Develop Reference

How to use AffineTransform with very little coordinates?

I have a set of two dimensions points. Their X and Y are greater than -2 and lesser than 2. Such point could be : (-0.00012 ; 1.2334 ).
I would want to display these points on a graph, using rectangles (a rectangle illustrates a point, and has its coordinates set to its point's ones - moreover, it has a size of 10*10).
Rectangles like (... ; Y) should be displayed above any rectangles like (... ; Y-1) (positive Y direction is up). Thus, I must set the graph's origin not at the top-left hand-corner, but somewhere else.
I'm trying to use Graphics2D's AffineTransform to do that.
I get the minimal value for all the X coordinates
I get the minimal value for all the Y coordinates
I get the maximal value for all the X coordinates
I get the maximal value for all the Y coordinates
I get the distance xmax-xmin and ymax-ymin
Then, I wrote the code I give you below.
Screenshots
Some days ago, using my own method to scale, I had this graph:
(so as I explained, Y are inverted and that's not a good thing)
For the moment, i.e., with the code I give you below, I have only one point that takes all the graph's place! Not good at all.
I would want to have:
(without lines, and without graph's axis. The important here is that points are correctly displayed, according to their coordinates).
Code
To get min and max coordinates value:
x_min = Double.parseDouble((String) list_all_points.get(0).get(0));
x_max = Double.parseDouble((String) list_all_points.get(0).get(0));
y_min = Double.parseDouble((String) list_all_points.get(0).get(1));
y_max = Double.parseDouble((String) list_all_points.get(0).get(1));
for(StorableData s : list_all_points) {
if(Double.parseDouble((String) s.get(0)) < x_min) {
x_min = Double.parseDouble((String) s.get(0));
}
if(Double.parseDouble((String) s.get(0)) > x_max) {
x_max = Double.parseDouble((String) s.get(0));
}
if(Double.parseDouble((String) s.get(1)) < y_min) {
y_min = Double.parseDouble((String) s.get(1));
}
if(Double.parseDouble((String) s.get(1)) > y_max) {
y_max = Double.parseDouble((String) s.get(1));
}
}
To draw a point:
int x, y;
private void drawPoint(Cupple storable_data) {
//x = (int) (storable_data.getNumber(0) * scaling_coef + move_x);
//y = (int) (storable_data.getNumber(1) * scaling_coef + move_y);
x = storable_data.getNumber(0).intValue();
y = storable_data.getNumber(1).intValue();
graphics.fillRect(x, y, 10, 10);
graphics.drawString(storable_data.toString(), x - 5, y - 5);
}
To paint the graph:
#Override
public void paint(Graphics graphics) {
this.graphics = graphics;
Graphics2D graphics_2d = ((Graphics2D) this.graphics);
AffineTransform affine_transform = graphics_2d.getTransform();
affine_transform.scale(getWidth()/(x_max - x_min), getHeight()/(y_max - y_min));
affine_transform.translate(x_min, y_min);
graphics_2d.transform(affine_transform);
for(StorableData storable_data : list_all_points) {
graphics_2d.setColor(Color.WHITE);
this.drawPoint((Cupple) storable_data);
}

I suggest you map each data point to a point on the screen, thus avoiding the following coordinate system pitfalls. Take your list of points and create from them a list of points to draw. Take into account that:
The drawing is pixel-based, so you will want to scale your points (or you would have rectangles 1 to 4 pixels wide...).
You will need to translate all your points because negative values will be outside the boundaries of the component on which you draw.
The direction of the y axis is reversed in the drawing coordinates.
Once that is done, use the new list of points for the drawing and the initial one for calculations. Here is an example:
public class Graph extends JPanel {
private static int gridSize = 6;
private static int scale = 100;
private static int size = gridSize * scale;
private static int translate = size / 2;
private static int pointSize = 10;
List<Point> dataPoints, scaledPoints;
Graph() {
setBackground(Color.WHITE);
// points taken from your example
Point p1 = new Point(-1, -2);
Point p2 = new Point(-1, 0);
Point p3 = new Point(1, 0);
Point p4 = new Point(1, -2);
dataPoints = Arrays.asList(p1, p2, p3, p4);
scaledPoints = dataPoints.stream()
.map(p -> new Point(p.x * scale + translate, -p.y * scale + translate))
.collect(Collectors.toList());
}
#Override
public Dimension getPreferredSize() {
return new Dimension(size, size);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
// draw a grid
for (int i = 0; i < gridSize; i++) {
g2d.drawLine(i * scale, 0, i * scale, size);
g2d.drawLine(0, i * scale, size, i * scale);
}
// draw the rectangle
g2d.setPaint(Color.RED);
g2d.drawPolygon(scaledPoints.stream().mapToInt(p -> p.x).toArray(),
scaledPoints.stream().mapToInt(p -> p.y).toArray(),
scaledPoints.size());
// draw the points
g2d.setPaint(Color.BLUE);
// origin
g2d.fillRect(translate, translate, pointSize, pointSize);
g2d.drawString("(0, 0)", translate, translate);
// data
for (int i = 0; i < dataPoints.size(); i++) {
Point sp = scaledPoints.get(i);
Point dp = dataPoints.get(i);
g2d.fillRect(sp.x, sp.y, pointSize, pointSize);
g2d.drawString("(" + dp.x + ", " + dp.y + ")", sp.x, sp.y);
}
}
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.setContentPane(new Graph());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}
And another:
You might want to have the points aligned on the grid intersections and not below and to the right of them. I trust you will figure this one out.
Also, I ordered the points so that drawPolygon will paint the lines in the correct order. If your points are arbitrarily arranged, look for ways to find the outline. If you want lines between all points like in your example, iterate over all combinations of them with drawLine.

