Add ZoomChanged listener to MessageDialogue

When a zoom change occurs, the OS automatically scales the window based
on the scale factor. However, since fonts do not always scale linearly,
this can cause text in dialogues to be cut off.

This change adds a ZoomChanged listener to MessageDialogue. When a
zoomChanged event is triggered, the shell size is recomputed so that the
contents are fit properly and text is not clipped.

Author: arunjose696

bundles/org.eclipse.jface/src/org/eclipse/jface/dialogs/MessageDialog.java

@@ -20,12 +20,15 @@
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.custom.CLabel;
 import org.eclipse.swt.graphics.Image;
+import org.eclipse.swt.graphics.Point;
 import org.eclipse.swt.layout.GridData;
 import org.eclipse.swt.layout.GridLayout;
 import org.eclipse.swt.widgets.Button;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Control;
+import org.eclipse.swt.widgets.Event;
 import org.eclipse.swt.widgets.Label;
+import org.eclipse.swt.widgets.Listener;
 import org.eclipse.swt.widgets.Shell;
 
 /**
@@ -283,6 +286,13 @@ protected void configureShell(Shell shell) {
 		if (titleImage != null) {
 			shell.setImage(titleImage);
 		}
+		shell.addListener(SWT.ZoomChanged, new Listener() {
+			@Override
+			public void handleEvent(Event e) {
+				Point newSize = shell.computeSize(SWT.DEFAULT, SWT.DEFAULT, true);
+				shell.setBounds(shell.getBounds().x, shell.getBounds().y, newSize.x, newSize.y);
+			}
+		});
 	}
 
 	@Override