Generalised concept of derivable icons.

Added arbitrary rotations for rotatable icon.

property-loader/src/main/java/com/github/weisj/darklaf/icons/DarkSVGIcon.java

@@ -41,7 +41,7 @@ import com.kitfox.svg.app.beans.SVGIcon;
  * @author Jannis Weis
  * @since  2019
  */
-public class DarkSVGIcon implements Icon, Serializable {
+public class DarkSVGIcon implements DerivableIcon<DarkSVGIcon>, Serializable {
 
     private static final Logger LOGGER = LogUtil.getLogger(DarkSVGIcon.class);
     private final Dimension size;
@@ -72,6 +72,7 @@ public class DarkSVGIcon implements Icon, Serializable {
         this.loaded = icon.loaded;
     }
 
+    @Override
     public DarkSVGIcon derive(final int width, final int height) {
         return new DarkSVGIcon(width, height, this);
     }

property-loader/src/main/java/com/github/weisj/darklaf/icons/DerivableIcon.java

@@ -0,0 +1,39 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020 Jannis Weis
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ */
+package com.github.weisj.darklaf.icons;
+
+import javax.swing.*;
+
+public interface DerivableIcon<T extends Icon> extends Icon {
+
+    /**
+     * Derive a new icon with the specified size.
+     *
+     * @param  width  the new width
+     * @param  height the new height.
+     * @return        the derived icon.
+     */
+    T derive(final int width, final int height);
+}

property-loader/src/main/java/com/github/weisj/darklaf/icons/IconLoader.java

@@ -214,10 +214,10 @@ public final class IconLoader {
             key.w = -1; // Enable wild card search. Find any icon that matches path.
             if (iconMap.containsKey(key)) {
                 Icon icon = iconMap.get(key);
-                if (icon instanceof DarkSVGIcon) {
+                if (icon instanceof DerivableIcon) {
                     // If the desired icon is an DarkSVGIcon we can create a view that shares the underlying svg with
                     // the existing icon.
-                    Icon derived = ((DarkSVGIcon) icon).derive(w, h);
+                    Icon derived = ((DerivableIcon<Icon>) icon).derive(w, h);
                     key.w = w;
                     iconMap.put(key, derived);
                     return derived;

property-loader/src/main/java/com/github/weisj/darklaf/icons/RotatableIcon.java

@@ -35,6 +35,7 @@ public class RotatableIcon implements Icon {
 
     private Icon icon;
     private Alignment alignment;
+    private double angle;
 
     public RotatableIcon() {
         this(null);
@@ -42,7 +43,6 @@ public class RotatableIcon implements Icon {
 
     public RotatableIcon(final Icon icon) {
         setIcon(icon);
-        setOrientation(null);
     }
 
     public void setIcon(final Icon icon) {
@@ -62,36 +62,8 @@ public class RotatableIcon implements Icon {
         }
     }
 
-    private double getAngle() {
-        double angle = 0.0;
-        switch (alignment) {
-            case NORTH :
-            case CENTER :
-                angle = 0.0;
-                break;
-            case SOUTH :
-                angle = 180.0;
-                break;
-            case EAST :
-                angle = 90.0;
-                break;
-            case WEST :
-                angle = 270.0;
-                break;
-            case NORTH_EAST :
-                angle = 45.0;
-                break;
-            case NORTH_WEST :
-                angle = 315.0;
-                break;
-            case SOUTH_EAST :
-                angle = 135.0;
-                break;
-            case SOUTH_WEST :
-                angle = 225.0;
-                break;
-        }
-        return Math.toRadians(angle);
+    public double getAngle() {
+        return angle;
     }
 
     @Override
@@ -110,5 +82,11 @@ public class RotatableIcon implements Icon {
 
     public void setOrientation(final Alignment alignment) {
         this.alignment = alignment != null ? alignment : Alignment.NORTH;
+        this.angle = this.alignment.getAngle();
+    }
+
+    public void setRotation(final double angle) {
+        this.alignment = null;
+        this.angle = angle;
     }
 }