m_view_center_degrees_x;
                var y = state.m_view_center_degrees_y;
                if (x < map_extent.MinX)
                    x = map_extent.MinX;
                else if (x > map_extent.MaxX)
                    x = map_extent.MaxX;
                if (y < map_extent.MinY)
                    y = map_extent.MinY;
                else if (y > map_extent.MaxY)
                    y = map_extent.MaxY;
                m_framework.SetViewCenter(x, y, CartoType.CoordType.Degree);

            }
            else
                Draw(m_map_drag_graphics);
        }
    }

Answer 1

You can now use the function SetViewLimits:

Result CartoType.Framework.SetViewLimits(double aMinScaleDenominator,double aMaxScaleDenominator,Geometry aPanArea)

Zooming is restricted to the range between aMinScaleDenominator and aMaxScaleDenominator, and panning is restricted so that the edges of the display always touch the bounds of aPanArea.

Use the value zero to remove either or both of the two zoom limits. Use an empty (not null) geometry object to remove panning limits. Use a null geometry object to limit panning to the extent of the map.

To solve the problem given here, use the C# statement:

SetViewLimits(0,0,null);