/// <summary>
/// Refreshes the list of items obtained from the API and populates the view model
/// </summary>
public async Task Refresh()
{
// get bounding box of current map
var topLeft = TheMap.ConvertViewportPointToGeoCoordinate(new Point(0, 0));
var bottomRight = TheMap.ConvertViewportPointToGeoCoordinate(new Point(TheMap.ActualWidth, TheMap.ActualHeight));
var box = new BoundingBox(topLeft.Latitude, bottomRight.Latitude, topLeft.Longitude, bottomRight.Longitude);
//
// TODO: invoke API that returns a list of point-of-interest items now in view on the map. This will populate
// an observable collection of IMappable items on the ApiViewModel class (with the name Results). As that
// collection is populated, the Results_CollectionChanged callback will fire to create the appropriate
// point-of-interest pins and associate them with the map.
//
this.DefaultViewModel.ApiStatus = await _tomTomApi.GetCameras(box, (Int32)App.Current.Resources["MaxResults"]);
// if there's a problem in the request, show a message box
if (!DefaultViewModel.ApiStatus.IsSuccessStatusCode)
{
MessageBox.Show(
String.Format("There was an error in handling the last request.\n\nCode: {0}\n\nMessage: {1}",
(Int32) DefaultViewModel.ApiStatus.StatusCode,
String.IsNullOrEmpty(DefaultViewModel.ApiStatus.Message) ? DefaultViewModel.ApiStatus.StatusCode.ToString() : DefaultViewModel.ApiStatus.Message),
"Request Error",
MessageBoxButton.OK);
}
}
/// <summary>
/// Refreshes the list of items obtained from the API and populates the view model
/// </summary>
/// <param name="box">Bounding box of current map view</param>
/// <param name="id">Id of IMappable item that should be selected</param>
public async Task Refresh(BoundingBox box, String id = null)
{
//
// TODO: refresh the items in the panel to reflect points of interest in the current map view. You
// will invoke your target API that populates the view model's ObservableCollection and returns
// a status object. The "NoResults" entry in the view model is used to drive the visibility
// of text that appears when the query returns no elements (versus providing no feedback).
//
//
this.DefaultViewModel["ApiStatus"] =
await _tomTomApi.GetCameras(box, this.MaxResults);
this.DefaultViewModel["NoResults"] = _tomTomApi.TomTomViewModel.Results.Count == 0;
// if there's an IMappable ID provided, select that item automatically
if (id != null)
MappableListView.SelectedItem = MappableListView.Items.Where((c) => (c as IMappable).Id == id).FirstOrDefault();
// signal that panel has been refreshed
OnRefreshed();
}
public MainPage()
{
this.InitializeComponent();
// view model
this.DefaultViewModel["PendingRefresh"] = false;
// check to see if this is the first time application is being executed by checking for data in local settings.
// After checking add some notional data as marker for next time app is run. This will be used to determine whether
// to prompt the user (or not) that location services are not turned on for the app/system. Without this check, the
// first time the app is run, it will provide a system prompt, and if that prompt is dismissed without granting
// access the propmpt displayed by the application would also appear unnecessarily.
