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How to center a text in a rectangle in JavaFX

I am trying to draw a string exactly in the center of a rectangle using JavaFX GraphicsContext2D.
I don't want to use JavaFX components so please do not recommend them.
For example, I stroke a rectangle with attributes: x = 10, y = 10, width = 100, height = 100. Now I want to stroke a text in a way that it comes exactly in the center(horizontally and vertically) of the rectangle. How can I do it?

As #James_D comments, you can use the GraphicsContext methods setTextAlign() and setTextBaseline() to center the fillText() in an arbitrary Rectangle. Starting from this example, I added the following lines in the tooltips loop in order to produce the image shown:
gc.setTextAlign(TextAlignment.CENTER);
gc.setTextBaseline(VPos.CENTER);
gc.setFill(Color.BLACK);
gc.fillText(color.toString(),
bounds.getX() + bounds.getWidth() / 2,
bounds.getY() + bounds.getHeight() / 2);

How to draw shape like below image

Please help me to draw a shape like the image below. I have tried many things, but none of the code worked.
This is what I have tried
private Point mFirstCurveStartPoint = new Point();
private Point mFirstCurveEndPoint = new Point();
.................................................
.................................................
mFirstCurveStartPoint.set((mNavigationBarWidth / 2) - (CURVE_CIRCLE_RADIUS * 2) - (CURVE_CIRCLE_RADIUS / 3), 0);
// the coordinates (x,y) of the end point after curve
mFirstCurveEndPoint.set(mNavigationBarWidth / 2, CURVE_CIRCLE_RADIUS + (CURVE_CIRCLE_RADIUS / 4));
mFirstCurveControlPoint1.set(mFirstCurveStartPoint.x + CURVE_CIRCLE_RADIUS + (CURVE_CIRCLE_RADIUS / 4), mFirstCurveStartPoint.y);
// the coordinates (x,y) of the 2nd control point on a cubic curve
mFirstCurveControlPoint2.set(mFirstCurveEndPoint.x - (CURVE_CIRCLE_RADIUS * 2) + CURVE_CIRCLE_RADIUS, mFirstCurveEndPoint.y);
mPath.reset();
mPath.moveTo(0, 0);
mPath.lineTo(mFirstCurveStartPoint.x, mFirstCurveStartPoint.y);
mPath.cubicTo(mFirstCurveControlPoint1.x, mFirstCurveControlPoint1.y,
mFirstCurveControlPoint2.x, mFirstCurveControlPoint2.y,
mFirstCurveEndPoint.x, mFirstCurveEndPoint.y);
is there any way to done this using Xml layout

Since I can't add comments because of low reputation, check this link.
Adding another link if you're going to use Java here, in Areas section some great example how to achieve your shape using setVisible.

If you have an image in svg format, use Asset Studio to convert it to xml drawable. Otherwise, use code like that:
<vector xmlns:android="http://schemas.android.com/apk/res/android"
android:width="500dp"
android:height="300dp"
android:viewportWidth="500"
android:viewportHeight="300">
<path
android:pathData="M0,0h500v300h-500z"
android:fillColor="#e3e3e3"/>
<path
android:pathData="M0,80C0,250 487,104 550,247L500,300L0,300"
android:fillColor="#3e47cb"/>
</vector>

How to define an offset for a PatternColor fill in iText?

I am trying to add tiled diagonal watermarks to the pdf, but it seems that pattern fills in iText are always tiled from the bottom left of the page, meaning that the tiles at the top and right side of the page can be cut abruptly. Is there an option to tile from the top left or with an offset instead?
Here is a sample of the code:
List<String> watermarkLines = getWatermarkLines();
Rectangle watermarkRect = getWatermarkRect();
PdfContentByte over = stamper.getOverContent(1);
PdfPatternPainter painter = over.createPattern(watermarkRect.getWidth(), watermarkRect.getHeight();
for (int x = 0; x < watermarkLines.size(); x++) {
AffineTransform trans = getWatermarkTransform(watermarkLines, x);
ColumnText.showTextAligned(painter, 0, watermarkLines.get(x), (float) trans.getTranslateX(), (float) trans.getTranslateY(), 45f);
}
over.setColorFill(new PatternColor(painter));
over.rectangle(0, 0, pageSize.getWidth(), pageSize.getHeight());
over.fill();
I tried changing the x and y of the rectangle function to negative or positive values, but it seems that the watermark is still stamped in the pattern as if it was tiled from the bottom left, cutting it in the same place as before.

