//TODO For some reason, even though it shows up in the debugger as having a BindingContext, the line, "(MenuItem)sender.BindingContext" fails
//to compile. Because of this, even though both a menuitem and a button have a BindingContext, I can't reference it with a single line
//of code. So, I have these two methods that do exactly the same thing. Is there a better way?
public void OnToggleCartMenuClicked(object sender, EventArgs args)
{
MenuItem m = (MenuItem)sender;
MyPlant p = (MyPlant)m.BindingContext;
AppData appData = (AppData)BindingContext;
appData.MasterViewModel.PlantList.ToggleStatus(p);
}
public void OnToggleCartButtonClicked(object sender, EventArgs args)
{
Button b = (Button)sender;
MyPlant p = (MyPlant)b.BindingContext;
AppData appData = (AppData)BindingContext;
appData.MasterViewModel.PlantList.ToggleStatus(p);
}
//Attempt to toggle the cart status of the item passed in
public bool ToggleStatus(MyPlant p)
{
//First, find the plant that matches the one passed in (this assumes each plant's name is spelled consistently, that
//the name is unique, and that it exists exactly once). And then, toggle the status of that plant.
bool value = allPlants.Find(x => x.Plant.Name == p.Plant.Name).TogglePlantCartStatus();
//Now, regenerate the list so that it reflects the right set of plants and everybody knows it has changed
RefreshShoppingListPlants();
return(value);
}
// When the "More Info" link is tapped, then open a new pop-over window and load the URL of the selected plant into this
async void OnMoreInfoTapped(object sender, EventArgs e)
{
Label label = (Label)sender;
MyPlant thePlant = (MyPlant)label.BindingContext;
if (thePlant.Plant.URL != null)
{
await Navigation.PushAsync(new MoreInfoPage(thePlant.Plant.URL));
}
else
{
//TODO: what to do if there is no URL for the plant
}
}
public App()
{
InitializeComponent();
// The Application ResourceDictionary is available in Xamarin.Forms 1.3 and later
if (Application.Current.Resources == null)
{
Application.Current.Resources = new ResourceDictionary();
}
//In theory, this should instantiate our view model and make it accessible to the other pages
AppData = new AppData();
// Load previous AppData if it exists.
if (Properties.ContainsKey("appData"))
{
//Load the list of the scientific names of the plants the user wants
List <CartItem> shoppingList = AppData.Deserialize((string)Properties["appData"]);
if (shoppingList != null)
{
//rehydrate the list
foreach (CartItem aPlant in shoppingList)
{
//Check that the plant exists before adding it to the cart. Store this in a variable so we don't do the query twice. The query
//returns a reference to the actual object, not a copy of it, so this works as expected.
MyPlant p = this.AppData.MasterViewModel.PlantList.AllPlants.Find(x => x.Plant.ScientificName == aPlant.Name);
if (p != null)
{
p.InCart = true;
p.Count = aPlant.Count;
}
}
this.AppData.MasterViewModel.PlantList.RefreshShoppingListPlants();
}
}//end if Properties
MainPage = new NavigationPage(new TopLevelPage());
}