working on line height issues with #4936

app/src/processing/app/ui/ExamplesFrame.java

@@ -183,6 +183,9 @@ public class ExamplesFrame extends JFrame {
       tree.setToggleClickCount(1);
     }
 
+    // Special cell renderer that takes the UI zoom into account
+    tree.setCellRenderer(new ZoomTreeCellRenderer());
+
     JScrollPane treePane = new JScrollPane(tree);
     treePane.setPreferredSize(new Dimension(250, 300));
     treePane.setBorder(new EmptyBorder(2, 0, 0, 0));

app/src/processing/app/ui/ZoomTreeCellRenderer.java

@@ -0,0 +1,53 @@
+/* -*- mode: java; c-basic-offset: 2; indent-tabs-mode: nil -*- */
+
+/*
+  Part of the Processing project - http://processing.org
+
+  Copyright (c) 2017 The Processing Foundation
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program; if not, write to the Free Software Foundation,
+  Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+*/
+
+package processing.app.ui;
+
+import java.awt.Component;
+
+import javax.swing.JTree;
+import javax.swing.tree.DefaultTreeCellRenderer;
+
+
+class ZoomTreeCellRenderer extends DefaultTreeCellRenderer {
+
+  @Override
+  public Component getTreeCellRendererComponent(JTree tree, Object value,
+                                                boolean selected,
+                                                boolean expanded,
+                                                boolean leaf, int row,
+                                                boolean hasFocus) {
+
+    // Adjust height for magnified displays. The font is scaled properly,
+    // but the rows don't automatically use the scaled preferred size.
+    // https://github.com/processing/processing/issues/4936
+    int high = getPreferredSize().height;
+    if (high != 0) {
+      int current = getSize().height;
+      if (current != high) {
+        tree.setRowHeight(high);
+      }
+    }
+    return super.getTreeCellRendererComponent(tree, value, selected,
+                                              expanded, leaf, row, hasFocus);
+  }
+}