Added 'Value Notation' to the Config menu

diylc/diylc-core/src/main/java/org/diylc/common/IPlugInPort.java

@@ -90,6 +90,7 @@ public interface IPlugInPort extends ISelectionProcessor, IMouseProcessor, IKeyP
   public static final String FONT_SCALE_FACTOR_KEY = "fontScaleFactor";
   public static final String SHOW_RESIZE_DIMENSIONS_TOOLTIP_KEY = "showResizeDimensionsTooltip";
   public static final String AUTO_UNIT_CONVERSION_KEY = "autoUnitConversion";
+  public static final String VALUE_NOTATION_KEY = "valueNotation";
 
 
   public static final String RULER_IN_SUBDIVISION_2 = "base of 2";
@@ -101,6 +102,10 @@ public interface IPlugInPort extends ISelectionProcessor, IMouseProcessor, IKeyP
   public static final String SNAP_TO_COMPONENTS = "Components";
   public static final String SNAP_TO_DEFAULT = SNAP_TO_GRID;
 
+  public static final String VALUE_NOTATION_DECIMAL = "Decimal (4.7K, 0.22uF)";
+  public static final String VALUE_NOTATION_RKM = "RKM (4K7, 0u22)";
+  public static final String VALUE_NOTATION_DEFAULT = VALUE_NOTATION_DECIMAL;
+
   public static final String SHOW_NODE_NAME_TOOLTIPS_KEY = "showNodeNameTooltips";
 
   public static final String LOCKED_ALPHA = "lockedAlpha";

diylc/diylc-core/src/main/java/org/diylc/core/measures/Capacitance.java

@@ -41,14 +41,16 @@ public class Capacitance extends AbstractMeasure<CapacitanceUnit> {
   }
 
   public static Capacitance parseCapacitance(String value) {
-    value = value.replace("*", "");
-    for (CapacitanceUnit unit : CapacitanceUnit.values()) {
-      if (value.toLowerCase().endsWith(unit.toString().toLowerCase())) {
-        value = value.substring(0, value.length() - unit.toString().length()).trim();
-        return new Capacitance(parse(value), unit);
-      }
+    ValueNotation.ParsedMeasure<CapacitanceUnit> parsed;
+    try {
+      parsed = ValueNotation.parse(value, CapacitanceUnit::fromSymbol);
+    } catch (IllegalArgumentException e) {
+      throw new IllegalArgumentException("Could not parse capacitance: " + value, e);
     }
-    throw new IllegalArgumentException("Could not parse capacitance: " + value);
+    if (parsed.unit() == null) {
+      throw new IllegalArgumentException("Could not parse capacitance: " + value);
+    }
+    return new Capacitance(parsed.value(), parsed.unit());
   }
   
   public Double getNormalizedValue() {
@@ -56,4 +58,12 @@ public class Capacitance extends AbstractMeasure<CapacitanceUnit> {
       return null;
     return value * unit.getFactor(); 
   }
+
+  @Override
+  public String toString() {
+    if (ValueNotation.getCurrent() == ValueNotation.RKM && value != null && unit != null) {
+      return ValueNotation.formatRkm(value, unit.getRkmSymbol());
+    }
+    return super.toString();
+  }
 }

diylc/diylc-core/src/main/java/org/diylc/core/measures/CapacitanceUnit.java

@@ -23,14 +23,16 @@ package org.diylc.core.measures;
 
 public enum CapacitanceUnit implements Unit {
 
-  pF(1e-6, "pF"), nF(1e-3, "nF"), uF(1, "uF"), mF(1e3, "mF"), F(1e6, "F");
+  pF(1e-6, "pF", "p"), nF(1e-3, "nF", "n"), uF(1, "uF", "u"), mF(1e3, "mF", "m"), F(1e6, "F", "F");
 
   double factor;
   String display;
+  String rkmSymbol;
 
-  private CapacitanceUnit(double factor, String display) {
+  private CapacitanceUnit(double factor, String display, String rkmSymbol) {
     this.factor = factor;
     this.display = display;
+    this.rkmSymbol = rkmSymbol;
   }
 
   @Override
@@ -38,8 +40,49 @@ public enum CapacitanceUnit implements Unit {
     return factor;
   }
 
+  public String getRkmSymbol() {
+    return rkmSymbol;
+  }
+
   @Override
   public String toString() {
     return display;
   }
+
+  /**
+   * Resolves the unit written after a capacitance value, e.g. "nF", "n", "u", "\u00B5F" or "F".
+   * Case does not matter when the trailing "F" is present, which is how values have always been
+   * parsed. Without it, "M" is rejected so that it is never mistaken for mega.
+   * 
+   * @param symbol unit text with no surrounding whitespace
+   * @return the unit, or null when the text is not a capacitance unit
+   */
+  public static CapacitanceUnit fromSymbol(String symbol) {
+    if (symbol.equalsIgnoreCase("F")) {
+      return F;
+    }
+    String prefix = symbol;
+    if (symbol.length() == 2 && (symbol.endsWith("F") || symbol.endsWith("f"))) {
+      prefix = symbol.substring(0, 1).toLowerCase();
+    } else if (symbol.equals("M")) {
+      return null;
+    }
+    switch (prefix) {
+      case "p":
+      case "P":
+        return pF;
+      case "n":
+      case "N":
+        return nF;
+      case "u":
+      case "U":
+      case "\u00B5":
+      case "\u03BC":
+        return uF;
+      case "m":
+        return mF;
+      default:
+        return null;
+    }
+  }
 }

diylc/diylc-core/src/main/java/org/diylc/core/measures/Resistance.java

@@ -109,14 +109,16 @@ public class Resistance extends AbstractMeasure<ResistanceUnit> {
   }
 
   public static Resistance parseResistance(String value) {
-    value = value.replace("*", "").replace("R", "\u2126");
-    for (ResistanceUnit unit : ResistanceUnit.values()) {
-      if (value.toLowerCase().endsWith(unit.toString().toLowerCase())) {
-        value = value.substring(0, value.length() - unit.toString().length()).trim();
-        return new Resistance(parse(value), unit);
-      }
+    ValueNotation.ParsedMeasure<ResistanceUnit> parsed;
+    try {
+      parsed = ValueNotation.parse(value, ResistanceUnit::fromSymbol);
+    } catch (IllegalArgumentException e) {
+      throw new IllegalArgumentException("Could not parse resistance: " + value, e);
     }
-    throw new IllegalArgumentException("Could not parse resistance: " + value);
+    if (parsed.unit() == null) {
+      throw new IllegalArgumentException("Could not parse resistance: " + value);
+    }
+    return new Resistance(parsed.value(), parsed.unit());
   }
 
   public Double getNormalizedValue() {
@@ -124,4 +126,12 @@ public class Resistance extends AbstractMeasure<ResistanceUnit> {
       return null;
     return value * unit.getFactor(); 
   }
+
+  @Override
+  public String toString() {
+    if (ValueNotation.getCurrent() == ValueNotation.RKM && value != null && unit != null) {
+      return ValueNotation.formatRkm(value, unit.getRkmSymbol());
+    }
+    return super.toString();
+  }
 }

diylc/diylc-core/src/main/java/org/diylc/core/measures/ResistanceUnit.java

@@ -23,14 +23,16 @@ package org.diylc.core.measures;
 
 public enum ResistanceUnit implements Unit {
 
-  R(1, "\u03A9"), K(1e3, "K"), M(1e6, "M");
+  R(1, "\u03A9", "R"), K(1e3, "K", "K"), M(1e6, "M", "M");
 
   double factor;
   String display;
+  String rkmSymbol;
 
-  private ResistanceUnit(double factor, String display) {
+  private ResistanceUnit(double factor, String display, String rkmSymbol) {
     this.factor = factor;
     this.display = display;
+    this.rkmSymbol = rkmSymbol;
   }
 
