added possibility to snap only to selected layers instead of all

Changelog.md

@@ -24,6 +24,7 @@ Be aware that code written for 1.9 will not work out of the box because DotSpati
 - Possibility to drag layers out of their group into the parent group (in legend) (#1008)
 - Clear parameter to Select function to speed up drawing (#1024)
 - LayoutControl.InitialOpenFileDirectory property that allows to set the folder that is shown in the OpenFileDialog that is used to open an existing layout
+- FeatureLayer.Snappable to indicate whether the layer can be used for snapping
 
 ### Changed
 - Switched to VS2015 and C#6
@@ -44,6 +45,8 @@ Be aware that code written for 1.9 will not work out of the box because DotSpati
 - Made Shapefile class abstract, because we already have FeatureSet for creating unspecified Shapefiles (#890)
 - Moved MapFrame extension methods to Group (#1008)
 - Drawing functions so selected features are drawn on top (#897)
+- ShapeEditors AddFeature and MoveVertex functions, so they snap only to the layers that allow snapping
+- ShapeEditors SnapSettingsDialog to allow the users to select the layers the editor functions may snap to
 
 ### Removed
 - Removed DotSpatial.Topology assembly (#633)

Source/DotSpatial.Plugins.ShapeEditor/ButtonHandler.cs

@@ -352,14 +352,33 @@ private void SetSnapLayers(SnappableMapFunction func)
 
         private void SnappingButtonClick(object sender, EventArgs e)
         {
-            SnapSettingsDialog dlg = new SnapSettingsDialog
+            using (SnapSettingsDialog dlg = new SnapSettingsDialog(_geoMap)
             {
                 DoSnapping = _doSnapping
-            };
-            dlg.ShowDialog();
-            _doSnapping = dlg.DoSnapping;
-            if (_moveVertexFunction != null) _moveVertexFunction.DoSnapping = _doSnapping; // changed by jany_ (2016-02-24) update the snap settings of the functions without having to stop editing
-            if (_addShapeFunction != null) _addShapeFunction.DoSnapping = _doSnapping;
+            })
+            {
+                if (dlg.ShowDialog() == DialogResult.OK)
+                {
+                    _doSnapping = dlg.DoSnapping;
+                    if (_moveVertexFunction != null)
+                    {
+                        _moveVertexFunction.DoSnapping = _doSnapping; // changed by jany_ (2016-02-24) update the snap settings of the functions without having to stop editing
+                        if (_doSnapping)
+                        {
+                            SetSnapLayers(_moveVertexFunction);
+                        }
+                    }
+
+                    if (_addShapeFunction != null)
+                    {
+                        _addShapeFunction.DoSnapping = _doSnapping;
+                        if (_doSnapping)
+                        {
+                            SetSnapLayers(_addShapeFunction);
+                        }
+                    }
+                }
+            }
         }
 
         private void UpdateAddShapeFunctionLayer()

Source/DotSpatial.Plugins.ShapeEditor/DotSpatial.Plugins.ShapeEditor.csproj

@@ -132,6 +132,7 @@
       <DesignTime>True</DesignTime>
       <DependentUpon>ShapeEditorResources.resx</DependentUpon>
     </Compile>
+    <Compile Include="SnapLayer.cs" />
     <Compile Include="SnappableMapFunction.cs">
       <SubType>Code</SubType>
     </Compile>

Source/DotSpatial.Plugins.ShapeEditor/SnapLayer.cs

@@ -0,0 +1,60 @@
+// Copyright (c) DotSpatial Team. All rights reserved.
+// Licensed under the MIT license. See License.txt file in the project root for full license information.
+
+using DotSpatial.Symbology;
+
+namespace DotSpatial.Plugins.ShapeEditor
+{
+    /// <summary>
+    /// Class to control layers snappable property through the datagridview.
+    /// </summary>
+    public class SnapLayer
+    {
+        #region Fields
+
+        /// <summary>
+        /// Layer, whose snappable property can be changed.
+        /// </summary>
+        private readonly IFeatureLayer _layer;
+
+        #endregion
+
+        #region Constructors
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="SnapLayer"/> class.
+        /// </summary>
+        /// <param name="pLayer">Layer, for which the SnapLayer-object gets created.</param>
+        public SnapLayer(IFeatureLayer pLayer)
+        {
+            _layer = pLayer;
+        }
+
+        #endregion
+
+        #region Properties
+
+        /// <summary>
+        /// Gets the layer name so it can be shown in the DataGridView.
+        /// </summary>
+        public string LayerName => _layer.LegendText;
+
+        /// <summary>
+        /// Gets or sets a value indicating whether snapping to the coordinates of the layers features is allowed.
+        /// </summary>
+        public bool Snappable
+        {
+            get
+            {
+                return _layer.Snappable;
+            }
+
+            set
+            {
+                _layer.Snappable = value;
+            }
+        }
+
+        #endregion
+    }
+}

Source/DotSpatial.Plugins.ShapeEditor/SnapSettingsDialog.cs

@@ -1,7 +1,9 @@
 // Copyright (c) DotSpatial Team. All rights reserved.
 // Licensed under the MIT license. See License.txt file in the project root for full license information.
 
