I know this/similar question has been asked before but the solution given is not working for me so I'm asking again. I tried the solution given in that answer but still my OnKeyListener is never being invoked on some devices, especially the ones with stock OS. I need to detect pressing of del key of soft keyboard when when there is no character in editText. Here is my code;
EditText et = (EditText) findViewById(R.id.et);
et.setOnKeyListener(new EditText.OnKeyListener() {
@Override
public boolean onKey(View v, int keyCode, KeyEvent event) {
Log.d("OnKeyListener", keyCode + " character(code) to send");
return false;
}
});
Finally solved myself by implementing this feature through TextWatcher
. The major hurdle was that, I needed to detect backspace press even when there is no character in EditText
or at least the end user perceives that there is no character there. The fist thing couldn't be achieved however I did the later one. Following is the detailed solution.
First of all, I always retained a space ' ' character in my editText
.
editText.addTextChangedListener(new TextWatcher() {
@Override
public void onTextChanged(CharSequence cs, int arg1, int arg2, int arg3) {
if(cs.toString().length() == 0)
editText.setText(" ");
}
@Override
public void beforeTextChanged(CharSequence arg0, int arg1, int arg2, int arg3) { }
@Override
public void afterTextChanged(Editable arg0) { }
});
Then I customized EditText
to notify me for every cursor position change. This purpose is achieved by overriding onSelectionChanged
method of EditText
. My customized EditText
looks like this.
public class SelectionEnabledEditText extends EditText {
public SelectionEnabledEditText(Context context) {
super(context);
}
public SelectionEnabledEditText(Context context, AttributeSet attrs) {
super(context, attrs);
}
public SelectionEnabledEditText(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
@Override
protected void onSelectionChanged(int selStart, int selEnd) {
super.onSelectionChanged(selStart, selEnd);
if(onSelectionChangeListener != null)
onSelectionChangeListener.onSelectionChanged(selStart, selEnd);
}
public static interface OnSelectionChangeListener{
public void onSelectionChanged(int selStart, int selEnd);
}
private OnSelectionChangeListener onSelectionChangeListener;
public void setOnSelectionChangeListener(OnSelectionChangeListener onSelectionChangeListener) {
this.onSelectionChangeListener = onSelectionChangeListener;
}
}
Finally, in my activity, I'm listening for cursor position changed event and resetting my cursor position in editText
if it's there at the necessary space charatcer start i.e. at 0th index, like this;
editText.setOnSelectionChangeListener(new SelectionEnabledEditText.OnSelectionChangeListener() {
@Override
public void onSelectionChanged(int selStart, int selEnd) {
if (selEnd == 0) {
if (editText.getText().toString().length() == 0)
editText.setText(" ");
editText.setSelection(1);
}
}
});
Hope this would be helpful in similar situations. Suggestions are welcomed for improvements/optimizations.