¿Cómo desarrollar un teclado virtual para Android? [cerrado]

Me gustaría jugar con algunas ideas y desarrollar un teclado virtual para Android para reemplazar el predeterminado.

• ¿Existe alguna información general sobre el desarrollo de teclados virtuales para Android? ¿Alguna mejor práctica o pauta?

• ¿Puedo hacer con mi aplicación de teclado prácticamente cualquier cosa que pueda hacer con una aplicación normal de Android?

• ¿Puedo hacer conexiones HTTP para sincronizar los datos del teclado con una base de datos en la nube y otros teléfonos que tengo?

• ¿Puedo abrir otras ventanas / pantallas presionando una tecla, por ejemplo, para mostrar una interfaz de entrada personalizada diferente a una QWERTY normal? Si eso no funciona, ¿puedo usar un cuadro de diálogo emergente en su lugar?

Algunos consejos:

• Lea este tutorial: Creación de un método de entrada
• clonar este repositorio: LatinIME

Sobre tus preguntas:

Un inputMethod es básicamente un Android Service, así que sí, puedes hacer HTTP y todas las cosas que puedes hacer en un Service.

Puede abrir los Activitiescuadros de diálogo y desde InputMethod. Una vez más, es solo un Service.

He estado desarrollando un IME, así que vuelve a preguntar si tienes algún problema.

Crear teclado personalizado para su propio texto de edición

Descargar el código completo

En esta publicación, creé un teclado simple que contiene algunas teclas especiales como (teclas de Francia) y es compatible con letras mayúsculas y minúsculas y teclas numéricas y algunos símbolos.

package sra.keyboard;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.WindowManager;
import android.view.View.OnClickListener;
import android.view.View.OnFocusChangeListener;
import android.view.View.OnTouchListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.RelativeLayout;

public class Main extends Activity implements OnTouchListener, OnClickListener,
  OnFocusChangeListener {
 private EditText mEt, mEt1; // Edit Text boxes
 private Button mBSpace, mBdone, mBack, mBChange, mNum;
 private RelativeLayout mLayout, mKLayout;
 private boolean isEdit = false, isEdit1 = false;
 private String mUpper = "upper", mLower = "lower";
 private int w, mWindowWidth;
 private String sL[] = { "a", "b", "c", "d", "e", "f", "g", "h", "i", "j",
   "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w",
   "x", "y", "z", "ç", "à", "é", "è", "û", "î" };
 private String cL[] = { "A", "B", "C", "D", "E", "F", "G", "H", "I", "J",
   "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W",
   "X", "Y", "Z", "ç", "à", "é", "è", "û", "î" };
 private String nS[] = { "!", ")", "'", "#", "3", "$", "%", "&", "8", "*",
   "?", "/", "+", "-", "9", "0", "1", "4", "@", "5", "7", "(", "2",
   "\"", "6", "_", "=", "]", "[", "<", ">", "|" };
 private Button mB[] = new Button[32];

 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  try {
   setContentView(R.layout.main);
   // adjusting key regarding window sizes
   setKeys();
   setFrow();
   setSrow();
   setTrow();
   setForow();
   mEt = (EditText) findViewById(R.id.xEt);
   mEt.setOnTouchListener(this);
   mEt.setOnFocusChangeListener(this);
   mEt1 = (EditText) findViewById(R.id.et1);

   mEt1.setOnTouchListener(this);
   mEt1.setOnFocusChangeListener(this);
   mEt.setOnClickListener(this);
   mEt1.setOnClickListener(this);
   mLayout = (RelativeLayout) findViewById(R.id.xK1);
   mKLayout = (RelativeLayout) findViewById(R.id.xKeyBoard);

  } catch (Exception e) {
   Log.w(getClass().getName(), e.toString());
  }

 }

 @Override
 public boolean onTouch(View v, MotionEvent event) {
  if (v == mEt) {
   hideDefaultKeyboard();
   enableKeyboard();

  }
  if (v == mEt1) {
   hideDefaultKeyboard();
   enableKeyboard();

