Scale Table.INSET by zoom level instead of using fixed pixels

[ShahzaibIbrahim]

The Table.INSET constant defines the spacing in the width of a table cell. Previously, this was a fixed value of 3px, which looks correct at 100% zoom but causes the image and text to appear cramped on higher-DPI displays.

This change defines INSET in points and converts it to pixels based on the current zoom level (e.g. 6px at 200%), ensuring consistent spacing across different monitor scale.

How to Test

• Run the following snippet with 100% primary and 250% secondary monitor zoom
• Note down the width of a cell by moving it from one monitor to other.
• See if the values adhere to zoom levels.

import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.widgets.*;

public class TableInsetTest {

public static void main (String [] args) {
	System.setProperty("swt.autoScale", "quarter");
	System.setProperty("swt.autoScale.updateOnRuntime", "true");
	Display display = new Display ();
	Shell shell = new Shell (display);
	shell.setText("Table Inset Test");
	Table table = new Table (shell, SWT.BORDER | SWT.MULTI);
	table.setLinesVisible(true);
	Rectangle clientArea = shell.getClientArea ();
	table.setBounds (clientArea.x, clientArea.y, 200, 200);
	for (int i=0; i<128; i++) {
		TableItem item = new TableItem (table, SWT.NONE);
		item.setText ("Item " + i);
	}
	table.setSelection (95);
	shell.pack ();
	shell.open ();
	while (!shell.isDisposed ()) {
		if (!display.readAndDispatch ()) display.sleep ();
	}
	display.dispose ();
}
}

Results:
Before Change
Width 150% = 77
Width 250% = 128

After change
Width 150% = 84
Width 250% = 139

[github-actions]

Test Results

   546 files  ±0     546 suites  ±0   32m 59s ⏱️ +43s
 4 431 tests ±0   4 410 ✅  - 4   17 💤 ±0  4 ❌ +4 
16 764 runs  ±0  16 633 ✅  - 4  127 💤 ±0  4 ❌ +4 

For more details on these failures, see this check.

Results for commit feb86f6. ± Comparison against base commit 508ad4a.

♻️ This comment has been updated with latest results.