Painting an arbitrary collection of points quickly

I am writing a darts application, and have implemented a Dartboard which is painted as a BufferedImage.
When rendering the dartboard, I first iterate over the co-ordinates of the BufferedImage and calculate the 'segment' that it resides in. I wrap this up into a DartboardSegment, which is basically just a collection of points with a small amount of extra structure (what number on the board it corresponds to, etc).
Currently, to actually render the dartboard I paint each point individually, like the following:
for (Point pt : allPoints)
{
DartboardSegment segment = getSegmentForPoint(pt);
Color colour = DartboardUtil.getColourForSegment(segment);
int rgb = colour.getRGB();
int x = (int)pt.getX();
int y = (int)pt.getY();
dartboardImage.setRGB(x, y, rgb);
}
Obviously this takes some time. It's not an intolerable amount (~2-3s to paint a 500x500 area), but I'd like to eliminate this 'lag' if I can. In other areas of my application I have encountered alternate methods (such as Graphics.fillRect()) which are much faster.
I've seen that there is a fillPolgyon() method on the Graphics class, however I don't think I can easily convert my segments into polygons because their shapes vary (e.g. the shape of a triple, a circle for the bullseye...). Is there a faster way in java to paint an arbitrary array of Points at once, rather than looping through and painting individually?
The code that I want to write is something like:
for (DartboardSegment segment : allSegments)
{
Color colour = DartboardUtil.getColourForSegment(segment);
Polgyon poly = segment.toPolygon();
Graphics gfx = dartboardImage.getGraphics();
gfx.setColor(colour);
gfx.fillPolygon(poly);
}

I don't think I can easily convert my segments into polygons because their shapes vary (e.g. the shape of a triple, a circle for the bullseye...)
Here is something that may give you some ideas.
You can create Shape objects to represent each area of the dartboard:
import java.awt.*;
import java.util.*;
import javax.swing.*;
import java.awt.geom.*;
public class Dartboard extends JPanel
{
private ArrayList<DartboardSegment> segments = new ArrayList<DartboardSegment>();
private int size = 500;
private int radius = size / 2;
private int border = 25;
private int doubleSize = size - (2 * border);
private int tripleSize = size / 2;
private int thickness = 10;
public Dartboard()
{
createSegmentWedges();
int innerRadius = size - (2 * border);
Shape outer = new Ellipse2D.Double(0, 0, size, size);
Shape inner = new Ellipse2D.Double(border, border, innerRadius, innerRadius);
Area circle = new Area( outer );
circle.subtract( new Area(inner) );
segments.add( new DartboardSegment(circle, Color.BLACK) );
createBullsEye();
}
private void createSegmentWedges()
{
int angle = -99;
for (int i = 0; i < 20; i++)
{
// Create the wedge shape
GeneralPath path = new GeneralPath();
path.moveTo(250, 250);
double radians1 = Math.toRadians( angle );
double x1 = Math.cos(radians1) * radius;
double y1 = Math.sin(radians1) * radius;
path.lineTo(x1 + 250, y1 + 250);
angle += 18;
double radians2 = Math.toRadians( angle );
double x2 = Math.cos(radians2) * radius;
double y2 = Math.sin(radians2) * radius;
path.lineTo(x2 + 250, y2 + 250);
path.closePath();
Color wedgeColor = (i % 2 == 0) ? Color.BLACK : Color.WHITE;
segments.add( new DartboardSegment(path, wedgeColor) );
// Create the double/triple shapes
Color color = (i % 2 == 0) ? Color.RED : Color.GREEN;
createShape(doubleSize, path, color);
createShape(tripleSize, path, color);
}
}
private void createShape(int outerSize, GeneralPath path, Color color)
{
int outerOffset = (size - outerSize) / 2;
int innerSize = outerSize - (2 * thickness);
int innerOffset = (size - innerSize) / 2;
Shape outer = new Ellipse2D.Double(outerOffset, outerOffset, outerSize, outerSize);
Shape inner = new Ellipse2D.Double(innerOffset, innerOffset, innerSize, innerSize);
Area circle = new Area( outer );
circle.subtract( new Area(inner) );
circle.intersect( new Area(path) );
segments.add( new DartboardSegment(circle, color) );
}
private void createBullsEye()
{
int radius1 = 40;
int offset1 = (size - radius1) / 2;
Ellipse2D.Double bullsEye1 = new Ellipse2D.Double(offset1, offset1, radius1, radius1);
segments.add( new DartboardSegment(bullsEye1, Color.GREEN) );
int radius2 = 20;
int offset2 = (size - radius2) / 2;
Ellipse2D.Double bullsEye2 = new Ellipse2D.Double(offset2, offset2, radius2, radius2);
segments.add( new DartboardSegment(bullsEye2, Color.RED) );
}
#Override
protected void paintComponent(Graphics g)
{
super.paintComponent(g);
Graphics2D g2d = (Graphics2D)g.create();
for (DartboardSegment segment: segments)
{
g2d.setColor( segment.getColor() );
g2d.fill( segment.getShape() );
}
}
#Override
public Dimension getPreferredSize()
{
return new Dimension(500, 500);
}
class DartboardSegment
{
private Shape shape;
private Color color;
public DartboardSegment(Shape shape, Color color)
{
this.shape = shape;
this.color = color;
}
public Shape getShape()
{
return shape;
}
public Color getColor()
{
return color;
}
}
private static void createAndShowGUI()
{
JFrame frame = new JFrame("DartBoard");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new Dartboard());
frame.setLocationByPlatform( true );
frame.pack();
frame.setVisible( true );
}
public static void main(String[] args)
{
EventQueue.invokeLater( () -> createAndShowGUI() );
/*
EventQueue.invokeLater(new Runnable()
{
public void run()
{
createAndShowGUI();
}
});
*/
}
}

After a bit more digging, I think one solution to this is to do the following. It's not the neatest, but I think it will work:
int i = 0;
for (int y=0; y<height; y++)
{
for (int x=0; x<width; x++)
{
Point pt = new Point(x, y);
DartboardSegment segment = getSegmentForPoint(pt);
Color colour = DartboardUtil.getColourForSegment(segment);
pixels[i] = colorToUse.getRGB();
i++;
}
}
dartboardImage.setRGB(0, 0, width, height, pixels, 0, width);
I am open to better suggestions, however!

