Android自定义键盘的实现（数字键盘和字母键盘）

 /**
   * Creates a keyboard from the given xml key layout file.
   * @param context the application or service context
   * @param xmlLayoutResId the resource file that contains the keyboard layout and keys.
   */
  public Keyboard(Context context, int xmlLayoutResId) {
    this(context, xmlLayoutResId, 0);
  }

  /**
   * Creates a keyboard from the given xml key layout file. Weeds out rows
   * that have a keyboard mode defined but don't match the specified mode.
   * @param context the application or service context
   * @param xmlLayoutResId the resource file that contains the keyboard layout and keys.
   * @param modeId keyboard mode identifier
   * @param width sets width of keyboard
   * @param height sets height of keyboard
   */
  public Keyboard(Context context, @XmlRes int xmlLayoutResId, int modeId, int width,
      int height) {
      ...
  }

<?xml version="1.0" encoding="UTF-8"?>
<Keyboard android:keyWidth="24.9%p"
     android:keyHeight="49dp"
     android:horizontalGap="0.1333%p"
     android:verticalGap="1px"
     xmlns:android="http://schemas.android.com/apk/res/android">
  <Row>
    <Key android:codes="49" android:keyEdgeFlags="left"
       android:keyLabel="1" />
    <Key android:codes="50" android:keyLabel="2" />
    <Key android:codes="51" android:keyLabel="3" />
    <Key android:codes="-5" android:iconPreview="@drawable/key_num_del_bg"
       android:isRepeatable="true"/>
  </Row>
  ...
</Keyboard>

public abstract class BaseKeyboard extends Keyboard implements KeyboardView.OnKeyboardActionListener{

 @Override
 public void onKey(int primaryCode, int[] keyCodes) {
    if(null != mEditText && mEditText.hasFocus() && !handleSpecialKey(primaryCode)) {
      Editable editable = mEditText.getText();
      int start = mEditText.getSelectionStart();
      int end = mEditText.getSelectionEnd();
      if (end > start){
        editable.delete(start,end);
      }
      if(primaryCode == KEYCODE_DELETE) {
        if(!TextUtils.isEmpty(editable)) {
          if(start > 0) {
            editable.delete(start-1,start);
          }
        }
      }else if(primaryCode == getKeyCode(R.integer.hide_keyboard)){
        hideKeyboard();
      }else {
        editable.insert(start,Character.toString((char) primaryCode));
      }
    }
  }

 public abstract boolean handleSpecialKey(int primaryCode);
}

public void bindToEditor(EditText editText, BaseKeyboard keyboard) {
  hideSystemSoftKeyboard(editText);
  editText.setTag(R.id.bind_keyboard_2_editor, keyboard);
  if (keyboard.getKeyStyle() == null) {
    keyboard.setKeyStyle(mDefaultKeyStyle);
  }
  editText.setOnFocusChangeListener(editorFocusChangeListener);
}

private final View.OnFocusChangeListener editorFocusChangeListener = new View.OnFocusChangeListener() {
  @Override
  public void onFocusChange(final View v, boolean hasFocus) {
    if (v instanceof EditText) {
      if (hasFocus) {
       v.postDelayed(new Runnable() {
          @Override
          public void run() {
            showSoftKeyboard((EditText) v);
          }
        },300);
      } else {
        hideSoftKeyboard();
      }
    }
  }
};

public void showSoftKeyboard(EditText editText) {
  mRootView.addOnLayoutChangeListener(mOnLayoutChangeListener);
  BaseKeyboard keyboard = getBindKeyboard(editText);
  if (keyboard == null) {
    Log.e(TAG, "edit text not bind to keyboard");
    return;
  }
  keyboard.setEditText(editText);
  keyboard.setNextFocusView(mKeyboardWithSearchView.getEditText());
  initKeyboard(keyboard);
  ...
}

KeyboardManager keyboardManagerNumber = new KeyboardManager(this);
keyboardManagerNumber.bindToEditor(editText2, new NumberKeyboard(context,NumberKeyboard.DEFAULT_NUMBER_XML_LAYOUT));

KeyboardManager keyboardManagerAbc = new KeyboardManager(this);
keyboardManagerAbc.bindToEditor(editText1, new ABCKeyboard(context, ABCKeyboard.DEFAULT_ABC_XML_LAYOUT));