  }
  return true;
 }

 @Override
 public void onClick(View v) {

  if (v == mBChange) {

   if (mBChange.getTag().equals(mUpper)) {
    changeSmallLetters();
    changeSmallTags();
   } else if (mBChange.getTag().equals(mLower)) {
    changeCapitalLetters();
    changeCapitalTags();
   }

  } else if (v != mBdone && v != mBack && v != mBChange && v != mNum) {
   addText(v);

  } else if (v == mBdone) {

   disableKeyboard();

  } else if (v == mBack) {
   isBack(v);
  } else if (v == mNum) {
   String nTag = (String) mNum.getTag();
   if (nTag.equals("num")) {
    changeSyNuLetters();
    changeSyNuTags();
    mBChange.setVisibility(Button.INVISIBLE);

   }
   if (nTag.equals("ABC")) {
    changeCapitalLetters();
    changeCapitalTags();
   }

  }

 }

 @Override
 public void onFocusChange(View v, boolean hasFocus) {
  if (v == mEt && hasFocus == true) {
   isEdit = true;
   isEdit1 = false;

  } else if (v == mEt1 && hasFocus == true) {
   isEdit = false;
   isEdit1 = true;

  }

 }

 private void addText(View v) {
  if (isEdit == true) {
   String b = "";
   b = (String) v.getTag();
   if (b != null) {
    // adding text in Edittext
    mEt.append(b);

   }
  }

  if (isEdit1 == true) {
   String b = "";
   b = (String) v.getTag();
   if (b != null) {
    // adding text in Edittext
    mEt1.append(b);

   }

  }

 }

 private void isBack(View v) {
  if (isEdit == true) {
   CharSequence cc = mEt.getText();
   if (cc != null && cc.length() > 0) {
    {
     mEt.setText("");
     mEt.append(cc.subSequence(0, cc.length() - 1));
    }

   }
  }

  if (isEdit1 == true) {
   CharSequence cc = mEt1.getText();
   if (cc != null && cc.length() > 0) {
    {
     mEt1.setText("");
     mEt1.append(cc.subSequence(0, cc.length() - 1));
    }
   }
  }
 }
 private void changeSmallLetters() {
  mBChange.setVisibility(Button.VISIBLE);
  for (int i = 0; i < sL.length; i++)
   mB[i].setText(sL[i]);
  mNum.setTag("12#");
 }
 private void changeSmallTags() {
  for (int i = 0; i < sL.length; i++)
   mB[i].setTag(sL[i]);
  mBChange.setTag("lower");
  mNum.setTag("num");
 }
 private void changeCapitalLetters() {
  mBChange.setVisibility(Button.VISIBLE);
  for (int i = 0; i < cL.length; i++)
   mB[i].setText(cL[i]);
  mBChange.setTag("upper");
  mNum.setText("12#");

 }

 private void changeCapitalTags() {
  for (int i = 0; i < cL.length; i++)
   mB[i].setTag(cL[i]);
  mNum.setTag("num");

 }

 private void changeSyNuLetters() {

  for (int i = 0; i < nS.length; i++)
   mB[i].setText(nS[i]);
  mNum.setText("ABC");
 }

 private void changeSyNuTags() {
  for (int i = 0; i < nS.length; i++)
   mB[i].setTag(nS[i]);
  mNum.setTag("ABC");
 }

 // enabling customized keyboard
 private void enableKeyboard() {

  mLayout.setVisibility(RelativeLayout.VISIBLE);
  mKLayout.setVisibility(RelativeLayout.VISIBLE);

 }

 // Disable customized keyboard
 private void disableKeyboard() {
  mLayout.setVisibility(RelativeLayout.INVISIBLE);
  mKLayout.setVisibility(RelativeLayout.INVISIBLE);

 }

 private void hideDefaultKeyboard() {
  getWindow().setSoftInputMode(
    WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);