How to determine remaining space on a pdf page with itext [duplicate]

I have a pdf file where-in I am adding a stamp to all it's pages.
But, the problem is, the stamp is added to the upper-left corner of each page. If, the page has text in that part, the stamp appears on the text.
My question is, is there any method by which I can read each page and if there is no text in that part add the stamp else search for nearest available free space, just like what a density scanner does?
I am using IText and Java 1.7.
The free space fider class and the distance calculation function are the same that is there in the accepted answer.
Following is the edited code I am using:
// The resulting PDF file
String RESULT = "K:\\DCIN_TER\\DCIN_EPU2\\CIRCUIT FROM BRANCH\\RAINBOW ORDERS\\" + jtfSONo.getText().trim() + "\\PADR Release\\Final PADR Release 1.pdf";
// Create a reader
PdfReader reader = new PdfReader("K:\\DCIN_TER\\DCIN_EPU2\\CIRCUIT FROM BRANCH\\RAINBOW ORDERS\\" + jtfSONo.getText().trim() + "\\PADR Release\\Final PADR Release.pdf");
// Create a stamper
PdfStamper stamper = new PdfStamper(reader, new FileOutputStream(RESULT));
// Loop over the pages and add a footer to each page
int n = reader.getNumberOfPages();
for(int i = 1; i <= n; i++)
{
Collection<Rectangle2D> rectangles = find(reader, 300, 100, n, stamper); // minimum width & height of a rectangle
Iterator itr = rectangles.iterator();
while(itr.hasNext())
{
System.out.println(itr.next());
}
if(!(rectangles.isEmpty()) && (rectangles.size() != 0))
{
Rectangle2D best = null;
double bestDist = Double.MAX_VALUE;
Point2D.Double point = new Point2D.Double(200, 400);
float x = 0, y = 0;
for(Rectangle2D rectangle: rectangles)
{
double distance = distance(rectangle, point);
if(distance < bestDist)
{
best = rectangle;
bestDist = distance;
x = (float) best.getX();
y = (float) best.getY();
int left = (int) best.getMinX();
int right = (int) best.getMaxX();
int top = (int) best.getMaxY();
int bottom = (int) best.getMinY();
System.out.println("x : " + x);
System.out.println("y : " + y);
System.out.println("left : " + left);
System.out.println("right : " + right);
System.out.println("top : " + top);
System.out.println("bottom : " + bottom);
}
}
getFooterTable(i, n).writeSelectedRows(0, -1, x, y, stamper.getOverContent(i)); // 0, -1 indicates 1st row, 1st column upto last row and last column
}
else
getFooterTable(i, n).writeSelectedRows(0, -1, 94, 140, stamper.getOverContent(i)); // bottom left corner
}
// Close the stamper
stamper.close();
// Close the reader
reader.close();
public Collection<Rectangle2D> find(PdfReader reader, float minWidth, float minHeight, int page, PdfStamper stamper) throws IOException
{
Rectangle cropBox = reader.getCropBox(page);
Rectangle2D crop = new Rectangle2D.Float(cropBox.getLeft(), cropBox.getBottom(), cropBox.getWidth(), cropBox.getHeight());
FreeSpaceFinder finder = new FreeSpaceFinder(crop, minWidth, minHeight);
PdfReaderContentParser parser = new PdfReaderContentParser(reader);
parser.processContent(page, finder);
System.out.println("finder.freeSpaces : " + finder.freeSpaces);
return finder.freeSpaces;
}
// Create a table with page X of Y, #param x the page number, #param y the total number of pages, #return a table that can be used as footer
public static PdfPTable getFooterTable(int x, int y)
{
java.util.Date date = new java.util.Date();
SimpleDateFormat sdf = new SimpleDateFormat("dd MMM yyyy");
String month = sdf.format(date);
System.out.println("Month : " + month);
PdfPTable table = new PdfPTable(1);
table.setTotalWidth(120);
table.setLockedWidth(true);
table.getDefaultCell().setFixedHeight(20);
table.getDefaultCell().setBorder(Rectangle.TOP);
table.getDefaultCell().setBorder(Rectangle.LEFT);
table.getDefaultCell().setBorder(Rectangle.RIGHT);
table.getDefaultCell().setBorderColorTop(BaseColor.BLUE);
table.getDefaultCell().setBorderColorLeft(BaseColor.BLUE);
table.getDefaultCell().setBorderColorRight(BaseColor.BLUE);
table.getDefaultCell().setBorderWidthTop(1f);
table.getDefaultCell().setBorderWidthLeft(1f);
table.getDefaultCell().setBorderWidthRight(1f);
table.getDefaultCell().setHorizontalAlignment(Element.ALIGN_CENTER);
Font font1 = new Font(FontFamily.HELVETICA, 10, Font.BOLD, BaseColor.BLUE);
table.addCell(new Phrase("CONTROLLED COPY", font1));
table.getDefaultCell().setFixedHeight(20);
table.getDefaultCell().setBorder(Rectangle.LEFT);
table.getDefaultCell().setBorder(Rectangle.RIGHT);
table.getDefaultCell().setBorderColorLeft(BaseColor.BLUE);
table.getDefaultCell().setBorderColorRight(BaseColor.BLUE);
table.getDefaultCell().setBorderWidthLeft(1f);
table.getDefaultCell().setBorderWidthRight(1f);
table.getDefaultCell().setHorizontalAlignment(Element.ALIGN_CENTER);
Font font = new Font(FontFamily.HELVETICA, 10, Font.BOLD, BaseColor.RED);
table.addCell(new Phrase(month, font));
table.getDefaultCell().setFixedHeight(20);
table.getDefaultCell().setBorder(Rectangle.LEFT);
table.getDefaultCell().setBorder(Rectangle.RIGHT);
table.getDefaultCell().setBorder(Rectangle.BOTTOM);
table.getDefaultCell().setBorderColorLeft(BaseColor.BLUE);
table.getDefaultCell().setBorderColorRight(BaseColor.BLUE);
table.getDefaultCell().setBorderColorBottom(BaseColor.BLUE);
table.getDefaultCell().setBorderWidthLeft(1f);
table.getDefaultCell().setBorderWidthRight(1f);
table.getDefaultCell().setBorderWidthBottom(1f);
table.getDefaultCell().setHorizontalAlignment(Element.ALIGN_CENTER);
table.addCell(new Phrase("BLR DESIGN DEPT.", font1));
return table;
}

