Revised Note Pad sample, new test app for Note Pad

Change-Id: Ia41a33d935ead704c1de439a0cfb0a55806cfe12

samples/NotePad/src/com/example/android/notepad/NotesLiveFolder.java

@@ -18,48 +18,91 @@ package com.example.android.notepad;
 
 import android.app.Activity;
 import android.content.Intent;
-import android.net.Uri;
+import android.content.Intent.ShortcutIconResource;
 import android.os.Bundle;
 import android.provider.LiveFolders;
 
+/**
+ * This Activity creates a live folder Intent and
+ * sends it back to HOME. From the data in the Intent, HOME creates a live folder and displays
+ * its icon in the Home view.
+ * When the user clicks the icon, Home uses the data it got from the Intent to retrieve information
+ * from a content provider and display it in a View.
+ *
+ * The intent filter for this Activity is set to ACTION_CREATE_LIVE_FOLDER, which
+ * HOME sends in response to a long press and selection of Live Folder.
+ */
 public class NotesLiveFolder extends Activity {
     /**
-     * The URI for the Notes Live Folder content provider.
+     * All of the work is done in onCreate(). The Activity doesn't actually display a UI.
+     * Instead, it sets up an Intent and returns it to its caller (the HOME activity).
      */
-    public static final Uri CONTENT_URI = Uri.parse("content://"
-            + NotePad.AUTHORITY + "/live_folders/notes");
-
-    public static final Uri NOTE_URI = Uri.parse("content://"
-            + NotePad.AUTHORITY + "/notes/#");
-
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
 
+        /*
+         * Gets the incoming Intent and its action. If the incoming Intent was
+         * ACTION_CREATE_LIVE_FOLDER, then create an outgoing Intent with the
+         * necessary data and send back OK. Otherwise, send back CANCEL.
+         */
         final Intent intent = getIntent();
         final String action = intent.getAction();
 
         if (LiveFolders.ACTION_CREATE_LIVE_FOLDER.equals(action)) {
-            // Build the live folder intent.
+            // Create a new Intent.
             final Intent liveFolderIntent = new Intent();
 
-            liveFolderIntent.setData(CONTENT_URI);
-            liveFolderIntent.putExtra(LiveFolders.EXTRA_LIVE_FOLDER_NAME,
-                    getString(R.string.live_folder_name));
-            liveFolderIntent.putExtra(LiveFolders.EXTRA_LIVE_FOLDER_ICON,
-                    Intent.ShortcutIconResource.fromContext(this,
-                            R.drawable.live_folder_notes));
-            liveFolderIntent.putExtra(LiveFolders.EXTRA_LIVE_FOLDER_DISPLAY_MODE,
-                    LiveFolders.DISPLAY_MODE_LIST);
-            liveFolderIntent.putExtra(LiveFolders.EXTRA_LIVE_FOLDER_BASE_INTENT,
-                    new Intent(Intent.ACTION_EDIT, NOTE_URI));
+            /*
+             * The following statements put data into the outgoing Intent. Please see
+             * {@link android.provider.LiveFolders for a detailed description of these
+             * data values. From this data, HOME sets up a live folder.
+             */
+            // Sets the URI pattern for the content provider backing the folder.
+            liveFolderIntent.setData(NotePad.Notes.LIVE_FOLDER_URI);
 
-            // The result of this activity should be a live folder intent.
+            // Adds the display name of the live folder as an Extra string.
+            String foldername = getString(R.string.live_folder_name);
+            liveFolderIntent.putExtra(LiveFolders.EXTRA_LIVE_FOLDER_NAME, foldername);
+
+            // Adds the display icon of the live folder as an Extra resource.
+            ShortcutIconResource foldericon =
+                Intent.ShortcutIconResource.fromContext(this, R.drawable.live_folder_notes);
+            liveFolderIntent.putExtra(LiveFolders.EXTRA_LIVE_FOLDER_ICON, foldericon);
+
+            // Add the display mode of the live folder as an integer. The specified
+            // mode causes the live folder to display as a list.
+            liveFolderIntent.putExtra(
+                    LiveFolders.EXTRA_LIVE_FOLDER_DISPLAY_MODE,
+                    LiveFolders.DISPLAY_MODE_LIST);
+
+            /*
+             * Adds a base action for items in the live folder list, as an Intent. When the
+             * user clicks an individual note in the list, the live folder fires this Intent.
+             *
+             * Its action is ACTION_EDIT, so it triggers the Note Editor activity. Its
+             * data is the URI pattern for a single note identified by its ID. The live folder
+             * automatically adds the ID value of the selected item to the URI pattern.
+             *
+             * As a result, Note Editor is triggered and gets a single note to retrieve by ID.
+             */
+            Intent returnIntent
+                    = new Intent(Intent.ACTION_EDIT, NotePad.Notes.CONTENT_ID_URI_PATTERN);
+            liveFolderIntent.putExtra(LiveFolders.EXTRA_LIVE_FOLDER_BASE_INTENT, returnIntent);
+
+            /* Creates an ActivityResult object to propagate back to HOME. Set its result indicator
+             * to OK, and sets the returned Intent to the live folder Intent that was just
+             * constructed.
+             */
             setResult(RESULT_OK, liveFolderIntent);
+
         } else {
+            // If the original action was not ACTION_CREATE_LIVE_FOLDER, creates an
+            // ActivityResult with the indicator set to CANCELED, but do not return an Intent
             setResult(RESULT_CANCELED);
         }
-
+        // Closes the Activity. The ActivityObject is propagated back to the caller.
         finish();
+
     }
 }