Select by Line, Rectangle, or Circle

TatukGIS Internet Server Samples

Select by line:
Click first Point

Source code

This interactive TatukGIS Internet Server sample demonstrates the use of ASP.NET technology to allow the on-line user to select vector shapes using a line, rectangle, or circle drawn by the on-line user.

Simply pick a selection mode – line, polygon, or circle – and click on two locations on the map to form the selection figure. The shapes that are selected (which overlap the selection line, rectangle, or circle) become highlighted on the map and the names of each selected shape will be listed in the box below the map.

select.aspx    Top 

                            
                            
<%@ Page Language="VB" Debug="True" %>
<%@ Register TagPrefix="ttkGIS" Namespace="TatukGIS.IS" Assembly="TatukGIS.IS" %>
<script runat="server">

    Dim GisUtils As API.XGIS_Utils

    Sub Page_Load(sender As Object, e As EventArgs)
        If not Page.IsPostBack then
            Table_Desc.Visible = True
            Lbl_Desc_1.Visible = True
            Lbl_Desc_2.Visible = True
            Lbl_Desc_1.Text = "Select by line:"
            Lbl_Desc_2.Text = "Click first Point"
        end if
    End Sub

    Sub GIS_FullExtent_Click(sender As Object, e As ImageClickEventArgs)
        GIS.FullExtent
    End Sub

    Sub GIS_ZoomIn_Click(sender As Object, e As ImageClickEventArgs)
        GIS.ZoomIn
    End Sub

    Sub GIS_ZoomOut_Click(sender As Object, e As ImageClickEventArgs)
        GIS.ZoomOut
    End Sub

    Sub GIS_Smaller_Click(sender As Object, e As ImageClickEventArgs)
        GIS.Width  = Unit.Pixel( GIS.Width.Value  - 54 )
        GIS.Height = Unit.Pixel( GIS.Height.Value - 40 )
    End Sub

    Sub GIS_Larger_Click(sender As Object, e As ImageClickEventArgs)
        GIS.Width  = Unit.Pixel( GIS.Width.Value  + 54 )
        GIS.Height = Unit.Pixel( GIS.Height.Value + 40 )
    End Sub

    Sub GIS_Load(sender As Object, e As EventArgs)
        GisUtils = New API.XGIS_Utils

        Dim ll As API.XGIS_LayerSHP
        Dim ll1 As API.XGIS_LayerVector

       'add new layers
        ll = New API.XGIS_LayerSHP
        ll.OutCodePage = 1250
        ll.Path = GisUtils.GisSamplesDataDir + "states.shp"
        ll.Name = "states"
        ll.UseConfig = False
        ll.Params.Area.OutlineWidth = 2
        ll.Params.Area.OutlineColor = RGB(100, 100, 100)
        ll.Params.Area.Color = RGB(180, 220, 180)
        GIS.API.Add(ll)

       'add new layers
        ll = New API.XGIS_LayerSHP
        ll.Path = GisUtils.GisSamplesDataDir + "rivers.shp"
        ll.Name = "rivers"
        ll.UseConfig = False
        ll.Params.Line.Color=RGB(70,150,190)
        ll.Params.Line.Width=-2
        GIS.API.Add(ll)

        ll1 = New API.XGIS_LayerVector
        ll1.Name = "points"
        GIS.API.Add(ll1)

        ll1 = New API.XGIS_LayerVector
        ll1.Name = "buffers"
        GIS.API.Add(ll1)

       'set full extent
        GIS.FullExtent()
        GIS.Zoom = GIS.Zoom * 2
        GIS.ImageType = XgisImageType.PNG24

        GIS.Api.SelectionColor=System.Convert.ToUInt32(RGB(255,255,0))
        GIS.Api.SelectionTransparency=60