is there any method by which I can read each page and if there is no text in that part add the stamp else search for nearest available free space, just like what a density scanner does?
iText does not offer that functionality out of the box. Depending of what kind of content you want to evade, though, you might consider either rendering the page to an image and looking for white spots in the image or doing text extraction with a strategy that tries to find locations without text.
The first alternative, analyzing a rendered version of the page, would be the focus of a separate question as an image processing library would have to be chosen first.
There are a number of situations, though, in which that first alternative is not the best way to go. E.g. if you only want to evade text but not necessarily graphics (like watermarks), or if you also want to evade invisible text (which usually can be marked in a PDF viewer and, therefore, interfere with your addition).
The second alternative (using text and image extraction abilities of iText) can be the more appropriate approach in such situations.
Here a sample RenderListener for such a task:
public class FreeSpaceFinder implements RenderListener
{
//
// constructors
//
public FreeSpaceFinder(Rectangle2D initialBox, float minWidth, float minHeight)
{
this(Collections.singleton(initialBox), minWidth, minHeight);
}
public FreeSpaceFinder(Collection<Rectangle2D> initialBoxes, float minWidth, float minHeight)
{
this.minWidth = minWidth;
this.minHeight = minHeight;
freeSpaces = initialBoxes;
}
//
// RenderListener implementation
//
#Override
public void renderText(TextRenderInfo renderInfo)
{
Rectangle2D usedSpace = renderInfo.getAscentLine().getBoundingRectange();
usedSpace.add(renderInfo.getDescentLine().getBoundingRectange());
remove(usedSpace);
}
#Override
public void renderImage(ImageRenderInfo renderInfo)
{
Matrix imageMatrix = renderInfo.getImageCTM();
Vector image00 = rect00.cross(imageMatrix);
Vector image01 = rect01.cross(imageMatrix);
Vector image10 = rect10.cross(imageMatrix);
Vector image11 = rect11.cross(imageMatrix);
Rectangle2D usedSpace = new Rectangle2D.Float(image00.get(Vector.I1), image00.get(Vector.I2), 0, 0);
usedSpace.add(image01.get(Vector.I1), image01.get(Vector.I2));
usedSpace.add(image10.get(Vector.I1), image10.get(Vector.I2));
usedSpace.add(image11.get(Vector.I1), image11.get(Vector.I2));
remove(usedSpace);
}
#Override
public void beginTextBlock() { }
#Override
public void endTextBlock() { }
//
// helpers
//
void remove(Rectangle2D usedSpace)
{
final double minX = usedSpace.getMinX();
final double maxX = usedSpace.getMaxX();
final double minY = usedSpace.getMinY();
final double maxY = usedSpace.getMaxY();
final Collection<Rectangle2D> newFreeSpaces = new ArrayList<Rectangle2D>();
for (Rectangle2D freeSpace: freeSpaces)
{
final Collection<Rectangle2D> newFragments = new ArrayList<Rectangle2D>();
if (freeSpace.intersectsLine(minX, minY, maxX, minY))
newFragments.add(new Rectangle2D.Double(freeSpace.getMinX(), freeSpace.getMinY(), freeSpace.getWidth(), minY-freeSpace.getMinY()));
if (freeSpace.intersectsLine(minX, maxY, maxX, maxY))
newFragments.add(new Rectangle2D.Double(freeSpace.getMinX(), maxY, freeSpace.getWidth(), freeSpace.getMaxY() - maxY));
if (freeSpace.intersectsLine(minX, minY, minX, maxY))
newFragments.add(new Rectangle2D.Double(freeSpace.getMinX(), freeSpace.getMinY(), minX - freeSpace.getMinX(), freeSpace.getHeight()));
if (freeSpace.intersectsLine(maxX, minY, maxX, maxY))
newFragments.add(new Rectangle2D.Double(maxX, freeSpace.getMinY(), freeSpace.getMaxX() - maxX, freeSpace.getHeight()));
if (newFragments.isEmpty())
{
add(newFreeSpaces, freeSpace);
}
else
{
for (Rectangle2D fragment: newFragments)
{
if (fragment.getHeight() >= minHeight && fragment.getWidth() >= minWidth)
{
add(newFreeSpaces, fragment);
}
}
}
}
freeSpaces = newFreeSpaces;
}
void add(Collection<Rectangle2D> rectangles, Rectangle2D addition)
{
final Collection<Rectangle2D> toRemove = new ArrayList<Rectangle2D>();
boolean isContained = false;
for (Rectangle2D rectangle: rectangles)
{
if (rectangle.contains(addition))
{
isContained = true;
break;
}
if (addition.contains(rectangle))
toRemove.add(rectangle);
}
rectangles.removeAll(toRemove);
if (!isContained)
rectangles.add(addition);
}
//
// members
//
public Collection<Rectangle2D> freeSpaces = null;
final float minWidth;
final float minHeight;
final static Vector rect00 = new Vector(0, 0, 1);
final static Vector rect01 = new Vector(0, 1, 1);
final static Vector rect10 = new Vector(1, 0, 1);
final static Vector rect11 = new Vector(1, 1, 1);
}
Using this FreeSpaceFinder you can find empty areas with given minimum dimensions in a method like this:
public Collection<Rectangle2D> find(PdfReader reader, float minWidth, float minHeight, int page) throws IOException
{
Rectangle cropBox = reader.getCropBox(page);
Rectangle2D crop = new Rectangle2D.Float(cropBox.getLeft(), cropBox.getBottom(), cropBox.getWidth(), cropBox.getHeight());
FreeSpaceFinder finder = new FreeSpaceFinder(crop, minWidth, minHeight);
PdfReaderContentParser parser = new PdfReaderContentParser(reader);
parser.processContent(page, finder);
return finder.freeSpaces;
}
For your task you now have to choose from the returned rectangles the one which suits you best.
Beware, this code still may have to be tuned to your requirements:
It ignores clip paths, rendering modes, colors, and covering objects. Thus, it considers all text and all bitmap images, whether they are actually visible or not.
It does not consider vector graphics (because the iText parser package does not consider them).
It is not very optimized.
Applied to this PDF page:
with minimum width 200 and height 50, you get these rectangles:
x y w h
000,000 000,000 595,000 056,423
000,000 074,423 595,000 168,681
000,000 267,304 314,508 088,751
000,000 503,933 351,932 068,665
164,296 583,598 430,704 082,800
220,803 583,598 374,197 096,474
220,803 583,598 234,197 107,825
000,000 700,423 455,000 102,396
000,000 700,423 267,632 141,577
361,348 782,372 233,652 059,628
or, more visually, here as rectangles on the page:
The paper plane is a vector graphic and, therefore, ignored.
Of course you could also change the PDF rendering code to not draw stuff you want to ignore and to visibly draw originally invisible stuff which you want to ignore, and then use bitmap image analysis nonetheless...
EDIT
In his comments the OP asked how to find the rectangle in the rectangle collection returned by find which is nearest to a given point.
First of all there not necessarily is the nearest rectangle, there may be multiple.
That been said, one can choose a nearest rectangle as follows:
First one needs to calculate a distance between point and rectangle, e.g.:
double distance(Rectangle2D rectangle, Point2D point)
{
double x = point.getX();
double y = point.getY();
double left = rectangle.getMinX();
double right = rectangle.getMaxX();
double top = rectangle.getMaxY();
double bottom = rectangle.getMinY();
if (x < left) // point left of rect
{
if (y < bottom) // and below
return Point2D.distance(x, y, left, bottom);
if (y > top) // and top
return Point2D.distance(x, y, left, top);
return left - x;
}
if (x > right) // point right of rect
{
if (y < bottom) // and below
return Point2D.distance(x, y, right, bottom);
if (y > top) // and top
return Point2D.distance(x, y, right, top);
return x - right;
}
if (y < bottom) // and below
return bottom - y;
if (y > top) // and top
return y - top;
return 0;
}
Using this distance measurement one can select a nearest rectangle using code like this for a Collection<Rectangle2D> rectangles and a Point2D point:
Rectangle2D best = null;
double bestDist = Double.MAX_VALUE;
for (Rectangle2D rectangle: rectangles)
{
double distance = distance(rectangle, point);
if (distance < bestDist)
{
best = rectangle;
bestDist = distance;
}
}
After this best contains a best rectangle.
For the sample document used above, this method returns the colored rectangles for the page corners and left and right centers:
EDIT TWO
Since iText 5.5.6, the RenderListener interface has been extended as ExtRenderListener to also be signaled about Path construction and path drawing operations. Thus, the FreeSpaceFinder above could also be extended to handle paths:
//
// Additional ExtRenderListener methods
//
#Override
public void modifyPath(PathConstructionRenderInfo renderInfo)
{
List<Vector> points = new ArrayList<Vector>();
if (renderInfo.getOperation() == PathConstructionRenderInfo.RECT)
{
float x = renderInfo.getSegmentData().get(0);
float y = renderInfo.getSegmentData().get(1);
float w = renderInfo.getSegmentData().get(2);
float h = renderInfo.getSegmentData().get(3);
points.add(new Vector(x, y, 1));
points.add(new Vector(x+w, y, 1));
points.add(new Vector(x, y+h, 1));
points.add(new Vector(x+w, y+h, 1));
}
else if (renderInfo.getSegmentData() != null)
{
for (int i = 0; i < renderInfo.getSegmentData().size()-1; i+=2)
{
points.add(new Vector(renderInfo.getSegmentData().get(i), renderInfo.getSegmentData().get(i+1), 1));
}
}
for (Vector point: points)
{
point = point.cross(renderInfo.getCtm());
Rectangle2D.Float pointRectangle = new Rectangle2D.Float(point.get(Vector.I1), point.get(Vector.I2), 0, 0);
if (currentPathRectangle == null)
currentPathRectangle = pointRectangle;
else
currentPathRectangle.add(pointRectangle);
}
}
#Override
public Path renderPath(PathPaintingRenderInfo renderInfo)
{
if (renderInfo.getOperation() != PathPaintingRenderInfo.NO_OP)
remove(currentPathRectangle);
currentPathRectangle = null;
return null;
}
#Override
public void clipPath(int rule)
{
// TODO Auto-generated method stub
}
Rectangle2D.Float currentPathRectangle = null;
(FreeSpaceFinderExt.java)
Using this class the result above is improved to
As you see the paper plane and the table background colorations now also are taken into account.