   @Override
@@ -39,8 +41,45 @@ public enum ResistanceUnit implements Unit {
     
   }
 
+  public String getRkmSymbol() {
+    return rkmSymbol;
+  }
+
   @Override
   public String toString() {
     return display;
   }
+
+  /**
+   * Resolves the unit written after a resistance value, e.g. "K", "kohm", "R", "\u03A9" or "Meg".
+   * A lower-case "m" means mega, because there is no milliohm unit and parts lists commonly write
+   * "1m" for one megohm.
+   * 
+   * @param symbol unit text with no surrounding whitespace
+   * @return the unit, or null when the text is not a resistance unit
+   */
+  public static ResistanceUnit fromSymbol(String symbol) {
+    String prefix = symbol;
+    String lower = symbol.toLowerCase();
+    for (String ohm : new String[] {"ohms", "ohm", "\u03A9", "\u2126"}) {
+      if (lower.endsWith(ohm.toLowerCase())) {
+        prefix = symbol.substring(0, symbol.length() - ohm.length());
+        if (prefix.isEmpty()) {
+          return R;
+        }
+        break;
+      }
+    }
+    switch (prefix.toLowerCase()) {
+      case "r":
+        return R;
+      case "k":
+        return K;
+      case "m":
+      case "meg":
+        return M;
+      default:
+        return null;
+    }
+  }
 }

diylc/diylc-core/src/main/java/org/diylc/core/measures/ValueNotation.java

@@ -0,0 +1,128 @@
+/*
+
+    DIY Layout Creator (DIYLC).
+    Copyright (c) 2009-2025 held jointly by the individual authors.
+
+    This file is part of DIYLC.
+
+    DIYLC 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 3 of the License, or
+    (at your option) any later version.
+
+    DIYLC 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 DIYLC.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+package org.diylc.core.measures;
+
+import java.text.DecimalFormat;
+import java.text.DecimalFormatSymbols;
+import java.util.Locale;
+import java.util.function.Function;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+/**
+ * Notation used to write resistance and capacitance values: plain decimal ("4.7K", "0.22uF") or
+ * RKM as defined by IEC 60062, where the unit symbol takes the place of the decimal point ("4K7",
+ * "0u22"). Parsing accepts both regardless of the selected notation.
+ *
+ * @author Branislav Stojkovic
+ */
+public enum ValueNotation {
+
+  DECIMAL, RKM;
+
+  private static final DecimalFormat RKM_FORMAT =
+      new DecimalFormat("0.####", DecimalFormatSymbols.getInstance(Locale.US));
+
+  private static final Pattern RKM_PATTERN = Pattern.compile("^(-?)(\\d*)([^\\d.\\-]+)(\\d+)([^\\d.]*)$");
+
+  // read on every repaint through toString(), so it is kept here rather than looked up in the
+  // configuration
+  private static volatile ValueNotation current = DECIMAL;
+
+  public static ValueNotation getCurrent() {
+    return current;
+  }
+
+  public static void setCurrent(ValueNotation notation) {
+    current = notation == null ? DECIMAL : notation;
+  }
+
+  /**
+   * Writes a value in RKM notation, e.g. 4.7 with "K" becomes "4K7" and 100 with "R" becomes
+   * "100R". The value is kept in the unit it is stored in and never renormalized.
+   *
+   * @param value value expressed in the unit
+   * @param rkmSymbol symbol that stands in for the decimal point
+   * @return RKM code
+   */
+  public static String formatRkm(double value, String rkmSymbol) {
+    String text;
+    synchronized (RKM_FORMAT) {
+      text = RKM_FORMAT.format(value);
+    }
+    int dot = text.indexOf('.');
+    if (dot < 0) {
+      return text + rkmSymbol;
+    }
+    return text.substring(0, dot) + rkmSymbol + text.substring(dot + 1);
+  }
+
+  /**
+   * Parses a value written either in decimal notation with an optional unit ("4.7", "4.7k",
+   * "0.22 uF") or in RKM notation ("4K7", "R22", "2n2F").
+   *
+   * @param text text to parse
+   * @param unitResolver maps the unit text to a unit, returning null when it is not recognized
+   * @return parsed value; its unit is null when the text carries no unit
+   * @throws IllegalArgumentException when the text cannot be parsed
+   */
+  public static <U extends Unit> ParsedMeasure<U> parse(String text,
+      Function<String, U> unitResolver) {
+    if (text == null) {
+      throw new IllegalArgumentException("Nothing to parse");
+    }
+    String value = text.replace("*", "").replace(",", ".").replaceAll("\\s", "");
+    if (value.isEmpty()) {
+      throw new IllegalArgumentException("Nothing to parse");
+    }
+
+    int unitStart = value.length();
+    while (unitStart > 0 && !Character.isDigit(value.charAt(unitStart - 1))
+        && value.charAt(unitStart - 1) != '.') {
+      unitStart--;
+    }
+    String number = value.substring(0, unitStart);
+    String unitText = value.substring(unitStart);
+    U unit = unitText.isEmpty() ? null : unitResolver.apply(unitText);
+    if (unitText.isEmpty() || unit != null) {
+      try {
+        return new ParsedMeasure<U>(Double.parseDouble(number), unit);
+      } catch (NumberFormatException e) {
+        // not a decimal number, try RKM below
+      }
+    }
+
+    Matcher matcher = RKM_PATTERN.matcher(value);
+    if (matcher.matches()) {
+      unit = unitResolver.apply(matcher.group(3) + matcher.group(5));
+      if (unit != null) {
+        String integerPart = matcher.group(2).isEmpty() ? "0" : matcher.group(2);
+        double parsed = Double.parseDouble(integerPart + "." + matcher.group(4));
+        return new ParsedMeasure<U>(matcher.group(1).isEmpty() ? parsed : -parsed, unit);
+      }
+    }
+    throw new IllegalArgumentException("Could not parse value: " + text);
+  }
+
+  public record ParsedMeasure<U extends Unit>(double value, U unit) {
+  }
+}

diylc/diylc-core/src/main/java/org/diylc/presenter/ValueNotationBinder.java

@@ -0,0 +1,54 @@
+/*
+
+    DIY Layout Creator (DIYLC).
+    Copyright (c) 2009-2025 held jointly by the individual authors.
+
+    This file is part of DIYLC.
+
+    DIYLC 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 3 of the License, or
+    (at your option) any later version.
+
+    DIYLC 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 DIYLC.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+package org.diylc.presenter;
+
+import org.diylc.appframework.miscutils.IConfigurationManager;
+
+import org.diylc.common.IPlugInPort;
+import org.diylc.core.measures.ValueNotation;
+
+/**
+ * Keeps {@link ValueNotation#getCurrent()} in sync with the value notation the user picked in the
+ * configuration, and redraws the project when it changes. The notation is global, so only the
+ * main window binds it; secondary presenters (previews, thumbnails, batch conversion, regression
+ * runs) run on in-memory configurations and must not reset it.
+ *
+ * @author Branislav Stojkovic
+ */
+public class ValueNotationBinder {
+
+  public static void bind(IConfigurationManager<?> configManager, Runnable refresh) {
+    apply(configManager.readString(IPlugInPort.VALUE_NOTATION_KEY,
+        IPlugInPort.VALUE_NOTATION_DEFAULT));
+    configManager.addConfigListener(IPlugInPort.VALUE_NOTATION_KEY, (key, value) -> {
+      apply(value == null ? null : value.toString());
+      // cached component images still carry the labels drawn in the previous notation
+      DrawingCache.Instance.clear();
+      refresh.run();
+    });
+  }
+
+  static void apply(String configValue) {
+    ValueNotation.setCurrent(IPlugInPort.VALUE_NOTATION_RKM.equalsIgnoreCase(configValue)
+        ? ValueNotation.RKM : ValueNotation.DECIMAL);
+  }
+}

diylc/diylc-core/src/main/resources/update.xml

@@ -629,6 +629,10 @@
 			<releaseDate>2026-11-07 00:00:00.000 CET</releaseDate>
 			<name></name>
 			<changes>
+				<org.diylc.appframework.update.Change>
+					<changeType>NEW_FEATURE</changeType>
+					<description>Added 'Value Notation' to the Config menu to show resistance and capacitance values in RKM notation, e.g. 4K7, 0R22, 2n2 or 0u22, instead of decimal; values can be typed in either notation, and typing the unit together with the value, e.g. 4K7 or 2.2nF, sets the unit at the same time</description>
+				</org.diylc.appframework.update.Change>
 				<org.diylc.appframework.update.Change>
 					<changeType>BUG_FIX</changeType>
 					<description>Rotated labels in pasted components and building blocks were drawn in the wrong place and at the wrong angle while following the mouse, until the components were placed</description>

