Added AddCustomStyle and ApplyCustomStyle to UiStyle to allow for easy custom styling of elements

CHANGELOG.md

@@ -39,6 +39,7 @@ Removals
 Additions
 - Added AutoInlineCenter and AutoInlineBottom anchors
 - Added UiAnimation system
+- Added AddCustomStyle and ApplyCustomStyle to UiStyle to allow for easy custom styling of elements
 
 Improvements
 - Increased Element area calculation recursion limit to 64

MLEM.Ui/Elements/Element.cs

@@ -1290,8 +1290,11 @@ namespace MLEM.Ui.Elements {
             this.SelectionIndicator = this.SelectionIndicator.OrStyle(style.SelectionIndicator);
             this.ActionSound = this.ActionSound.OrStyle(style.ActionSound);
             this.SecondActionSound = this.SecondActionSound.OrStyle(style.ActionSound);
+            this.MouseEnterAnimation = this.MouseEnterAnimation.OrStyle(style.MouseEnterAnimation);
+            this.MouseExitAnimation = this.MouseExitAnimation.OrStyle(style.MouseExitAnimation);
 
             this.System?.InvokeOnElementStyleInit(this);
+            style.ApplyCustomStyle(this);
         }
 
         /// <summary>

MLEM.Ui/Elements/Panel.cs

@@ -212,6 +212,7 @@ namespace MLEM.Ui.Elements {
         protected override void InitStyle(UiStyle style) {
             base.InitStyle(style);
             this.Texture = this.Texture.OrStyle(style.PanelTexture);
+            this.DrawColor = this.DrawColor.OrStyle(style.PanelColor);
             this.StepPerScroll = this.StepPerScroll.OrStyle(style.PanelStepPerScroll);
             this.ScrollerSize = this.ScrollerSize.OrStyle(style.PanelScrollerSize);
             this.ScrollBarOffset = this.ScrollBarOffset.OrStyle(style.PanelScrollBarOffset);

MLEM.Ui/Parsers/UiParser.cs

@@ -109,11 +109,11 @@ namespace MLEM.Ui.Parsers {
 
         /// <summary>
         /// Specifies an action to be invoked when a new element with the given <see cref="ElementType"/> is parsed in <see cref="Parse"/> or <see cref="ParseInto"/>.
-        /// These actions can be used to modify the style properties of the created elements.
+        /// These actions can be used to modify the style properties of the created elements similarly to <see cref="UiStyle.AddCustomStyle{T}"/>.
         /// </summary>
         /// <param name="types">The element types that should be styled. Can be a combined flag.</param>
         /// <param name="style">The action that styles the elements with the given element type.</param>
-        /// <param name="add">Whether the <paramref name="style"/> function should be added to the existing style settings, or replace them.</param>
+        /// <param name="add">Whether the <paramref name="style"/> function should be added to the existing style settings rather than replacing them.</param>
         /// <typeparam name="T">The type of elements that the given <see cref="ElementType"/> flags are expected to be.</typeparam>
         /// <returns>This parser, for chaining.</returns>
         public UiParser Style<T>(ElementType types, Action<T> style, bool add = false) where T : Element {

MLEM.Ui/Style/UiStyle.cs

@@ -13,7 +13,7 @@ namespace MLEM.Ui.Style {
     /// <summary>
     /// The style settings for a <see cref="UiSystem"/>.
     /// Each <see cref="Element"/> uses these style settings by default, however you can also change these settings per element using the elements' individual style settings.
-    /// Note that this class is a <see cref="GenericDataHolder"/>, meaning additional styles for custom components can easily be added using <see cref="GenericDataHolder.SetData"/>
+    /// Additional styles for built-in or custom element types can easily be added using <see cref="AddCustomStyle{T}"/>.
     /// </summary>
     public class UiStyle : GenericDataHolder {
 
@@ -22,6 +22,14 @@ namespace MLEM.Ui.Style {
         /// </summary>
         public NinePatch SelectionIndicator;
         /// <summary>
+        /// A <see cref="UiAnimation"/> that is played when the mouse enters an element.
+        /// </summary>
+        public UiAnimation MouseEnterAnimation;
+        /// <summary>
+        /// A <see cref="UiAnimation"/> that is played when the mouse exists an element.
+        /// </summary>
+        public UiAnimation MouseExitAnimation;
+        /// <summary>
         /// The texture that the <see cref="Button"/> element uses
         /// </summary>
         public NinePatch ButtonTexture;
@@ -47,6 +55,10 @@ namespace MLEM.Ui.Style {
         /// </summary>
         public NinePatch PanelTexture;
         /// <summary>
+        /// The color that the <see cref="Panel"/> element draws with.
+        /// </summary>
+        public Color PanelColor = Color.White;
+        /// <summary>
         /// The <see cref="Element.ChildPadding"/> to apply to a <see cref="Panel"/> by default
         /// </summary>
         public Padding PanelChildPadding = new Vector2(5);
@@ -222,5 +234,40 @@ namespace MLEM.Ui.Style {
         /// </summary>
         public Dictionary<string, GenericFont> AdditionalFonts = new Dictionary<string, GenericFont>();
 
+        private readonly Dictionary<Type, Action<Element>> elementStyles = new Dictionary<Type, Action<Element>>();
+
+        /// <summary>
+        /// Adds an action to the given <see cref="Element"/> type <typeparamref name="T"/> that allows applying any kind of custom styling or behavior to it.
+        /// Custom styles added in this manner can be applied to an element using <see cref="ApplyCustomStyle"/>.
+        /// </summary>
+        /// <param name="style">The style action to add.</param>
+        /// <param name="add">Whether the <paramref name="style"/> function should be added to the existing style settings rather than replacing them.</param>
+        /// <typeparam name="T">The <see cref="Element"/> type that the <paramref name="style"/> should apply to.</typeparam>
+        public void AddCustomStyle<T>(Action<T> style, bool add = false) where T : Element {
+            if (add && this.elementStyles.ContainsKey(typeof(T))) {
+                this.elementStyles[typeof(T)] += Action;
+            } else {
+                this.elementStyles[typeof(T)] = Action;
+            }
+
+            void Action(Element e) {
+                style.Invoke((T) e);
+            }
+        }
+
+        /// <summary>
+        /// Applies a set of custom styling actions to the given <paramref name="element"/> which were added through <see cref="AddCustomStyle{T}"/>.
+        /// This method is automatically invoked in <see cref="Element.InitStyle"/>.
+        /// </summary>
+        /// <param name="element">The element to apply custom styling to.</param>
+        /// <returns>Whether any custom styling exists for the given <paramref name="element"/>.</returns>
+        public bool ApplyCustomStyle(Element element) {
+            if (this.elementStyles.TryGetValue(element.GetType(), out var style)) {
+                style?.Invoke(element);
+                return true;
+            }
+            return false;
+        }
+
     }
 }