MPAndroidChart:让一个图形反映姐妹图上的缩放/滑动

我有两个线图,显示同一时间段内的补充数据.有没有办法将一张图表收到的任何触摸事件发送给另一张图表？我基本上想要它,以便图形始终显示相同的查看矩形(至少在水平方向上).因此,如果用户在顶部图表上向左滑动"n"个单位,则底部图表将自动向左滚动"n"个单位以匹配.

可以使用当前的MPAndroidChart版本完成缩放,滚动签出或等待我的扩展合并:https: //github.com/PhilJay/MPAndroidChart/pull/545

您需要在主图表上设置一个OnChartGestureListener,将转换矩阵值复制到从属图表:

public class CoupleChartGestureListener implements OnChartGestureListener {

    private Chart srcChart;
    private Chart[] dstCharts;

    public CoupleChartGestureListener(Chart srcChart, Chart[] dstCharts) {
        this.srcChart = srcChart;
        this.dstCharts = dstCharts;
    }

    [...other overrides...]

    @Override
    public void onChartScale(MotionEvent me, float scaleX, float scaleY) {
        //Log.d(TAG, "onChartScale " + scaleX + "/" + scaleY + " X=" + me.getX() + "Y=" + me.getY());
        syncCharts();
    }

    @Override
    public void onChartTranslate(MotionEvent me, float dX, float dY) {
        //Log.d(TAG, "onChartTranslate " + dX + "/" + dY + " X=" + me.getX() + "Y=" + me.getY());
        syncCharts();
    }

    public void syncCharts() {
        Matrix srcMatrix;
        float[] srcVals = new float[9];
        Matrix dstMatrix;
        float[] dstVals = new float[9];

        // get src chart translation matrix:
        srcMatrix = srcChart.getViewPortHandler().getMatrixTouch();
        srcMatrix.getValues(srcVals);

        // apply X axis scaling and position to dst charts:
        for (Chart dstChart : dstCharts) {
            if (dstChart.getVisibility() == View.VISIBLE) {
                dstMatrix = dstChart.getViewPortHandler().getMatrixTouch();
                dstMatrix.getValues(dstVals);
                dstVals[Matrix.MSCALE_X] = srcVals[Matrix.MSCALE_X];
                dstVals[Matrix.MTRANS_X] = srcVals[Matrix.MTRANS_X];
                dstMatrix.setValues(dstVals);
                dstChart.getViewPortHandler().refresh(dstMatrix, dstChart, true);
            }
        }
    }

}

然后设置主/从连接,例如:

//
// Couple chart viewports:
//

tripChart.setOnChartGestureListener(new CoupleChartGestureListener(
        tripChart, new Chart[] { powerChart, energyChart }));
powerChart.setOnChartGestureListener(new CoupleChartGestureListener(
        powerChart, new Chart[] { tripChart, energyChart }));
energyChart.setOnChartGestureListener(new CoupleChartGestureListener(
        energyChart, new Chart[] { tripChart, powerChart }));