My other answer focuses on the original question, i.e. how to find free space with given minimum dimensions on a page.
Since that answer had been written, the OP provided code trying to make use of that original answer.
This answer deals with that code.
The code has a number of shortcoming.
The choice of free space on a page depends on the number of pages in the document.
The reason for this is to be found at the start of the loop over the pages:
for(int i = 1; i <= n; i++)
{
Collection<Rectangle2D> rectangles = find(reader, 300, 100, n, stamper);
...
The OP surely meant i, not n there. The code as is always looks for free space on the last document page.
The rectangles are lower than they should be.
The reason for this is to be found in the retrieval and use of the rectangle coordinates:
x = (float) best.getX();
y = (float) best.getY();
...
getFooterTable(i, n).writeSelectedRows(0, -1, x, y, stamper.getOverContent(i));
The Rectangle2D methods getX and getY return the coordinates of the lower left rectangle corner; the PdfPTable methods writeSelectedRows, on the other hand, require the upper left rectangle corner. Thus, getMaxY should be used instead of getY.

Set item shape size in jFreechart

I am plotting a line chart using jFreeChart, which is a series of (x, y) value connected by a straight line.
But the problem is the shape, a circle or a rect that represents a data point is too big, since I have a lot of values in one series. You can see how it looks like in this screenshot:
Also, I learned the shapes that represent data point do not scale as the rest of the plot does when I resize the chart panel.
Question:
How to make the shape(the circles and rects that represent data point) smaller so that they won't clog together?
Here is my code to generate the chart, and I used a customized renderer to draw different color for different part of the line in one data series.
private JFreeChart createChart(XYDataset dataCollection) {
// create the chart...
JFreeChart chart = ChartFactory.createXYLineChart(
fileName, // chart title
"Count", // x axis label
"Price", // y axis label
dataCollection, // data
PlotOrientation.VERTICAL,
true, // include legend
true, // tooltips
false // urls
);
// customize chart
XYPlot plot = (XYPlot) chart.getPlot();
// find out the max and min value for price series
XYSeriesCollection collection = (XYSeriesCollection)plot.getDataset();
XYSeries priceSeries = collection.getSeries(0);
double maxY = priceSeries.getMaxY();
double minY = priceSeries.getMinY();
// set max and min for range axis (y axis)
NumberAxis rangeAxis = (NumberAxis)plot.getRangeAxis();
rangeAxis.setRange(minY, maxY);
XYLineAndShapeRenderer renderer = new XYLineAndShapeRenderer() {
public Color getItemColor(int series, int item) {
// modify code here to change color for different part of the line in one serie line
if(series == 1) {
System.out.println("getting color at: " + item);
int isBuy = 0;
if(item < kFilter.buySellSignal.size()) {
isBuy = kFilter.buySellSignal.get(item);
}
if(isBuy == 1) {
return Color.red;
} else {
return Color.green;
}
} else {
return Color.yellow;
}
}
#Override
protected void drawFirstPassShape(Graphics2D g2, int pass, int series, int item, Shape shape) {
super.drawFirstPassShape(g2, pass, series, item, shape);
//g2.setStroke(getItemStroke(series, item));
Color c1 = getItemColor(series, item - 1);
Color c2 = getItemColor(series, item);
GradientPaint linePaint = new GradientPaint(0, 0, c1, 0, 300, c2);
g2.setPaint(linePaint);
g2.draw(shape);
}
};
plot.setRenderer(renderer);
return chart;
}

You can override getItemShape() in your XYLineAndShapeRenderer to return any desired Shape, as shown here. Alternatively, invoke one of the abstract parent's methods, setSeriesShape(), setBaseShape() etc.
#Nicolas S.Xu reports using code similar to the following:
Rectangle rect = new Rectangle(2, 2);
renderer.setSeriesShape(1, rect);
See also ShapeUtilities.

AffineTransform.rotate() - how do I xlate, rotate, and scale at the same time?

