[Win32] Use exact selected font size from FontDialog

The FontDialog implementation creates a font handle based on the
selection in the dialog to extract information about the font size out
of that created font. Due to point/pixel conversion and roundings that
depend on the current DPI (affected by the primary monitor zoom), the
resulting font size selected differs from what the user has selected.
For example, when selecting a 10pt font, the result of the dialog will
contain a height of 9.75pt on a 100% monitor and of 10.2pt on a 125%
monitor.
At the same time, the dialog manages the logically selected size, i.e.,
in the given scenario the selected 10pt, which could be used instead.

This change replaces the complex and imprecise font height extraction
logic with a simple read of the actual value selected by the user.

Author: HeikoKlare

bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/widgets/FontDialog.java

@@ -249,36 +249,7 @@ public FontData open () {
 		if (success) {
 			LOGFONT logFont = new LOGFONT();
 			OS.MoveMemory(logFont, lpLogFont, LOGFONT.sizeof);
-
-			/*
-			 * This will not work on multiple screens or for printing. Should use DC for the
-			 * proper device.
-			 */
-			int logPixelsY = getDPI();
-			int pixels = 0;
-			long hDC = OS.GetDC(0);
-			if (logFont.lfHeight > 0) {
-				/*
-				 * Feature in Windows. If the lfHeight of the LOGFONT structure is positive, the
-				 * lfHeight measures the height of the entire cell, including internal leading,
-				 * in logical units. Since the height of a font in points does not include the
-				 * internal leading, we must subtract the internal leading, which requires a
-				 * TEXTMETRIC, which in turn requires font creation.
-				 */
-				long hFont = OS.CreateFontIndirect(logFont);
-				long oldFont = OS.SelectObject(hDC, hFont);
-				TEXTMETRIC lptm = new TEXTMETRIC();
-				OS.GetTextMetrics(hDC, lptm);
-				OS.SelectObject(hDC, oldFont);
-				OS.DeleteObject(hFont);
-				pixels = logFont.lfHeight - lptm.tmInternalLeading;
-			} else {
-				pixels = -logFont.lfHeight;
-			}
-			OS.ReleaseDC(0, hDC);
-
-			float points = pixels * 72f / logPixelsY;
-			fontData = FontData.win32_new(logFont, points);
+			fontData = FontData.win32_new(logFont, lpcf.iPointSize / 10f);
 			if (effectsVisible) {
 				int red = lpcf.rgbColors & 0xFF;
 				int green = (lpcf.rgbColors >> 8) & 0xFF;