Mark Murphy - Beginning Android

android:orientation="vertical"

android:layout_width="fill_parent"

android:layout_height="fill_parent"

>

android:orientation="horizontal"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

>

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:src="@drawable/icon"

/>

android:layout_width="fill_parent"

android:layout_height="wrap_content"

/>

android:layout_width="fill_parent"

android:layout_height="wrap_content"

/>

Next, we need to put an image file in res/drawablewith a base name of icon. In this case, we use a 32×32 PNG file from the Nuvola [16] http://en.wikipedia.org/wiki/Nuvola icon set. Finally, we twiddle the Java source, replacing our Buttonwith an ImageButton:

packagecom.commonsware.android.resources;

importandroid.app.Activity;

importandroid.os.Bundle;

importandroid.text.TextUtils;

importandroid.text.Html;

importandroid.view.View;

importandroid.widget.Button;

importandroid.widget.ImageButton;

importandroid.widget.EditText;

importandroid.widget.TextView;

public classImagesDemo extendsActivity {

EditText name;

TextView result;

@Override

publicvoid onCreate(Bundle icicle) {

super. onCreate(icicle);

setContentView(R.layout.main);

name = (EditText) findViewById(R.id.name);

result = (TextView) findViewById(R.id.result);

ImageButton btn = (ImageButton) findViewById(R.id.format);

btn. setOnClickListener( newButton. OnClickListener() {

publicvoid onClick(View v) {

applyFormat();

}

});

}

privatevoid applyFormat() {

String format = getString(R.string.funky_format);

String simpleResult = String. format(format,

TextUtils. htmlEncode(name. getText(). toString()));

result. setText(Html. fromHtml(simpleResult));

}

}

Now, our button has the desired icon (see Figure 19-3).

Figure 19-3. The ImagesDemo sample application

In Chapter 18, we showed how you can package XML files as raw resources and get access to them for parsing and usage. There is another way of packaging static XML with your application: the XML resource.

Simply put the XML file in res/xml/, and you can access it by getXml()on a Resources object, supplying it a resource ID of R.xml.plus the base name of your XML file. So, in an activity, with an XML file of words.xml, you could call getResources().getXml(R.xml.words).

This returns an instance of the currently-undocumented XmlPullParser, found in the org.xmlpull.v1Java namespace. Documentation for this library can be found at the parser’s site [17] http://www.xmlpull.org/v1/doc/api/org/xmlpull/v1/package-summary.html as of this writing.

An XML pull parser is event-driven: you keep calling next()on the parser to get the next event, which could be START_TAG, END_TAG, END_DOCUMENT, etc. On a START_TAGevent, you can access the tag’s name and attributes; a single TEXTevent represents the concatenation of all text nodes that are direct children of this element. By looping, testing, and invoking per-element logic, you parse the file.

To see this in action, let’s rewrite the Java code for the Files/Staticsample project to use an XML resource. This new project, Resources/XML, requires that you place the words.xmlfile from Staticnot in res/raw/, but in res/xml/. The layout stays the same, so all that needs replacing is the Java source:

packagecom.commonsware.android.resources;

importandroid.app.Activity;

importandroid.os.Bundle;

importandroid.app.ListActivity;

importandroid.view.View;

importandroid.widget.AdapterView;

importandroid.widget.ArrayAdapter;

importandroid.widget.ListView;

importandroid.widget.TextView;

importandroid.widget.Toast;

importjava.io.InputStream;

importjava.util.ArrayList;

importorg.xmlpull.v1.XmlPullParser;

importorg.xmlpull.v1.XmlPullParserException;

public classXMLResourceDemo extendsListActivity {

TextView selection;

ArrayList items = newArrayList();

@Override

publicvoid onCreate(Bundle icicle) {

super. onCreate(icicle);

setContentView(R.layout.main);

selection = (TextView) findViewById(R.id.selection);

try{

XmlPullParser xpp = getResources(). getXml(R.xml.words);

while(xpp. getEventType()!=XmlPullParser.END_DOCUMENT) {

if(xpp. getEventType()==XmlPullParser.START_TAG) {

if(xpp. getName(). equals("word")) {

items. add(xpp. getAttributeValue(0));

}

}

xpp. next();

}

} catch(Throwable t) {

Toast

. makeText( this, "Request failed: " + t. toString(), 4000). show();

}

setListAdapter( newArrayAdapter( this,