[Components] ♻️ Move min sizes defined by components' specs to their …

…skin as protected static members (not final! makes them easily changeable)

Signed-off-by: palexdev <[email protected]>

modules/components/src/main/java/io/github/palexdev/mfxcomponents/skins/MFXButtonSkin.java

@@ -52,6 +52,9 @@ public class MFXButtonSkin<T extends MFXButtonBase<B>, B extends MFXButtonBehavi
     //================================================================================
     protected final MaterialSurface surface;
 
+    // Specs
+    protected static double MIN_HEIGHT = 40.0;
+
     //================================================================================
     // Constructors
     //================================================================================
@@ -131,6 +134,11 @@ protected void initBehavior(B behavior) {
         );
     }
 
+    @Override
+    public double computeMinHeight(double width, double topInset, double rightInset, double bottomInset, double leftInset) {
+        return Math.max(MIN_HEIGHT, super.computeMinHeight(width, topInset, rightInset, bottomInset, leftInset));
+    }
+
     @Override
     public double computePrefWidth(double height, double topInset, double rightInset, double bottomInset, double leftInset) {
         T button = getSkinnable();

modules/components/src/main/java/io/github/palexdev/mfxcomponents/skins/MFXFabSkin.java

@@ -61,7 +61,6 @@ public class MFXFabSkin extends MFXButtonSkin<MFXFabBase, MFXButtonBehaviorBase<
 	//================================================================================
 	// Properties
 	//================================================================================
-	// TODO define min sizes in Skins
 	private Animation ecAnimation;
 	private Animation sAnimation;
 	private final Scale scale = new Scale(1, 1);
@@ -82,6 +81,15 @@ public class MFXFabSkin extends MFXButtonSkin<MFXFabBase, MFXButtonBehaviorBase<
 	protected Duration OPACITY_DURATION_EXTENDED = M3Motion.EXTRA_LONG2;
 	protected Interpolator RESIZE_CURVE = M3Motion.EMPHASIZED;
 
+	// Specs
+	protected static double MIN_HEIGHT = 56.0;
+	protected static double MIN_WIDTH = 56.0;
+	protected static double MIN_WIDTH_EXTENDED = 80.0;
+
+	// Specs Small
+	protected static double MIN_SIZE_SMALL = 40.0;
+	protected static double MIN_SIZE_LARGE = 96.0;
+
 	//================================================================================
 	// Constructors
 	//================================================================================
@@ -219,6 +227,29 @@ protected double computeLabelDisplacement(double w) {
 		return snapPositionX(((w - iW) / 2.0) - label.getLayoutX());
 	}
 
+	/**
+	 * Returns the appropriate minimum width as specified by the Material Design 3 guidelines for "collapsed" FABs
+	 * according to the variant:
+	 * <p> - {@link FABVariants#SMALL} -> {@link #MIN_SIZE_SMALL}
+	 * <p> - {@link FABVariants#LARGE} -> {@link #MIN_SIZE_LARGE}
+	 * <p> - Standard -> {@link #MIN_WIDTH}
+	 * <p>
+	 * Little note: since this skin is for any FAB implementation starting from {@link MFXFabBase}, and because variants
+	 * are only managed by the default implementation {@link MFXFab}, this will also check if the {@link #getSkinnable()}
+	 * instance is the default implementation to use {@link WithVariants#isVariantApplied(Variant)}.
+	 * Otherwise always returns {@link #MIN_WIDTH}.
+	 */
+	protected double getSpecsMinWidth() {
+		MFXFabBase base = getSkinnable();
+		if (base instanceof MFXFab) {
+			MFXFab fab = (MFXFab) base;
+			return fab.isVariantApplied(FABVariants.SMALL) ? MIN_SIZE_SMALL :
+				fab.isVariantApplied(FABVariants.LARGE) ? MIN_SIZE_LARGE :
+					MIN_WIDTH;
+		}
+		return MIN_WIDTH;
+	}
+
 	//================================================================================
 	// Overridden Methods
 	//================================================================================
@@ -277,15 +308,16 @@ public double computeMinWidth(double height, double topInset, double rightInset,
 			MFXFontIcon icon = fab.getIcon();
 			double iW = (icon != null) ? LayoutUtils.getWidth(icon) + leftInset + rightInset : 0.0;
 			double iH = (icon != null) ? LayoutUtils.getHeight(icon) + topInset + bottomInset : 0.0;
-			return Math.max(Math.max(iW, iH), 56.0);
+			double minW = getSpecsMinWidth();
+			return Math.max(Math.max(iW, iH), minW);
 		}
-		return 80.0;
+		return MIN_WIDTH_EXTENDED;
 	}
 
 	@Override
 	public double computeMinHeight(double width, double topInset, double rightInset, double bottomInset, double leftInset) {
 		MFXFabBase fab = getSkinnable();
-		return !fab.isExtended() ? computeMinWidth(-1) : 56.0;
+		return !fab.isExtended() ? computeMinWidth(-1) : MIN_HEIGHT;
 	}
 
 	@Override

modules/components/src/main/java/io/github/palexdev/mfxcomponents/skins/MFXSegmentedButtonSkin.java

@@ -48,6 +48,10 @@ public class MFXSegmentedButtonSkin extends MFXSkinBase<MFXSegmentedButton, MFXS
     protected WeakReference<MFXSegment> first;
     protected WeakReference<MFXSegment> last;
 
+    // Specs
+    protected static double MIN_SEGMENT_WIDTH = 48.0;
+    protected static double MIN_HEIGHT = 40.0;
+
     //================================================================================
     // Constructors
     //================================================================================
@@ -119,6 +123,14 @@ protected void updateFirstLast() {
     @Override
     protected void initBehavior(MFXSegmentedButtonBehavior behavior) {}
 
+    @Override
+    public double computeMinHeight(double width, double topInset, double rightInset, double bottomInset, double leftInset) {
+        MFXSegmentedButton button = getSkinnable();
+        int density = button.getDensity();
+        double minH = MIN_HEIGHT - (4.0 * density);
+        return Math.max(minH, super.computeMinHeight(width, topInset, rightInset, bottomInset, leftInset));
+    }
+
     @Override
     public double computePrefWidth(double height, double topInset, double rightInset, double bottomInset, double leftInset) {
         ObservableList<MFXSegment> segments = getSkinnable().getSegments();
@@ -240,7 +252,7 @@ public void setIcon(MFXFontIcon icon) {
     /**
      * Default skin used by {@link MFXSegment} and simple extension of {@link MFXButtonSkin}.
      * <p>
-     * What changes is the layout strategy. According to MD3 guidelines a segment's label (text + icon) is always centered.
+     * What changes is the layout strategy. According to MD3 guidelines, a segment's label (text + icon) is always centered.
      */
     public static class MFXSegmentSkin extends MFXButtonSkin<MFXSegment, MFXSelectableBehaviorBase<MFXSegment>> {
 
@@ -251,6 +263,11 @@ public MFXSegmentSkin(MFXSegment button) {
         @Override
         protected void addListeners() {}
 
+        @Override
+        public double computeMinWidth(double height, double topInset, double rightInset, double bottomInset, double leftInset) {
+            return Math.max(MIN_SEGMENT_WIDTH, super.computeMinWidth(height, topInset, rightInset, bottomInset, leftInset));
+        }
+
         @Override
         public double computePrefWidth(double height, double topInset, double rightInset, double bottomInset, double leftInset) {
             MFXSegment segment = getSkinnable();