add gui for setting the zoom level

app/src/processing/app/ui/PreferencesFrame.java

@@ -49,7 +49,6 @@ public class PreferencesFrame {
   GroupLayout layout;
 
   static final Integer[] FONT_SIZES = { 10, 12, 14, 18, 24, 36, 48 };
-  static final String[] ZOOM_OPTIONS = { "100%", "150%", "200%", "300%" };
 
   JTextField sketchbookLocationField;
   JTextField presentColor;
@@ -167,7 +166,7 @@ public class PreferencesFrame {
 
     JLabel zoomLabel = new JLabel(Language.text("preferences.zoom") + ": ");
     zoomSelectionBox = new JComboBox<String>();
-    zoomSelectionBox.setModel(new DefaultComboBoxModel<String>(ZOOM_OPTIONS));
+    zoomSelectionBox.setModel(new DefaultComboBoxModel<String>(Toolkit.zoomOptions.array()));
     zoomRestartLabel = new JLabel(" (" + Language.text("preferences.requires_restart") + ")");
 
 
@@ -658,6 +657,9 @@ public class PreferencesFrame {
       fontSizeField.setSelectedItem(Preferences.getInteger("editor.font.size"));
     }
 
+    Preferences.set("editor.zoom",
+                    String.valueOf(zoomSelectionBox.getSelectedItem()));
+
     try {
       Object selection = consoleFontSizeField.getSelectedItem();
       if (selection instanceof String) {
@@ -727,6 +729,14 @@ public class PreferencesFrame {
     fontSizeField.setSelectedItem(Preferences.getInteger("editor.font.size"));
     consoleFontSizeField.setSelectedItem(Preferences.getInteger("console.font.size"));
 
+    String zoomSel = Preferences.get("editor.zoom");
+    int zoomIndex = Toolkit.zoomOptions.index(zoomSel);
+    if (zoomIndex != -1) {
+      zoomSelectionBox.setSelectedIndex(zoomIndex);
+    } else {
+      zoomSelectionBox.setSelectedIndex(0);
+    }
+
     presentColor.setBackground(Preferences.getColor("run.present.bgcolor"));
     presentColorHex.setText(Preferences.get("run.present.bgcolor").substring(1));
 

app/src/processing/app/ui/Toolkit.java

@@ -75,6 +75,7 @@ import processing.app.Messages;
 import processing.app.Platform;
 import processing.app.Preferences;
 import processing.app.Util;
+import processing.core.PApplet;
 import processing.data.StringList;
 
 
@@ -809,7 +810,7 @@ public class Toolkit {
   // . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
 
 
-  static float zoom = 3;
+  static float zoom = 0;
 
 
   /*
@@ -832,11 +833,31 @@ public class Toolkit {
   */
 
 
+  static final StringList zoomOptions =
+    new StringList("100%", "150%", "200%", "300%");
+
   static public int zoom(int pixels) {
+    if (zoom == 0) {
+      zoom = parseZoom();
+    }
     return (int) (zoom * pixels);
   }
 
 
+  static private float parseZoom() {
+    String zoomSel = Preferences.get("editor.zoom");
+    if (zoomOptions.hasValue(zoomSel)) {
+      // shave off the % symbol at the end
+      zoomSel = zoomSel.substring(0, zoomSel.length() - 1);
+      return PApplet.parseInt(zoomSel, 100) / 100f;
+
+    } else {
+      Preferences.set("editor.zoom", "100%");
+      return 1;
+    }
+  }
+
+
   static BasicStroke zoomStroke;
 
   static private void zoomStroke(Graphics2D g2) {

build/shared/lib/defaults.txt

@@ -105,6 +105,9 @@ editor.window.height.min.windows = 530
 # tested with Raspberry Pi display
 editor.window.height.min.linux = 480
 
+# scaling for the interface (to handle Windows and Linux HiDPI displays)
+editor.zoom = 100%
+
 # font size for editor
 #editor.font = Monospaced,plain,12
 # Monaco is nicer on Mac OS X, so use that explicitly