    End Sub

    Sub GIS_Options_SelectedIndexChanged(sender As Object, e As EventArgs)
        Unselect_All()
        Select Case GIS_Options.SelectedItem.Value
        Case 1
            Table_Desc.Visible = True
            Lbl_Desc_1.Visible = True
            Lbl_Desc_2.Visible = True
            Lbl_Desc_1.Text = "Select by line:"
            Lbl_Desc_2.Text = "Click first Point"
        Case 2
            Table_Desc.Visible = True
            Lbl_Desc_1.Visible = True
            Lbl_Desc_2.Visible = True
            Lbl_Desc_1.Text = "Select by circle:"
            Lbl_Desc_2.Text = "Click first Point"
        Case 3
            Table_Desc.Visible = True
            Lbl_Desc_1.Visible = True
            Lbl_Desc_2.Visible = True
            Lbl_Desc_1.Text = "Select by rectangle:"
            Lbl_Desc_2.Text = "Click first Point"
        End select
    End Sub

    Sub Unselect_All()
        session("point_1") = Nothing
        session("point_2") = Nothing
        Table_Desc.Visible = False
        Lbl_Desc_1.Visible = False
        Lbl_Desc_2.Visible = False
        Lbl_Desc_1.Text = ""
        Lbl_Desc_2.Text = ""
        StatesList.Visible = False
    End Sub

    Sub GIS_Paint(sender As Object, e As PaintEventArgs)
        if Page.IsPostBack then
           'draw a polygon if necessary
            DrawSelectedPoly()
        end if
        GIS.Draw()
    End Sub

    Sub GIS_Click(sender As Object, e As ImageClickEventArgs)
        GIS_GetPoints(sender, e)
    End Sub

    Sub GIS_GetPoints(sender As Object, e As ImageClickEventArgs)
        dim p As API.XPoint
        dim p_gis As API.XGIS_Point

        if session("point_1") Is Nothing
        'create first point
        Lbl_Desc_2.Text = "Click second point"
        p = GisUtils.Point(e.X, e.Y )
        p_gis = GIS.API.ScreenToMap(p)
        session("point_1") = GisUtils.GisPoint( p_gis.X, p_gis.Y )
        else
        'create second point
        p = GisUtils.Point(e.X, e.Y )
        p_gis = GIS.API.ScreenToMap(p)
        session("point_2") = GisUtils.GisPoint( p_gis.X, p_gis.Y )
        end if
    End sub

    Sub DrawSelectedPoly()
        Dim lshp, shp, pshp, cshp as API.XGIS_Shape
        Dim pll as API.XGIS_LayerVector

        dim p1, p2, cp As API.XGIS_Point
        dim p3x, p3y, p4x, p4y As double
        dim radius as integer
        dim tpl as New API.XGIS_TopologyClass

        p1 = session("point_1")
        p2 = session("point_2")

        pll = GIS.API.Get("points")

        if (Not p1 is Nothing) then

        pshp = pll.CreateShape(API.XGIS_ShapeType.XgisShapeTypePoint)
        pshp.Lock(API.XGIS_Lock.XgisLockExtent)
        pshp.AddPart()
        pshp.AddPoint(p1)
        pshp.Unlock()
        pshp = pll.AddShape(pshp)
        pll.Params.Marker.Size=120
        pll.Params.Marker.Color=System.Convert.ToUInt32(RGB(80,200,60))
        pll.Params.Marker.OutlineColor=System.Convert.ToUInt32(RGB(80,60,200))
        pll.Params.Marker.OutlineWidth=30
        pll.Params.Marker.Style=API.XGIS_MarkerStyle.XgisMarkerStyleCircle

        if (Not p1 is Nothing) and (Not p2 Is nothing) then

            pshp.Lock(API.XGIS_Lock.XgisLockExtent)
            pshp.AddPart()
            pshp.AddPoint(p2)
            pshp.Unlock()
            pshp = pll.AddShape(pshp)
            Select Case GIS_Options.SelectedItem.Value
                Case 1
                lshp = GIS.API.Get("buffers").CreateShape(API.XGIS_ShapeType.XgisShapeTypeArc )
                lshp.Lock(2)
                lshp.AddPart()
                lshp.AddPoint( GisUtils.GisPoint( p1.X, p1.Y ) )
                lshp.AddPoint( GisUtils.GisPoint( p2.X, p2.Y ) )
                lshp.Unlock()
                Lbl_Desc_1.Text = "States selected by line:"
                Lbl_Desc_2.Visible = False
                StatesList.Visible = True