 }

 private void setFrow() {
  w = (mWindowWidth / 13);
  w = w - 15;
  mB[16].setWidth(w);
  mB[22].setWidth(w + 3);
  mB[4].setWidth(w);
  mB[17].setWidth(w);
  mB[19].setWidth(w);
  mB[24].setWidth(w);
  mB[20].setWidth(w);
  mB[8].setWidth(w);
  mB[14].setWidth(w);
  mB[15].setWidth(w);
  mB[16].setHeight(50);
  mB[22].setHeight(50);
  mB[4].setHeight(50);
  mB[17].setHeight(50);
  mB[19].setHeight(50);
  mB[24].setHeight(50);
  mB[20].setHeight(50);
  mB[8].setHeight(50);
  mB[14].setHeight(50);
  mB[15].setHeight(50);

 }

 private void setSrow() {
  w = (mWindowWidth / 10);
  mB[0].setWidth(w);
  mB[18].setWidth(w);
  mB[3].setWidth(w);
  mB[5].setWidth(w);
  mB[6].setWidth(w);
  mB[7].setWidth(w);
  mB[26].setWidth(w);
  mB[9].setWidth(w);
  mB[10].setWidth(w);
  mB[11].setWidth(w);
  mB[26].setWidth(w);

  mB[0].setHeight(50);
  mB[18].setHeight(50);
  mB[3].setHeight(50);
  mB[5].setHeight(50);
  mB[6].setHeight(50);
  mB[7].setHeight(50);
  mB[9].setHeight(50);
  mB[10].setHeight(50);
  mB[11].setHeight(50);
  mB[26].setHeight(50);
 }

 private void setTrow() {
  w = (mWindowWidth / 12);
  mB[25].setWidth(w);
  mB[23].setWidth(w);
  mB[2].setWidth(w);
  mB[21].setWidth(w);
  mB[1].setWidth(w);
  mB[13].setWidth(w);
  mB[12].setWidth(w);
  mB[27].setWidth(w);
  mB[28].setWidth(w);
  mBack.setWidth(w);

  mB[25].setHeight(50);
  mB[23].setHeight(50);
  mB[2].setHeight(50);
  mB[21].setHeight(50);
  mB[1].setHeight(50);
  mB[13].setHeight(50);
  mB[12].setHeight(50);
  mB[27].setHeight(50);
  mB[28].setHeight(50);
  mBack.setHeight(50);

 }

 private void setForow() {
  w = (mWindowWidth / 10);
  mBSpace.setWidth(w * 4);
  mBSpace.setHeight(50);
  mB[29].setWidth(w);
  mB[29].setHeight(50);

  mB[30].setWidth(w);
  mB[30].setHeight(50);

  mB[31].setHeight(50);
  mB[31].setWidth(w);
  mBdone.setWidth(w + (w / 1));
  mBdone.setHeight(50);

 }

 private void setKeys() {
  mWindowWidth = getWindowManager().getDefaultDisplay().getWidth(); // getting
  // window
  // height
  // getting ids from xml files
  mB[0] = (Button) findViewById(R.id.xA);
  mB[1] = (Button) findViewById(R.id.xB);
  mB[2] = (Button) findViewById(R.id.xC);
  mB[3] = (Button) findViewById(R.id.xD);
  mB[4] = (Button) findViewById(R.id.xE);
  mB[5] = (Button) findViewById(R.id.xF);
  mB[6] = (Button) findViewById(R.id.xG);
  mB[7] = (Button) findViewById(R.id.xH);
  mB[8] = (Button) findViewById(R.id.xI);
  mB[9] = (Button) findViewById(R.id.xJ);
  mB[10] = (Button) findViewById(R.id.xK);
  mB[11] = (Button) findViewById(R.id.xL);
  mB[12] = (Button) findViewById(R.id.xM);
  mB[13] = (Button) findViewById(R.id.xN);
  mB[14] = (Button) findViewById(R.id.xO);
  mB[15] = (Button) findViewById(R.id.xP);
  mB[16] = (Button) findViewById(R.id.xQ);
  mB[17] = (Button) findViewById(R.id.xR);
  mB[18] = (Button) findViewById(R.id.xS);
  mB[19] = (Button) findViewById(R.id.xT);
  mB[20] = (Button) findViewById(R.id.xU);
  mB[21] = (Button) findViewById(R.id.xV);
  mB[22] = (Button) findViewById(R.id.xW);
  mB[23] = (Button) findViewById(R.id.xX);
  mB[24] = (Button) findViewById(R.id.xY);
  mB[25] = (Button) findViewById(R.id.xZ);
  mB[26] = (Button) findViewById(R.id.xS1);
  mB[27] = (Button) findViewById(R.id.xS2);
  mB[28] = (Button) findViewById(R.id.xS3);
  mB[29] = (Button) findViewById(R.id.xS4);
  mB[30] = (Button) findViewById(R.id.xS5);
  mB[31] = (Button) findViewById(R.id.xS6);
  mBSpace = (Button) findViewById(R.id.xSpace);
  mBdone = (Button) findViewById(R.id.xDone);
  mBChange = (Button) findViewById(R.id.xChange);
  mBack = (Button) findViewById(R.id.xBack);
  mNum = (Button) findViewById(R.id.xNum);
  for (int i = 0; i < mB.length; i++)
   mB[i].setOnClickListener(this);
  mBSpace.setOnClickListener(this);
  mBdone.setOnClickListener(this);
  mBack.setOnClickListener(this);
  mBChange.setOnClickListener(this);
  mNum.setOnClickListener(this);

