I would like to know more about the coordinates of a Rectangle, in particular:
Every time, I get confused about how to make dimensions based on these coordinates to draw rectangle. If possible, can I get a graphical representation briefly about these coordinates positions?
iText 7 Rectangle object has the following parameters:
y are the lower-left X, lower-left Y coordinates.
You need to know about the coordinate system as explained in the answer to the question "Where is the origin (x,y) of a PDF page?"
The main thing is that the origin of the coordinate system is (0, 0). Positive X values are to the right of the origin, positive Y values are above the origin. If you need to create a page size, it's also possible to use negative values. Let’s consider two examples:
Rectangle rectangle1 = new Rectangle(0, 0, 595, 842); Rectangle rectangle2 = new Rectangle(20, 35, 100, 150);
As you see,
rectangle1 has (0, 0) coordinate as a lower-left corner and (595, 842) as an upper-right corner,
rectangle2 has (20, 35) as a lower-left corner and (120, 185) as an upper-right.
Click this link if you want to see how to answer this question in iText 5.