First of, I cannot fathom which iText version you are using,
List<String> watermarkLines = getWatermarkLines();
...
ColumnText.showTextAligned(painter, 0, watermarkLines.get(x), (float) trans.getTranslateX(), (float) trans.getTranslateY(), 45f);
implies that the third parameter of the ColumnText.showTextAligned method you use is typed as String or Object. The iText 5 version I have at hand, though, requires a Phrase there. Below I'll show how to apply an offset with the current iText 5.5.13. You'll have to check whether it also works for your version.
Yes, you can apply an offset... in the pattern definition!
If instead of
PdfPatternPainter painter = over.createPattern(watermarkRect.getWidth(), watermarkRect.getHeight());
you create the pattern like this
PdfPatternPainter painter = over.createPattern(2 * watermarkRect.getWidth(), 2 * watermarkRect.getHeight(),
watermarkRect.getWidth(), watermarkRect.getHeight());
you have the same step size of pattern application (watermarkRect.getWidth(), watermarkRect.getHeight()) but a canvas twice that width and twice that height to position you text on. By positioning the text with an offset, you effectively move the whole pattern by that offset.
E.g. if you calculate the offsets as
Rectangle pageSize = pdfReader.getCropBox(1);
float xOff = pageSize.getLeft();
float yOff = pageSize.getBottom() + ((int)pageSize.getHeight()) % ((int)watermarkRect.getHeight());
and draw the text using
ColumnText.showTextAligned(painter, 0, new Phrase(watermarkLines.get(x)), (float) trans.getTranslateX() + xOff, (float) trans.getTranslateY() + yOff, 45f);
the pattern should fill the page as if starting at the top left corner of the visible page.
You haven't supplied getWatermarkLines, getWatermarkRect, and getWatermarkTransform. If I use
static AffineTransform getWatermarkTransform(List<String> watermarkLines, int x) {
return AffineTransform.getTranslateInstance(6 + 15*x, 6);
}
static Rectangle getWatermarkRect() {
return new Rectangle(65, 50);
}
static List<String> getWatermarkLines() {
return Arrays.asList("Test line 1", "Test line 2");
}
your original code for me creates a top left corner like this
and the code with the above offset creates one like this

Center a minus on the screen in java

I am trying to center a minus sign on the screen using the following code:
text = "-";
textPosition = new Point();
Rect bounds = new Rect();
paint.getTextBounds(text, 0, text.length(), bounds);
paint.setTextAlign(Paint.Align.CENTER);
textPosition.x = (int) (myArea.left + myArea.width() / 2);
textPosition.y = (int) (myArea.top + myArea.height() / 2 + bounds.height() / 2);
canvas.drawText(text, textPosition.x, textPosition.y, paint);
This code works like a charm when "text" is something else (for example a plus sign), but in this case the minus sign is positioned too high on the screen.
EDIT:
Here is the result for four different operators.
And... the funny thing is, that I created my own font to display these operators. So I know, that it should be centered correctly.
PS: Now that I look at it, all off them seem a little off, though the minus-sign is the worst...

Okay, I fixed it. Not by changing the code, but by changing the font. I have now aligned all characters on the baseline and that seems to work.

Can someone please explain iTexts canvas drawing order?