 }

}

Un buen lugar para comenzar es la aplicación de muestra proporcionada en los documentos para desarrolladores .

• Las pautas serían simplemente hacerlo lo más utilizable posible. Eche un vistazo a los demás disponibles en el mercado para ver a qué debería aspirar.
• Sí, los servicios pueden hacer la mayoría de las cosas, incluido Internet; siempre que haya solicitado esos permisos
• Puede abrir actividades y hacer lo que quiera en ellas si tiene problemas para hacer algunas cosas en el teclado. Por ejemplo, el teclado de HTC tiene un botón para abrir la actividad de configuración y otro para abrir un diálogo para cambiar de idioma.

Eche un vistazo a otros IME para ver a qué debería apuntar. Algunos (como el oficial) son de código abierto.

En primer lugar, debe definir un archivo .xml y crear la interfaz de usuario del teclado en él:

<?xml version="1.0" encoding="utf-8"?>
<Keyboard xmlns:android="http://schemas.android.com/apk/res/android"
android:keyWidth="12.50%p"
android:keyHeight="7%p">
<!--
android:horizontalGap="0.50%p"
android:verticalGap="0.50%p"
NOTE When we add a horizontalGap in pixels, this interferes with keyWidth in percentages adding up to 100%
NOTE When we have a horizontalGap (on Keyboard level) of 0, this make the horizontalGap (on Key level) to move from after the key to before the key... (I consider this a bug) 
-->
<Row>
    <Key android:codes="-5" android:keyLabel="remove"  android:keyEdgeFlags="left" />
    <Key android:codes="48"    android:keyLabel="0" />
    <Key android:codes="55006" android:keyLabel="clear" />
</Row>
<Row>
    <Key android:codes="49"    android:keyLabel="1"  android:keyEdgeFlags="left" />
    <Key android:codes="50"    android:keyLabel="2" />
    <Key android:codes="51"    android:keyLabel="3" />
</Row>
<Row>
    <Key android:codes="52"    android:keyLabel="4"  android:keyEdgeFlags="left" />
    <Key android:codes="53"    android:keyLabel="5" />
    <Key android:codes="54"    android:keyLabel="6" />
</Row>

<Row>
    <Key android:codes="55"    android:keyLabel="7"  android:keyEdgeFlags="left" />
    <Key android:codes="56"    android:keyLabel="8" />
    <Key android:codes="57"    android:keyLabel="9" />
</Row>

En este ejemplo tiene 4 filas y en cada fila tiene 3 llaves. también puedes poner un icono en cada tecla que quieras.

