How to change border thickness around images in HelloGallery
<p>I'm not really sure if it's the thickness of the border or the margin around the image that needs to be changed.  I have never worked with styles before, and just created a styles.xml and colors.xml file for the first time.  I have changed the background color to Red, using the code below in image_border.xml.  But I do not know how to change the border thickness around the images in HelloGallery.  </p>

<p>Perhaps it's not in this file.  But what exactly needs to be written in the code?</p>

<pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
&lt;layer-list xmlns:android="http://schemas.android.com/apk/res/android"&gt;
    &lt;item android:top="1dp" android:left="1dp" 
        android:right="1dp" android:bottom="1dp"&gt;
        &lt;shape android:shape="rectangle"&gt;
            &lt;solid android:color="@color/red" /&gt;
        &lt;/shape&gt;
    &lt;/item&gt;
&lt;/layer-list&gt;
</code></pre>

<p><strong>Edit:</strong> The answer might actually be a matter of modifying this portion of the code, since I was able to change the border <em>color</em> and image size here:</p>

<pre><code>    public View getView(int position, View convertView,
      ViewGroup parent) {
        ImageView i = new ImageView(mContext);

        Bitmap bm = BitmapFactory.decodeFile(
        FileList.get(position).toString());
        i.setImageBitmap(bm);
        i.setLayoutParams(new Gallery.LayoutParams(160, 180));
        i.setScaleType(ImageView.ScaleType.FIT_XY);
        i.setBackgroundResource(mGalleryItemBackground);
        i.setBackgroundColor(Color.BLUE);
        return i;
    }
</code></pre>
