Donation Model & Base Class

In order to keep our application design coherent, we now bring in an Base class and a Donation class to manage our Donations. You can continue with your own version of the app or start with the solution from the previous lab - Donation.2.0

First, create a new package called ‘app.models’ and bring in this class here:

  1. package app.models;
  3. public class Donation
  4. {
  5.   public int    amount;
  6.   public String method;
  8.   public Donation (int amount, String method)
  9.   {
  10.     this.amount = amount;
  11.     this.method = method;
  12.   }
  13. }

Next, Create a new class called ‘Base’ and add it to the ‘app.activities’ package:

  1. public class Base extends Activity
  2. {
  3.   public final int       target       = 10000;
  4.   public int             totalDonated = 0;
  5.   public static List <Donation> donations    = new ArrayList<Donation>();
  7.   public boolean newDonation(Donation donation)
  8.   {
  9.     boolean targetAchieved = totalDonated > target;
  10.     if (!targetAchieved)
  11.     {
  12.       donations.add(donation);
  13.       totalDonated += donation.amount;
  14.     }
  15.     else
  16.     {
  17.       Toast toast = Toast.makeText(this, "Target Exceeded!", Toast.LENGTH_SHORT);
  18.       toast.show();
  19.     }
  20.     return targetAchieved;
  21.   }
  23.   @Override
  24.   public boolean onCreateOptionsMenu(Menu menu)
  25.   {
  26.     getMenuInflater().inflate(R.menu.donate, menu);
  27.     return true;
  28.   }
  30.   @Override
  31.   public boolean onPrepareOptionsMenu (Menu menu){
  32.       super.onPrepareOptionsMenu(menu);
  33.       MenuItem report = menu.findItem(R.id.menuReport);
  34.       MenuItem donate = menu.findItem(R.id.menuDonate);
  36.       if(donations.isEmpty())     
  37.            report.setEnabled(false);
  38.       else
  39.         report.setEnabled(true); 
  41.       if(this instanceof Donate){
  42.           donate.setVisible(false);
  43.           if(!donations.isEmpty())     
  44.                 report.setVisible(true);
  45.         }
  46.       else {
  47.         report.setVisible(false);
  48.         donate.setVisible(true);
  49.         }
  51.       return true;  
  52.   }
  54.   public void settings(MenuItem item)
  55.   {
  56.     Toast.makeText(this, "Settings Selected", Toast.LENGTH_SHORT).show();
  57.   }
  59.   public void report(MenuItem item)
  60.   {
  61.     startActivity (new Intent(this, Report.class));
  62.   }
  64.   public void donate(MenuItem item)
  65.   {
  66.     startActivity (new Intent(this, Donate.class));
  67.   }
  68. }

Notice our List of Donations in the Base class - we will use this list to display our Donations in the Report.

Your project should now look as follows:

Step 01 - 图1