title: (R.dimen.padding_medium) Cannot be resolved or is not a field?
body: <p>I'm trying to create a new gallery style app since Gallery got depreciated.</p>
  
  <p>The main problem that I am having is that when I try to run the following code I can't shake the error "dimen cannot be resolved or is not a field".  I've read some website and some posts here that say it is to do with importing "import com.example.test.R;" however even with that the error persists if anyone could help it would be amazing.</p>
  
  <p>Gall.java:</p>
  
  <pre><code>package com.example.test;
  
  import android.app.Activity;
  import android.os.Bundle;
  import android.support.v4.view.ViewPager;
  
  
  
  public class Gall extends Activity {
  
  
      @Override
      public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_gall);
  
        ViewPager viewPager = (ViewPager) findViewById(R.id.view_pager);
        ImgAdapt adapter = new ImgAdapt(this);
        viewPager.setAdapter(adapter);
      }
  
    }
  </code></pre>
  
  <p>activity_gall.xml:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;RelativeLayout 
      xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:tools="http://schemas.android.com/tools"
  
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:orientation="vertical" &gt;
  
      &lt;android.support.v4.view.ViewPager
      android:id="@+id/view_pager"
      android:layout_width="match_parent"
      android:layout_height="match_parent" /&gt;
  
  &lt;/RelativeLayout&gt;
  </code></pre>
  
  <p>ImgAdapt.java:</p>
  
  <pre><code>package com.example.test;
  
  import android.content.Context;
  import android.support.v4.view.PagerAdapter;
  import android.support.v4.view.ViewPager;
  import android.view.View;
  import android.view.ViewGroup;
  import android.widget.ImageView;
  
  
  
  
  public class ImgAdapt extends PagerAdapter {
  Context context;
  
  private int[] GalImages = new int[] 
          {
              R.drawable.one,
              R.drawable.two,
              R.drawable.three
  
          };
  
  ImgAdapt(Context context){
  this.context=context;
  }
  
  public int getCount() {
  return GalImages.length;
  }
  
  
  public boolean isViewFromObject(View view, Object object) {
  return view == ((ImageView) object);
  }
  
  
  public Object instantiateItem(ViewGroup container, int position) {
  
  ImageView imageView = new ImageView(context);
  int padding = context.getResources().getDimensionPixelSize(R.dimen.padding_medium);
  imageView.setPadding(padding, padding, padding, padding);
  imageView.setScaleType(ImageView.ScaleType.CENTER_INSIDE);
  imageView.setImageResource(GalImages[position]);
  ((ViewPager) container).addView(imageView, 0);
  return imageView;
  }
  
  
  public void destroyItem(ViewGroup container, int position, Object object) {
  ((ViewPager) container).removeView((ImageView) object);
  }
  }
  </code></pre>
  
  <p>Lots of code, sorry if it's a vague question but the 'dimen' in the line</p>
  
  <pre><code>int padding = context.getResources().getDimensionPixelSize(R.dimen.padding_medium);
  </code></pre>
  
  <p>is the only part that is giving me an error.</p>