how i can add bitmap to pdfview, bitmap can transform and move when i touch it. i use pdfviewer from joan zapata https://github.com/JoanZapata/android-pdfview. is there way to solve it. or is there other libary for me. this my activity. i try to addi ontouchlistener in pdfview, but zoom and sweep in pdfview didn't work.
package com.example.irfan.signatureapp;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.os.Environment;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.ContextMenu;
import android.view.Menu;
import android.view.MenuItem;
import android.view.MotionEvent;
import android.view.View;
import com.joanzapata.pdfview.PDFView;
import com.joanzapata.pdfview.listener.OnDrawListener;
import com.joanzapata.pdfview.model.PagePart;
import java.io.File;
public class PdfEditorActivity extends AppCompatActivity{
String pdfname;
Bitmap signatureBitmap;
PDFView pdfView;
OnDrawListener drawListener;
Canvas gCanvas;
PagePart pagePart;
private long then;
private int longClickDuration = 2000;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_pdf_editor);
    pdfView = (PDFView) findViewById(R.id.pdfView);
    Intent intent = getIntent();
    pdfname = intent.getStringExtra("filename");
}
@Override
protected void onResume() {
    super.onResume();
    loadPdfFile(pdfname);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    super.onCreateOptionsMenu(menu);
    getMenuInflater().inflate(R.menu.pdf_editor_menu,menu);
    return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
    super.onOptionsItemSelected(item);
    if(item.getItemId()==R.id.menu_add_signature){
        drawSignature();
    }
    return true;
}
void loadPdfFile(String path){
    File file = new File(path);
    pdfView.fromFile(file)
            .defaultPage(0)
            .load();
}
void drawSignature(){
    final String signaturePath = Environment.getExternalStorageDirectory().toString() + "/saved_signature/mysignature.png";
    signatureBitmap = BitmapFactory.decodeFile(signaturePath);
}
}