Entonces debe agregar la etiqueta xml en la interfaz de usuario de su actividad de esta manera:

<android.inputmethodservice.KeyboardView
        android:id="@+id/keyboardview1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@color/white"
        android:focusable="true"
        android:focusableInTouchMode="true"
        android:visibility="visible" />

También en su archivo de actividad .java debe definir el teclado y asignarlo a un EditText:

CustomKeyboard mCustomKeyboard1 = new CustomKeyboard(this,
            R.id.keyboardview1, R.xml.horizontal_keyboard);
    mCustomKeyboard1.registerEditText(R.id.inputSearch);

Este código asigna inputSearch (que es un EditText) a su teclado.

import android.app.Activity;
import android.inputmethodservice.Keyboard;
import android.inputmethodservice.KeyboardView;
import android.inputmethodservice.KeyboardView.OnKeyboardActionListener;
import android.text.Editable;
import android.text.InputType;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnFocusChangeListener;
import android.view.View.OnTouchListener;
import android.view.WindowManager;
import android.view.inputmethod.InputMethodManager;
import android.widget.EditText;


public class CustomKeyboard {

/** A link to the KeyboardView that is used to render this CustomKeyboard. */
private KeyboardView mKeyboardView;
/** A link to the activity that hosts the {@link #mKeyboardView}. */
private Activity mHostActivity;

/** The key (code) handler. */
private OnKeyboardActionListener mOnKeyboardActionListener = new OnKeyboardActionListener() {

    public final static int CodeDelete = -5; // Keyboard.KEYCODE_DELETE
    public final static int CodeCancel = -3; // Keyboard.KEYCODE_CANCEL
    public final static int CodePrev = 55000;
    public final static int CodeAllLeft = 55001;
    public final static int CodeLeft = 55002;
    public final static int CodeRight = 55003;
    public final static int CodeAllRight = 55004;
    public final static int CodeNext = 55005;
    public final static int CodeClear = 55006;

    @Override
    public void onKey(int primaryCode, int[] keyCodes) {
        // NOTE We can say '<Key android:codes="49,50" ... >' in the xml
        // file; all codes come in keyCodes, the first in this list in
        // primaryCode
        // Get the EditText and its Editable
        View focusCurrent = mHostActivity.getWindow().getCurrentFocus();
        if (focusCurrent == null
                || focusCurrent.getClass() != EditText.class)
            return;
        EditText edittext = (EditText) focusCurrent;
        Editable editable = edittext.getText();
        int start = edittext.getSelectionStart();
        // Apply the key to the edittext
        if (primaryCode == CodeCancel) {
            hideCustomKeyboard();
        } else if (primaryCode == CodeDelete) {
            if (editable != null && start > 0)
                editable.delete(start - 1, start);
        } else if (primaryCode == CodeClear) {
            if (editable != null)
                editable.clear();
        } else if (primaryCode == CodeLeft) {
            if (start > 0)
                edittext.setSelection(start - 1);
        } else if (primaryCode == CodeRight) {
            if (start < edittext.length())
                edittext.setSelection(start + 1);
        } else if (primaryCode == CodeAllLeft) {
            edittext.setSelection(0);
        } else if (primaryCode == CodeAllRight) {
            edittext.setSelection(edittext.length());
        } else if (primaryCode == CodePrev) {
            View focusNew = edittext.focusSearch(View.FOCUS_BACKWARD);
            if (focusNew != null)
                focusNew.requestFocus();
        } else if (primaryCode == CodeNext) {
            View focusNew = edittext.focusSearch(View.FOCUS_FORWARD);
            if (focusNew != null)
                focusNew.requestFocus();
        } else { // insert character
            editable.insert(start, Character.toString((char) primaryCode));
        }
    }

    @Override
    public void onPress(int arg0) {
    }

    @Override
    public void onRelease(int primaryCode) {
    }

    @Override
    public void onText(CharSequence text) {
    }

    @Override
    public void swipeDown() {
    }

    @Override
    public void swipeLeft() {
    }

    @Override
    public void swipeRight() {
    }

    @Override
    public void swipeUp() {
    }
};

