如何在PieChart中设置字体大小？

Question

We have an activity page with a pie chart. Currently, the font size in each of the segments is abysmally small.

Our pie chart with its small font size

Here is our code:

package tech.pattullo.teamzero;

import android.graphics.Color;
import android.graphics.EmbossMaskFilter;
import android.graphics.PointF;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.widget.SeekBar;
import android.widget.TextView;

import com.androidplot.pie.PieChart;
import com.androidplot.pie.PieRenderer;
import com.androidplot.pie.Segment;
import com.androidplot.pie.SegmentFormatter;
import com.androidplot.util.PixelUtils;

import java.util.List;


public class Statistics extends AppCompatActivity {

    DatabaseHelper stats = new DatabaseHelper(this);

    public static final int SELECTED_SEGMENT_OFFSET = 50;

    private TextView donutSizeTextView;
    private SeekBar donutSizeSeekBar;

    public PieChart pie;

    private Segment s1;
    private Segment s2;
    private Segment s3;
    private Segment s4;

    public Statistics() {

    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_statistics);
        Log.i("STATISTICS", "Switched to statistics panel.");

        pie = (PieChart) findViewById(R.id.myPie);

        final float padding = PixelUtils.dpToPix(30);
        pie.getPie().setPadding(padding, padding, padding, padding);

        pie.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View view, MotionEvent motionEvent) {
                PointF click = new PointF(motionEvent.getX(), motionEvent.getY());
                if (pie.getPie().containsPoint(click)) {
                    Segment segment = pie.getRenderer(PieRenderer.class).getContainingSegment(click);
                    final boolean isSelected = getFormatter(segment).getOffset() != 0;
                    deselectAll();
                    setSelected(segment, !isSelected);
                    pie.redraw();
                }
                return false;
            }

            private SegmentFormatter getFormatter(Segment segment) {
                return pie.getFormatter(segment, PieRenderer.class);
            }

            private void deselectAll() {
                List<Segment> segments = pie.getSeriesRegistry().getSeriesList();
                for (Segment segment : segments) {
                    setSelected(segment, false);
                }
            }

            private void setSelected(Segment segment, boolean isSelected) {
                SegmentFormatter f = getFormatter(segment);
                if (isSelected) {
                    f.setOffset(SELECTED_SEGMENT_OFFSET);
                } else {
                    f.setOffset(0);
                }
            }
        });

        donutSizeSeekBar = (SeekBar) findViewById(R.id.donutSizeSeekBar);
        donutSizeSeekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
            @Override
            public void onProgressChanged(SeekBar seekBar, int i, boolean b) {
            }

            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {
            }

            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {
                pie.getRenderer(PieRenderer.class).setDonutSize(seekBar.getProgress() / 100f,
                        PieRenderer.DonutMode.PERCENT);
                pie.redraw();
                updateDonutText();
            }
        });
        donutSizeTextView = (TextView) findViewById(R.id.donutSizeTextView);
        updateDonutText();

        s1 = new Segment("s1", 3);
        s2 = new Segment("s2", 1);
        s3 = new Segment("s3", 7);
        s4 = new Segment("s4", 18);

        EmbossMaskFilter emf = new EmbossMaskFilter(
                new float[]{1, 1, 1}, 0.4f, 10, 8.2f);

        SegmentFormatter sf1 = new SegmentFormatter(this, R.xml.pie_segment_formatter1);
        sf1.getLabelPaint().setShadowLayer(3, 0, 0, Color.BLACK);
        sf1.getFillPaint().setMaskFilter(emf);

        SegmentFormatter sf2 = new SegmentFormatter(this, R.xml.pie_segment_formatter2);
        sf2.getLabelPaint().setShadowLayer(3, 0, 0, Color.BLACK);
        sf2.getFillPaint().setMaskFilter(emf);

        SegmentFormatter sf3 = new SegmentFormatter(this, R.xml.pie_segment_formatter3);
        sf3.getLabelPaint().setShadowLayer(3, 0, 0, Color.BLACK);
        sf3.getFillPaint().setMaskFilter(emf);

        SegmentFormatter sf4 = new SegmentFormatter(this, R.xml.pie_segment_formatter4);
        sf4.getLabelPaint().setShadowLayer(3, 0, 0, Color.BLACK);
        sf4.getFillPaint().setMaskFilter(emf);

        pie.addSegment(s1, sf1);
        pie.addSegment(s2, sf2);
        pie.addSegment(s3, sf3);
        pie.addSegment(s4, sf4);

        pie.getBorderPaint().setColor(Color.TRANSPARENT);
        pie.getBackgroundPaint().setColor(Color.TRANSPARENT);
    }

    protected void updateDonutText() {
        donutSizeTextView.setText(donutSizeSeekBar.getProgress() + "%");
    }

    private void getUserData() {

    }

    void displayStats() {

    }

    void analyzeData() {

    }

    String offerSuggestions() {
        int number = 6;
        String message;

        if (number > 5)
            message = "You should get out more!";
        else
            message = "Keep doing what you're doing!";

        return message;
    }
}

To add some detail, we are using the com.androidplot.pie library. I tried looking at the documentation, but there's nothing remotely close to setting a font size. Is there nothing I can do about this?

Answer 1

You should be able to set the font size in the xml of your segment formatter by setting the labelPaint.textSize

https://github.com/halfhp/androidplot/blob/36933d2639b5f9ff49f4b7aaca8a9a0d4f87fd40/demoapp/src/main/res/xml/pie_segment_formatter1.xml