Workaround for Error in area charts w/stairs w/origin

[Miguel]

Hello

Some weeks ago I found a bug and reported to TeeCharts, they are working on it but I need a workaround, the problem is as follows: If you create an area chart with stairs and set the origin on the max value (to see it up side down) the chart doesn't shows fine.

What could be a workaround for this problem? I need an upside down stairs chart, or something like it

Thanks in advance

[Yeray]

Hi Miguel,

You could use a Bar3D serie sinstead of using an Area series with stairs:

Code: Select all

    private void initChart() {
        tChart1.getAspect().setView3D(false);

        com.steema.teechart.styles.Area area1 = new com.steema.teechart.styles.Area(tChart1.getChart());
        area1.fillSampleValues();

        area1.setUseOrigin(false);
        area1.setOrigin(area1.getMinYValue() + Math.round((area1.getMaxYValue() - area1.getMinYValue()) / 2));
        area1.setUseOrigin(true);
        area1.setStairs(true);

        com.steema.teechart.styles.Bar3D bar1 = new com.steema.teechart.styles.Bar3D(tChart1.getChart());
        bar1.setDataSource(area1);
        bar1.getMarks().setVisible(false);
        bar1.setBarWidthPercent(100);

        for (int i=0; i<bar1.getCount(); i++)
        {
            bar1.getOffsetValues().setValue(i, area1.getOrigin());
        }

        area1.setActive(false);
        tChart1.getAxes().getLeft().setMinMax(bar1.getYValues().getMinimum() - tChart1.getAxes().getLeft().getMinimumOffset(), bar1.getYValues().getMaximum() + tChart1.getAxes().getLeft().getMaximumOffset());
    }

[Miguel]

Hi Yeray, I have a problem with this solution, when I zoom horizontally the first (most left) Bar doesn't show up, do you know how to fix that?

Thanks for the workaround though

[Yeray]

Hi Miguel,

I've seen that, if you scroll a chart with a Bar series, each bar disappears when half bar is out of the bar (only in the left side of the chart). I've added it to the wish list to be enhanced in future releases (TJ71015425).
To reproduce it you only need a Bar series and scroll a little bit:

Code: Select all

        tChart1.getAspect().setView3D(false);

        com.steema.teechart.styles.Bar bar1 = new com.steema.teechart.styles.Bar(tChart1.getChart());
        bar1.fillSampleValues(6);

TeeChart1.png (15.9 KiB) Viewed 26879 times

TeeChart2.png (15.74 KiB) Viewed 26874 times

could you please confirm if this is what you are experiencing?

[Miguel]

Hello Yeray

Yes, that's what I'm experiencing

My problem is that I can't wait for a future release Is there another way to get an up side down stairs area chart? or to add the feature myself by editing the source code? maybe regarding the bug TJ71015368 (the source of all of the conversation

Thanks again!

[Yeray]

Hi Miguel,

In the meanwhile, a workaround could be to draw manually the hidden portion of the bar:

Code: Select all

        tChart1.addChartPaintListener(new ChartPaintListener() {

            @Override
            public void axesPainting(ChartDrawEvent e) {
            }

            @Override
            public void chartPainted(ChartDrawEvent e) {
                for(int i=0;i<bar1.getCount()-1;i++)
                {
                    int right = bar1.calcXPos(i+1);

                    if (tChart1.getAxes().getBottom().getMinimum()>bar1.getXValues().getValue(i) && (right > tChart1.getChart().getChartRect().getLeft()))
                    {
                        tChart1.getGraphics3D().getBrush().setColor(bar1.getColor());
                        tChart1.getGraphics3D().getPen().setColor(bar1.getPen().getColor());
                        
                        int left = tChart1.getChart().getChartRect().getLeft();
                        int top = Math.max(bar1.calcYPos(i), tChart1.getChart().getChartRect().getTop());
                        int bottom = tChart1.getAxes().getLeft().calcPosValue(bar1.getOffsetValues().getValue(0));
                        
                        tChart1.getGraphics3D().rectangle(left, top, right, bottom);
                        break;
                    }
                }
            }

            @Override
            public void chartPainting(ChartDrawEvent e) {
            }

            @Override
            public void seriesPainting(ChartDrawEvent e) {
            }

            @Override
            public void seriesPainted(ChartDrawEvent e) {
            }
        });

The code above works for a Bar Series with BarWidhPercent = 100.

[Miguel]

Hi Yeray, the last code doesn't work for me (maybe because I'm using Bar3D)

Do you know where, on the source code, can I deactivate the default 'half out bar disappearance' ?

