Question

Instead of using EditTexts, I have elected to use clickable categories that prompt a Dialog that accepts a user’s input. This reusable Dialog class is stored in an AllMethods.class. The initial theory was that I pass a bunch of text (for description, title, and such) and a target TextView (to setText that the user inputted in the Dialog). However, upon execution, I get the nullpointer exception when trying to do the TextView.setText(str) line of code.

So, My question: How do I successfully change the textView OR pass a string back only after the user clicks the OK button?

Also note, that the TextView had been declared and instantiated. I assume the nullpointer is because it is in a remote class. Here is the code:

import android.app.Activity;
import android.app.Dialog;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.TextView;

public class AllMethods {


    //fieldRequest is a reusable prompt to get a user's input for a field without taking up so much space
    /* Legend of inputs:
     * requestingActivity=the activity which is prompting the popup
     * dialogMessage = the description of the editText being requested
     * dialogTitle = the title to be displayed on the dialogbox
     * editTextHint = the Hint attribute that will give the user an example of the expected input
     * inputType = numeric, text, phone number, etc
     */



    public static void fieldRequest(Activity activity, String dialogMessage, String dialogTitle, final TextView outputText, int inputType, String optionalFieldSuffix){
        final Dialog dialog= new Dialog(activity);
        dialog.setContentView(R.layout.dialog_layout);
        dialog.setTitle(dialogTitle);
        //If the message/description exists, put it in
        if(dialogMessage!=null||dialogMessage!=""){TextView description = (TextView) dialog.findViewById(R.id.dialog_description);
        description.setText(dialogMessage);
        }
        //Identify the editText, set the input type appropriately and fill in the hint if applicable
        final EditText inputField = (EditText) dialog.findViewById(R.id.dialog_inputbox);
        if(Integer.toString(inputType)!=null){inputField.setInputType(inputType);}

        if(optionalFieldSuffix!=null){TextView suffix = (TextView) dialog.findViewById(R.id.dialog_optionalFieldSuffix);            
        suffix.setText(optionalFieldSuffix);}

        ImageButton dialogCancel = (ImageButton) dialog.findViewById(R.id.dialog_cancel);
        ImageButton dialogDone = (ImageButton) dialog.findViewById(R.id.dialog_done);
        dialogCancel.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {

                dialog.dismiss();

            }
        });

        dialogDone.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                outputText.setText(inputField.getText().toString());
                dialog.dismiss();

            }
        });

        dialog.show();
    }

}

Answer 1

Implement the interface in your class like this, as shown below. You do not need to pass the textview as input to this function.

import android.app.Activity;
import android.app.Dialog;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.TextView;

public class AllMethods {


    //fieldRequest is a reusable prompt to get a user's input for a field without taking up so much space
    /* Legend of inputs:
     * requestingActivity=the activity which is prompting the popup
     * dialogMessage = the description of the editText being requested
     * dialogTitle = the title to be displayed on the dialogbox
     * editTextHint = the Hint attribute that will give the user an example of the expected input
     * inputType = numeric, text, phone number, etc
     */



    public static void fieldRequest(Activity activity, String dialogMessage, String dialogTitle, int inputType, String optionalFieldSuffix, final DialogResponse dr){
        final Dialog dialog= new Dialog(activity);
        final DialogResponse dialogResponse = dr;
        dialog.setContentView(R.layout.dialog_layout);
        dialog.setTitle(dialogTitle);
        //If the message/description exists, put it in
        if(dialogMessage!=null||dialogMessage!=""){TextView description = (TextView) dialog.findViewById(R.id.dialog_description);
        description.setText(dialogMessage);
        }
        //Identify the editText, set the input type appropriately and fill in the hint if applicable
        final EditText inputField = (EditText) dialog.findViewById(R.id.dialog_inputbox);
        if(Integer.toString(inputType)!=null){inputField.setInputType(inputType);}

        if(optionalFieldSuffix!=null){TextView suffix = (TextView) dialog.findViewById(R.id.dialog_optionalFieldSuffix);            
        suffix.setText(optionalFieldSuffix);}

        ImageButton dialogCancel = (ImageButton) dialog.findViewById(R.id.dialog_cancel);
        ImageButton dialogDone = (ImageButton) dialog.findViewById(R.id.dialog_done);
        dialogCancel.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                dialogResponse.actionNo();
                dialog.dismiss();

            }
        });

        dialogDone.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                dialogResponse.actionYes(inputField.getText().toString());
                dialog.dismiss();
            }
        });

        dialog.show();
    }

    public interface DialogResponse {
        public void actionYes(String str);

        public void actionNo();
    }


}

Usage:

DialogUtility.DialogResponse dr = new DialogResponse() {

            @Override
            public void actionYes(String str) {
                // TODO Auto-generated method stub

                 **// your code to set your string to textview**
            }



            @Override
            public void actionNo() {

            }
        };
        **//Make sure you modify code to match your variables**
         AllMethods
                .fieldRequest(activity, dialogMessage, dialogTitle, inputType, optionalFieldSuffix, dr);