diylc/diylc-core/src/test/java/org/diylc/core/measures/ValueNotationTest.java

@@ -0,0 +1,203 @@
+/*
+
+    DIY Layout Creator (DIYLC).
+    Copyright (c) 2009-2025 held jointly by the individual authors.
+
+    This file is part of DIYLC.
+
+    DIYLC 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 3 of the License, or
+    (at your option) any later version.
+
+    DIYLC 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 DIYLC.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+package org.diylc.core.measures;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.fail;
+
+import org.junit.After;
+import org.junit.Test;
+
+public class ValueNotationTest {
+
+  private static final double DELTA = 1e-9;
+
+  @After
+  public void resetNotation() {
+    ValueNotation.setCurrent(ValueNotation.DECIMAL);
+  }
+
+  // --- formatting ---
+
+  @Test
+  public void decimalResistanceIsUnchanged() {
+    assertEquals("4.7\u03A9", new Resistance(4.7, ResistanceUnit.R).toString());
+    assertEquals("0.22\u03A9", new Resistance(0.22, ResistanceUnit.R).toString());
+    assertEquals("4.7K", new Resistance(4.7, ResistanceUnit.K).toString());
+    assertEquals("1M", new Resistance(1d, ResistanceUnit.M).toString());
+  }
+
+  @Test
+  public void decimalCapacitanceIsUnchanged() {
+    assertEquals("0.22uF", new Capacitance(0.22, CapacitanceUnit.uF).toString());
+    assertEquals("100nF", new Capacitance(100d, CapacitanceUnit.nF).toString());
+  }
+
+  @Test
+  public void rkmResistance() {
+    ValueNotation.setCurrent(ValueNotation.RKM);
+    assertEquals("4R7", new Resistance(4.7, ResistanceUnit.R).toString());
+    assertEquals("0R22", new Resistance(0.22, ResistanceUnit.R).toString());
+    assertEquals("100R", new Resistance(100d, ResistanceUnit.R).toString());
+    assertEquals("4K7", new Resistance(4.7, ResistanceUnit.K).toString());
+    assertEquals("47K", new Resistance(47d, ResistanceUnit.K).toString());
+    assertEquals("1M", new Resistance(1d, ResistanceUnit.M).toString());
+    assertEquals("4700R", new Resistance(4700d, ResistanceUnit.R).toString());
+    assertEquals("0R", new Resistance(0d, ResistanceUnit.R).toString());
+    assertEquals("4K7501", new Resistance(4.75012, ResistanceUnit.K).toString());
+  }
+
+  @Test
+  public void rkmCapacitance() {
+    ValueNotation.setCurrent(ValueNotation.RKM);
+    assertEquals("0u22", new Capacitance(0.22, CapacitanceUnit.uF).toString());
+    assertEquals("2n2", new Capacitance(2.2, CapacitanceUnit.nF).toString());
+    assertEquals("100n", new Capacitance(100d, CapacitanceUnit.nF).toString());
+    assertEquals("4p7", new Capacitance(4.7, CapacitanceUnit.pF).toString());
+    assertEquals("1000u", new Capacitance(1000d, CapacitanceUnit.uF).toString());
+  }
+
+  // --- parsing ---
+
+  @Test
+  public void parsesDecimalResistance() {
+    assertResistance(4.7, ResistanceUnit.K, "4.7K");
+    assertResistance(4.7, ResistanceUnit.K, "4.7k");
+    assertResistance(4.7, ResistanceUnit.K, "4.7 K");
+    assertResistance(4.7, ResistanceUnit.K, "4,7K");
+    assertResistance(4.7, ResistanceUnit.K, "4.7kohm");
+    assertResistance(4.7, ResistanceUnit.R, "4.7ohm");
+    assertResistance(4.7, ResistanceUnit.R, "4.7 ohms");
+    assertResistance(4.7, ResistanceUnit.R, "4.7\u03A9");
+    assertResistance(4.7, ResistanceUnit.R, "4.7\u2126");
+    assertResistance(4.7, ResistanceUnit.K, "4.7K\u03A9");
+    assertResistance(1, ResistanceUnit.M, "1M");
+    assertResistance(1, ResistanceUnit.M, "1m");
+    assertResistance(2.2, ResistanceUnit.M, "2.2Meg");
+    assertResistance(100, ResistanceUnit.R, "100R");
+    assertResistance(100, ResistanceUnit.R, "100r");
+    assertResistance(0.5, ResistanceUnit.K, ".5K");
+    assertResistance(10, ResistanceUnit.K, "10K*");
+  }
+
+  @Test
+  public void parsesRkmResistance() {
+    assertResistance(4.7, ResistanceUnit.R, "4R7");
+    assertResistance(0.22, ResistanceUnit.R, "0R22");
+    assertResistance(0.22, ResistanceUnit.R, "R22");
+    assertResistance(4.7, ResistanceUnit.K, "4K7");
+    assertResistance(4.7, ResistanceUnit.K, "4k7");
+    assertResistance(4.75, ResistanceUnit.K, "4K75");
+    assertResistance(2.2, ResistanceUnit.M, "2M2");
+  }
+
+  @Test
+  public void parsesDecimalCapacitance() {
+    assertCapacitance(0.22, CapacitanceUnit.uF, "0.22uF");
+    assertCapacitance(0.22, CapacitanceUnit.uF, "0.22UF");
+    assertCapacitance(0.22, CapacitanceUnit.uF, "0.22u");
+    assertCapacitance(220, CapacitanceUnit.nF, "220 nF");
+    assertCapacitance(220, CapacitanceUnit.nF, "220n");
+    assertCapacitance(47, CapacitanceUnit.pF, "47pf");
+    assertCapacitance(4.7, CapacitanceUnit.uF, "4.7\u00B5F");
+    assertCapacitance(1, CapacitanceUnit.F, "1F");
+    assertCapacitance(1, CapacitanceUnit.mF, "1mF");
+    assertCapacitance(1, CapacitanceUnit.mF, "1MF");
+    assertCapacitance(1, CapacitanceUnit.mF, "1m");
+  }
+
+  @Test
+  public void parsesRkmCapacitance() {
+    assertCapacitance(0.22, CapacitanceUnit.uF, "0u22");
+    assertCapacitance(0.22, CapacitanceUnit.uF, "u22");
+    assertCapacitance(2.2, CapacitanceUnit.nF, "2n2");
+    assertCapacitance(2.2, CapacitanceUnit.nF, "2n2F");
+    assertCapacitance(4.7, CapacitanceUnit.uF, "4u7");
+    assertCapacitance(4.7, CapacitanceUnit.uF, "4\u00B57");
+    assertCapacitance(4.7, CapacitanceUnit.uF, "4\u03BC7");
+    assertCapacitance(4.7, CapacitanceUnit.pF, "4p7");
+  }
+
+  @Test
+  public void bareNumberHasNoUnit() {
+    ValueNotation.ParsedMeasure<ResistanceUnit> parsed =
+        ValueNotation.parse("4.7", ResistanceUnit::fromSymbol);
+    assertEquals(4.7, parsed.value(), DELTA);
+    assertNull(parsed.unit());
+  }
+
+  @Test
+  public void rejectsInvalidText() {
+    assertRejected("4u7", ResistanceUnit.class);
+    assertRejected("4K7K", ResistanceUnit.class);
+    assertRejected("K", ResistanceUnit.class);
+    assertRejected("", ResistanceUnit.class);
+    assertRejected("100", ResistanceUnit.class);
+    assertRejected("4R7", CapacitanceUnit.class);
+    assertRejected("1M", CapacitanceUnit.class);
+    assertRejected("4M7", CapacitanceUnit.class);
+  }
+
+  @Test
+  public void roundTripsInBothNotations() {
+    double[] values = {0.22, 1, 4.7, 47, 100, 4700, 0.0047};
+    for (ValueNotation notation : ValueNotation.values()) {
+      ValueNotation.setCurrent(notation);
+      for (double value : values) {
+        for (ResistanceUnit unit : ResistanceUnit.values()) {
+          Resistance resistance = new Resistance(value, unit);
+          assertEquals(resistance, Resistance.parseResistance(resistance.toString()));
+        }
+        for (CapacitanceUnit unit : CapacitanceUnit.values()) {
+          Capacitance capacitance = new Capacitance(value, unit);
+          assertEquals(capacitance, Capacitance.parseCapacitance(capacitance.toString()));
+        }
+      }
+    }
+  }
+
+  private static void assertResistance(double value, ResistanceUnit unit, String text) {
+    Resistance parsed = Resistance.parseResistance(text);
+    assertEquals(text, value, parsed.getValue(), DELTA);
+    assertEquals(text, unit, parsed.getUnit());
+  }
+
+  private static void assertCapacitance(double value, CapacitanceUnit unit, String text) {
+    Capacitance parsed = Capacitance.parseCapacitance(text);
+    assertEquals(text, value, parsed.getValue(), DELTA);
+    assertEquals(text, unit, parsed.getUnit());
+  }
+
+  private static void assertRejected(String text, Class<?> unitType) {
+    try {
+      if (unitType == ResistanceUnit.class) {
+        Resistance.parseResistance(text);
+      } else {
+        Capacitance.parseCapacitance(text);
+      }
+      fail("Expected " + text + " to be rejected");
+    } catch (IllegalArgumentException e) {
+      // expected
+    }
+  }
+}

diylc/diylc-swing/src/main/java/org/diylc/swing/gui/editor/MeasureArrayEditor.java

