Android™ Requires Chilkat v11.7.0+

Remove PDF Objects Nothing Refers To

See more PDF Optimization Examples

Demonstrates removeUnreferenced. When a page, an image or a whole section is replaced in an editor, the objects it used often stay in the file with nothing pointing at them any more. They are not old revisions -- they are in the current revision, simply unreachable -- so only a reachability walk from the document catalog finds them. In a publication assembled over several editing passes this is frequently the largest single saving. Android™

// Important: Don't forget to include the call to System.loadLibrary
// as shown at the bottom of this code sample.
package com.test;

import android.app.Activity;
import com.chilkatsoft.*;

import android.widget.TextView;
import android.os.Bundle;

public class SimpleActivity extends Activity {

  private static final String TAG = "Chilkat";

  // Called when the activity is first created.
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    boolean success = false;

    //  This example requires the Chilkat API to have been previously unlocked.
    //  See Global Unlock Sample for sample code.

    //  The PDF used in this example is available at watersense_accomplishments.pdf

    CkPdf pdf = new CkPdf();
    success = pdf.LoadFile("qa_data/pdf/watersense_accomplishments.pdf");
    if (success == false) {
        Log.i(TAG, pdf.lastErrorText());
        return;
        }

    CkJsonObject json = new CkJsonObject();
    CkJsonObject jsonOut = new CkJsonObject();
    success = pdf.Optimize("audit",json,jsonOut);
    if (success == false) {
        Log.i(TAG, pdf.lastErrorText());
        return;
        }

    Log.i(TAG, "fileSize: " + String.valueOf(jsonOut.IntOf("fileSize")));
    Log.i(TAG, "removeUnreferenced would save: " + String.valueOf(jsonOut.IntOf("estimatedSavings.removeUnreferenced")));

    //  Optimize with the defaults and see how many objects were actually dropped.
    success = pdf.Optimize("optimize",json,jsonOut);
    if (success == false) {
        Log.i(TAG, pdf.lastErrorText());
        return;
        }

    success = pdf.WriteFile("qa_output/watersense_optimized.pdf");
    if (success == false) {
        Log.i(TAG, pdf.lastErrorText());
        return;
        }

    Log.i(TAG, "objects removed: " + String.valueOf(jsonOut.IntOf("actions.removeUnreferenced.count")));
    Log.i(TAG, "bytes saved:     " + String.valueOf(jsonOut.IntOf("actions.removeUnreferenced.bytesSaved")));

    //  Nothing a page needs is ever removed: the walk starts at the document catalog and follows every
    //  reference, including the ones in annotations, the structure tree, named destinations and the
    //  optional-content configuration.
    Log.i(TAG, "pages after: " + String.valueOf(pdf.get_NumPages()));

  }

  static {
      System.loadLibrary("chilkat");

      // Note: If the incorrect library name is passed to System.loadLibrary,
      // then you will see the following error message at application startup:
      //"The application <your-application-name> has stopped unexpectedly. Please try again."
  }
}