How to insert a newline into an ASCII stream for Android

Question

Application is using an Android tablet as a hand-held terminal communicating via USB with a PIC device. The device is returning an ASCII stream which I am displaying in a textView.

The text stream into Android is terminated with ASCII 0x0A (LF). There is no problem with this and it generates a new line for each string as required. However, I also want to be able to break an incoming stream into lines for formatting/display purposes. I am injecting a CR (0x0D) into the ASCII stream for this.

I have tried a number of ways to get the textView to display the stream correctly - replacing the 0x0D with '\n', "\n\r", and nl = System.getProperty("line.separator"). However, in every case the insertion does nothing. I have used CatLog to check what is happening to the string and it appears to be OK - what am I missing?

The code is:

public void onAnimationUpdate(ValueAnimator timeAnim)
        {
            if ((mConnection != null) && mConnection.claimInterface(mInterface, true))
            {
             // Check serial port for incoming FORTH response on ep1i
                inForthReq = new UsbRequest();
                inForthReq.initialize(mConnection, ep1i);
                inForthReq.queue(InBuffer, 8);
                mConnection.requestWait();
                InBytes = InBuffer.array();
             // No data is indicated by a NAK - ASCII 0x15 = dec 21
                if (InBytes[0] != 21)
                {
                    lastChar = false;
                    int length = 8;
                    for (int i = 0; i < 8; i++)
                    {
                        Log.d(TAG, "FORTH response byte " + i + " = " + InBytes[i]);
                     // Check for end of string - LF = ASCII 0x0A = dec 10
                        if (InBytes[i] == 10)
                        {
                            lastChar = true;
                            length = i;
                            Log.d(TAG, "FORTH string terminated - length " + i);
                        }
                      // Check for CR in mid-stream  
                        if (InBytes[i] == 13)
                        {
                            InBytes[i] = 10;
                            Log.d(TAG,"CR replaced with " + InBytes[i]);
                        }
                    }
                    rxString = new String(InBytes, 0, length);
                    INString = INString.concat(rxString);
                    Log.d(TAG, "+++ Returned FORTH string = -" + INString + "- +++");
                    if (lastChar)
                    {
                        replyString = INString;
                        ForthPanelFragment.traffic = ForthPanelFragment.traffic.append(Html.fromHtml("<font color=\"blue\">"
                                + replyString + "</font>"));
                        ForthPanelFragment.traffic = ForthPanelFragment.traffic.append('\n');

                        if (ForthPanelFragment.traffic_panel != null)
                            ((TextView) ForthPanelFragment.traffic_panel).setText(ForthPanelFragment.traffic);
                        INString = emptyString;
                    }
                }

To explain what I am doing - the USB call returns an 8-byte array. This is scanned for special cases (as indicated by the comments) before being converted to an 8-character string. Successive strings are concatenated until the LF is detected, when the result is added to the view pane in a fragment.

As an example of the traffic -

12-19 09:30:46.250 D/HMI/4th terminal(6164): Starting animator

12-19 09:31:11.610 D/HMI/4th terminal(6164): Received A 1 .LINE

12-19 09:31:11.610 D/HMI/4th terminal(6164): from PanelFragment.

12-19 09:31:11.610 D/HMI/4th terminal(6164): Length = 10 1 2-19 09:31:11.610 D/HMI/4th terminal(6164): Last Packet = 2

12-19 09:31:11.610 D/HMI/4th terminal(6164): No of Packets = 2

12-19 09:31:11.660 D/HMI/4th terminal(6164): Sending FORTH command string A 1 .LIN

12-19 09:31:11.660 D/HMI/4th terminal(6164): Length = 8: last char = 78

12-19 09:31:11.660 D/HMI/4th terminal(6164): FORTH command string OK

12-19 09:31:11.730 D/HMI/4th terminal(6164): Sending FORTH command string E

12-19 09:31:11.730 D/HMI/4th terminal(6164): Length = 2: last char = 10

12-19 09:31:11.760 D/HMI/4th terminal(6164): FORTH command string OK

12-19 09:31:11.820 D/HMI/4th terminal(6164): FORTH response byte 0 = 73

12-19 09:31:11.820 D/HMI/4th terminal(6164): FORTH response byte 1 = 110

12-19 09:31:11.820 D/HMI/4th terminal(6164): FORTH response byte 2 = 32

12-19 09:31:11.820 D/HMI/4th terminal(6164): FORTH response byte 3 = 112

12-19 09:31:11.820 D/HMI/4th terminal(6164): FORTH response byte 4 = 114

12-19 09:31:11.820 D/HMI/4th terminal(6164): FORTH response byte 5 = 111

12-19 09:31:11.820 D/HMI/4th terminal(6164): FORTH response byte 6 = 116

12-19 09:31:11.820 D/HMI/4th terminal(6164): FORTH response byte 7 = 101

12-19 09:31:11.820 D/HMI/4th terminal(6164): +++ Returned FORTH string = -In prote- +++

12-19 09:31:11.920 D/HMI/4th terminal(6164): FORTH response byte 0 = 99

12-19 09:31:11.920 D/HMI/4th terminal(6164): FORTH response byte 1 = 116

12-19 09:31:11.920 D/HMI/4th terminal(6164): FORTH response byte 2 = 101

12-19 09:31:11.920 D/HMI/4th terminal(6164): FORTH response byte 3 = 100

12-19 09:31:11.920 D/HMI/4th terminal(6164): FORTH response byte 4 = 32

12-19 09:31:11.920 D/HMI/4th terminal(6164): FORTH response byte 5 = 100 12-19 09:31:11.920 D/HMI/4th terminal(6164): FORTH response byte 6 = 105