@@ -26,6 +26,8 @@ import java.awt.Color;
 import java.awt.Container;
 import java.awt.event.ActionEvent;
 import java.awt.event.ActionListener;
+import java.awt.event.FocusAdapter;
+import java.awt.event.FocusEvent;
 import java.awt.event.KeyListener;
 import java.beans.PropertyChangeEvent;
 import java.beans.PropertyChangeListener;
@@ -34,12 +36,19 @@ import java.lang.reflect.Constructor;
 import java.lang.reflect.Method;
 import java.lang.reflect.ParameterizedType;
 import java.lang.reflect.Type;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.function.Function;
 import javax.swing.JComboBox;
+import javax.swing.JTextField;
 import org.apache.log4j.Logger;
 import org.diylc.swingframework.DoubleArrayTextField;
 
 import org.diylc.common.PropertyWrapper;
 import org.diylc.core.measures.AbstractMeasure;
+import org.diylc.core.measures.Unit;
+import org.diylc.core.measures.ValueNotation;
+import org.diylc.core.measures.ValueNotation.ParsedMeasure;
 import org.diylc.utils.Constants;
 
 public class MeasureArrayEditor extends Container {
@@ -50,52 +59,59 @@ public class MeasureArrayEditor extends Container {
 			.getLogger(MeasureArrayEditor.class);
 
 	private Color oldBg;
-	private DoubleArrayTextField valueField;
+	private JTextField valueField;
 	private JComboBox<Object> unitBox;
+	private boolean ignoreUnitChanges = false;
 	
+	@SuppressWarnings("unchecked")
 	public MeasureArrayEditor(final PropertyWrapper property) {
 		setLayout(new BorderLayout());
 		final AbstractMeasure<?>[] measure = ((AbstractMeasure<?>[]) property
 				.getValue());
-		Double[] values = new Double[measure.length];
-		for (int i = 0; i < measure.length; i++) {
-			values[i] = measure[i] == null ? null : measure[i].getValue();
-		}
-		valueField = new DoubleArrayTextField(measure == null ? null : values);
-		if (property.isReadOnly())
-	      valueField.setEnabled(false);
-		oldBg = valueField.getBackground();
-		valueField.addPropertyChangeListener(
-				DoubleArrayTextField.VALUE_PROPERTY,
-				new PropertyChangeListener() {
+		final Function<String, Unit> unitResolver = MeasureEditor
+				.getUnitResolver(property.getType().getComponentType());
+		if (unitResolver == null) {
+			valueField = createDoubleField(property, measure);
+		} else {
+			final MeasureTextField<List<ParsedMeasure<Unit>>> measureField = new MeasureTextField<List<ParsedMeasure<Unit>>>(
+					formatForField(measure), text -> parseSections(text, unitResolver));
+			measureField.addPropertyChangeListener(MeasureTextField.VALUE_PROPERTY,
+					new PropertyChangeListener() {
 
-					@Override
-					public void propertyChange(PropertyChangeEvent evt) {
-						try {
-							Constructor<?> ctor = property.getType().getComponentType()
-									.getConstructors()[0];
-							Double[] newValues = (Double[]) evt.getNewValue();
-							AbstractMeasure<?>[] newMeasure;
-							if (newValues == null)
-								newMeasure = null;
-							else {
-								newMeasure = (AbstractMeasure<?>[]) Array.newInstance(property.getType().getComponentType(), newValues.length);
-								for (int i = 0; i < newValues.length; i++) {
-									newMeasure[i] = (AbstractMeasure<?>) ctor
-											.newInstance(newValues[i],
-													unitBox.getSelectedItem());
+						@Override
+						public void propertyChange(PropertyChangeEvent evt) {
+							List<ParsedMeasure<Unit>> parsed = (List<ParsedMeasure<Unit>>) evt
+									.getNewValue();
+							// the unit box shows the unit of the first section
+							if (parsed != null && !parsed.isEmpty() && parsed.get(0) != null
+									&& parsed.get(0).unit() != null
+									&& parsed.get(0).unit() != unitBox.getSelectedItem()) {
+								ignoreUnitChanges = true;
+								try {
+									unitBox.setSelectedItem(parsed.get(0).unit());
+								} finally {
+									ignoreUnitChanges = false;
 								}
 							}
-
-							property.setValue(newMeasure);
-							property.setChanged(true);
-							valueField.setBackground(oldBg);
-							unitBox.setBackground(oldBg);
-						} catch (Exception e) {
-							LOG.error("Error while updating property value", e);
+							applySections(property, parsed, false);
 						}
+					});
+			measureField.addFocusListener(new FocusAdapter() {
+
+				@Override
+				public void focusLost(FocusEvent e) {
+					if (measureField.getValue() != null) {
+						measureField.setDisplayText(
+								formatForField((AbstractMeasure<?>[]) property.getValue()));
 					}
-				});
+				}
+			});
+			valueField = measureField;
+		}
+		if (property.isReadOnly()) {
+			valueField.setEnabled(false);
+		}
+		oldBg = valueField.getBackground();
 		add(valueField, BorderLayout.CENTER);
 		try {
 			Type type = ((ParameterizedType) property.getType().getComponentType()
@@ -108,29 +124,18 @@ public class MeasureArrayEditor extends Container {
 
 				@Override
 				public void actionPerformed(ActionEvent evt) {
-					try {
-						Constructor<?> ctor = property.getType().getComponentType()
-								.getConstructors()[0];
-						
-						AbstractMeasure<?>[] newMeasure;
-						Double[] newValues = valueField.getValue();
-						if (newValues == null)
-							newMeasure = null;
-						else {
-							newMeasure = (AbstractMeasure<?>[]) Array.newInstance(property.getType().getComponentType(), newValues.length);
-							for (int i = 0; i < newValues.length; i++) {
-								newMeasure[i] = (AbstractMeasure<?>) ctor
-										.newInstance(newValues[i],
-												unitBox.getSelectedItem());
-							}
+					if (ignoreUnitChanges) {
+						return;
+					}
+					if (valueField instanceof DoubleArrayTextField doubleField) {
+						applyValues(property, doubleField.getValue());
+					} else {
+						MeasureTextField<List<ParsedMeasure<Unit>>> measureField = (MeasureTextField<List<ParsedMeasure<Unit>>>) valueField;
+						if (measureField.getValue() != null) {
+							applySections(property, measureField.getValue(), true);
+							measureField.setDisplayText(
+									formatForField((AbstractMeasure<?>[]) property.getValue()));
 						}
-						
-						property.setValue(newMeasure);
-						property.setChanged(true);
-						valueField.setBackground(oldBg);
-						unitBox.setBackground(oldBg);
-					} catch (Exception e) {
-						LOG.error("Error while updating property units", e);
 					}
 				}
 			});
@@ -145,6 +150,101 @@ public class MeasureArrayEditor extends Container {
 		}
 	}
 
+	private DoubleArrayTextField createDoubleField(final PropertyWrapper property,
+			AbstractMeasure<?>[] measure) {
+		Double[] values = new Double[measure.length];
+		for (int i = 0; i < measure.length; i++) {
+			values[i] = measure[i] == null ? null : measure[i].getValue();
+		}
+		DoubleArrayTextField valueField = new DoubleArrayTextField(measure == null ? null : values);
+		valueField.addPropertyChangeListener(
+				DoubleArrayTextField.VALUE_PROPERTY,
+				new PropertyChangeListener() {
+
+					@Override
+					public void propertyChange(PropertyChangeEvent evt) {
+						applyValues(property, (Double[]) evt.getNewValue());
+					}
+				});
+		return valueField;
+	}
+
+	private void applyValues(PropertyWrapper property, Double[] newValues) {
+		try {
+			Constructor<?> ctor = property.getType().getComponentType()
+					.getConstructors()[0];
+			AbstractMeasure<?>[] newMeasure;
+			if (newValues == null)
+				newMeasure = null;
+			else {
+				newMeasure = (AbstractMeasure<?>[]) Array.newInstance(property.getType().getComponentType(), newValues.length);
+				for (int i = 0; i < newValues.length; i++) {
+					newMeasure[i] = (AbstractMeasure<?>) ctor
+							.newInstance(newValues[i],
+									unitBox.getSelectedItem());
+				}
+			}
+
+			property.setValue(newMeasure);
+			property.setChanged(true);
+			valueField.setBackground(oldBg);
+			unitBox.setBackground(oldBg);
+		} catch (Exception e) {
+			LOG.error("Error while updating property value", e);
+		}
+	}
+
+	/**
+	 * Sections typed with their own unit keep it, the others take the unit selected in the box.
+	 * When the box itself changed, its unit is applied to every section.
+	 */
+	private void applySections(PropertyWrapper property, List<ParsedMeasure<Unit>> sections,
+			boolean forceBoxUnit) {
+		try {
+			Constructor<?> ctor = property.getType().getComponentType()
+					.getConstructors()[0];
+			AbstractMeasure<?>[] newMeasure = null;
+			if (sections != null) {
+				newMeasure = (AbstractMeasure<?>[]) Array.newInstance(property.getType().getComponentType(), sections.size());
+				for (int i = 0; i < sections.size(); i++) {
+					ParsedMeasure<Unit> section = sections.get(i);
+					Object unit = section == null || section.unit() == null || forceBoxUnit
+							? unitBox.getSelectedItem() : section.unit();
+					newMeasure[i] = (AbstractMeasure<?>) ctor
+							.newInstance(section == null ? null : section.value(), unit);
+				}
+			}
+			property.setValue(newMeasure);
+			property.setChanged(true);
+			valueField.setBackground(oldBg);
+			unitBox.setBackground(oldBg);
+		} catch (Exception e) {
+			LOG.error("Error while updating property value", e);
+		}
+	}
+
+	private static List<ParsedMeasure<Unit>> parseSections(String text,
+			Function<String, Unit> unitResolver) {
+		List<ParsedMeasure<Unit>> sections = new ArrayList<ParsedMeasure<Unit>>();
+		for (String part : text.split("/", -1)) {
+			sections.add(part.trim().isEmpty() ? null : ValueNotation.parse(part, unitResolver));
+		}
+		return sections;
+	}
+
+	private static String formatForField(AbstractMeasure<?>[] measure) {
+		if (measure == null) {
+			return "";
+		}
+		Object boxUnit = measure.length == 0 || measure[0] == null ? null : measure[0].getUnit();
+		List<String> parts = new ArrayList<String>();
+		for (AbstractMeasure<?> section : measure) {
+			parts.add(MeasureEditor.formatForField(section,
+					section == null || section.getUnit() == boxUnit));
+		}
+		return String.join(" / ", parts);
+	}
+
 	@Override
 	public void requestFocus() {
 		this.valueField.requestFocus();

