mpandroidchart - How can I avoid the repeated values in Y-Axis?

Question

I want to avoid the repeated values and the -0 values in Y-Axis, avoiding the image situation.

I have these ideas to solve this, but any solution:

Answer 1

tl;dr You can do this by changing the label count in onChartScale.

First, you want your listener set up:

chart.setOnChartGestureListener(this); // set a listener ;)

You try to get the top/bottom drawn values and check what gets drawn on the screen. Apply some basic calculations, and you're set.

The following code will draw 2 labels if the zoom level gets (too) high and up to 9 otherwise:

@Override
public void onChartScale(MotionEvent me, float scaleX, float scaleY) {
    final YAxis yAxis = mChart.getAxisLeft();
    final Transformer transformer = mChart.getTransformer(YAxis.AxisDependency.LEFT);

    // ...minor dirty hack
    final PointD top = transformer.getValuesByTouchPoint(0, 0);
    final PointD bottom = transformer.getValuesByTouchPoint(0, mChart.getHeight());
    final int diff = (int)(top.y - bottom.y);

    // draw 2-9 axis labels
    final int count = Math.min(9, Math.max(diff, 2));

    Log.d("scale", String.format("scale %f: diff %d and count %d", scaleY, diff, count));

    // "force" the count, for there are drawing issues where none get drawn on high zoom levels (just try it out)
    yAxis.setLabelCount(count, true);
}

// todo implement other interface methods

The value formatter and everything else stays the same.

And some ugly screenshot to show that it works :D