Prepare for disk image selector.

src/com/froop/app/kegs/ConfigFile.java

@@ -1,6 +1,7 @@
 package com.froop.app.kegs;
 
 import android.content.Context;
+import android.os.Environment;
 import android.util.Log;
 import java.io.File;
 import java.io.BufferedInputStream;
@@ -39,6 +40,17 @@ class ConfigFile {
     return mContext.getExternalCacheDir().getPath();
   }
 
+  public String[] getAllImageDirs() {
+    String externalStorage = Environment.getExternalStorageDirectory().getPath();
+    String[] dirs = {
+      getImagePath(),
+      externalStorage,
+      externalStorage + "/kegs",
+      externalStorage + "/Download"
+    };
+    return dirs;
+  }
+
   public void ensureAssetCopied(String destPath, String zipfile, String exampleFile) {
     // We only check for a local copy of a single file before unzipping...
     final File local_copy = new File(destPath, exampleFile);

src/com/froop/app/kegs/KegsMain.java

@@ -265,8 +265,7 @@ public class KegsMain extends SherlockFragmentActivity implements KegsKeyboard.S
         public void run() {
           withUIActive(new Runnable() {
             public void run() {
-              new DiskImageFragment().show(getSupportFragmentManager(),
-                                           FRAGMENT_DISKIMAGE);
+              new DiskImageFragment(mConfigFile).show(getSupportFragmentManager(), FRAGMENT_DISKIMAGE);
             }
           });
         }
@@ -438,7 +437,7 @@ public class KegsMain extends SherlockFragmentActivity implements KegsKeyboard.S
       supportInvalidateOptionsMenu();  // update icon
       return true;
     } else if (item_id == R.id.action_diskimage) {
-      new DiskImageFragment().show(getSupportFragmentManager(), FRAGMENT_DISKIMAGE);
+      new DiskImageFragment(mConfigFile).show(getSupportFragmentManager(), FRAGMENT_DISKIMAGE);
       return true;
     } else if (item_id == R.id.action_more_keys) {
       final int vis = areControlsVisible() ? View.GONE : View.VISIBLE;

src/com/froop/app/kegs/diskimage/DiskImage.java

@@ -4,7 +4,10 @@ import android.util.Log;
 import java.lang.Integer;
 import java.io.File;
 
-class DiskImage {
+class DiskImage implements Comparable {
+  // NOTE: "this class has a natural ordering that is inconsistent with equals"
+  //       (sorted on the filename excluding path, case insensitive)
+
   // template
   public static final String BOOT_SLOT_5 = "boot_slot_5";
   public static final String BOOT_SLOT_6 = "boot_slot_6";
@@ -111,4 +114,12 @@ class DiskImage {
       return null;
     }
   }
+
+  public int compareTo(Object other) {
+    if (other instanceof DiskImage) {
+      return this.getTitle().compareToIgnoreCase(((DiskImage)other).getTitle());
+    } else {
+      throw new ClassCastException();
+    }
+  }
 }