diylc/diylc-swing/src/main/java/org/diylc/swing/gui/editor/MeasureEditor.java

@@ -26,6 +26,8 @@ import java.awt.Color;
 import java.awt.Container;
 import java.awt.event.ActionEvent;
 import java.awt.event.ActionListener;
+import java.awt.event.FocusAdapter;
+import java.awt.event.FocusEvent;
 import java.awt.event.KeyListener;
 import java.beans.PropertyChangeEvent;
 import java.beans.PropertyChangeListener;
@@ -33,12 +35,22 @@ import java.lang.reflect.Constructor;
 import java.lang.reflect.Method;
 import java.lang.reflect.ParameterizedType;
 import java.lang.reflect.Type;
+import java.text.DecimalFormat;
+import java.text.Format;
+import java.util.function.Function;
 import javax.swing.JComboBox;
+import javax.swing.JTextField;
 import org.apache.log4j.Logger;
 import org.diylc.appframework.miscutils.ConfigurationManager;
 import org.diylc.common.IPlugInPort;
+import org.diylc.core.measures.Capacitance;
+import org.diylc.core.measures.CapacitanceUnit;
+import org.diylc.core.measures.Resistance;
+import org.diylc.core.measures.ResistanceUnit;
 import org.diylc.core.measures.Size;
 import org.diylc.core.measures.SizeUnit;
+import org.diylc.core.measures.ValueNotation;
+import org.diylc.core.measures.ValueNotation.ParsedMeasure;
 import org.diylc.swingframework.DoubleTextField;
 
 import org.diylc.common.PropertyWrapper;
@@ -52,39 +64,70 @@ public class MeasureEditor extends Container {
 
   private final static Logger LOG = Logger.getLogger(MeasureEditor.class);
 
+  private static final Format DECIMAL_FORMAT = new DecimalFormat("0.#####");
+
   private Color oldBg;
-  private DoubleTextField valueField;
+  private JTextField valueField;
   private JComboBox<Object> unitBox;
+  private boolean ignoreUnitChanges = false;
 
   @SuppressWarnings("unchecked")
   public MeasureEditor(final PropertyWrapper property) {
     setLayout(new BorderLayout());
     AbstractMeasure<?> measure = ((AbstractMeasure<?>) property.getValue());
     measure = convertUnitsIfNeeded(measure);
-    valueField = new DoubleTextField(measure == null ? null : measure.getValue());
-    oldBg = valueField.getBackground();
-    valueField.addPropertyChangeListener(DoubleTextField.VALUE_PROPERTY, new PropertyChangeListener() {
+    final Function<String, Unit> unitResolver = getUnitResolver(property.getType());
+    if (unitResolver == null) {
+      final DoubleTextField doubleField =
+          new DoubleTextField(measure == null ? null : measure.getValue());
+      doubleField.addPropertyChangeListener(DoubleTextField.VALUE_PROPERTY,
+          new PropertyChangeListener() {
 
-      @Override
-      public void propertyChange(PropertyChangeEvent evt) {
-        try {
-          Double newValue = (Double) evt.getNewValue();
-          if (newValue == null) {
-            property.setValue(null);
-          } else {
-            Constructor<?> ctor = property.getType().getConstructors()[0];
-            AbstractMeasure<?> newMeasure =
-                (AbstractMeasure<?>) ctor.newInstance(newValue, unitBox.getSelectedItem());
-            property.setValue(newMeasure);
+            @Override
+            public void propertyChange(PropertyChangeEvent evt) {
+              applyValue(property, (Double) evt.getNewValue(), unitBox.getSelectedItem());
+            }
+          });
+      valueField = doubleField;
+    } else {
+      final MeasureTextField<ParsedMeasure<Unit>> measureField =
+          new MeasureTextField<ParsedMeasure<Unit>>(formatForField(measure, true),
+              text -> ValueNotation.parse(text, unitResolver));
+      measureField.addPropertyChangeListener(MeasureTextField.VALUE_PROPERTY,
+          new PropertyChangeListener() {
+
+            @Override
+            public void propertyChange(PropertyChangeEvent evt) {
+              ParsedMeasure<Unit> parsed = (ParsedMeasure<Unit>) evt.getNewValue();
+              if (parsed == null) {
+                applyValue(property, null, unitBox.getSelectedItem());
+                return;
+              }
+              // a unit typed together with the value, e.g. 4K7, also switches the unit box
+              if (parsed.unit() != null && parsed.unit() != unitBox.getSelectedItem()) {
+                ignoreUnitChanges = true;
+                try {
+                  unitBox.setSelectedItem(parsed.unit());
+                } finally {
+                  ignoreUnitChanges = false;
+                }
+              }
+              applyValue(property, parsed.value(), unitBox.getSelectedItem());
+            }
+          });
+      measureField.addFocusListener(new FocusAdapter() {
+
+        @Override
+        public void focusLost(FocusEvent e) {
+          if (measureField.getValue() != null) {
+            measureField.setDisplayText(
+                formatForField((AbstractMeasure<?>) property.getValue(), true));
           }
-          property.setChanged(true);
-          valueField.setBackground(oldBg);
-          unitBox.setBackground(oldBg);
-        } catch (Exception e) {
-          LOG.error("Error while updating property value", e);
         }
-      }
-    });
+      });
+      valueField = measureField;
+    }
+    oldBg = valueField.getBackground();
     add(valueField, BorderLayout.CENTER);
     try {
       Type type = ((ParameterizedType) property.getType().getGenericSuperclass()).getActualTypeArguments()[0];
@@ -95,33 +138,27 @@ public class MeasureEditor extends Container {
 
         @Override
         public void actionPerformed(ActionEvent evt) {
+          if (ignoreUnitChanges) {
+            return;
+          }
           try {
-            Double newValue = valueField.getValue();
-            if (newValue == null) {
-              property.setValue(null);
-            } else {
-              Constructor<?> ctor = property.getType().getConstructors()[0];
-              if (property.isReadOnly()) {
-                double oldFactor = ((Unit)((AbstractMeasure<?>)property.getValue()).getUnit()).getFactor();
-                double newFactor = ((Unit)unitBox.getSelectedItem()).getFactor();
-                newValue = newValue * oldFactor / newFactor;
-                valueField.setValue(newValue);
-              }
-              AbstractMeasure<?> newMeasure =
-                  (AbstractMeasure<?>) ctor.newInstance(newValue,
-                      (Enum<? extends Unit>) unitBox.getSelectedItem());
-              property.setValue(newMeasure);
+            Double newValue = getFieldValue();
+            if (newValue != null && property.isReadOnly()) {
+              double oldFactor = ((Unit)((AbstractMeasure<?>)property.getValue()).getUnit()).getFactor();
+              double newFactor = ((Unit)unitBox.getSelectedItem()).getFactor();
+              newValue = newValue * oldFactor / newFactor;
+            }
+            applyValue(property, newValue, unitBox.getSelectedItem());
+            if (newValue != null && (property.isReadOnly() || unitResolver != null)) {
+              setFieldValue((AbstractMeasure<?>) property.getValue());
             }
-            property.setChanged(true);
-            valueField.setBackground(oldBg);
-            unitBox.setBackground(oldBg);
           } catch (Exception e) {
             LOG.error("Error while updating property units", e);
           }
         }
       });
       add(unitBox, BorderLayout.EAST);
-      
+
       if (property.isReadOnly()) {
         valueField.setEnabled(false);
         unitBox.setEnabled(true);
@@ -136,6 +173,70 @@ public class MeasureEditor extends Container {
     }
   }
 