/**
 * Create a custom keyboard, that uses the KeyboardView (with resource id
 * <var>viewid</var>) of the <var>host</var> activity, and load the keyboard
 * layout from xml file <var>layoutid</var> (see {@link Keyboard} for
 * description). Note that the <var>host</var> activity must have a
 * <var>KeyboardView</var> in its layout (typically aligned with the bottom
 * of the activity). Note that the keyboard layout xml file may include key
 * codes for navigation; see the constants in this class for their values.
 * Note that to enable EditText's to use this custom keyboard, call the
 * {@link #registerEditText(int)}.
 * 
 * @param host
 *            The hosting activity.
 * @param viewid
 *            The id of the KeyboardView.
 * @param layoutid
 *            The id of the xml file containing the keyboard layout.
 */
public CustomKeyboard(Activity host, int viewid, int layoutid) {
    mHostActivity = host;
    mKeyboardView = (KeyboardView) mHostActivity.findViewById(viewid);
    mKeyboardView.setKeyboard(new Keyboard(mHostActivity, layoutid));
    mKeyboardView.setPreviewEnabled(false); // NOTE Do not show the preview
                                            // balloons
    mKeyboardView.setOnKeyboardActionListener(mOnKeyboardActionListener);
    // Hide the standard keyboard initially
    mHostActivity.getWindow().setSoftInputMode(
            WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);
}

/** Returns whether the CustomKeyboard is visible. */
public boolean isCustomKeyboardVisible() {
    return mKeyboardView.getVisibility() == View.VISIBLE;
}

/**
 * Make the CustomKeyboard visible, and hide the system keyboard for view v.
 */
public void showCustomKeyboard(View v) {
    mKeyboardView.setVisibility(View.VISIBLE);
    mKeyboardView.setEnabled(true);
    if (v != null)
        ((InputMethodManager) mHostActivity
                .getSystemService(Activity.INPUT_METHOD_SERVICE))
                .hideSoftInputFromWindow(v.getWindowToken(), 0);
}

/** Make the CustomKeyboard invisible. */
public void hideCustomKeyboard() {
    mKeyboardView.setVisibility(View.GONE);
    mKeyboardView.setEnabled(false);
}

/**
 * Register <var>EditText<var> with resource id <var>resid</var> (on the
 * hosting activity) for using this custom keyboard.
 * 
 * @param resid
 *            The resource id of the EditText that registers to the custom
 *            keyboard.
 */
public void registerEditText(int resid) {
    // Find the EditText 'resid'
    EditText edittext = (EditText) mHostActivity.findViewById(resid);
    // Make the custom keyboard appear
    edittext.setOnFocusChangeListener(new OnFocusChangeListener() {
        // NOTE By setting the on focus listener, we can show the custom
        // keyboard when the edit box gets focus, but also hide it when the
        // edit box loses focus
        @Override
        public void onFocusChange(View v, boolean hasFocus) {
            if (hasFocus)
                showCustomKeyboard(v);
            else
                hideCustomKeyboard();
        }
    });
    edittext.setOnClickListener(new OnClickListener() {
        // NOTE By setting the on click listener, we can show the custom
        // keyboard again, by tapping on an edit box that already had focus
        // (but that had the keyboard hidden).
        @Override
        public void onClick(View v) {
            showCustomKeyboard(v);
        }
    });
    // Disable standard keyboard hard way
    // NOTE There is also an easy way:
    // 'edittext.setInputType(InputType.TYPE_NULL)' (but you will not have a
    // cursor, and no 'edittext.setCursorVisible(true)' doesn't work )
    edittext.setOnTouchListener(new OnTouchListener() {
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            EditText edittext = (EditText) v;
            int inType = edittext.getInputType(); // Backup the input type
            edittext.setInputType(InputType.TYPE_NULL); // Disable standard
                                                        // keyboard
            edittext.onTouchEvent(event); // Call native handler
            edittext.setInputType(inType); // Restore input type
            return true; // Consume touch event
        }
    });
    // Disable spell check (hex strings look like words to Android)
    edittext.setInputType(edittext.getInputType()
            | InputType.TYPE_TEXT_FLAG_NO_SUGGESTIONS);
}

}

// NOTE How can we change the background color of some keys (like the
// shift/ctrl/alt)?
// NOTE What does android:keyEdgeFlags do/mean