progress bar for http request - Blackberry

Question

in my project i am using popupscreen with GaugeField for http request.Currently we are just incrementing the value of gaugefield with fixed rate and after http response we just remove the popupscreen. so some times http request is completed when gauge field is in 40% or 60%.

But i want to synchronize gaugefield value with http request/responses. it means that popupscreen will always remove at 100%.

Answer 1

I don't have the code in front of me, but I something similar in a project several years ago.

I wrote a subclass of InputStream that wrapped around the InputStream object I got back from openInputStream(), reimplementing all the read() methods so they would increment a counter with the number of bytes read. Whenever the counter reached a certain threshold, it would update a GaugeField object that was passed into the subclass's constructor.

So your subclass would look something like this:

public GaugedInputStream extends InputStream
{
    private InputStream _inputStream = null;
    private GaugeField _gaugeField = null;
    private int _counter = 0;
    private int _threshold = 0;

    public void GaugedInputStream(InputStream inputStream, GaugeField gaugeField)
    {
        _inputStream = inputStream;
        _gaugeField = gaugeField;

        ... other constructor stuff ...
    }

    public int read() 
    {
        int byte = _inputStream.read();
        increment(1);
        return byte;
    }

    public int read(byte[] b) 
    {
        int bytes = _inputStream.read(b);
        increment(bytes);
        return bytes;
    }

    public int read(byte[] b, int off, int len)  
    {
        int bytes = _inputStream.read(b, off, len);
        increment(bytes);
        return bytes;
    }

    ... override other InputStream methods here ...

    private void increment(int bytes)
    {
        _counter = _counter + bytes;
        _threshold = _threshold + bytes;
        updateGaugeIfNeeded();
    }

    private void updateGaugeIfNeeded()
    {
        if (_threshold > 100)
        {
            updateGauge();
            _threshold = 0;
        }
    }

    private void updateGauge()
    {
        ... code to update the gauge ...
    }
}

I'm leaving out a lot of the guts here, but I hope this sets you in the right direction.