Layer Information

The Layer Information tab of the Layer Properties dialog provides general information about a map layer.

Steps To Display Layer Information

Right-click on the layer in the legend. Click on Layer Properties on the popup menu. The LayerProperties dialog will display. Click on the Layer Information tab. The information displayed will depend on the type of map layer, vector, raster, or web service.

Layer Information For Vector Layers

• Location The physical location of the data store for the layer.
• Friendly Name The name of the layer as it appears in the legend. This can be changed.
• Geometry Type The type of geometry stored in this layer.
• Format The format of the layer.
• Always Draw Features If this option is turned off it is possible to draw labels for features, without actually drawing the features themselves.
• Crop Features When Drawn To The Map Labels are always drawn in the center of a feature. In some cases the center of a feature may be outside the visible extent of the current map display. By turning this option on, features are cropped to the current visible extent, and as a result their center is always visible and so are their labels.
• Bounding Box The bounding area of the map layer in map coordinates.
• Scale Dependency By default, both values will be -1, meaning the layer will be drawn at all scales. Set the Maximum Scale to prevent the layer be drawn over a certain scale. Set the Minimum Scale to prevent the layer being drawn below a certain scale.
• Timing The time it took the layer to draw on the last screen refresh.

Layer Information For Raster Layers

• Location The physical location of the data store for the layer.
• Friendly Name The name of the layer as it appears in the legend. This can be changed.
• Geometry Type The type of geometry stored in this layer.
• Format The format of the layer.
• Bounding Box The bounding area of the map layer in map coordinates.
• Scale Dependency By default, both values will be -1, meaning the layer will be drawn at all scales. Set the Maximum Scale to prevent the layer be drawn over a certain scale. Set the Minimum Scale to prevent the layer being drawn below a certain scale.
• Timing The time it took the layer to draw on the last screen refresh.
• Image Properties : Transparency Check this option on to make a particular color or color range of a raster image appear transparent. Use the Color Red, Green and Blue settings to pick the color. Use the Threshold Red, Green and Blue settings to pick a range. If the Color Red setting is 128, and the Threshold Red setting is 1, then values of 127, 128 and 129 will be treated as transparent (assuming the green and blue color match also).
• Image Options : Layer Opacity Set this value between 0 and 100. 0 will make the layer completely invisible, 100 will make it fully visible. Values in between will wash out the image. The lower the value the more washed out the layer will be. With washed out layers it is possible to see layers below them in the draw order.

Layer Information For Web Map Service (WMS) Layers

WMS servers return a raster image, so all of the information that applies to raster layer applies to WMS layers. In addition, a new tab, OGC WMS, is added to the Layer Properties dialog. This tab contains the foloowing information.

• Coordinate Reference System WMS servers can typically return the map image in difeerent coordiante systems. Use this drop-down box to see what coordinate reference systems the WMS server support, and set which one the map should be returned in.
• Bounding Box This is the same Bounding Box information as displayed on the Layer Information tab.
• Styles Some WMS servers optionally support returning the map image in different styles. Pick the style using the drop-down. This will not be available for all WMS servers.
• Image Format Some WMS servers can return the map image in different formats. Use the drop-down list to pick the image format to return the map as.
• Exception Format WMS servers can return errors in different ways. Use this drop-down to select how to receive errors for this layer.
• Flags These are read-only information flags returned by the WMS server for this layer.