I have the following code which does (the first part of) what I want drawing a chessboard with some pieces on it.
Image pieceImage = getImage(currentPiece);
int pieceHeight = pieceImage.getHeight(null);
double scale = (double)side/(double)pieceHeight;
AffineTransform transform = new AffineTransform();
transform.setToTranslation(xPos, yPos);
transform.scale(scale, scale);
realGraphics.drawImage(pieceImage, transform, this);
that is, it gets a chess piece's image and the image's height, it translates the drawing of that image to the square the piece is on and scales the image to the size of the square.
Llet's say I want to rotate the black pieces 180 degrees. Somewhere I expect to have something like:
transform.rotate(Math.toRadians(180) /* ?, ? */);
But I can't figure out what to put in as X and Y. If I put nothing, the image is nicely rotated around the 0,0 point of its chessboard square, putting the piece upside down in the square to the northeast of where it is supposed to be. I've guessed at various other combinations of x,y, with no luck yet.
I am already using translation to put the piece in the right square, the rotation transform wants another x,y around which to rotate things, but I don't know how to tell the transform to rotate the piece around one x,y and write the image to a different x,y. Can someone help me with the rotation parameters, or point me to something that explains how these things work? I've found examples of things that don't explain how they work, and so far I haven't figured out how to alter them to my situation...
Major edit: addition of working code. Sorry, I don't know how to post images, please substitute your own.
When I run the following I get a 2x2 chess board with a rook at the top left and a knight at the bottom right.
If I go into SmallChessboardComponent and take the comment delims off the first rotation transform statement, I get the rook in its original place upside down and the knight does not appear. If I instead take the comment delims off the second transform statement, neither piece appears at all.
I am looking for a way to turn the pieces upside down on the square on which they would appear anyway. I want to draw each piece onto the board; I don't want code that flips the board.
main program:
package main;
import java.awt.BorderLayout;
import javax.swing.JFrame;
import directredraw.SmallChessboardComponent;
public class SmallChessboardMain
{
private static void dbg (String message) { System.out.println(message); }
public static void main(String[] args)
{
//Create the top-level container and add contents to it.
final JFrame frame = new JFrame("Small Chessboard");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
// create the chessboard itself and set it in the component
SmallChessboard chessboard = new SmallChessboard();
// create the GUI component that will contain the chessboard
SmallChessboardComponent chessboardComponent = new SmallChessboardComponent();
chessboardComponent.setBoard (chessboard);
frame.getContentPane().add(chessboardComponent, BorderLayout.CENTER);
// pack and display all this
frame.pack();
frame.setVisible(true);
}
}
chessboard class:
package main;
public class SmallChessboard
{
Piece [][] squares = new Piece[2][2];
public SmallChessboard()
{
squares[0][0] = new Piece(Piece.WHITECOLOR, Piece.ROOK);
squares[1][1] = new Piece(Piece.WHITECOLOR, Piece.KNIGHT);
}
/**
* get the piece at the given rank and file; null if
* no piece exists there.
*/
public Piece getPiece(int rank, int file)
{
if (0 > rank || rank > 2 || 0 > file || file > 2) { return null; }
else { return squares[rank][file]; }
}
}
chessboard component class:
package directredraw;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Rectangle;
import java.awt.geom.AffineTransform;
import javax.swing.JPanel;
import main.Piece;
import main.PieceImages;
import main.SmallChessboard;
public class SmallChessboardComponent extends JPanel
{
private static final long serialVersionUID = 1L;
Color whiteSquareColor = Color.yellow;
Color blackSquareColor = Color.blue;
private static void dbg (String msg) { System.out.println(msg); }
private SmallChessboard chessboard = null;
// currently playing with rotating images; this affine transform
// should help
AffineTransform rotationTransform = null;
private final int DEFAULT_PREFERRED_SIDE = 400;
int wholeSide = DEFAULT_PREFERRED_SIDE;
int side = DEFAULT_PREFERRED_SIDE / 8;
public void setBoard (SmallChessboard givenBoard)
{ chessboard = givenBoard;
}
/**
* set either or both colors for this chessboard; if either of
* the arguments are null, they do not change the existing color
* setting.
*/
public void setColors (Color darkSquare, Color lightSquare)
{
if (darkSquare != null) { blackSquareColor = darkSquare; }
if (lightSquare != null) { whiteSquareColor = lightSquare; }
}
/**
* return the preferred size for this component.s
*/
public Dimension getPreferredSize()
{ return new Dimension(wholeSide, wholeSide);
}
/*
* return the image object for the given piece
*/
private Image getImage(Piece piece)
{ return PieceImages.getPieceImage(this, piece);
}
public void paintComponent (Graphics graphics)
{
Graphics2D realGraphics = (Graphics2D) graphics;
// the image container might have been stretched.
// calculate the largest square held by the current container,
// and then 1/2 of that size for an individual square.
