CODEWITHSUNDEEP
androidmpandroidchart
Kanagalingam
Kanagalingam

Reputation: 2204

Scroll finish listener of Line chart in mpandroidchart

How to listen to the scroll finish event in mpandroidchart.

I overrided the OnChartGestureListener and OnChartValueSelectedListener but it does not seems to work. onChartTranslate() method gets callback even after the scroll gets end.

onChartGestureStart() gets called when the user touches the chart and onChartGestureEnd() gets called once the user stops touching the chart.

So, i need to catch the event which gets called when the scroll gets finished.

So, Can you give a headsup on how to listen to the scroll end of linechart in mpandroidchart.

Upvotes: 11

Views: 3144

Answers (4)

Deadvin
Deadvin

Reputation: 51

I struggled with the same problem a lot. After i could not find solution, what i did is to set

chart.setDragDecelerationEnabled(false);

Thus there is no continuation of scrolling after touch up and i could get the last X coordinates with

  chart.setOnChartGestureListener(new OnChartGestureListener() {

        @Override
        public void onChartGestureStart(MotionEvent me, ChartTouchListener.ChartGesture lastPerformedGesture) {
        }

        @Override
        public void onChartGestureEnd(MotionEvent me, ChartTouchListener.ChartGesture lastPerformedGesture) {

            float lastX = holder.chart.getLowestVisibleX();
            saved_x.set(position,  lowX);
        }

});

Upvotes: 1

Asad
Asad

Reputation: 1439

the more better way is to use library's own listener with this logic like: 

override fun onChartTranslate(me: MotionEvent?, dX: Float, dY: Float) {
                if(dX > 0){
                    //backward dragging
                }
                else if(mChart.highestVisibleX == mChart.xAxis.axisMaximum){
                    //forward dragging reached at max (can not be dragged more)
                }
            }

Upvotes: 1

Mahesh Chandra
Mahesh Chandra

Reputation: 31

this worked for me checked both the start and end of scroll in chart

chart.setOnTouchListener(new View.OnTouchListener() {
    @Override
    public boolean onTouch(View v, MotionEvent event) {
    if(!(chart.getLowestVisibleX() == chart.getXAxis().getAxisMinimum() || chart.getHighestVisibleX() == chart.getXAxis().getAxisMaximum())){
        // Do your work here
        Toast.makeText(getContext(),"Hello Scroll to end check working",Toast.LENGTH_LONG).show();
        return false;
    }
});

Upvotes: 2

Muhammad Saad Rafique
Muhammad Saad Rafique

Reputation: 3189

You need to do something as follows:

@Override
        public void onChartGestureEnd(MotionEvent me, ChartTouchListener.ChartGesture lastPerformedGesture)
        {
            if(data.getEntryCount() == (int) chart.getHighestVisibleX())
            {
                // Do your work here
                Toast.makeText(getContext(),"Hello Scroll to end check working",Toast.LENGTH_LONG).show();
            }
        }

This will check if your scroll has reached for last value on x-Axis. You may need little bit customization in that but this is the way to do so.

Upvotes: 1

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