clarified state: node_required is guarded by PIDE.editor.document_active (e.g. open panel);
/***************************************************************************
Title: graphbrowser/AWTFontMetrics.java
Author: Gerwin Klein, TU Muenchen
AbstractFontMetrics avoids dependency on java.awt.FontMetrics in
batch mode.
***************************************************************************/
package isabelle.graphbrowser;
public interface AbstractFontMetrics {
public int stringWidth(String str);
public int getAscent();
public int getDescent();
}