Made custom values of Element.Style persist when a new ui style is set

CHANGELOG.md

@@ -22,15 +22,23 @@ Fixes
 - Fixed StaticSpriteBatch handling rotated sprites incorrectly
 
 ### MLEM.Ui
+Additions
+- Added Element.OnStyleInit event
+
 Improvements
 - Allow for checkboxes and radio buttons to be disabled
 - Only set a paragraph's area dirty when a text change would cause it to change size
 - Ensure that a panel gets notified of all relevant changes by calling OnChildAreaDirty for all grandchildren
 - Avoid unnecessary panel updates by using an Epsilon comparison when scrolling children
+- