android - MPAndroidChart：让一个图形镜像姐妹图形上的缩放/滑动

Question

我有两个折线图，它们显示了同一时间段内的互补数据。有没有办法将一个图形接收到的任何触摸事件发送到另一个图形？我本质上想要它，以便图表始终显示相同的查看矩形（至少在水平方向上）。因此，如果用户在顶部图形上向左滑动“n”个单位，底部图形将自动向左滚动“n”个单位以匹配。

Answer 1

可以使用当前的 MPAndroidChart 版本进行缩放，以滚动签出或等待我的扩展被合并： 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);
            }
        }
    }

}

然后设置您的主/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 }));

Answer 2

您需要将此添加到 CoupleChartGestureListener

    @Override
public void onChartGestureStart(MotionEvent me, ChartTouchListener.ChartGesture lastPerformedGesture) {
    ((BarLineChartTouchListener) srcChart.getOnTouchListener()).stopDeceleration();
    for (Chart dstChart : dstCharts) {
        if (dstChart.getVisibility() == View.VISIBLE) {
            ((BarLineChartTouchListener) dstChart.getOnTouchListener()).stopDeceleration();
        }
    }
}