Question

i m new to android. I m using Achartengine to plot a dynamic graph reading values from a binary file. Given below is my code.I want to have a dynamic running graph, in which values are being updated regularly. For this i tries to do it with and without a timer. But every time i am getting the graph with the final values when the last values have been updated. I mean i m getting a static graph after all the updates have been done. I can’t figure out how to correct this. I am using the emulator to test the code. Could there be some problem with the emulator or something wrong with my code ? Thanks in advance

code without timer :

public class RandomActivity extends Activity {
private XYMultipleSeriesDataset eeg1 = new XYMultipleSeriesDataset();
private XYMultipleSeriesRenderer renderer_eeg1 = new XYMultipleSeriesRenderer();
private XYSeries series1;
private GraphicalView view_eeg1;


public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

renderer_eeg1.setAxisTitleTextSize(16);
renderer_eeg1.setChartTitleTextSize(20);
renderer_eeg1.setLabelsTextSize(15);
renderer_eeg1.setLegendTextSize(15);
renderer_eeg1.setMargins(new int[] {20, 30, 15, 0});
renderer_eeg1.setAxesColor(Color.BLUE);
renderer_eeg1.setXTitle("Time");
renderer_eeg1.setChartTitle("eeg1");
XYSeriesRenderer seriesrenderer1 = new XYSeriesRenderer();
seriesrenderer1.setColor(Color.YELLOW);
renderer_eeg1.addSeriesRenderer(seriesrenderer1); 
series1= new XYSeries("eeg1");
eeg1.addSeries(series1);
int a;
int b;
add();

for(int r=0;r<=600;r++){

   if(r%2==0){
      a=1;
      b=-1;
   }
   else{
      a=-1;
      b=1;
   }

   series1.add(r, a);
       if(r<=50){
      renderer_eeg1.setXAxisMax(50);
       }
       else if(r>50){
          double maxX = series1.getMaxX();
      double minX = maxX - 50;
          renderer_eeg1.setXAxisMin(minX);
       }
       view_eeg1.repaint();
}
}


protected void onResume() {
super.onResume();  
if (view_eeg1== null) {
LinearLayout layout_eeg1 = (LinearLayout) findViewById(R.id.chart1);
view_eeg1= ChartFactory.getLineChartView(this, eeg1, renderer_eeg1);
layout_eeg1.addView(view_eeg1,new LayoutParams(LayoutParams.FILL_PARENT,  LayoutParams.FILL_PARENT));
} else {
 view_eeg1.repaint();}
}

}

code with timer :

public class RandomActivity extends Activity {
private XYMultipleSeriesDataset eeg1 = new XYMultipleSeriesDataset();
private XYMultipleSeriesRenderer renderer_eeg1 = new XYMultipleSeriesRenderer();
private XYSeries series1;
private GraphicalView view_eeg1;


public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

renderer_eeg1.setAxisTitleTextSize(16);
renderer_eeg1.setChartTitleTextSize(20);
renderer_eeg1.setLabelsTextSize(15);
renderer_eeg1.setLegendTextSize(15);
renderer_eeg1.setMargins(new int[] {20, 30, 15, 0});
renderer_eeg1.setAxesColor(Color.BLUE);
renderer_eeg1.setXTitle("Time");
renderer_eeg1.setChartTitle("eeg1");
XYSeriesRenderer seriesrenderer1 = new XYSeriesRenderer();
seriesrenderer1.setColor(Color.YELLOW);
renderer_eeg1.addSeriesRenderer(seriesrenderer1); 
series1= new XYSeries("eeg1");
eeg1.addSeries(series1);
int a;
int b;
add();

for(int r=0;r<=600;r++){

      Thread timer = new Thread(){
            public void run(){
                try{
                    sleep(500);
                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } 
            }
        };


   if(r%2==0){
      a=1;
      b=-1;
   }
   else{
      a=-1;
      b=1;
   }

   series1.add(r, a);
       if(r<=50){
      renderer_eeg1.setXAxisMax(50);
       }
       else if(r>50){
          double maxX = series1.getMaxX();
      double minX = maxX - 50;
          renderer_eeg1.setXAxisMin(minX);
       }
       view_eeg1.repaint();
}
}


protected void onResume() {
super.onResume();  
if (view_eeg1== null) {
LinearLayout layout_eeg1 = (LinearLayout) findViewById(R.id.chart1);
view_eeg1= ChartFactory.getLineChartView(this, eeg1, renderer_eeg1);
layout_eeg1.addView(view_eeg1,new LayoutParams(LayoutParams.FILL_PARENT,  LayoutParams.FILL_PARENT));
} else {
 view_eeg1.repaint();}
}

}

Answer 1

1. You repaint before your chart is actually added to the view so it doesn’t get painted.
2. Your code is not inside the threads you are creating.
3. You are creating 600 threads but you run none of them.
4. Your onResume code looks like you think onResume is called many times which is usually false.
5. Activity does not have any Add() function, do you have one what is that supposed to do?

I think this will work better:

public class RandomActivity extends Activity {
private XYMultipleSeriesDataset eeg1 = new XYMultipleSeriesDataset();
private XYMultipleSeriesRenderer renderer_eeg1 = new XYMultipleSeriesRenderer();
private XYSeries series1;
private GraphicalView view_eeg1;

public void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    renderer_eeg1.setAxisTitleTextSize(16);
    renderer_eeg1.setChartTitleTextSize(20);
    renderer_eeg1.setLabelsTextSize(15);
    renderer_eeg1.setLegendTextSize(15);
    renderer_eeg1.setMargins(new int[] {20, 30, 15, 0});
    renderer_eeg1.setAxesColor(Color.BLUE);
    renderer_eeg1.setXTitle("Time");
    renderer_eeg1.setChartTitle("eeg1");
    XYSeriesRenderer seriesrenderer1 = new XYSeriesRenderer();
    seriesrenderer1.setColor(Color.YELLOW);
    renderer_eeg1.addSeriesRenderer(seriesrenderer1); 
    series1= new XYSeries("eeg1");
    eeg1.addSeries(series1);
    int a;
    Thread timer = new Thread(){
        public void run(){
            try{
                for(int r=0;r<=600;r++){
                    sleep(500);
                    if(r%2==0){
                        a=1;
                    }
                    else{
                        a=-1;
                    }
                    series1.add(r, a);
                    if(r<=50){
                        renderer_eeg1.setXAxisMax(50);
                    }
                    else if(r>50){
                        double maxX = series1.getMaxX();
                        double minX = maxX - 50;
                        renderer_eeg1.setXAxisMin(minX);
                    }
                    view_eeg1.repaint();

                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } 
            }
        };
    timer.start()
    }

    protected void onResume() {
        super.onResume();  
            if (view_eeg1== null) {
                LinearLayout layout_eeg1 = (LinearLayout) findViewById(R.id.chart1);
                view_eeg1= ChartFactory.getLineChartView(this, eeg1, renderer_eeg1);
                layout_eeg1.addView(view_eeg1,new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));
                } else {
                view_eeg1.repaint();}
            }
        }
    }
}