Question

I’m fairly new to Java & Android, so I have little idea what I am doing.

My test program successfully creates view objects, so now I am trying to organize my code.
I want to make a separate class to manage my GUI, but it always fails.

Basic info about my gui class:

package horc.gui;
   ...
public class GUI{
    private Context context;

From my main activity, I constructed that gui class with the app context.

gui=new GUI(getApplicationContext());   // gui is a var of type GUI, & this sets the context of the class

The problem is when I make/modify a view object that is in the class from outside, it throws an exception.

My main activity…

package horc.test;
   ...
GUI gui;
LinearLayout test=gui.newLinear("ff", "v"); // <-- this sets fill parent for width/height
                                            // & vertical orientation of the vertical layout.
                                            // Doesnt work for the reason stated above.
                                            // I cannot manage any view objects from a separate class.
gui.lastText.setText("@@@@@@@@@@"); // <-- a variable in the class to hold the view object I am manipulating
setContentView(t);

…calls this class function:

public TextView newText(String text){
    TextView test=new TextView(context);
    lastLinear.addView(test);
    return test;
}

I tested this similar body within the main activity & it worked fine. It only fails when I do anything from outside that gui class.

Is there a common issue that people run into when managing view objects in separate classes? I have absolutely no idea what I am doing at this point. Coming from C++, java seems like a nutty language. I cannot plan things the way I would in C++.

Answer 1

instead of

gui=new GUI(getApplicationContext()); 

try

gui=new GUI(MyActivity.this); 

Please put your activity name instead of MyActivity