MacaronLover MacaronLover - 7 months ago 55
Java Question

"Field can be converted to a local variable" message appearing when setting action bar colour

After setting the colour of the action bar,

actionBarColor
in
private String actionBarColor = "#B36305";
gets highlighted yellow and a warning is returned for some reason. What can be done to get rid of this warning?


Field can be converted to a local variable


public class MainActivity extends AppCompatActivity {

private String actionBarColor = "#B36305";

private int getFactorColor(int color, float factor) {
float[] hsv = new float[3];
Color.colorToHSV(color, hsv);
hsv[2] *= factor;
color = Color.HSVToColor(hsv);
return color;
}

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);

setContentView(R.layout.fragment_activity_main);

ActionBar actionBar = getSupportActionBar();
if(actionBar != null) {
actionBar.setBackgroundDrawable(new ColorDrawable(Color.parseColor(actionBarColor)));
}
}
}

Answer

What the warning is telling you is that actionBarColor shouldn't be a global variable (i.e. a field), because it's only used in one method (onCreate). This is good advice: you should always minimize the scope of your variables, because it improves readability and reduces possibilities for programming errors.

To get rid of the warning, fix the problem by declaring the variable within onCreate:

final String actionBarColor = "#B36305";

if(actionBar != null) {
    actionBar.setBackgroundDrawable(
        new ColorDrawable(Color.parseColor(actionBarColor)));
}