A simple indeterminate progress dialog. Call with MyProgressDialog.show(context) and dismiss with MyProgressDialog.dismiss(myProgressDialog).

MyProgressDialog.java

import android.app.Dialog;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Color;
import android.graphics.drawable.GradientDrawable;
import android.view.ViewGroup;
import android.view.Window;
import android.view.WindowManager;
import android.widget.ProgressBar;
import android.widget.RelativeLayout;

/**
 * @author Dhagz
 * @since 5/12/2016
 */
public class MyProgressDialog extends Dialog {

  public static MyProgressDialog show(Context context) {
    MyProgressDialog dialog = new MyProgressDialog(context);
    try {
      dialog.show();
    } catch (WindowManager.BadTokenException badTokenException) {
      badTokenException.printStackTrace();
    }
    return dialog;
  }

  public static void dismiss(MyProgressDialog dialog) {
    if (dialog != null && dialog.isShowing()) {
      try {
        dialog.dismiss();
      } catch (IllegalArgumentException ex) {
        //
      }
    }
  }

  public MyProgressDialog(Context context) {
    super(context);
    requestWindowFeature(Window.FEATURE_NO_TITLE);

    RelativeLayout layout = new RelativeLayout(context);
    ProgressBar progressBar = new ProgressBar(context);
    RelativeLayout.LayoutParams params =
        new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,
                                        ViewGroup.LayoutParams.WRAP_CONTENT);
    params.addRule(RelativeLayout.CENTER_IN_PARENT);
    int dp16 = dpToPx(16);
    layout.setPadding(dp16, dp16, dp16, dp16);
    layout.addView(progressBar, params);

    setContentView(layout);

    GradientDrawable shape = new GradientDrawable();
    shape.setColor(Color.parseColor("#A2FFFFFF"));
    shape.setCornerRadius(dp16);

    getWindow().setBackgroundDrawable(shape);

    setCancelable(false);
  }

  @Override public void onBackPressed() {
    // disable on back pressed
    // super.onBackPressed();
  }

  /**
   * Source: http://stackoverflow.com/questions/8295986/how-to-calculate-dp-from-pixels-in-android-programmatically
   *
   * @param dp value to be converted to pixels
   * @return pixel value for dp
   */
  public static int dpToPx(int dp) {
    return (int) (dp * Resources.getSystem().getDisplayMetrics().density);
  }
}

MyProgressDialog.kt

import android.app.Dialog
import android.content.Context
import android.content.res.Resources
import android.graphics.Color
import android.graphics.drawable.GradientDrawable
import android.view.ViewGroup
import android.view.Window
import android.widget.ProgressBar
import android.widget.RelativeLayout

class MyProgressDialog(context: Context) : Dialog(context) {

    companion object {
        fun show(context: Context?): MyProgressDialog? {
            // Return null if context is null
            if (context == null) return null

            val dialog = MyProgressDialog(context)
            try {
                dialog.show()
            } catch (ex: Exception) {
                ex.printStackTrace()
            }
            return dialog
        }

        fun dismiss(dialog: MyProgressDialog) {
            try {
                dialog.dismiss()
            } catch (ex: Exception) {
                ex.printStackTrace()
            }
        }
    }

    init {
        requestWindowFeature(Window.FEATURE_NO_TITLE)

        val layout = RelativeLayout(context)
        val progressBar = ProgressBar(context)
        val params = RelativeLayout.LayoutParams(
            ViewGroup.LayoutParams.WRAP_CONTENT,
            ViewGroup.LayoutParams.WRAP_CONTENT
        )
        params.addRule(RelativeLayout.CENTER_IN_PARENT)
        val dp16 = dpToPx(16)
        layout.setPadding(dp16, dp16, dp16, dp16)
        layout.addView(progressBar, params)

        setContentView(layout)

        val shape = GradientDrawable()
        shape.setColor(Color.parseColor("#A2FFFFFF"))
        shape.cornerRadius = dp16.toFloat()

        window?.setBackgroundDrawable(shape)

        setCancelable(false)
    }

    /**
     * Source: http://stackoverflow.com/questions/8295986/how-to-calculate-dp-from-pixels-in-android-programmatically
     *
     * @param dp value to be converted to pixels
     * @return pixel value for dp
     */
    fun dpToPx(dp: Int): Int {
        return (dp * Resources.getSystem().displayMetrics.density).toInt()
    }
}