Xaxis.java :  » Image » bungee-view » log » Java Open Source

package log;

import java.awt.Color;
import java.text.DateFormat;
import java.util.Date;

import edu.cmu.cs.bungee.piccoloUtils.gui.APText;
import edu.cmu.cs.bungee.piccoloUtils.gui.LazyPNode;
import edu.cmu.cs.bungee.piccoloUtils.gui.MyInputEventHandler;
import edu.cmu.cs.bungee.javaExtensions.Util;
import edu.umd.cs.piccolo.PNode;
import edu.umd.cs.piccolo.event.PInputEvent;
import edu.umd.cs.piccolo.util.PDimension;

class Xaxis extends LazyPNode {

  Date min;
  Date max;
  long zoomMin;
  long zoomMax;
  int nTicks = 5;
  double tickLength = 6;

  Xaxis(Date _min, Date _max) {
    min = _min;
    max = _max;
    zoomMin = min.getTime();
    zoomMax = max.getTime();
    addInputEventListener(new AxisEventHandler());
  }

  void draw(double length) {
    removeAllChildren();
    setBounds(0, 0, length, 100);
    for (int i = 0; i < nTicks; i++) {
      LazyPNode tick = new LazyPNode();
      double x = i * length / (nTicks - 1);
      tick.setBounds(x, 0, 1, tickLength);
      tick.setPaint(Color.black);
      addChild(tick);

      long mid = zoomMin + ((zoomMax - zoomMin) * i) / (nTicks - 1);
      APText label = new APText();
      label.setText(DateFormat.getDateInstance().format(new Date(mid)));
      label.setOffset(Math.round(x - label.getWidth() / 2), tickLength);
      addChild(label);
    }
  }

  double encode(Date value) {
    double percent = (value.getTime() - zoomMin)
        / (double) (zoomMax - zoomMin);
    // Util.print("x encode " + percent + " " + value.getTime());
    return Math.round(getWidth() * percent);
  }

  private class AxisEventHandler extends MyInputEventHandler {

    private double dragStartOffset;

    AxisEventHandler() {
      super(Xaxis.class);
    }

    @Override
    protected boolean press(PNode node, PInputEvent e) {
      assert node == Xaxis.this;
      dragStartOffset = e.getPositionRelativeTo(node).getX();
      return true;
    }

    @Override
    protected boolean drag(PNode node, PInputEvent e) {
      assert Util.ignore(node);
      PDimension delta = e.getDelta();
      double vertical = delta.getHeight();
      double horizontal = delta.getWidth();
      // If you want to just pan, zooming screws you up, and vice-versa,
      // so
      // choose one or the other.
      if (Math.abs(vertical) > Math.abs(horizontal))
        horizontal = 0;
      else
        vertical = 0;
      double deltaZoom = Math.pow(2, -vertical / 20.0);
      long minTime = min.getTime();
      long maxTime = max.getTime();
      long range = maxTime - minTime;
      long zoomRange = zoomMax - zoomMin;
      double logicalWidth = getWidth() * range / zoomRange;
      double leftEdge = getWidth() * (zoomMin - minTime) / zoomRange;
      double newLogicalWidth = logicalWidth * deltaZoom;
      double newLeftEdge = 0;
      if (newLogicalWidth < getWidth()) {
        zoomMin = minTime;
        zoomMax = maxTime;
      } else {
        // recalculate zoom after rounding newLogicalWidth
        deltaZoom = newLogicalWidth / logicalWidth;
        double pan = -horizontal;
        newLeftEdge = Util.constrain(leftEdge + pan
            + (leftEdge + dragStartOffset) * (deltaZoom - 1), 0,
            newLogicalWidth - getWidth());
        zoomMin = minTime + (long) (newLeftEdge * range / newLogicalWidth);
        zoomMax = minTime
            + (long) ((newLeftEdge + getWidth()) * range / newLogicalWidth);
      }
      ((Chart) getParent()).redraw();
      return true;
    }
  }
}