Improved data model for storing transparency alpha and other properties that are edited using a slider widget; as a result, the editing is more precise and does not randomly change to neighboring values

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

@@ -0,0 +1,75 @@
+/*
+
+    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.common;
+
+import java.io.Serializable;
+
+public class Percentage implements Serializable, Cloneable {
+
+  private static final long serialVersionUID = 1L;
+
+  private int value;
+
+  public Percentage(int value) {
+    this.value = value;
+  }
+
+  public int getValue() {
+    return value;
+  }
+
+  public void setValue(int value) {
+    this.value = value;
+  }
+
+  @Override
+  public int hashCode() {
+    final int prime = 31;
+    int result = 1;
+    result = prime * result + value;
+    return result;
+  }
+
+  @Override
+  public boolean equals(Object obj) {
+    if (this == obj)
+      return true;
+    if (obj == null)
+      return false;
+    if (getClass() != obj.getClass())
+      return false;
+    Percentage other = (Percentage) obj;
+    if (value != other.value)
+      return false;
+    return true;
+  }
+
+  @Override
+  public String toString() {
+    return value + "%";
+  }
+
+  @Override
+  public Object clone() throws CloneNotSupportedException {
+    return super.clone();
+  }
+}

diylc/diylc-core/src/main/java/org/diylc/components/AbstractCurvedComponent.java

@@ -149,10 +149,7 @@ public abstract class AbstractCurvedComponent<T> extends AbstractTransparentComp
       path.curveTo(p[4].getX(), p[4].getY(), p[5].getX(), p[5].getY(), p[6].getX(), p[6].getY());
     }
 
-    Composite oldComposite = g2d.getComposite();
-    if (alpha < MAX_ALPHA) {
-      g2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 1f * alpha / MAX_ALPHA));
-    }
+    Composite oldComposite = applyAlpha(g2d, componentState);
 
     drawCurve(path, g2d, componentState, drawingObserver);
 

diylc/diylc-core/src/main/java/org/diylc/components/AbstractTransparentComponent.java

@@ -22,24 +22,46 @@
 package org.diylc.components;
 
 import org.diylc.core.annotations.EditableProperty;
+import org.diylc.core.ComponentState;
+import org.diylc.common.Percentage;
+
+import java.awt.*;
 
 public abstract class AbstractTransparentComponent<T> extends AbstractComponent<T> {
 
   private static final long serialVersionUID = 1L;
 
-  public static byte MAX_ALPHA = 127;
+  public static byte MAX_ALPHA_LEGACY = Byte.MAX_VALUE;
+  public static int MAX_ALPHA = 100;
 
-  protected Byte alpha = MAX_ALPHA;
+  @Deprecated
+  protected Byte alpha;
 
-  @EditableProperty
-  public Byte getAlpha() {
-    if (alpha == null) {
-      alpha = MAX_ALPHA;
+  protected Percentage alphaPercent = new Percentage(100);
+
+  @EditableProperty(name = "Alpha")
+  public Percentage getAlpha() {
+    if (alphaPercent == null) {
+      if (alpha != null) {
+        alphaPercent = new Percentage(Math.round(100f * alpha / MAX_ALPHA_LEGACY));
+        alpha = null;
+      } else {
+        alphaPercent = new Percentage(100);
+      }
     }
-    return alpha;
+    return alphaPercent;
   }
 
-  public void setAlpha(Byte alpha) {
-    this.alpha = alpha;
+  public void setAlpha(Percentage alphaPercent) {
+    this.alphaPercent = alphaPercent;
+  }
+
+  public Composite applyAlpha(Graphics2D g2d, ComponentState componentState) {
+    Composite oldComposite = g2d.getComposite();
+    int alpha = componentState == ComponentState.DRAGGING ? 0 : getAlpha().getValue();
+    if (alpha < MAX_ALPHA) {
+      g2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, alpha / 100f));
+    }
+    return oldComposite;
   }
 }

diylc/diylc-core/src/main/java/org/diylc/core/annotations/PercentEditor.java

@@ -27,5 +27,7 @@ import java.lang.annotation.RetentionPolicy;
 @Retention(RetentionPolicy.RUNTIME)  
 public @interface PercentEditor {
   
-  public byte _100PercentValue();
+  public int minValue() default 0;
+
+  public int maxValue() default 100;
 }

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

@@ -68,7 +68,7 @@ import org.diylc.utils.Constants;
 public class DrawingManager {
 
   private static final Logger LOG = Logger.getLogger(DrawingManager.class);
-  public static final byte MIRROR_ALPHA = 64;
+  public static final Percentage MIRROR_ALPHA = new Percentage(50);
 
   public static int CONTROL_POINT_SIZE = 7;
   public static double EXTRA_SPACE = 0.25;

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

@@ -317,6 +317,10 @@
 					<changeType>NEW_FEATURE</changeType>
 					<description>Added more ceramic resistor variants to 'Resistor' component</description>
 				</org.diylc.appframework.update.Change>
+				<org.diylc.appframework.update.Change>
+					<changeType>IMPROVEMENT</changeType>
+					<description>Improved data model for storing transparency alpha and other properties that are edited using a slider widget; as a result, the editing is more precise and does not randomly change to neighboring values</description>
+				</org.diylc.appframework.update.Change>
 				<org.diylc.appframework.update.Change>
 					<changeType>IMPROVEMENT</changeType>
 					<description>Improved editing experience of integer properties (e.g. number of terminals on a tag strip) by using the spinner text field</description>

diylc/diylc-core/src/test/java/org/diylc/presenter/CalcUtilsTest.java

@@ -235,7 +235,7 @@ public class CalcUtilsTest {
         assertEquals(Color.BLACK.getRed(), result.getRed());
         assertEquals(Color.BLACK.getGreen(), result.getGreen());
         assertEquals(Color.BLACK.getBlue(), result.getBlue());
-        assertEquals(128, result.getAlpha());
+        assertEquals(128, result.getAlpha().getValue());
         
         // Test light color with alpha - should become WHITE
         Color transparentLight = new Color(255, 255, 200, 128);
@@ -243,16 +243,16 @@ public class CalcUtilsTest {
         assertEquals(Color.WHITE.getRed(), result.getRed());
         assertEquals(Color.WHITE.getGreen(), result.getGreen());
         assertEquals(Color.WHITE.getBlue(), result.getBlue());
-        assertEquals(128, result.getAlpha());
+        assertEquals(128, result.getAlpha().getValue());
         
         // Test fully transparent color
         Color transparent = new Color(100, 150, 200, 0);
         result = CalcUtils.convertToMonochrome(transparent);
-        assertEquals(0, result.getAlpha());
+        assertEquals(0, result.getAlpha().getValue());
         
         // Test opaque color - alpha should remain 255
         Color opaque = new Color(50, 50, 50);
         result = CalcUtils.convertToMonochrome(opaque);
-        assertEquals(255, result.getAlpha());
+        assertEquals(255, result.getAlpha().getValue());
     }
 }