_firstRun = ApplicationData.Current.LocalSettings.Values.Count == 0;
if (_firstRun)
ApplicationData.Current.LocalSettings.Values.Add(
new System.Collections.Generic.KeyValuePair<string, object>("InitialRunDate", DateTime.UtcNow.ToString()));
this.SizeChanged += (s, e) =>
{
// determine if there's been a change in orientation that doesn't require notice that the map view has changed (e.g., app open, snapped mode transitions)
if (_priorOrientation == ApplicationView.Value) return;
_noRefreshRequiredViewChange = (_priorOrientation == ApplicationViewState.Snapped || ApplicationView.Value == ApplicationViewState.Snapped);
_priorOrientation = ApplicationView.Value;
VisualStateManager.GoToState(LeftPanel, ApplicationView.Value.ToString(), true);
};
// whenever map view changes track center point and zoom level in page state
TheMap.ViewChangeEnded += (s, e) =>
{
// save new center/zoom for page state
_pageState.MapCenter = new LatLong(TheMap.TargetCenter.Latitude, TheMap.TargetCenter.Longitude);
_pageState.Zoom = TheMap.TargetZoomLevel;
// ViewChangeEnded fires a bit too often, so retain bounding box to determine if the view truly has changed
BoundingBox thisBox = new BoundingBox(TheMap.TargetBounds.North, TheMap.TargetBounds.South,
TheMap.TargetBounds.West, TheMap.TargetBounds.East);
// determine if view change should notify user of pending refresh requirement
if (_retainRefreshRequiredViewChange)
this.DefaultViewModel["PendingRefresh"] = _pageState.PendingRefresh;
else if (_noRefreshRequiredViewChange)
this.DefaultViewModel["PendingRefresh"] = false;
else if (App.InitialMapResizeHasOccurred)
this.DefaultViewModel["PendingRefresh"] = (thisBox != _lastBox);
// update state variables
_lastBox = thisBox;
if (App.InitialMapResizeHasOccurred) _noRefreshRequiredViewChange = false;
_retainRefreshRequiredViewChange = false;
App.InitialMapResizeHasOccurred = true;
};
// if refresh prompt is tapped, refresh the map
RefreshPrompt.Tapped += async (s, e) =>
{
await LeftPanel.Refresh(_lastBox);
this.DefaultViewModel["PendingRefresh"] = false;
};
// a tap on map will cause refresh is one is predicated
TheMap.Tapped += async (s, e) =>
{
if ((Boolean)this.DefaultViewModel["PendingRefresh"])
{
await LeftPanel.Refresh(_lastBox);
this.DefaultViewModel["PendingRefresh"] = false;
}
};
// set the reference to the current map for the LeftPanel (note: using Element binding will not handle all of the page navigation scenarios)
LeftPanel.Map = TheMap;
// whenever the contents of left panel are refreshed, save the map coordinates that were in play as part of the page state
LeftPanel.Refreshed += (s, e) =>
{
_pageState.MapBox = new BoundingBox(TheMap.TargetBounds.North, TheMap.TargetBounds.South, TheMap.TargetBounds.West, TheMap.TargetBounds.East);
};
// whenver a new item is selected in the left panel, update the map pins and save the item selected as part of the page state
LeftPanel.ItemSelected += (s, e) =>
{
TheMap.HighlightPointOfInterestPin(e.NewItem, true);
TheMap.HighlightPointOfInterestPin(e.OldItem, false);
this._pageState.SelectedItemId = e.NewItem == null ? null : e.NewItem.Id;
};
// whenever a new location is selected from the SearchFlyout (this is NOT the Search charm) update the position accordingly
SearchFlyout.LocationChanged += (s, e) =>
{
GotoLocation(e.Position);
SearchFlyout.Hide();
};
// manage SearchFlyout visibility/interaction
this.Tapped += (s, e) =>
{
if (SearchFlyout.IsOpen)
{
SearchFlyout.Hide();
e.Handled = true;
}
};
BottomAppBar.Opened += (s, e) => { SearchFlyout.Hide(); };
SearchFlyout.Tapped += (s, e) => { e.Handled = true; };
// allow type-to-search for Search charm
SearchPane.GetForCurrentView().ShowOnKeyboardInput = true;
// The BingMaps API allows use of a "session key" if the application leverages the Bing Maps control. By using the session
// key instead of the API key, only one transaction is logged agains the key versus one transaction for every API call! This
// code sets the key asynchronously and stored it as a resource so it's available when the REST API's are invoked.
TheMap.Loaded += async (s, e) =>
{
if (!Application.Current.Resources.ContainsKey("BingMapsSessionKey"))
Application.Current.Resources.Add("BingMapsSessionKey", await TheMap.GetSessionIdAsync());
};
}