[Yeray]

Hi Miguel,

The workaround proposed works for me in the example I posted some posts above.
The complete example would be this:

Code: Select all

    com.steema.teechart.styles.Bar3D bar1;
    private void initChart() {
        tChart1.getAspect().setView3D(false);

        com.steema.teechart.styles.Area area1 = new com.steema.teechart.styles.Area(tChart1.getChart());
        area1.fillSampleValues();

        area1.setUseOrigin(false);
        area1.setOrigin(area1.getMinYValue() + Math.round((area1.getMaxYValue() - area1.getMinYValue()) / 2));
        area1.setUseOrigin(true);
        area1.setStairs(true);

        bar1 = new com.steema.teechart.styles.Bar3D(tChart1.getChart());
        bar1.setDataSource(area1);
        bar1.getMarks().setVisible(false);
        bar1.setBarWidthPercent(100);

        for (int i=0; i<bar1.getCount(); i++)
        {
            bar1.getOffsetValues().setValue(i, area1.getOrigin());
        }

        area1.setActive(false);
        tChart1.getAxes().getLeft().setMinMax(bar1.getYValues().getMinimum() - tChart1.getAxes().getLeft().getMinimumOffset(), bar1.getYValues().getMaximum() + tChart1.getAxes().getLeft().getMaximumOffset());

        tChart1.addChartPaintListener(new ChartPaintListener() {

            @Override
            public void axesPainting(ChartDrawEvent e) {
            }

            @Override
            public void chartPainted(ChartDrawEvent e) {
                for(int i=0;i<bar1.getCount()-1;i++)
                {
                    int right = bar1.calcXPos(i+1);

                    if (tChart1.getAxes().getBottom().getMinimum()>bar1.getXValues().getValue(i) && (right > tChart1.getChart().getChartRect().getLeft()))
                    {
                        tChart1.getGraphics3D().getBrush().setColor(bar1.getColor());
                        tChart1.getGraphics3D().getPen().setColor(bar1.getPen().getColor());

                        int left = tChart1.getChart().getChartRect().getLeft();
                        int top = Math.max(bar1.calcYPos(i), tChart1.getChart().getChartRect().getTop());
                        int bottom = tChart1.getAxes().getLeft().calcPosValue(bar1.getOffsetValues().getValue(0));

                        tChart1.getGraphics3D().rectangle(left, top, right, bottom);
                        break;
                    }
                }
            }

            @Override
            public void chartPainting(ChartDrawEvent e) {
            }

            @Override
            public void seriesPainting(ChartDrawEvent e) {
            }

            @Override
            public void seriesPainted(ChartDrawEvent e) {
            }
        });
    }

If you still have problems with it don't hesitate to let us know.

[Miguel]

Hi Yeray, I implemented the code with another series plotted (as I have several on my project) and the result is the attachment, it doesn't work for me the fisrt left bar doesn't show up

[Miguel]

Yeray, the rectangle shows up when I keep the mouse pressed down on the plot :s that's weird

[Miguel]

Any ideas for get this to work?

[Yeray]

Hi Miguel,

I've only set the Brush and the Pen color to draw the bar portions manually. Assigning the whole bar brush could fix the problem.
Change the following in the example above:

Code: Select all

                        tChart1.getGraphics3D().setBrush(bar1.getBrush());
                        //tChart1.getGraphics3D().getBrush().setColor(bar1.getColor());
                        //tChart1.getGraphics3D().getPen().setColor(bar1.getPen().getColor());

[Marc]

Hello,

This issue, id TJ71015368, is resolved for inclusion in the next maintenance release.

The problem does not occur in SWT but does occur in Swing although the same underlying graphics calls/libraries are used.

If you wish to apply the fix pending receipt of the maintenance release this is the required modification:

In TeeChart's Graphics3DAWT.java unit, replace the following line:

Code: Select all

  /**
   * Draws a Rectangle (Rectangle r).
   *
   * @param r Rectangle
   */
  public void rectangle(Rectangle r) {

with

Code: Select all

  private Rectangle invertNegativeRect(Rectangle r)
  {
      if (r.width < 0)
      {
          int tmpL=r.getLeft();
          r.setLeft(r.getRight());
          r.setRight(tmpL);
      }
      if (r.height < 0)
      {
          int tmpT=r.getTop();
          r.setTop(r.getBottom());
          r.setBottom(tmpT);
      }
      return r;
  }

  /**
   * Draws a Rectangle (Rectangle r).
   *
   * @param r Rectangle
   */
  public void rectangle(Rectangle r) {
    r=invertNegativeRect(r);  //TJ71015368

Regards,
Marc Meumann