3 files changed, 26 insertions, 1 deletions
diff --git a/platform/android/jni/mupdf.c b/platform/android/jni/mupdf.c
index 927fef3c..04f1ceff 100644
--- a/platform/android/jni/mupdf.c
+++ b/platform/android/jni/mupdf.c
@@ -514,6 +514,22 @@ JNI_FN(MuPDFCore_fileFormatInternal)(JNIEnv * env, jobject thiz)
 	return (*env)->NewStringUTF(env, info);
 }
 
+JNIEXPORT jboolean JNICALL
+JNI_FN(MuPDFCore_isUnencryptedPDFInternal)(JNIEnv * env, jobject thiz)
+{
+	globals *glo = get_globals_any_thread(env, thiz);
+	if (glo == NULL)
+		return JNI_FALSE;
+
+	pdf_document *idoc = pdf_specifics(glo->doc);
+	if (idoc == NULL)
+		return JNI_FALSE; // Not a PDF
+
+	int cryptVer = pdf_crypt_version(idoc);
+	return (cryptVer == 0) ? JNI_TRUE : JNI_FALSE;
+}
+
+
 JNIEXPORT void JNICALL
 JNI_FN(MuPDFCore_gotoPageInternal)(JNIEnv *env, jobject thiz, int page)
 {
diff --git a/platform/android/src/com/artifex/mupdfdemo/MuPDFActivity.java b/platform/android/src/com/artifex/mupdfdemo/MuPDFActivity.java
index 066b6d5f..6bb45a93 100644
--- a/platform/android/src/com/artifex/mupdfdemo/MuPDFActivity.java
+++ b/platform/android/src/com/artifex/mupdfdemo/MuPDFActivity.java
@@ -483,7 +483,7 @@ public class MuPDFActivity extends Activity implements FilePicker.FilePickerSupp
 			}
 		});
 
-		if (core.fileFormat().startsWith("PDF"))
+		if (core.fileFormat().startsWith("PDF") && core.isUnencryptedPDF())
 		{
 			mAnnotButton.setOnClickListener(new View.OnClickListener() {
 				public void onClick(View v) {
diff --git a/platform/android/src/com/artifex/mupdfdemo/MuPDFCore.java b/platform/android/src/com/artifex/mupdfdemo/MuPDFCore.java
index ec35ef7c..68aed29e 100644
--- a/platform/android/src/com/artifex/mupdfdemo/MuPDFCore.java
+++ b/platform/android/src/com/artifex/mupdfdemo/MuPDFCore.java
@@ -21,11 +21,13 @@ public class MuPDFCore
 	private long globals;
 	private byte fileBuffer[];
 	private String file_format;
+	private boolean isUnencryptedPDF;
 
 	/* The native functions */
 	private native long openFile(String filename);
 	private native long openBuffer();
 	private native String fileFormatInternal();
+	private native boolean isUnencryptedPDFInternal();
 	private native int countPagesInternal();
 	private native void gotoPageInternal(int localActionPageNum);
 	private native float getPageWidth();
@@ -109,6 +111,7 @@ public class MuPDFCore
 			throw new Exception(String.format(context.getString(R.string.cannot_open_file_Path), filename));
 		}
 		file_format = fileFormatInternal();
+		isUnencryptedPDF = isUnencryptedPDFInternal();
 	}
 
 	public MuPDFCore(Context context, byte buffer[]) throws Exception
@@ -120,6 +123,7 @@ public class MuPDFCore
 			throw new Exception(context.getString(R.string.cannot_open_buffer));
 		}
 		file_format = fileFormatInternal();
+		isUnencryptedPDF = isUnencryptedPDFInternal();
 	}
 
 	public  int countPages()
@@ -135,6 +139,11 @@ public class MuPDFCore
 		return file_format;
 	}
 
+	public boolean isUnencryptedPDF()
+	{
+		return isUnencryptedPDF;
+	}
+
 	private synchronized int countPagesSynchronized() {
 		return countPagesInternal();
 	}