                Case 2
                'create center point of circle
                p3x = (p1.x + p2.x)/2
                p3y = (p1.y + p2.y)/2

                cp = GisUtils.GisPoint(p3x, p3y)
                cshp = pll.CreateShape(API.XGIS_ShapeType.XgisShapeTypePoint)
                cshp.Lock(API.XGIS_Lock.XgisLockExtent)
                cshp.AddPart()
                cshp.AddPoint(cp)
                cshp.Unlock()

                radius = Math.Round(Math.Sqrt(((p1.X - p2.x) * (p1.X - p2.x)) + ((p1.Y - p2.y) * (p1.Y - p2.y))))/2
                shp = tpl.MakeBuffer(cshp, radius, 0, True)
                cshp.Delete()
                Lbl_Desc_1.Text = "States selected by circle:"
                Lbl_Desc_2.Visible = False
                StatesList.Visible = True


                Case 3
                p3x = p1.x
                p3y = p2.y
                p4x = p2.x
                p4y = p1.y

                shp = GIS.API.Get("buffers").CreateShape(API.XGIS_ShapeType.XgisShapeTypePolygon )
                shp.Lock(2)
                shp.AddPart()
                shp.AddPoint( GisUtils.GisPoint( p1.X, p1.Y ) )
                shp.AddPoint( GisUtils.GisPoint( p3x, p3y ) )
                shp.AddPoint( GisUtils.GisPoint( p2.X, p2.Y ) )
                shp.AddPoint( GisUtils.GisPoint( p4x, p4y ) )
                shp.Unlock()
                Lbl_Desc_1.Text = "States selected by rectangle:"
                Lbl_Desc_2.Visible = False
                StatesList.Visible = True
            End select

            if not pshp is nothing then
                SelectStates(pshp)
            end if
            if not shp is nothing then
                shp.Params.Area.Pattern=API.XBrushStyle.XbsClear
                shp.Params.Area.Color=System.Convert.ToUInt32(RGB(80,60,200))
                shp.Params.Area.OutlineColor=System.Convert.ToUInt32(RGB(80,60,200))
                shp.Params.Area.OutlineWidth=-3
                shp = GIS.API.Get("buffers").AddShape(shp)
                SelectStates(shp)
            end if
            if not lshp is nothing then
                lshp = GIS.API.Get("buffers").AddShape(lshp)
                lshp.Params.Line.Width=-3
                lshp.Params.Line.Color=System.Convert.ToUInt32(RGB(80,60,200))
                SelectStates(lshp)
            end if
        end if
    end if
    End sub

    Sub SelectStates(buf as API.XGIS_Shape)
        dim tmp as API.XGIS_Shape
        dim ll as API.XGIS_LayerVector
        dim i as integer

        ll = GIS.API.Get("states")
        If ll Is Nothing Then
            'GIS.CtlUpdate()
            Exit Sub
        End If

        ll.DeselectAll()

        'check all shapes
        dim Table as System.Data.DataTable = New System.Data.DataTable()
        dim dr as System.Data.DataRow

        Table.Columns.Add("Sid", GetType(String))
        Table.Columns.Add("Name", GetType(String))

        tmp = ll.FindFirst(buf.Extent, "", buf, "T********", True)
        i=1
        While Not tmp Is Nothing
            tmp = tmp.MakeEditable
            dr = Table.NewRow()
            dr(0) = cstr(i)
            dr(1) = tmp.GetField("name")
            Table.Rows.Add(dr)
            'tmp.Params.Area.Color = Convert.ToUInt32(RGB(0, 200, 80))
            'tmp.Params.Area.Pattern = API.XBrushStyle.XbsHorizontal
            'tmp.Params.Labels.Field = "Name"
            'tmp.Params.Labels.Color = System.Convert.ToUInt32(RGB(255, 255, 255))
            'tmp.Params.Labels.FontColor = System.Convert.ToUInt32(RGB(80, 80, 80))
            'tmp.Params.Labels.Position = API.XGIS_LabelPositions.XgisLabelPositionMiddleCenter
            tmp.IsSelected=True
            i = i + 1
            tmp = ll.FindNext
        End While
        StatesList.DataSource = Table.DefaultView
        StatesList.DataBind
    End Sub