+  /**
+   * Returns the function that resolves unit symbols typed together with the value, or null when
+   * the measure only accepts a plain number.
+   */
+  static Function<String, Unit> getUnitResolver(Class<?> measureType) {
+    if (Resistance.class.equals(measureType)) {
+      return ResistanceUnit::fromSymbol;
+    }
+    if (Capacitance.class.equals(measureType)) {
+      return CapacitanceUnit::fromSymbol;
+    }
+    return null;
+  }
+
+  /**
+   * Text shown in the value field. It is always decimal, whatever the selected value notation,
+   * because the unit box beside it already shows the unit; the unit is written out only when it
+   * differs from the one in the box.
+   */
+  static String formatForField(AbstractMeasure<?> measure, boolean unitShownInBox) {
+    if (measure == null || measure.getValue() == null) {
+      return "";
+    }
+    String number;
+    synchronized (DECIMAL_FORMAT) {
+      number = DECIMAL_FORMAT.format(measure.getValue());
+    }
+    return unitShownInBox || measure.getUnit() == null ? number : number + measure.getUnit();
+  }
+
+  private void applyValue(PropertyWrapper property, Double newValue, Object unit) {
+    try {
+      if (newValue == null) {
+        property.setValue(null);
+      } else {
+        Constructor<?> ctor = property.getType().getConstructors()[0];
+        property.setValue((AbstractMeasure<?>) ctor.newInstance(newValue, unit));
+      }
+      property.setChanged(true);
+      valueField.setBackground(oldBg);
+      unitBox.setBackground(oldBg);
+    } catch (Exception e) {
+      LOG.error("Error while updating property value", e);
+    }
+  }
+
+  @SuppressWarnings("unchecked")
+  private Double getFieldValue() {
+    if (valueField instanceof DoubleTextField doubleField) {
+      return doubleField.getValue();
+    }
+    ParsedMeasure<Unit> parsed = ((MeasureTextField<ParsedMeasure<Unit>>) valueField).getValue();
+    return parsed == null ? null : parsed.value();
+  }
+
+  @SuppressWarnings("unchecked")
+  private void setFieldValue(AbstractMeasure<?> measure) {
+    if (valueField instanceof DoubleTextField doubleField) {
+      doubleField.setValue(measure == null ? null : measure.getValue());
+    } else {
+      ((MeasureTextField<ParsedMeasure<Unit>>) valueField).setDisplayText(formatForField(measure, true));
+    }
+  }
+
   private AbstractMeasure<?> convertUnitsIfNeeded(AbstractMeasure<?> value) {
     if (ConfigurationManager.getInstance().readBoolean(IPlugInPort.AUTO_UNIT_CONVERSION_KEY, true)
         && value instanceof Size sizeValue) {

diylc/diylc-swing/src/main/java/org/diylc/swing/gui/editor/MeasureTextField.java

@@ -0,0 +1,131 @@
+/*
+
+    DIY Layout Creator (DIYLC).
+    Copyright (c) 2009-2025 held jointly by the individual authors.
+
+    This file is part of DIYLC.
+
+    DIYLC 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 3 of the License, or
+    (at your option) any later version.
+
+    DIYLC 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 DIYLC.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+package org.diylc.swing.gui.editor;
+
+import java.awt.BorderLayout;
+import java.util.function.Function;
+import javax.swing.BorderFactory;
+import javax.swing.JLabel;
+import javax.swing.JTextField;
+import javax.swing.event.DocumentEvent;
+import javax.swing.event.DocumentListener;
+
+import org.diylc.utils.IconLoader;
+
+/**
+ * {@link JTextField} that parses its text on every change and fires {@link #VALUE_PROPERTY} with
+ * the result, showing a warning icon while the text cannot be parsed. Unlike
+ * {@code DoubleTextField} the text is never rewritten while the user types; call
+ * {@link #setDisplayText(String)} to reformat it.
+ *
+ * @author Branislav Stojkovic
+ *
+ * @param <T> type of the parsed value
+ */
+public class MeasureTextField<T> extends JTextField {
+
+  private static final long serialVersionUID = 1L;
+
+  public static final String VALUE_PROPERTY = "MeasureValue";
+
+  private final Function<String, T> parser;
+  private final JLabel errorLabel;
+
+  private T value;
+  private boolean ignoreChanges = false;
+
+  /**
+   * @param text initial text
+   * @param parser turns non-empty text into a value, throwing {@link IllegalArgumentException} when
+   *        it cannot
+   */
+  public MeasureTextField(String text, Function<String, T> parser) {
+    super();
+    this.parser = parser;
+    setLayout(new BorderLayout());
+    errorLabel = new JLabel(IconLoader.Warning.getIcon());
+    errorLabel.setBorder(BorderFactory.createEmptyBorder(3, 0, 0, 0));
+    add(errorLabel, BorderLayout.EAST);
+    setDisplayText(text);
+    getDocument().addDocumentListener(new DocumentListener() {
+
+      @Override
+      public void changedUpdate(DocumentEvent e) {
+        textChanged();
+      }
+
+      @Override
+      public void insertUpdate(DocumentEvent e) {
+        textChanged();
+      }
+
+      @Override
+      public void removeUpdate(DocumentEvent e) {
+        textChanged();
+      }
+    });
+  }
+
+  public T getValue() {
+    return value;
+  }
+
+  /**
+   * Replaces the text without firing {@link #VALUE_PROPERTY}.
+   */
+  public void setDisplayText(String text) {
+    ignoreChanges = true;
+    try {
+      setText(text);
+      value = parseQuietly(text);
+      errorLabel.setVisible(value == null);
+    } finally {
+      ignoreChanges = false;
+    }
+  }
+
+  private T parseQuietly(String text) {
+    try {
+      return text == null || text.trim().isEmpty() ? null : parser.apply(text);
+    } catch (IllegalArgumentException e) {
+      return null;
+    }
+  }
+
+  private void textChanged() {
+    if (ignoreChanges) {
+      return;
+    }
+    T newValue;
+    try {
+      newValue = getText().trim().isEmpty() ? null : parser.apply(getText());
+    } catch (IllegalArgumentException e) {
+      value = null;
+      errorLabel.setVisible(true);
+      return;
+    }
+    T oldValue = value;
+    value = newValue;
+    errorLabel.setVisible(false);
+    firePropertyChange(VALUE_PROPERTY, oldValue, newValue);
+  }
+}

diylc/diylc-swing/src/main/java/org/diylc/swing/plugins/config/ConfigPlugin.java

@@ -40,6 +40,7 @@ import org.diylc.core.Theme;
 import org.diylc.utils.FlagLoader;
 import org.diylc.lang.LangUtil;
 import org.diylc.lang.Language;
+import org.diylc.presenter.ValueNotationBinder;
 import org.diylc.swing.ActionFactory;
 import org.diylc.swing.ISwingUI;
 import org.diylc.utils.IconLoader;
@@ -58,6 +59,7 @@ public class ConfigPlugin implements IPlugIn {
   private static final String THEME_MENU = "Theme";
   private static final String RULER_MENU = "Ruler Inch Subdivision...";
   private static final String SNAP_MENU = "Snap To";
+  private static final String VALUE_NOTATION_MENU = "Value Notation";
   private static final String CATEGORIES_MENU = "Component Categories";
   private static final String COMPONENT_BROWSER_MENU = "Toolbox";
   public static final String COMPONENT_BROWSER = "componentBrowser";
@@ -196,6 +198,17 @@ public class ConfigPlugin implements IPlugIn {
         ActionFactory.getInstance()
             .createConfigAction(plugInPort, "Sticky Points", IPlugInPort.STICKY_POINTS_KEY, true), CONFIG_MENU);      
 
