Question

I want to update a TextView in main activity from inside a custom object.

The custom object is a number picker written from scratch. It has an EditText and 2 button (+/-).
My purpose is that when a user press the + or – button the TextView will be updated with that value.

Now i can think 2 possible solutions:

1. The custom object update the TextView when the + or – button is pressed (inside the onClickListener).
2. I define another class that extend the custom picker, with the logic for update the textview.

But my problem is that i want to keep the textView logic outside the custom picker (so if is possible to have the update function inside the activity).
There is a solution to that problem?

The custompicker xml code is that:

<org.croncalc.MyPicker android:id="@+id/hourpicker"
                android:orientation="vertical"
                android:layout_width="65dp"
                croncalc:maxnumber="24"
                croncalc:minnumber="1"
                croncalc:step="5"
                croncalc:cycle="true"
                android:layout_height="wrap_content">

Here a screenshot

I want that everytime one of the picker change its value the textview on the right corner will be updated.

If useful here the onClick() code for the +/- buttons:

    OnClickListener clickListener = new OnClickListener() {
    public void onClick(View v) {
        switch (v.getId()) {
        case R.id.decbtn:
            step(-1);
            break;
        case R.id.incbtn:
        default:
            step(1);
            break;
        }
    }                   
};

private void step(int step) {
    current += step;
    if (step > 0) {
        decButton.setEnabled(true);         
        if ( current > maxNumber) {
            if(cycle){
                current-=maxNumber;
            } else {
                current=maxNumber;
                incButton.setEnabled(false);
                incButton.setPressed(false);
            }           
        }
    } else {
        incButton.setEnabled(true);
        if ( current < minNumber) {
            if(cycle){
                current+= maxNumber;
            } else {
                current=minNumber;
                decButton.setEnabled(false);
                decButton.setPressed(false);
            }                       
        }
    }
    pickerText.setText(Integer.toString(current));      
}

Thanks in advance.
Ivan

Answer 1

Ok i answer myself (i found a solution).

I define a CustomListener for my objcet.
I declared an interface called:
package org.croncalc;
public interface OnMyPickerChangeListener {
public abstract void onMyPickerChanged(String srcTxt);
}

and then i added in MyPickerClass (this is the name of the object) a new class Variable:

OnMyPickerChangeListener onMyPickerChangeListener;

That variable will be initialized at null.
After i defined in MyPicker two new methods:

1. The first is the setOnMyPickerChangeListener with that method i can add a OnMyPickerChangeListener:

   public void setOnMyPickerChangeListener(OnMyPickerChangeListener listener) {
   onMyPickerChangeListener = listener;
   }

2. The second method is onMyPickerChanged, that method will be called everytime we want to trigger the Change Event:

   private void onMyPickerChanged(){
   if(onMyPickerChangeListener!=null){
   onMyPickerChangeListener.onMyPickerChanged(pickerText.getText().toString());
   }
   }

Now in the main activity i declared a new OnMyPickerChangeListener and implemented the interface method onMyPickerchanged:

OnMyPickerChangeListener pickerListener = new OnMyPickerChangeListener() {

    @Override
    public void onMyPickerChanged(String srcTxt) {          
        localTv.setText("Value: " + srcTxt);
    }
};

And i added that Listener to the Picker:

minutesPicker.setOnMyPickerChangeListener(pickerListener);

And now it works 🙂