</script>
<html>
<head>
    <title>TatukGIS IS Sample</title>
    <link href="style.css" type="text/css" rel="stylesheet" />
</head>
<body>
    <a name="top">
    <h1>Select by line, circle or rectangle
    </h1>
    <h2 class="comment"><a href="../../samplesAPI.htm">TatukGIS Internet Server Samples</a>
    </h2>
    <form runat="server">
        <table cellspacing="0" cellpadding="0" border="0">
            <tbody>
                <tr>
                    <td width="25%">
                        <asp:ImageButton id="GIS_FullExtent" onclick="GIS_FullExtent_Click" runat="server" ImageUrl="/TatukGIS_IS8/img/fullextent.gif"></asp:ImageButton>
                        <asp:ImageButton id="GIS_ZoomIn" onclick="GIS_ZoomIn_Click" runat="server" ImageUrl="/TatukGIS_IS8/img/zoomin.gif"></asp:ImageButton>
                        <asp:ImageButton id="GIS_ZoomOut" onclick="GIS_ZoomOut_Click" runat="server" ImageUrl="/TatukGIS_IS8/img/zoomout.gif"></asp:ImageButton>
                    </td>
                    <td width="60%">
                        <asp:RadioButtonList id="GIS_Options" runat="server" Width="160px" RepeatDirection="Horizontal" OnSelectedIndexChanged="GIS_Options_SelectedIndexChanged" AutoPostBack="True">
                            <asp:ListItem Value="1" Selected="True">Line</asp:ListItem>
                            <asp:ListItem Value="2">Circle</asp:ListItem>
                            <asp:ListItem Value="3">Rectangle</asp:ListItem>
                        </asp:RadioButtonList>
                    </td>
                    <td align="right" width="15%">
                        <asp:ImageButton id="GIS_Smaller" onclick="GIS_Smaller_Click" runat="server" ImageUrl="/TatukGIS_IS8/img/smaller.gif"></asp:ImageButton>
                        <asp:ImageButton id="GIS_Larger" onclick="GIS_Larger_Click" runat="server" ImageUrl="/TatukGIS_IS8/img/larger.gif"></asp:ImageButton>
                    </td>
                </tr>
                <tr>
                    <td colspan="3">
                        <ttkGIS:XGIS_VIEWERIS id="GIS" onclick="GIS_Click" runat="server" Width="360px" BorderWidth="1px" BorderColor="CornflowerBlue" OnLoad="GIS_Load" Height="280px" OnPaint="GIS_Paint"></ttkGIS:XGIS_VIEWERIS>
                    </td>
                </tr>
            </tbody>
        </table>
        <p>
            <asp:Table id="Table_Desc" runat="server" Width="364px" BorderWidth="2px" BorderColor="Navy" BackColor="LightBlue" Visible="False">
                <asp:TableRow>
                    <asp:TableCell>
                        <asp:Label runat="server" id="Lbl_Desc_1" font-bold="True"></asp:Label>
                        <br />
                        <asp:Label runat="server" id="Lbl_Desc_2"></asp:Label>
                        <asp:DataList id="StatesList" runat="server">
                            <ItemTemplate>
                                <asp:Label id="Sid" runat="server" text='<%# cstr(Container.DataItem("Sid")) %>' /> <asp:Label id="Name" runat="server" text='<%# Container.DataItem("name") %>' />
                            </ItemTemplate>
                        </asp:DataList>
                    </asp:TableCell>
                </asp:TableRow>
            </asp:Table>
        </p>
    </form>
    </a>
</body>
</html>