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How to create a util that can be referenced multiple times in different activities

I have successfully implemented a custom Dialog box that appears when the user tries to leave an activity via a back button or by using onBackPressed(). They can simply cancel the dialog box or continue, and leave the activity. This function has been implemented in multiple activities, however its making my code a lot longer than it needs to be. I wanted to know how to create a util that can be referenced in different activities, without the need for the chunk of code to copy pasted multiple times. Please note that I am retrieving the dialog title and description from string.xml
This is my code:
Dialog customDialog;
Button button_one, button_two;
TextView dialog_title, dialog_description;
customDialog = new Dialog(this);
//Back button will close app
#Override
public void onBackPressed() {
customDialog.setContentView(R.layout.custom_dialog_box);
dialog_title = customDialog.findViewById(R.id.dialog_title);
dialog_title.setText(getString(R.string.leaving_activity_warning_title));
dialog_description = customDialog.findViewById(R.id.dialog_description); dialog_description.setText(getString(R.string.leaving_activity_warning_description));
button_one = customDialog.findViewById(R.id.button_one);
button_one.setText(getString(R.string.cancel));
button_two = customDialog.findViewById(R.id.button_two);
button_two.setText(getString(R.string.leave_anyway));
button_one.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
customDialog.dismiss();
}
});
button_two.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
customDialog.dismiss();
finish();
overridePendingTransition(R.anim.slide_in_left, R.anim.slide_out_right);
}
});
Objects.requireNonNull(customDialog.getWindow()).setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));
customDialog.show();
}
UPDATE
Created a Java file called "DialogBoxMessage"
DialogBoxMessage Code:
class DialogBoxMessage {
private Dialog customDialog;
private TextView dialog_title, dialog_description;
private Button button_one, button_two;
//Custom Dialog Box Initialization
DialogBoxMessage(Button myButtonOne, TextView myDialogTitle, TextView myDialogDescription, Dialog myCustomDialog) {
customDialog = myCustomDialog;
button_one = myButtonOne;
button_two = myButtonOne;
dialog_title = myDialogTitle;
dialog_description = myDialogDescription;
}
void leaveActivity() {
customDialog.setContentView(R.layout.custom_dialog_box);
dialog_title = customDialog.findViewById(R.id.dialog_title);
dialog_title.setText(Resources.getSystem().getString(R.string.leaving_activity_warning_title));
dialog_description = customDialog.findViewById(R.id.dialog_description);
dialog_description.setText(Resources.getSystem().getString(R.string.leaving_activity_warning_description));
button_one = customDialog.findViewById(R.id.button_one);
button_one.setText(Resources.getSystem().getString(R.string.cancel));
button_two = customDialog.findViewById(R.id.button_two);
button_two.setText(Resources.getSystem().getString(R.string.leave_anyway));
button_one.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
customDialog.dismiss();
}
});
button_two.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
customDialog.dismiss();
}
});
Objects.requireNonNull(customDialog.getWindow()).setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));
customDialog.show();
}
}
I input the following code in another activity
Other activity code:
//Reusable exit dialog message
DialogBoxMessage dialogBoxMessage;
//Back button will close app
#Override
public void onBackPressed() {
dialogBoxMessage.leaveActivity();
finish();
}
But it doesn't seem to work, I think there are a lot of issues... please help :(

I assume customDialog is a seperate class you wrote - therefore i would suggest you put main information like contentview, title, message or type in the constructor when you initialize ur Dialog.
For your onClick Method I suggest you create an Interface to handle Button Clicks in your
customDialog class.

This could be implemented as a static method in a utilities class. The method would require 'this' as a parameter, which contains the activity context. The method should return the result of the button press. The activity can use this response to determine if finish() should be called or not.
UPDATE
I had suggested a simple static method, but you've gone down the object-oriented route. That's fine.
However, your constructor requires passing in several views, which wouldn't appear to achieve the code efficiency you are after.
Your constructor should just require the Activity context; everything else is encapsulated in your new class.
In each Activity's onBackPressed method you will need to create the object with
dialogBoxMessage = new DialogBoxMessage(this);
before you can call any of that object's methods.

How to make a button permanently unclickable

I am making a log-in system on Android. And I want the register Button to be unclickable when it has been clicked. I am using this code:
final Button register = (Button) findViewById(R.id.register);
register.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
register.setEnabled(false);
Intent register = new Intent(getApplicationContext(), register.class);
startActivity(register);
}
});
This is working great, but I want the Button to remain unclickable even when the application or phone has been restarted. Does anyone know a way to make the Button unclickable permanently even when the application has been shut down?

As I already said in the comments section something like this may work:
public class MyActivity extends Activity {
private static final String KEY_IS_BUTTON_CLICKABLE = "key_clickable";
#Override
public void onCreate(Bundle savedInstanceState) {
...
final Button register = (Button) findViewById(R.id.register);
SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
boolean isClickable = sharedPreferences.getBoolean(KEY_IS_BUTTON_CLICKABLE, true);
register.setEnabled(isClickable);
if(isClickable) {
register.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
register.setEnabled(false);
PreferenceManager.getDefaultSharedPreferences(getApplicationContext()).edit()
.putBoolean(KEY_IS_BUTTON_CLICKABLE, false);
Intent register = new Intent(getApplicationContext(), register.class);
startActivity(register);
}
});
}
}
...
}

In this case you could take a pessimistic approach and disable the button in the layout (by default) with android:clickable="false" and enable it in the condition where registration is required.

