update printQR method

src/hwapi.cpp

@@ -1920,8 +1920,39 @@ void hwapi::prn_printBarcode(uint8_t kindOf, uint8_t withText,  uint8_t offset,
 
 void hwapi::prn_sendQRdata(QByteArray *buf) const
 {
-    // maximal 150 alphanummeric bytes
+    // buf must be 256byte long
-    buf->clear();
+    // printer can use maximal 150 alphanummeric bytes
+    // but we send 256byte for reserve
+
+    //buf->clear();
+    QByteArray dataPart1, dataPart2, dataPart3, dataPart4;
+    int     bufLength=buf->length();
+    int     toFill=0;
+
+    // make sure that input buffer is long enough because program crashes when reading too much!
+    if (bufLength<256)
+    {
+        toFill=256-bufLength;
+        //toFill+=2; // just some byte more to be sure
+        buf->append(toFill, 0);
+    }
+    dataPart1.clear();
+    dataPart2.clear();
+    dataPart3.clear();
+    dataPart4.clear();
+    dataPart4=buf->right(64);
+    buf->chop(64);
+    dataPart3=buf->right(64);
+    buf->chop(64);
+    dataPart2=buf->right(64);
+    buf->chop(64);
+    dataPart1=buf->right(64);
+
+    longFDcmd_set(CMD2DC_STOR_QR_DATA, 0, 0, 64, &dataPart1);
+    longFDcmd_set(CMD2DC_STOR_QR_DATA, 0, 1, 64, &dataPart2);
+    longFDcmd_set(CMD2DC_STOR_QR_DATA, 0, 2, 64, &dataPart3);
+    longFDcmd_set(CMD2DC_STOR_QR_DATA, 0, 3, 64, &dataPart4);
+
 }
 
 void hwapi::prn_printQRcode(void) const