I try to draw some nested tables in iText as i thought it would be the easiest way to position everything.
So i have multiple tables inside another table who all have background color and/or strokes (via PdfPCellEvents). Unfortunately the strokes of the outer table are overlapping the background of the inner table.
I assume that comes from a wrong order of applying or some wrong set saveState or restoreState in my PdfPCellEvents.
Can anyone explain the right usage of saveState and restoreState to me and give me a hint how to apply backgrounds and strokes the right way?
Here is my code for adding a striped background cell:
PdfPCell scaleBackground = new PdfPCell();
scaleBackground.setBorder(Rectangle.NO_BORDER);
scaleBackground.setVerticalAlignment(Element.ALIGN_TOP);
scaleBackground.setCellEvent(new StripedScaleBackground(max, scaleHeight));
cellLayout method of StripedScaleBackground:
public void cellLayout(PdfPCell cell, Rectangle rect, PdfContentByte[] canvases)
{
PdfContentByte canvas = canvases[PdfPTable.LINECANVAS];
float llx = rect.getLeft();
float lly = rect.getBottom();
float urx = rect.getRight();
float ury = rect.getTop();
// Light scale lines with padding from left
canvas.setLineWidth(Constants.BORDER_WIDTH_THIN);
canvas.setColorStroke(Colors.LIGHT_GRAY);
float paddingLeft = 22f;
for (int i = 0; i <= this.maxValue; i++)
{
canvas.moveTo(llx + paddingLeft, lly + (this.scaleHeight * (i + 1)));
canvas.lineTo(urx, lly + (this.scaleHeight * (i + 1)));
}
// Vertical line
canvas.moveTo(llx + (((urx - llx) + paddingLeft) / 2), ury);
canvas.lineTo(llx + (((urx - llx) + paddingLeft) / 2), lly);
canvas.stroke();
// Fat line left and right
canvas.moveTo(llx, ury);
canvas.lineTo(llx, lly);
canvas.moveTo(urx, ury);
canvas.lineTo(urx, lly);
canvas.setLineWidth(0.8f);
canvas.setColorStroke(Colors.MEDIUM_GRAY);
canvas.stroke();
canvas.saveState();
canvas.restoreState();
}
The bar charts are tables where each cell has a cell event for gradient and border. The bar charts are added to the scaleBackground PdfPCell of the first piece of code and have following PdfPCellEvents (example of black part of the chart):
public void cellLayout(PdfPCell cell, Rectangle rect, PdfContentByte[] canvases)
{
PdfContentByte backgroundCanvas = canvases[PdfPTable.BACKGROUNDCANVAS];
float llx = rect.getLeft();
float lly = rect.getBottom();
float urx = rect.getRight();
float ury = rect.getTop();
// Draw background
// Define shading with direction and color
PdfShading shading = PdfShading.simpleAxial(this.writer,
llx, ury,
llx, lly,
Colors.BAR_CHART_BLACK_LIGHT, Colors.BAR_CHART_BLACK_DARK);
PdfShadingPattern pattern = new PdfShadingPattern(shading);
backgroundCanvas.setShadingFill(pattern);
// Draw shape with defined shading
backgroundCanvas.moveTo(llx, ury);
backgroundCanvas.lineTo(llx, lly);
backgroundCanvas.lineTo(urx, lly);
backgroundCanvas.lineTo(urx, ury);
backgroundCanvas.lineTo(llx, ury);
backgroundCanvas.fill();
backgroundCanvas.saveState();
backgroundCanvas.restoreState();
// Draw border
PdfContentByte lineCanvas = canvases[PdfPTable.LINECANVAS];
float lineWidth = Constants.BORDER_WIDTH_THIN;
lineCanvas.setLineWidth(lineWidth);
lineCanvas.moveTo(llx, ury - lineWidth);
lineCanvas.lineTo(llx, lly);
lineCanvas.lineTo(urx, lly);
lineCanvas.lineTo(urx, ury - lineWidth);
lineCanvas.setColorStroke(BaseColor.BLACK);
lineCanvas.stroke();
lineCanvas.saveState();
lineCanvas.restoreState();
}

This is the order of the different direct content layers:
PdfPtable.BASECANVAS—Anything placed here will be under the table.
PdfPtable.BACKGROUNDCANVAS—This is the layer where the backgrounds are
drawn.
PdfPtable.LINECANVAS—This is the layer where the lines are drawn.
PdfPtable.TEXTCANVAS—This is the layer where the text goes. Anything placed
here will cover the table.
This was taken from the book "iText in Action - Second Edition."
You also ask about saveState() and restoreState(). This is explained in Chapter 2 of the iText 7 tutorial:
First we save the current graphics state with the saveState() method, then we change the state and draw whatever lines or shapes we want to draw, finally, we use the restoreState() method to return to the original graphics state. All the changes that we applied after saveState() will be undone. This is especially interesting if you change multiple values (line width, color,...) or when it's difficult to calculate the reverse change (returning to the original coordinate system).
Your code was too long for me to inspect, but I highly doubt that saveState()/restoreState() would be the cause of your problem.
I would try to avoid nesting tables as much as possible. It is usually much easier (and more efficient) to use colspan and rowspan.
If this doesn't solve your problem, please explain your problem in one sentence.