int wholeWidth = this.getWidth();
int wholeHeight = this.getHeight();
wholeSide = (wholeWidth / 2) * 2;
if (wholeHeight < wholeWidth) { wholeSide = (wholeHeight / 2) * 2; }
side = wholeSide / 2;
Rectangle clip = realGraphics.getClipBounds();
boolean firstColumnWhite = false;
// for each file on the board:
// set whether top square is white
// set background color according to white/black square
//
for (int fileIndex=0; fileIndex<8; fileIndex++)
{ boolean currentColorWhite = firstColumnWhite;
firstColumnWhite = !firstColumnWhite;
// draw the board and all the pieces
int rankIndex = 2;
for (rankIndex=2; rankIndex>=0; rankIndex--)
{
currentColorWhite = !currentColorWhite;
// x and y position of the top left corner of the square we're drawing,
// and rect becomes the dimensions and position of the square itself.
int xPos = fileIndex * side;
int yPos = rankIndex * side;
Rectangle rect = new Rectangle(xPos, yPos, side, side);
// if this square intersects the clipping rectangle we're drawing,
// then we'll draw the square and the piece on the square.
if (rect.intersects(clip))
{
// this puts down the correct color of square
if (currentColorWhite) { realGraphics.setColor(whiteSquareColor); }
else { realGraphics.setColor(blackSquareColor); }
realGraphics.fillRect(xPos, yPos, side, side);
// if there is a piece on this square and it isn't selected at the
// moment, then draw it.
Piece currentPiece = chessboard.getPiece(rankIndex, fileIndex);
if (currentPiece != null)
{
Image pieceImage = getImage(currentPiece);
int pieceHeight = pieceImage.getHeight(null);
double scalePiece = (double)side/(double)pieceHeight;
AffineTransform transform = new AffineTransform();
// transform.setToRotation(Math.toRadians(180));
transform.setToRotation(Math.toRadians(180), side/2, side/2);
transform.scale(scalePiece, scalePiece);
transform.translate(xPos/scalePiece, yPos/scalePiece);
// if (currentPiece.isBlack())
// {
// transform.translate(xPos + (side+2), yPos + (side+2));
// transform.rotate(Math.toRadians(180) /*, ,*/ );
// }
// else
// {
// transform.translate(xPos, yPos);
// }
realGraphics.drawImage(pieceImage, transform, this);
}
}
}
}
}
}
Piece.java
package main;
public class Piece
{
// piece types; the sum of the piece type and the
// color gives a number unique to both type and color,
// which is used for things like image indices.
public static final int PAWN = 0;
public static final int KNIGHT = 1;
public static final int BISHOP = 2;
public static final int ROOK = 3;
public static final int QUEEN = 4;
public static final int KING = 5;
// one of these is the color of the current piece
public static final int NOCOLOR = -1;
// the sum of the piece type and the
// color gives a number unique to both type and color,
// which is used for things like image indices.
public static final int BLACKCOLOR = 0;
public static final int WHITECOLOR = 6;
int color = NOCOLOR;
int imageIndex;
public Piece(int color, int pieceType)
{
// dbg -- all pieces are white rooks for now...
this.color = color;
imageIndex = color + pieceType;
}
/**
* return the integer associated with this piece's color;
*/
int getPieceColor()
{ return color;
}
/**
* return true if the piece is black
*/
public boolean isBlack()
{
return (color == BLACKCOLOR);
}
/**
* set the color associated with this piece; constants
* found in this class.
*/
public void setPieceColor(int givenColor)
{ color = givenColor;
}
/**
* return the integer designated for the image used for this piece.
*/
int getImageIndex()
{ return imageIndex;
}
}
and PieceImages.java
package main;
import java.awt.Component;
import java.awt.Image;
import java.awt.MediaTracker;
import java.awt.Toolkit;
import java.net.URL;
public class PieceImages
{ static Image images[] = null;
private static void dbg (String msg) { System.out.println(msg); }
public static Image getPieceImage (Component target, Piece piece)
{
if (images == null)
try
{
MediaTracker tracker = new MediaTracker(target);
images = new Image[12];
images[Piece.BLACKCOLOR + Piece.PAWN] = getImage(tracker, "bPawn.gif");
images[Piece.BLACKCOLOR + Piece.KNIGHT] = getImage(tracker, "bKnight.gif");
images[Piece.BLACKCOLOR + Piece.BISHOP] = getImage(tracker, "bBishop.gif");
images[Piece.BLACKCOLOR + Piece.ROOK] = getImage(tracker, "bRook.gif");
images[Piece.BLACKCOLOR + Piece.QUEEN] = getImage(tracker, "bQueen.gif");
images[Piece.BLACKCOLOR + Piece.KING] = getImage(tracker, "bKing.gif");
images[Piece.WHITECOLOR + Piece.PAWN] = getImage(tracker, "wPawn.gif");
images[Piece.WHITECOLOR + Piece.KNIGHT] = getImage(tracker, "wKnight.gif");
images[Piece.WHITECOLOR + Piece.BISHOP] = getImage(tracker, "wBishop.gif");
images[Piece.WHITECOLOR + Piece.ROOK] = getImage(tracker, "wRook.gif");
images[Piece.WHITECOLOR + Piece.QUEEN] = getImage(tracker, "wQueen.gif");
images[Piece.WHITECOLOR + Piece.KING] = getImage(tracker, "wKing.gif");
if (!tracker.waitForAll(10000))
{ System.out.println("ERROR: not all piece main.images loaded");
}
dbg("piece images loaded");
}
catch (Exception xcp)
{ System.out.println("Error loading images");
xcp.printStackTrace();
}
return images[piece.getImageIndex()];
}
private static Image getImage(MediaTracker tracker, String file)
{
URL url = PieceImages.class.getResource("images/" + file);
Image image = Toolkit.getDefaultToolkit().getImage(url);
tracker.addImage(image, 1);
return image;
}
}

