Switch statement in non-anonymous private OnClickListener class not working?

Switch statement in non-anonymous private OnClickListener class not working?

I've tried quite a few different tactics to achieve my desired result, but
nothing is making these buttons do what they're 'sposed to... Basically I
have 14 buttons. Four with the text "X", digitOne, digitTwo, digitThree
and digitFour. Then, there are 10 with "1", "2", etc, named "one", "two",
etc. All the buttons are tied to the same OnClickListener that will use a
switch statement to determine which button was pressed, then find the
soonest display button (buttons initially marked "X"), and change that
buttons text to the entered digit. What I want to happen is:
Say someone clicks the "5" button. If its the first button pressed, the
first "digit" button will change from displaying "X" to "5", and so-on,
so-forth. This is not what is happening... In fact, nomatter what I've
tried, nothing is happening. Not even an error... An error would be nice,
at least I'd know where my logical flaw is -_-. Here's the code:
The button declarations:
one=(Button)findViewById(R.id.button1);
two=(Button)findViewById(R.id.Button2);
three=(Button)findViewById(R.id.Button3);
four=(Button)findViewById(R.id.Button4);
five=(Button)findViewById(R.id.Button5);
six=(Button)findViewById(R.id.Button6);
seven=(Button)findViewById(R.id.Button7);
eight=(Button)findViewById(R.id.Button8);
nine=(Button)findViewById(R.id.Button9);
zero=(Button)findViewById(R.id.Button0);
add=(Button)findViewById(R.id.buttonAdd);
digitOne=(Button)findViewById(R.id.Number1);
digitTwo=(Button)findViewById(R.id.Number2);
digitThree=(Button)findViewById(R.id.Number3);
digitFour=(Button)findViewById(R.id.Number4);
one.setOnClickListener(listener);
two.setOnClickListener(listener);
three.setOnClickListener(listener);
four.setOnClickListener(listener);
five.setOnClickListener(listener);
six.setOnClickListener(listener);
seven.setOnClickListener(listener);
eight.setOnClickListener(listener);
nine.setOnClickListener(listener);
zero.setOnClickListener(listener);
The OnClickListener private inner class (I guess that's what you'd call
it. It's inside Activity class):
private OnClickListener listener = new OnClickListener(){
public void onClick(View button) {
switch(button.getId()){
case R.id.Button0:
addANumber(0);
break;
case R.id.button1:
addANumber(1);
break;
case R.id.Button2:
addANumber(2);
break;
case R.id.Button3:
addANumber(3);
break;
case R.id.Button4:
addANumber(4);
break;
case R.id.Button5:
addANumber(5);
break;
case R.id.Button6:
addANumber(6);
break;
case R.id.Button7:
addANumber(7);
break;
case R.id.Button8:
addANumber(8);
break;
case R.id.Button9:
addANumber(9);
break;
}
}
};
And finally, the "addANumber" method being called:
public void addANumber(int i){
if(digitOne.getText()=="X"){
digitOne.setText(i);
}else if(digitTwo.getText()=="X"){
digitTwo.setText(i);
}else if(digitThree.getText()=="X"){
digitThree.setText(i);
}else if(digitFour.getText()=="X"){
digitFour.setText(i);
}
}
I've done this before... I know I'm missing something so blatantly stupid
it deserves a smack in the head...