Sobre teclado Android

package teste.teste;

import android.content.Context;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup.LayoutParams;
import android.widget.Button;
import android.widget.EditText;
import android.widget.LinearLayout;
import java.util.ArrayList;
import java.util.List;

/**
 *
 * @author eliangela
 */
public class TecladoNumerico {

	private LinearLayout principalLayout;
	private StringBuilder texto = new StringBuilder();
	private EditText ondeEscrever;
	private List<EditText> ondeEscreverList = new ArrayList<EditText>();
	private int focoAtual = 0;
	//
	private Context context;
	private LinearLayout tecladoLayout;
	private LinearLayout numerosLayout;
	private float textSize = 30;
	//layout dos numeros
	private LinearLayout row1; //1,2,3
	private LinearLayout row2; //4,5,6
	private LinearLayout row3; //7,8,9
	//
	private LinearLayout.LayoutParams rowNumLayoutParams;
	private LinearLayout.LayoutParams funcLayoutParams;

	public TecladoNumerico(Context context) {
		this.principalLayout = new LinearLayout(context);
		this.context = context;

		init();
		buildNumerico();
	}

	private void init() {
		tecladoLayout = new LinearLayout(context);
		numerosLayout = new LinearLayout(context);

		principalLayout.setLayoutParams(new LinearLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT));

		funcLayoutParams = new LinearLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
		funcLayoutParams.gravity = Gravity.CENTER;
		funcLayoutParams.weight = 0.5F;
	}

	private void buildNumerico() {
		principalLayout.setOrientation(LinearLayout.VERTICAL);
		numerosLayout.setOrientation(LinearLayout.VERTICAL);
		tecladoLayout.setOrientation(LinearLayout.HORIZONTAL);

		rowNumLayoutParams = new LinearLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
		rowNumLayoutParams.gravity = Gravity.CENTER;
		rowNumLayoutParams.weight = 0.5F;

		row1 = new LinearLayout(context);
		row1.setOrientation(LinearLayout.HORIZONTAL);

		Button n1Button = new Button(context);
		Button n2Button = new Button(context);
		Button n3Button = new Button(context);
		Button n4Button = new Button(context);
		Button n5Button = new Button(context);
		Button n6Button = new Button(context);
		Button n7Button = new Button(context);
		Button n8Button = new Button(context);
		Button n9Button = new Button(context);

		n1Button.setTextSize(textSize);
		n1Button.setText("1");
		n2Button.setTextSize(textSize);
		n2Button.setText("2");
		n3Button.setTextSize(textSize);
		n3Button.setText("3");
		n4Button.setTextSize(textSize);
		n4Button.setText("4");
		n5Button.setTextSize(textSize);
		n5Button.setText("5");
		n6Button.setTextSize(textSize);
		n6Button.setText("6");
		n7Button.setTextSize(textSize);
		n7Button.setText("7");
		n8Button.setTextSize(textSize);
		n8Button.setText("8");
		n9Button.setTextSize(textSize);
		n9Button.setText("9");

		row1.addView(n1Button, rowNumLayoutParams);
		row1.addView(n2Button, rowNumLayoutParams);
		row1.addView(n3Button, rowNumLayoutParams);

		row2 = new LinearLayout(context);
		row2.setOrientation(LinearLayout.HORIZONTAL);
		row2.addView(n4Button, rowNumLayoutParams);
		row2.addView(n5Button, rowNumLayoutParams);
		row2.addView(n6Button, rowNumLayoutParams);

		row3 = new LinearLayout(context);
		row3.setOrientation(LinearLayout.HORIZONTAL);
		row3.addView(n7Button, rowNumLayoutParams);
		row3.addView(n8Button, rowNumLayoutParams);
		row3.addView(n9Button, rowNumLayoutParams);

		numerosLayout.addView(row1);
		numerosLayout.addView(row2);
		numerosLayout.addView(row3);

		LinearLayout.LayoutParams numLayoutParams = new LinearLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
		numLayoutParams.gravity = Gravity.CENTER;
		numLayoutParams.weight = 0.3F;
		tecladoLayout.addView(numerosLayout, numLayoutParams);

		principalLayout.addView(tecladoLayout);
	}

	public void setTextSize(float size) {
		this.textSize = size;
	}

	private void setOndeEscrever(EditText ondeEscrever) {
		this.ondeEscrever = ondeEscrever;
		if (ondeEscrever == null) {
			this.texto = new StringBuilder();
			return;
		}
		this.texto = new StringBuilder(this.ondeEscrever.getText());
		this.ondeEscrever.requestFocus();
	}

	protected boolean isEmpty() {
		return texto.length() == 0;
	}

	protected void insertString(String texto) {
		if (ondeEscrever == null) {
			return;
		}

		String txt = ondeEscrever.getText().toString();
		if (!this.texto.toString().equals(txt)) {
			this.texto = new StringBuilder(txt);
		}

		this.texto.append(texto);
		ondeEscrever.setText(this.texto.toString());
	}

	public synchronized void backspace() {
		if (ondeEscrever == null) {
			return;
		}

		String txt = ondeEscrever.getText().toString();
		if (!texto.toString().equals(txt)) {
			texto = new StringBuilder(txt);
		}

		if (isEmpty()) {
			return;
		}

		texto.deleteCharAt(texto.length() - 1);
		ondeEscrever.setText(texto.toString());
	}

	public boolean isLastFocus() {
		return focoAtual == ondeEscreverList.size() - 1;
	}

	public boolean isFirstFocus() {
		return focoAtual == 0;
	}

	public void nextFocus() {
		if (++focoAtual >= ondeEscreverList.size()) {
			focoAtual = 0;
		}

		setOndeEscrever(this.ondeEscreverList.get(focoAtual));
	}

	public void prevFocus() {
		if (--focoAtual < 0) {
			focoAtual = this.ondeEscreverList.size() - 1;
		}

		setOndeEscrever(this.ondeEscreverList.get(focoAtual));
	}

	public void addOndeEscrever(EditText... edits) {
		for (EditText v : edits) {
			if (this.ondeEscreverList.contains(v)) {
				throw new IllegalArgumentException("O mesmo EditText não pode ser adicionado mais de uma vez");
			}

			v.setInputType(0);
			v.setOnFocusChangeListener(new View.OnFocusChangeListener() {

				public void onFocusChange(View view, boolean isFocado) {
					if (isFocado) {
						setOndeEscrever((EditText) view);
						focoAtual = ondeEscreverList.indexOf(view);
					} else {
						setOndeEscrever(null);
					}
				}
			});
			this.ondeEscreverList.add(v);
		}
	}

	public void setVisivel(boolean visivel) {
		principalLayout.setVisibility(visivel ? View.VISIBLE : View.INVISIBLE);
	}

	public boolean isVisivel() {
		return principalLayout.getVisibility() == View.VISIBLE;
	}

	public LinearLayout getTecladoAsLinearLayout() {
		return principalLayout;
	}
}