title: Android custom seekbar not showing before first touch
body: <p>I tried to make custom seekbar through xml. But only thumb is shown before first touch. After touch, custom seekbar is shown. </p>
  
  <p>Here is my xml in mainActivity.</p>
  
  <pre><code>&lt;RelativeLayout
      android:layout_width="match_parent"
      android:layout_height="129dp"
      &gt;
      &lt;!--seek bar--&gt;
  
      &lt;SeekBar
          android:layout_width="match_parent"
          android:layout_height="40dp"
          android:thumb="@mipmap/survey_bar_ic"
          android:thumbOffset="16dp"
          android:id="@+id/seekBar"
          android:layout_marginLeft="23dp"
          android:layout_marginRight="23dp"
          android:layout_centerInParent="true"&gt;
      &lt;/SeekBar&gt;
      &lt;RelativeLayout
          android:layout_width="37dp"
          android:layout_height="28dp"
          android:layout_above="@+id/seekBar"
          android:layout_marginBottom="8dp"
          android:id="@+id/bubble"
          &gt;
          &lt;ImageView
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              android:id="@+id/bubble_img"
              android:background="@mipmap/survey_bubble_green"&gt;&lt;/ImageView&gt;
          &lt;TextView
              android:id="@+id/bubble_txt"
              android:layout_width="match_parent"
              android:layout_height="match_parent"
              android:text="1"
              android:textColor="#ffffff"
              android:layout_centerInParent="true"
              android:gravity="center"
              &gt;&lt;/TextView&gt;
      &lt;/RelativeLayout&gt;
  &lt;/RelativeLayout&gt;
  </code></pre>
  
  <p>and this is survey_bar_free.xml</p>
  
  <pre><code>&lt;layer-list xmlns:android="http://schemas.android.com/apk/res/android"&gt;
  &lt;!--basic background--&gt;
  &lt;item android:id="@android:id/background"&gt;
      &lt;shape android:shape="line"&gt;
          &lt;stroke android:width="16dp" android:color="#dcdcdc"/&gt;
      &lt;/shape&gt;
  &lt;/item&gt;
  &lt;item android:id="@android:id/secondaryProgress"&gt;
      &lt;clip&gt;
          &lt;shape android:shape="line"&gt;
              &lt;stroke android:width="16dp" android:color="#8ed351"/&gt;
          &lt;/shape&gt;
      &lt;/clip&gt;
  &lt;/item&gt;
  &lt;item android:id="@android:id/progress"&gt;
      &lt;clip&gt;
          &lt;shape android:shape="line"&gt;
              &lt;stroke android:width="16dp" android:color="#8ed351"/&gt;
          &lt;/shape&gt;
      &lt;/clip&gt;
  &lt;/item&gt;
  &lt;/layer-list&gt;
  </code></pre>
  
  <p>And this is mainActivity.java</p>
  
  <pre><code>seekBar = (SeekBar)findViewById(R.id.seekBar);
  seekBar.setOnSeekBarChangeListener(new OnSeekBarChangeListener
  {
   if(i&gt;free_range)
              {
                  if(i&gt;point_range)
                  {
                      int cur = (i-point_range)/2+point_num;
                      bubbleText.setText(Integer.toString(cur));
                      seekBar.setProgressDrawable(
                      getDrawable(R.drawable.survey_bar_premium));
              int temp = i/2;
              seekBar.setProgress(temp*2);
              //seekBar.setProgress(cur*2);
              bubbleImg.setImageResource(R.mipmap.survey_bubble_blue);
          }
          else
          {
              int cur = i/6;
              bubbleText.setText(Integer.toString(cur));
              seekBar.setProgressDrawable(
                      getDrawable(R.drawable.survey_bar_point));
              seekBar.setProgress(cur*6);
              bubbleImg.setImageResource(R.mipmap.survey_bubble_skyblue);
          }
      }
      else
      {
          int cur = i/6;
          if(cur==0)
          {
              cur=1;
          }
          bubbleText.setText(Integer.toString(cur));
          seekBar.setProgressDrawable(
                  getDrawable(R.drawable.survey_bar_free));
          seekBar.setProgress(cur*6);
          bubbleImg.setImageResource(R.mipmap.survey_bubble_green);
      }
   });
   seekBar.setMax(seekBarMax);
   seekBar.setProgress(6);
   seekBar.setProgressDrawable(
              getDrawable(R.drawable.survey_bar_free));
  </code></pre>