+using System.Collections.Generic;
 using System.Windows.Forms;
+using DotSpatial.Controls;
 
 namespace DotSpatial.Plugins.ShapeEditor
 {
@@ -13,9 +15,19 @@ public partial class SnapSettingsDialog : Form
         /// <summary>
         /// Initializes a new instance of the <see cref="SnapSettingsDialog"/> class.
         /// </summary>
-        public SnapSettingsDialog()
+        /// <param name="map">The map that contains the layers.</param>
+        public SnapSettingsDialog(IMap map)
         {
             InitializeComponent();
+            List<SnapLayer> snaplist = new List<SnapLayer>();
+
+            foreach (var layer in map.GetFeatureLayers())
+            {
+                snaplist.Add(new SnapLayer(layer));
+            }
+
+            dgvLayer.AutoGenerateColumns = false;
+            dgvLayer.DataSource = snaplist;
         }
 
         /// <summary>
@@ -26,5 +38,21 @@ public bool DoSnapping
             get { return cbPerformSnap.Checked; }
             set { cbPerformSnap.Checked = value; }
         }
+
+        /// <summary>
+        /// Sets the check mark of the selected cell.
+        /// </summary>
+        /// <param name="sender">The sender of the event.</param>
+        /// <param name="e">The event args.</param>
+        private void DgvLayerCellContentClick(object sender, DataGridViewCellEventArgs e)
+        {
+            if (e.RowIndex < 0 || e.ColumnIndex < 0) return;
+
+            if (dgvLayer.Columns[e.ColumnIndex].Name == dgvcSnappable.Name)
+            {
+                DataGridViewRow row = dgvLayer.Rows[e.RowIndex];
+                row.Cells[e.ColumnIndex].Value = !(bool)row.Cells[e.ColumnIndex].Value;
+            }
+        }
     }
 }

Source/DotSpatial.Plugins.ShapeEditor/SnapSettingsDialog.resx

@@ -117,4 +117,10 @@
   <resheader name="writer">
     <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
   </resheader>
+  <metadata name="dgvcSnappable.UserAddedColumn" type="System.Boolean, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
+    <value>True</value>
+  </metadata>
+  <metadata name="dgvcLayerName.UserAddedColumn" type="System.Boolean, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
+    <value>True</value>
+  </metadata>
 </root>

Source/DotSpatial.Plugins.ShapeEditor/SnappableMapFunction.cs

@@ -3,6 +3,7 @@
 
 using System.Collections.Generic;
 using System.Drawing;
+using System.Linq;
 using DotSpatial.Controls;
 using DotSpatial.Data;
 using DotSpatial.Symbology;
@@ -97,7 +98,7 @@ protected bool ComputeSnappedLocation(GeoMouseArgs e, ref Coordinate snappedCoor
 
             Envelope env = pix.ToEnvelope();
 
-            foreach (IFeatureLayer layer in SnapLayers)
+            foreach (IFeatureLayer layer in SnapLayers.Where(_ => _.Snappable && _.IsVisible))
             {
                 foreach (IFeature feat in layer.DataSet.Features)
                 {

Source/DotSpatial.Symbology/FeatureLayer.cs

@@ -425,6 +425,14 @@ public virtual bool ShowLabels
             }
         }
 
+        /// <summary>
+        /// Gets or sets a value indicating whether this layer can be used for snapping.
+        /// </summary>
+        [Category("Behavior")]
+        [Description("Gets or sets a value indicating whether this layer can be used for snapping.")]
+        [Serialize("Snappable")]
+        public bool Snappable { get; set; }
+
         /// <summary>
         /// Gets or sets and interface for the shared symbol characteristics between point, line and polygon features
         /// </summary>
@@ -1709,6 +1717,7 @@ private void Configure(IFeatureSet featureSet)
         {
             _categoryExtents = new Dictionary<IFeatureCategory, Extent>();
             DrawingBounds = new Rectangle(-32000, -32000, 64000, 64000);
+            Snappable = true;
             DataSet = featureSet;
             LegendText = featureSet.Name;
             Name = featureSet.Name;

Source/DotSpatial.Symbology/IFeatureLayer.cs

@@ -90,6 +90,13 @@ public interface IFeatureLayer : ILayer
         [Description("Gets or sets whether labels should be drawn.")]
         bool ShowLabels { get; set; }
 
+        /// <summary>
+        /// Gets or sets a value indicating whether this layer can be used for snapping.
+        /// </summary>
+        [Category("Behavior")]
+        [Description("Gets or sets a value indicating whether this layer can be used for snapping.")]
+        bool Snappable { get; set; }
+
         /// <summary>
         /// Gets or sets and interface for the shared symbol characteristics between point, line and polygon features
         /// </summary>