Since volcanos are often associated with earthquakes, and vice versa, I decided to show recent volcanic activity on
the Earthquake Locator map. I am pulling
the data from a website created for a joint project between
the Smithsonian's Global Volcanism Program and
the US Geological Survey's Volcano Hazards Program, found here. They provide a Weekly Volcanic Activity Report as an RSS
feed.
I started implementing this new functionality by creating a new Volcano entity in
the domain model and adding
the following to
the EarthquakeService class (I also factored out
the common reading/parsing helper methods to a separate FeedReader class that can be used by multiple domain service classes):
private static readonly string VolcanoFeedUrl =
ConfigurationManager.AppSettings["VolcanoFeedUrl"];
/// <summary>
/// Gets
the volcano data for
the previous week.
/// </summary>
/// <returns>A queryable collection of <see cref="Volcano"/> objects.</returns>
public IQueryable<Volcano> GetVolcanos()
{
var
feed = FeedReader.Load(VolcanoFeedUrl);
var list = new List<Volcano>();
if (
feed != null )
{
foreach ( var item in
feed.Items )
{
var quake = CreateVolcano(item);
if ( quake != null )
{
list.Add(quake);
}
}
}
return list.AsQueryable();
}
/// <summary>
/// Creates a <see cref="Volcano"/> object for each item in
the RSS
feed.
/// </summary>
/// <param name="item">The RSS item.</param>
/// <returns></returns>
private Volcano CreateVolcano(SyndicationItem item)
{
Volcano volcano = null;
string title = item.Title.Text;
string desc = item.Summary.Text;
double? latitude = null;
double? longitude = null;
FeedReader.GetGeoRssPoint(item, out latitude, out longitude);
if ( !String.IsNullOrEmpty(title) )
{
title = title.Substring(0, title.IndexOf('-'));
}
if ( !String.IsNullOrEmpty(desc) )
{
desc = String.Join("\n\n", desc
.Replace("<p>", "")
.Split(
new string[] { "</p>" },
StringSplitOptions.RemoveEmptyEntries)
.Select(s => s.Trim())
.ToArray())
.Trim();
}
if ( latitude != null && longitude != null )
{
volcano = new Volcano()
{
Id = item.Id,
Title = title,
Description = desc,
Url = item.Links.Select(l => l.Uri.OriginalString).FirstOrDefault(),
Latitude = latitude.GetValueOrDefault(),
Longitude = longitude.GetValueOrDefault()
};
}
return volcano;
}
I then added
the corresponding LoadVolcanos() method and Volcanos collection to
the EarthquakeViewModel class in much
the same way I did with
the Earthquakes in my previous article in this series.
Now that I am starting to add more information to
the map, I wanted to give
the user some options as to what is displayed and allowing them to choose what gets turned off. I have updated
the MainPage.xaml to look like this:
<UserControl x:Class="EarthquakeLocator.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:basic="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls"
xmlns:bing="clr-namespace:Microsoft.Maps.MapControl;assembly=Microsoft.Maps.MapControl"
xmlns:vm="clr-namespace:EarthquakeLocator.ViewModel"
mc:Ignorable="d" d:DesignWidth="640" d:DesignHeight="480"
>
<UserControl.Resources>
<DataTemplate x:Key="EarthquakeTemplate">
<Ellipse Fill="Red" Stroke="Black" StrokeThickness="1"
Width="{Binding Size}" Height="{Binding Size}"
bing:MapLayer.Position="{Binding Location}"
bing:MapLayer.PositionOrigin="Center">
<ToolTipService.ToolTip>
<StackPanel>
<TextBlock Text="{Binding Title}" FontSize="14" FontWeight="Bold" />
<TextBlock Text="{Binding UtcTime}" />
<TextBlock Text="{Binding LocalTime}" />
<TextBlock Text="{Binding DepthDesc}" />
</StackPanel>
</ToolTipService.ToolTip>
</Ellipse>
</DataTemplate>
<DataTemplate x:Key="VolcanoTemplate">
<Polygon Fill="Gold" Stroke="Black" StrokeThickness="1" Points="0,10 5,0 10,10"
bing:MapLayer.Position="{Binding Location}"
bing:MapLayer.PositionOrigin="Center"
MouseLeftButtonUp="Volcano_MouseLeftButtonUp">
<ToolTipService.ToolTip>
<StackPanel>
<TextBlock Text="{Binding Title}" FontSize="14" FontWeight="Bold" />
<TextBlock Text="Click icon for more information..." />
</StackPanel>
</ToolTipService.ToolTip>
</Polygon>
</DataTemplate>
</UserControl.Resources>
<UserControl.DataContext>
<vm:EarthquakeViewModel AutoLoadData="True" />
</UserControl.DataContext>
<Grid x:Name="LayoutRoot">
<bing:Map x:Name="map" CredentialsProvider="--Your-Bing-Maps-Key--"
Center="{Binding MapCenter, Mode=TwoWay}"
ZoomLevel="{Binding ZoomLevel, Mode=TwoWay}">
<bing:MapItemsControl ItemsSource="{Binding Earthquakes}"
ItemTemplate="{StaticResource EarthquakeTemplate}" />
<bing:MapItemsControl ItemsSource="{Binding Volcanos}"
ItemTemplate="{StaticResource VolcanoTemplate}" />
</bing:Map>
<basic:TabControl x:Name="tabs" VerticalAlignment="Bottom" MaxHeight="25" Opacity="0.7">
<basic:TabItem Margin="90,0,-90,0" MouseLeftButtonUp="TabItem_MouseLeftButtonUp">
<basic:TabItem.Header>
<TextBlock x:Name="txtHeader" Text="Options"
FontSize="13" FontWeight="Bold" />
</basic:TabItem.Header>
<StackPanel Orientation="Horizontal">
<TextBlock Text="Earthquakes:" FontWeight="Bold" Margin="3" />
<StackPanel Margin="3">
<CheckBox Content=" < 4.0"
IsChecked="{Binding ShowLt4, Mode=TwoWay}" />
<CheckBox Content="4.0 - 4.9"
IsChecked="{Binding Show4s, Mode=TwoWay}" />
<CheckBox Content="5.0 - 5.9"
IsChecked="{Binding Show5s, Mode=TwoWay}" />
</StackPanel>
<StackPanel Margin="10,3,3,3">
<CheckBox Content="6.0 - 6.9"
IsChecked="{Binding Show6s, Mode=TwoWay}" />
<CheckBox Content="7.0 - 7.9"
IsChecked="{Binding Show7s, Mode=TwoWay}" />
<CheckBox Content="8.0 +"
IsChecked="{Binding ShowGe8, Mode=TwoWay}" />
</StackPanel>
<TextBlock Text="Other:" FontWeight="Bold" Margin="50,3,3,3" />
<StackPanel Margin="3">
<CheckBox Content="Volcanos"
IsChecked="{Binding ShowVolcanos, Mode=TwoWay}" />
</StackPanel>
</StackPanel>
</basic:TabItem>
</basic:TabControl>
</Grid>
</UserControl>
Notice that I added a VolcanoTemplate that uses a triangle-shaped Polygon to represent
the Volcano locations, and I also added a second <bing:MapItemsControl /> tag to
the map to bind to
the Volcanos collection.
The TabControl found below
the map houses
the options panel that will present
the user with several checkboxes so they can filter
the different points based on type and other properties (i.e. Magnitude). Initially,
the TabItem is collapsed to reduce it's footprint, but
the screen shot below shows
the options panel expanded to reveal
the available settings:
I have updated
the Source Code and Live Demo to include these new features.
Happy Mapping!