+    swingUI.injectSubmenu(VALUE_NOTATION_MENU, IconLoader.Decimal.getIcon(), CONFIG_MENU);
+    swingUI.injectMenuAction(
+        ActionFactory.getInstance().createToggleAction(IPlugInPort.VALUE_NOTATION_DECIMAL,
+            IPlugInPort.VALUE_NOTATION_KEY, VALUE_NOTATION_MENU, IPlugInPort.VALUE_NOTATION_DEFAULT),
+        VALUE_NOTATION_MENU);
+    swingUI.injectMenuAction(
+        ActionFactory.getInstance().createToggleAction(IPlugInPort.VALUE_NOTATION_RKM,
+            IPlugInPort.VALUE_NOTATION_KEY, VALUE_NOTATION_MENU, IPlugInPort.VALUE_NOTATION_DEFAULT),
+        VALUE_NOTATION_MENU);
+    ValueNotationBinder.bind(ConfigurationManager.getInstance(), plugInPort::refresh);
+
     Map<String, String> themeContents = ResourceUtils.getResourceContents(THEMES_DIR);
     if (!themeContents.isEmpty()) {
       XStream xStream = new XStream(new DomDriver());

diylc/diylc-swing/src/main/java/org/diylc/utils/IconLoader.java

@@ -51,8 +51,8 @@ public enum IconLoader {
       "coffeebean_edit.png"), Component("component.png"), ComponentAdd(
       "component_add.png"), ComponentLarge("component_large.png"), ComponentPreferences(
       "component_preferences.png"), ComponentReplace("component_replace.png"), Copy(
-      "copy.png"), Cut("cut.png"), Dashboard("dashboard.png"), DataFind("data_find.png"), Delete(
-      "delete.png"), DiskBlue("disk_blue.png"), DistributeCentersHorizontal(
+      "copy.png"), Cut("cut.png"), Dashboard("dashboard.png"), DataFind("data_find.png"), Decimal(
+      "decimal.png"), Delete("delete.png"), DiskBlue("disk_blue.png"), DistributeCentersHorizontal(
       "distribute_centers_horizontal.png"), DistributeCentersVertical(
       "distribute_centers_vertical.png"), DistributeSpacingHorizontal(
       "distribute_spacing_horizontal.png"), DistributeSpacingVertical(

diylc/diylc-swing/src/main/resources/lang/Deutsch.txt

@@ -729,3 +729,6 @@ Are you sure you want to delete variant "%s"?|Möchten Sie die Variante "%s" wir
 Delete|Löschen
 Set default model|Als Standardmodell festlegen
 Remove default model|Standardmodell entfernen
+Value Notation|Wertnotation
+Decimal (4.7K, 0.22uF)|Dezimal (4.7K, 0.22uF)
+RKM (4K7, 0u22)|RKM (4K7, 0u22)

diylc/diylc-swing/src/main/resources/lang/English.txt

@@ -722,3 +722,6 @@ Are you sure you want to delete variant "%s"?
 Delete
 Set default model
 Remove default model
+Value Notation
+Decimal (4.7K, 0.22uF)
+RKM (4K7, 0u22)

diylc/diylc-swing/src/main/resources/lang/Español.txt

@@ -725,3 +725,6 @@ Are you sure you want to delete variant "%s"?|¿Seguro que desea eliminar la var
 Delete|Eliminar
 Set default model|Establecer como modelo predeterminado
 Remove default model|Quitar modelo predeterminado
+Value Notation|Notación de valores
+Decimal (4.7K, 0.22uF)|Decimal (4.7K, 0.22uF)
+RKM (4K7, 0u22)|RKM (4K7, 0u22)

diylc/diylc-swing/src/main/resources/lang/Français.txt

@@ -724,3 +724,6 @@ Are you sure you want to delete variant "%s"?|Voulez-vous vraiment supprimer la
 Delete|Supprimer
 Set default model|Définir comme modèle par défaut
 Remove default model|Retirer le modèle par défaut
+Value Notation|Notation des valeurs
+Decimal (4.7K, 0.22uF)|Décimale (4.7K, 0.22uF)
+RKM (4K7, 0u22)|RKM (4K7, 0u22)

diylc/diylc-swing/src/main/resources/lang/Italiano.txt

@@ -726,3 +726,6 @@ Are you sure you want to delete variant "%s"?|Eliminare davvero la variante "%s"
 Delete|Elimina
 Set default model|Imposta come modello predefinito
 Remove default model|Rimuovi modello predefinito
+Value Notation|Notazione dei valori
+Decimal (4.7K, 0.22uF)|Decimale (4.7K, 0.22uF)
+RKM (4K7, 0u22)|RKM (4K7, 0u22)

diylc/diylc-swing/src/main/resources/lang/Nederlands.txt

@@ -730,3 +730,6 @@ Are you sure you want to delete variant "%s"?|Weet u zeker dat u variant "%s" wi
 Delete|Verwijderen
 Set default model|Instellen als standaardmodel
 Remove default model|Standaardmodel verwijderen
+Value Notation|Waardenotatie
+Decimal (4.7K, 0.22uF)|Decimaal (4.7K, 0.22uF)
+RKM (4K7, 0u22)|RKM (4K7, 0u22)

diylc/diylc-swing/src/main/resources/lang/Português.txt

@@ -725,3 +725,6 @@ Are you sure you want to delete variant "%s"?|Tem certeza de que deseja excluir
 Delete|Excluir
 Set default model|Definir como modelo padrão
 Remove default model|Remover modelo padrão
+Value Notation|Notação de valores
+Decimal (4.7K, 0.22uF)|Decimal (4.7K, 0.22uF)
+RKM (4K7, 0u22)|RKM (4K7, 0u22)

diylc/diylc-swing/src/main/resources/lang/Srpski.txt

@@ -721,3 +721,6 @@ Are you sure you want to delete variant "%s"?|Da li ste sigurni da želite da ob
 Delete|Obriši
 Set default model|Postavi kao podrazumevani model
 Remove default model|Ukloni podrazumevani model
+Value Notation|Zapis vrednosti
+Decimal (4.7K, 0.22uF)|Decimalni (4.7K, 0.22uF)
+RKM (4K7, 0u22)|RKM (4K7, 0u22)

diylc/diylc-swing/src/main/resources/lang/हिंदी.txt

@@ -723,3 +723,6 @@ Are you sure you want to delete variant "%s"?|क्या आप वाकई
 Delete|हटाएँ
 Set default model|डिफ़ॉल्ट मॉडल सेट करें
 Remove default model|डिफ़ॉल्ट मॉडल हटाएँ
+Value Notation|मान संकेतन
+Decimal (4.7K, 0.22uF)|दशमलव (4.7K, 0.22uF)
+RKM (4K7, 0u22)|RKM (4K7, 0u22)

diylc/diylc-swing/src/main/resources/lang/简体中文.txt

@@ -723,3 +723,6 @@ Are you sure you want to delete variant "%s"?|确定要删除变体“%s”吗
 Delete|删除
 Set default model|设为默认型号
 Remove default model|取消默认型号
+Value Notation|数值表示法
+Decimal (4.7K, 0.22uF)|小数 (4.7K, 0.22uF)
+RKM (4K7, 0u22)|RKM (4K7, 0u22)