12-19 09:31:11.920 D/HMI/4th terminal(6164): FORTH response byte 7 = 99

12-19 09:31:11.920 D/HMI/4th terminal(6164): +++ Returned FORTH string = -In protected dic- +++

12-19 09:31:11.980 D/HMI/4th terminal(6164): FORTH response byte 0 = 116

12-19 09:31:11.980 D/HMI/4th terminal(6164): FORTH response byte 1 = 105

12-19 09:31:11.980 D/HMI/4th terminal(6164): FORTH response byte 2 = 111

12-19 09:31:11.980 D/HMI/4th terminal(6164): FORTH response byte 3 = 110

12-19 09:31:11.980 D/HMI/4th terminal(6164): FORTH response byte 4 = 97

12-19 09:31:11.980 D/HMI/4th terminal(6164): FORTH response byte 5 = 114

12-19 09:31:11.980 D/HMI/4th terminal(6164): FORTH response byte 6 = 121

12-19 09:31:11.980 D/HMI/4th terminal(6164): FORTH response byte 7 = 33

12-19 09:31:11.980 D/HMI/4th terminal(6164): +++ Returned FORTH string = -In protected dictionary!- +++

12-19 09:31:12.050 D/HMI/4th terminal(6164): FORTH response byte 0 = 13

12-19 09:31:12.050 D/HMI/4th terminal(6164): LF replaced with 10

12-19 09:31:12.050 D/HMI/4th terminal(6164): FORTH response byte 1 = 32

12-19 09:31:12.050 D/HMI/4th terminal(6164): FORTH response byte 2 = 111

12-19 09:31:12.050 D/HMI/4th terminal(6164): FORTH response byte 3 = 107

12-19 09:31:12.050 D/HMI/4th terminal(6164): FORTH response byte 4 = 33

12-19 09:31:12.050 D/HMI/4th terminal(6164): FORTH response byte 5 = 32

12-19 09:31:12.050 D/HMI/4th terminal(6164): FORTH response byte 6 = 10

12-19 09:31:12.050 D/HMI/4th terminal(6164): FORTH string terminated - length 6

12-19 09:31:12.050 D/HMI/4th terminal(6164): FORTH response byte 7 = 0

12-19 09:31:12.050 D/HMI/4th terminal(6164): +++ Returned FORTH string = -In protected dictionary!

12-19 09:31:12.050 D/HMI/4th terminal(6164): ok! - +++

12-19 09:31:18.390 D/HMI/4th terminal(6164): FORTH response byte 0 = 0

12-19 09:31:18.390 D/HMI/4th terminal(6164): FORTH response byte 1 = 0

12-19 09:31:18.390 D/HMI/4th terminal(6164): FORTH response byte 2 = 0

12-19 09:31:18.390 D/HMI/4th terminal(6164): FORTH response byte 3 = 0

12-19 09:31:18.390 D/HMI/4th terminal(6164): FORTH response byte 4 = 0

12-19 09:31:18.390 D/HMI/4th terminal(6164): FORTH response byte 5 = 0

12-19 09:31:18.390 D/HMI/4th terminal(6164): FORTH response byte 6 = 0

12-19 09:31:18.390 D/HMI/4th terminal(6164): FORTH response byte 7 = 0

12-19 09:31:18.390 D/HMI/4th terminal(6164): +++ Returned FORTH string = -��- +++

12-19 09:31:18.760 D/HMI/4th terminal(6164): In onStop(activity)

This displays on the screen as -

In protected dictionary! ok!

whereas what I want is -

In protected dictionary!

ok!

Interestingly, the CatLog listing does give a new line before the ok!.

I've had no problem inserting "\n" into a TextView, for example `someView.setText("line 1\nline2");` Please post a minimum example (**using a self contained source of fake data**) which does not work as expected. Perhaps there is something about the conversion of your source data to a CharSequence or the buffer type you are choosing which is filtering this out. — Chris Stratton, Dec 18 '13 at 20:15
@Chris Stratton - I have looked at the byte stream making up my replyString, and the bytes that are added to the editText, and can confirm that the 0x0A LF character is simply deleted from the string. — user1815293, Dec 18 '13 at 23:33
You are passing your String through an HTML formatting engine, and newlines are meaningless in HTML. Either encode a valid HTML line break, or add the line break after in some fort appropriate to the resulting Spanned. — Chris Stratton, Dec 18 '13 at 23:41
@Chris Stratton - that makes sense! I'm using the html filter to give different colours to distinguish between text from the keyboard and the reply from the device. — user1815293, Dec 19 '13 at 00:33
@Chris Stratton - I've changed the way I alter the colors so as not to use html - using ForegroundColorSpan - (http://stackoverflow.com/questions/8405661/is-it-possible-to-change-the-text-color-in-a-string-to-multiple-colors-in-java) and its now doing what I want - at least as far as the Android part is concerned. Thanks for your help. — user1815293, Dec 19 '13 at 01:50

How to insert a newline into an ASCII stream for Android

0 Answers0