Simple CustomTextView

CustomTextView.java

class CustomTextView extends View {
	private static final String SUPERSTATE = "superState", TEXT = "text",
			TEXTSIZE = "textsize";
	private String mText = "";
	private Paint mTextPaint;
	private int mTextSize, mTextX, mTextY, mCenter;

	public CustomTextView(Context context) {
		this(context, null);
	}

	public CustomTextView(Context context, AttributeSet attrs) {
		super(context, attrs);
		if (attrs != null) {
			TypedArray a = context.obtainStyledAttributes(attrs,
					R.styleable.CustomTextView, 0, 0);

			try {
				mText = a.getString(R.styleable.CustomTextView_android_text);
				mTextSize = a.getDimensionPixelSize(
						R.styleable.CustomTextView_android_textSize, 15);
			} finally {
				a.recycle();
			}
		}
		init();
	}

	public void setText(CharSequence text) {
		if (text == null) {
			text = "";
		}
		mText = text.toString();
		invalidate();
	}

	private void setTextSize(int textSize) {
		mTextSize = textSize;
	}

	public String getText() {
		return mText;
	}

	public int getTextSize() {
		return mTextSize;
	}

	@Override
	public Parcelable onSaveInstanceState() {
		Bundle state = new Bundle();
		state.putParcelable(SUPERSTATE, super.onSaveInstanceState());
		state.putString(TEXT, getText());
		state.putFloat(TEXTSIZE, getTextSize());
		return (state);
	}

	@Override
	public void onRestoreInstanceState(Parcelable ss) {
		Bundle state = (Bundle) ss;
		super.onRestoreInstanceState(state.getParcelable(SUPERSTATE));
		setText(state.getString(TEXT));
		setTextSize(state.getInt(TEXTSIZE));
	}

	private void init() {
		mTextPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
		mTextPaint.setColor(0xFF000000);
		mTextPaint.setTextSize(mTextSize);
	}

	@Override
	protected void onDraw(Canvas canvas) {
		mTextX = mCenter - (int)(mTextPaint.measureText(mText)) / 2;
		canvas.drawText(mText, mTextX, mTextY, mTextPaint);
	}

	@Override
	protected void onSizeChanged(int w, int h, int oldw, int oldh) {
		super.onSizeChanged(w, h, oldw, oldh);
		mCenter = (w - getPaddingLeft() - getPaddingRight()) / 2;
		mTextX = mCenter - (int)(mTextPaint.measureText(mText)) / 2;
		mTextY = (int) mTextPaint.getTextSize();
	}
}

CustomTextViewActivity.java

public class CustomTextViewActivity extends Activity implements
		android.view.View.OnClickListener {

	private Button defButton, customButton;
	private TextView defTextView;
	private CustomTextView customTextView;
	private final int CYCLES = 10000;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.custom_text_view);
		defButton = (Button) findViewById(R.id.defButton);
		defButton.setOnClickListener(this);
		customButton = (Button) findViewById(R.id.customButton);
		customButton.setOnClickListener(this);
		defTextView = (TextView) findViewById(R.id.defTextView);
		customTextView = (CustomTextView) findViewById(R.id.customTextView);
	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		getMenuInflater().inflate(R.menu.custom_text_view, menu);
		return true;
	}

	@Override
	public void onClick(View v) {
		Date before = new Date();
		if (v.getId() == R.id.defButton) {
			for (int i = 0; i < CYCLES; i++) {
				defTextView.setText(String.valueOf(i));
			}
			long delta = new Date().getTime() - before.getTime();
			defTextView.setText("Time taken for " + String.valueOf(CYCLES)
					+ " text changes: " + String.valueOf(delta) + "ms");
		} else {
			for (int i = 0; i < CYCLES; i++) {
				customTextView.setText(String.valueOf(i));
			}
			long delta = new Date().getTime() - before.getTime();
			customTextView.setText("Time taken for " + String.valueOf(CYCLES)
					+ " text changes: " + String.valueOf(delta) + "ms");
		}
	}
}