Using a common dialog box, but calling different functions from diffrent activities in android

In my app i have to use same dialog box on all the activities but then on to the click of button on dialog box i need to perform different operations for different activities, i have kept a common code for dialog but then how to call different functions, here is my code:
final Dialog dialog = new Dialog(mContext,R.style.Theme_Levels);
dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
dialog.setContentView(R.layout.custom_alert);
TextView title = (TextView)dialog.findViewById(R.id.title);
title.setText("Network Error");
TextView msg = (TextView)dialog.findViewById(R.id.msg_txt);
msg.setText("The system is down, please check after some time ");
ImageView cancel = (ImageView)dialog.findViewById(R.id.cancel);
cancel.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View v) {
dialog.dismiss();
}
});
TextView continue_btn = (TextView)dialog.findViewById(R.id.continue_btn);
continue_btn.setBackgroundResource(R.drawable.feedback_button_purple);
continue_btn.setText("Retry");
continue_btn.setOnClickListener(new OnClickListener(){
#Override
public void onClick(View v) {
//TODO perform different operation depending upon from where this function has been called
dialog.dismiss();
}
});
dialog.show();

Create an interface, say DialogActivity, with one method "handlePositiveButton". Let all your Activities implement this interface. From the Dialog.onClick you do this:
DialogActivity activity = (DialogActivity) getActivity();
activity.handlePositiveButton();

Put the code you have specified in a function of a Utils file.
Then pass the positive button onclick listener in that function.
Refer the below code.
public static void showAlertDialog(OnClickListener listener) {
// enter your code here
continue_btn.setOnClickListener(listener);
// more code here
}

Closing an AlertDialog box after a button has been clicked

I have the following code which displays a dialog box to the user if no network connection is detected.
private void createNoNetworkDialog() {
LayoutInflater inflater = LayoutInflater.from(this);
AlertDialog.Builder builder = new AlertDialog.Builder(this);
View view = inflater.inflate(R.layout.offline_mode_dialog,null);
builder.setView(view);
builder.show();
}
There are two buttons in this dialog which have methods defined for their onClick actions. I would like to close the dialog pop-up after either of these button is pressed. Any ideas??

Yes,call dismiss() from the Listener's onClick since the DialogInterface reference is passed, which allows for dismissal.
Eg
builder.setPositiveButton ("Yes", new DialogInterface.OnClickListener()
{
public void onClick (DialogInterface dialog, int which)
{
//do stuff beforehand
dialog.dismiss();
}
});
Or if your buttons are inside the layout, show the dialog and keep a reference to it (final AlertDialog dialog = builder.show()). Then use dialog.findViewById() to find the respective buttons. Assign a normal View.OnClickListener and in it call dismiss() using the dialog reference you're holding.

Try this, Am using custom layout its working for me. inilitized Button custon_dialog.findViewById() and then write OncliclListner(). It will work
final Dialog custon_dialog = new Dialog(Login.this);
custon_dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
custon_dialog.setContentView(R.layout.forget_custom_dialog);
custon_dialog.setCancelable(true);
Button submit_Btn = (Button) custon_dialog
.findViewById(R.id.submit);
Button cancel_Btn = (Button) custon_dialog
.findViewById(R.id.cancel);
submit_Btn.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
//do your stuf
}
});
cancel_Btn.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
custon_dialog.dismiss();
}
});
custon_dialog.show();
}

Which context do i need?

I'm creating a dialog box and using the (this) isnt working. Up until now its just been a button calling a dialogbox but now the button within the called dialogbox needs to call another dialog. The Dialog dialogdelcon is the one with problem.
Here is the code:
case R.id.delappt:
//rmvall();
final Dialog dialogdelsel = new Dialog(this);
dialogdelsel.setContentView(R.layout.delsel);
dialogdelsel.setTitle("What would you like to do?");
dialogdelsel.setCancelable(true);
Button btndelsel = (Button) dialogdelsel.findViewById(R.id.btndelsel);
btndelsel.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// delete selected code here.
}
});
Button btndelall = (Button) dialogdelsel.findViewById(R.id.btndelall);
btndelall.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// delete all code here.
final Dialog dialogdelcon = new Dialog();
dialogdelcon.setContentView(R.layout.delcon);
dialogdelcon.setTitle("Deletion Confirmation");
dialogdelcon.setCancelable(true);
Button buttoncnclok = (Button) dialogdelcon.findViewById(R.id.btndelcon);
buttoncnclok.setOnClickListener(new OnClickListener() {
// on click for cancel button
#Override
public void onClick(View v) {
dialogdelcon.dismiss();
}
});
dialogdelcon.show();
}
});
dialogdelsel.show();
break;

getApplicationContext() or use YourActictyName.this Because this refers the button click listner ,not your class Object

If this code is in the onCreate() method, or similiar, add getApplicationContext() instead of this and you should be fine. That's because this in a Button-context will refer to the button environment.

To improve the isolation between the two dialogs, it would be best to call showDialog(R.id.delapptcon) from the onClick handler. Then load the new dialog in the onCreateDialog of your activity. In this way, you can create more reusable dialogs and avoid the scoping issue you have now.