diylc/docs/plans/rkm-value-notation.md

@@ -0,0 +1,185 @@
+# RKM Value Notation for Resistance and Capacitance
+
+Let users read and type resistor and capacitor values in RKM (IEC 60062) notation, where the unit
+letter replaces the decimal point (`4K7`, `0R22`, `2n2`, `0u22`), as well as in today's decimal
+form (`4.7K`, `0.22uF`). Typing a value with a unit letter in it, in either notation, also sets the
+unit, so `4K7` typed into a field whose unit is `Ω` becomes 4.7 K.
+
+## 1. User-facing behaviour
+
+### Config menu
+
+One radio submenu in `ConfigPlugin` covering both resistance and capacitance, built the same way
+as `Snap To` and `Ruler Inch Subdivision...` (`ToggleAction`, string config key, title stored as
+the value):
+
+```
+Config
+  ...
+  Value Notation >            (after Sticky Points, alphabetical like the rest)
+      (o) Decimal (4.7K, 0.22uF)
+      ( ) RKM (4K7, 0u22)
+  ...
+```
+
+- Key `IPlugInPort.VALUE_NOTATION_KEY = "valueNotation"`, values `VALUE_NOTATION_DECIMAL` /
+  `VALUE_NOTATION_RKM`, default decimal.
+- Switching notation repaints the canvas immediately, so labels on the board change at once.
+
+### What the notation controls (display)
+
+The notation governs `Resistance.toString()` and `Capacitance.toString()` and therefore everything
+built on them: labels drawn on the canvas, `getValueForDisplay()` (search, BOM, netlist text,
+project explorer, AI assistant context). The edit dialog's value field is the exception: it always
+shows the bare decimal number, because the unit box beside it already carries the unit and an RKM
+code there would repeat it.
+
+| Value | Decimal (unchanged) | RKM |
+| --- | --- | --- |
+| 4.7 Ω | `4.7Ω` | `4R7` |
+| 0.22 Ω | `0.22Ω` | `0R22` |
+| 100 Ω | `100Ω` | `100R` |
+| 4.7 K | `4.7K` | `4K7` |
+| 47 K | `47K` | `47K` |
+| 1 M | `1M` | `1M` |
+| 0.22 uF | `0.22uF` | `0u22` |
+| 2.2 nF | `2.2nF` | `2n2` |
+| 100 nF | `100nF` | `100n` |
+| 4.7 pF | `4.7pF` | `4p7` |
+| 1000 uF | `1000uF` | `1000u` |
+
+Rules: RKM keeps the stored unit (it never renormalises 4700 Ω to 4K7), uses `R` for ohms, drops
+the trailing `F` on capacitance, puts the unit letter where the decimal point was, and writes it
+as a suffix for whole numbers. The digits after the letter are rounded the same way as today's
+`0.####` decimal format.
+
+### What the user can type (input)
+
+The value field accepts, in **both** notations:
+
+- a bare number (`4.7`, `0,22`) — the unit is unchanged, as today;
+- a decimal number with a unit (`4.7k`, `0.22uF`, `220 nF`, `4.7ohm`, `4.7Ω`);
+- an RKM code (`4K7`, `4k7`, `0R22`, `R22`, `2n2`, `0u22`, `4µ7`, `1M`, `100R`).
+
+When the text carries a unit, the unit combo switches to it and the property gets the new value
+and unit together. Accepted unit letters, case-insensitive except where noted:
+
+- Resistance: `R`, `Ω`, `ohm`/`ohms` → Ω; `K`/`k` → K; `M`/`m`/`Meg` → M (there is no milliohm
+  unit, so a lower-case `m` on a resistor means mega, as it does on many parts lists).
+- Capacitance: `p` → pF; `n` → nF; `u`/`µ` → uF; `m` → mF (**case-sensitive**: `M` is not
+  accepted, to avoid reading "mega"); `F` alone → F. A trailing `F` after any of these is
+  optional (`4u7F`, `2.2nF`).
+
+A unit letter that does not belong to the measure (`4u7` on a resistor) shows the existing warning
+icon, as any unparseable text does today.
+
+**Commit behaviour.** The property is updated on every keystroke, as today — the edit dialog's
+Enter key commits straight away, so it cannot wait for focus loss. When the field loses focus,
+the text is rewritten as the bare decimal number (`4K7` typed → `4.7` with the combo showing `K`),
+whichever notation is selected. The text is not reformatted while the user is typing, so the
+caret never jumps.
+
+## 2. Design
+
+### Core (`diylc-core`, `org.diylc.core.measures`)
+
+- **`ValueNotation`** — new enum `DECIMAL, RKM` holding the formatting and parsing logic, so the
+  two measure classes stay thin:
+  - `String format(double value, Unit unit, String rkmSymbol)` — decimal falls through to the
+    existing `0.####` + `unit.toString()`; RKM implements the rules in §1.
+  - `static ParsedMeasure parse(String text, ...)` — returns value + unit (unit `null` for a bare
+    number), or throws `IllegalArgumentException`. One small record `ParsedMeasure<U>` at the
+    bottom of the file.
+- **Current notation.** One `private static volatile ValueNotation current` on `ValueNotation`
+  with static `getCurrent()` / `setCurrent()`, shared by `Resistance` and `Capacitance`.
+  `toString()` reads the field, never
+  `ConfigurationManager`: it runs from `draw()` on every repaint. Default `DECIMAL`, so headless
+  rendering, the regression suite and unit tests are unchanged unless they opt in.
+- **Unit display symbol for RKM.** `ResistanceUnit` and `CapacitanceUnit` get an `rkmSymbol`
+  constructor argument (`R`/`K`/`M`, `p`/`n`/`u`/`m`/`F`). Enum constant names and `toString()`
+  are untouched — XStream stores the constant name, so files are unaffected.
+- **Parsing.** `Resistance.parseResistance` / `Capacitance.parseCapacitance` delegate to
+  `ValueNotation.parse`, so RKM is accepted everywhere a string is turned into a value: the
+  editor, `V1FileParser`, `TangoNetlistParser`, `CapacitorDatasheetService` and — important once
+  `toString()` can emit `4K7` — the AI assistant, which receives values as text and writes them
+  back through these parsers. Existing accepted inputs must keep parsing identically.
+- `Inductance` and `Power` are out of scope; their names are left as they are.
+
+### Wiring the setting
+
+`org.diylc.presenter.ValueNotationBinder.bind(configManager, refresh)` reads the key once,
+pushes it into `ValueNotation.setCurrent()`, and on change updates the static, calls
+`DrawingCache.Instance.clear()` (cached component images contain the old labels) and refreshes
+the canvas. It is called from `ConfigPlugin.connect()`, not from the `Presenter` constructor:
+the notation is global, and the many secondary presenters (project preview, cloud thumbnails,
+batch converter, regression runner) are built on in-memory configurations and would reset it to
+decimal.
+
+### Swing (`diylc-swing`)
+
+- **`MeasureTextField`** — new field in `org.diylc.swing.gui.editor`, beside `MeasureEditor`.
+  Same look as `DoubleTextField` (warning icon on the right) but it parses through
+  `ValueNotation.parse` for the measure type and fires a `MEASURE_PROPERTY` change carrying
+  value + optional unit; on `focusLost` it reformats its text. It is generic over the unit enum
+  so it can serve `Inductance` later without changes.
+
+  Recommendation: keep it in DIYLC rather than extending `DoubleTextField` in
+  `bancika-gui-framework`. The framework is consumed as the vendored
+  `lib/swing-framework-1.1.jar`, so a change there means rebuilding and re-vendoring the jar for a
+  widget whose parsing rules are DIYLC domain knowledge. `DoubleTextField` keeps serving
+  `PercentageEditor`, `LoadlineEditorFrame` and every other plain-number measure.
+
+  One `DoubleTextField` bug is worth fixing in the framework separately, and the new field must
+  not copy it: `DecimalFormat.parseObject(String)` accepts a valid prefix, so `4R7` silently
+  parses as `4` today, with no warning.
+- **`MeasureEditor`** — uses `MeasureTextField` when the property type is `Resistance` or
+  `Capacitance`, `DoubleTextField` otherwise. On a value + unit event it sets the combo's
+  selected unit behind a guard flag, so the combo's own `ActionListener` does not fire a second
+  `setValue`. Read-only properties keep today's behaviour (disabled field, combo converts).
+- **`MeasureArrayEditor`** (`MultiSectionCapacitor`) — each section value is parsed with the same
+  rules. Units travel per section in the text (`47u / 22u / 10u`) and a section without a unit
+  takes the combo's unit, as today. The combo shows the first section's unit; in decimal notation a
+  section in a different unit is written with its unit (`47 / 100nF`). Changing the combo applies
+  its unit to every section, as before.
+- **`ConfigPlugin`** — the `Value Notation` submenu (`IconLoader.Decimal`), and the call to
+  `ValueNotationBinder.bind`.
+
+### Localization
+
+New keys in `English.txt` and every other file in `lang/`: `Value Notation`,
+`Decimal (4.7K, 0.22uF)`, `RKM (4K7, 0u22)`.
+Because `ToggleAction` stores its title as the config value, the stored values are the English
+titles and `MainFrame` translates only what is shown.
+
+## 3. Compatibility
+
+- `.diy` files store `value` and the unit enum name; neither changes. No serialization impact.
+- With the default (decimal) every string the app produces is byte-identical to today, so
+  regression references do not move. A regression run is still worth doing after implementation,
+  since `parseResistance` / `parseCapacitance` change.
+- A user who switches to RKM gets RKM in BOM and netlist exports as well. That is the intended
+  "everywhere" behaviour; anything that re-imports those files goes through the RKM-aware
+  parsers.
+
+## 4. Tests (`diylc-core`, JUnit 4)
+
+`ValueNotationTest`:
+
+- formatting: every row of the §1 table, both notations; zero, null, values ≥ 1000 in their unit,
+  rounding at the fourth decimal;
+- parsing: every input form in §1, per measure; case rules (`m` vs `M` for capacitance); comma as
+  decimal separator; rejects `4u7` on a resistor, `4K7K`, `K`, empty text;
+- round trip: `parse(format(x))` returns `x` for both notations;
+- regression guard: every string currently accepted by `parseResistance` / `parseCapacitance`
+  (the inputs in `V1FileParser`, `TangoNetlistParser` and `CapacitorDatasheetService` tests and
+  `AiEditScriptEditorTest`) still parses to the same value.
+
+## 5. Status and next steps
+
+Implemented as described; `mvn -q test` passes, including `ValueNotationTest`.
+
+1. Try it in the running app: the edit dialog (single value and `MultiSectionCapacitor`), canvas
+   labels after switching notation, BOM export.
+2. Run the regression suite to confirm decimal output is unchanged.
+3. Optional, in `bancika-gui-framework`: stop `DoubleTextField` / `DoubleArrayTextField`
+   accepting a valid prefix (`4R7` read as `4`).