Okay, this is a little slight of hand. The example code will only work for 90 degree increments (it was only designed this way), to do smaller increments you to use some trig to calculate the image width and height (there's a answer somewhere for that to ;))
public class ImagePane extends JPanel {
private BufferedImage masterImage;
private BufferedImage renderedImage;
public ImagePane(BufferedImage image) {
masterImage = image;
applyRotation(0);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(renderedImage.getWidth(), renderedImage.getHeight());
}
#Override
public Dimension getMinimumSize() {
return getPreferredSize();
}
protected int getVirtualAngle(int angle) {
float fRotations = (float) angle / 360f;
int rotations = (int) (fRotations - (fRotations / 1000));
int virtual = angle - (rotations * 360);
if (virtual < 0) {
virtual = 360 + virtual;
}
return virtual;
}
public void applyRotation(int angle) {
// This will only work for angles of 90 degrees...
// Normalize the angle to make sure it's only between 0-360 degrees
int virtualAngle = getVirtualAngle(angle);
Dimension size = new Dimension(masterImage.getWidth(), masterImage.getHeight());
int masterWidth = masterImage.getWidth();
int masterHeight = masterImage.getHeight();
double x = 0; //masterWidth / 2.0;
double y = 0; //masterHeight / 2.0;
switch (virtualAngle) {
case 0:
break;
case 180:
break;
case 90:
case 270:
size = new Dimension(masterImage.getHeight(), masterImage.getWidth());
x = (masterHeight - masterWidth) / 2.0;
y = (masterWidth - masterHeight) / 2.0;
break;
}
renderedImage = new BufferedImage(size.width, size.height, masterImage.getTransparency());
Graphics2D g2d = renderedImage.createGraphics();
AffineTransform at = AffineTransform.getTranslateInstance(x, y);
at.rotate(Math.toRadians(virtualAngle), masterWidth / 2.0, masterHeight / 2.0);
g2d.drawImage(masterImage, at, null);
g2d.dispose();
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
int width = getWidth() - 1;
int height = getHeight() - 1;
int x = (width - renderedImage.getWidth()) / 2;
int y = (height - renderedImage.getHeight()) / 2;
g2d.drawImage(renderedImage, x, y, this);
}
}
Now, you could simply "flip" the image vertically, if that works better for you
public class FlipPane extends JPanel {
private BufferedImage masterImage;
private BufferedImage renderedImage;
public FlipPane(BufferedImage image) {
masterImage = image;
flipMaster();
}
#Override
public Dimension getPreferredSize() {
return new Dimension(renderedImage.getWidth(), renderedImage.getHeight());
}
#Override
public Dimension getMinimumSize() {
return getPreferredSize();
}
protected void flipMaster() {
renderedImage = new BufferedImage(masterImage.getWidth(), masterImage.getHeight(), masterImage.getTransparency());
Graphics2D g2d = renderedImage.createGraphics();
g2d.setTransform(AffineTransform.getScaleInstance(1, -1));
g2d.drawImage(masterImage, 0, -masterImage.getHeight(), this);
g2d.dispose();
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
int width = getWidth() - 1;
int height = getHeight() - 1;
int x = (width - renderedImage.getWidth()) / 2;
int y = (height - renderedImage.getHeight()) / 2;
g2d.drawImage(renderedImage, x, y, this);
}
}
This basically results in:
Original | 180 degree rotation | Vertical inversion...
Now, if you change the flipMaster method to read:
g2d.setTransform(AffineTransform.getScaleInstance(-1, -1));
g2d.drawImage(masterImage, -masterImage.getWidth(), -masterImage.getHeight(), this);
You'll get the same effect as the 180 rotation ;)

Try performing the rotation before translating it into the correct position. Simply reorder the transformations so that first you scale, then you rotate (around the center point of the image), and then you translate:
transform.scale(scale, scale);
transform.rotate(Math.PI, pieceWidth / 2, pieceHeight /2);
transform.translation(xPos, yPos);
By the way, the black pieces on a chess board usually aren't rotated. :)
Update
In what way does it not work? The solution I provided also also differs from your code in that scaling is performed before translating. You can try the rotating, translating, and then scaling.
I strongly suggest that you modify your code so that you can perform the translation last. If you do this, everything will become a lot less complicated. Once you have done so, you only have to scale once to automatically take care of the rotation.
transform.scale(scale, scale); // or transform.scale(scale, -scale); to rotate
transform.translate(xPos, yPos);