More Impactful Current Line Number Font.

[omegaui]

Today I installed Fedora 36 which comes with gnome's new Text Editor.

Take a look

Notice the difference between the current line number and others.

See how the current line number is popping out because of higher font size and bold style.

First I implemented this feature on my copy of the library, with more impactful look that feels more like a 3d effect.

To achieve this I also needed to alter the updateCellWidths() function to include more size for the popping current line number.

void updateCellWidths() {

	int oldCellWidth = cellWidth;
	cellWidth = getRhsBorderWidth();

	// Adjust the amount of space the line numbers take up, if necessary.
	if (textArea!=null) {
		Font font = getFont();
		if (font!=null) {
			FontMetrics fontMetrics = getFontMetrics(font);
			int count = 0;
			int lineCount = textArea.getLineCount() +
			getLineNumberingStartIndex() - 1;
			do {
				lineCount = lineCount/10;
				count++;
			} while (lineCount >= 10);
			// This was required since the current line number has a higher font size so the previous method can cause the first digit of the
			// number to go out of bounds of the line number list.
			// Maybe there is some better solution to this situation.
			cellWidth += fontMetrics.charWidth('9')*(count+1) + (fontMetrics.charWidth('9') * (int)currentLineNumberFontIncreaseSize);
		}
	}

	if (cellWidth!=oldCellWidth) { // Always true
		revalidate();
	}

}

And that's it, the end results are amazing.

[bobbylight]

Generally I think this is a fine addition, but I have some suggestions for changes. Also, I think some lines might be > 120 characters and thus failing the linting?

[bobbylight]

The g.drawString() call could still be here instead of in the if- and else blocks if we create a new x variable and assign it a vale in the if/else blocks. I'd kind-of prefer a single g.drawString() here.

[bobbylight]

Same changes here as in the LTR case

[bobbylight]

If the new field is its own font then we don't have to derive the new font on each call to paintComponent().

[bobbylight]

Assuming we just move to a currentLineNumberFont variable, we can just pick the larger of the two FontMetrics values here to simplify things a bit:

Font font = getFont();
FontMetrics fontMetrics = font.getFontMetrics();
int charWidth = fontMetrics.charWidth('9');
if (currentLineNumberFont != null) {
  int charWidth2 = currentLineNumberFont.getFontMetrics().charWidth('9');
  charWidth = Math.max(charWidth, charWidth2);
}
...
cellWidth += charWidth * (count + 1) + 3;

Might even move that charWidth calculation logic into a private helper method just to make the code more readable,.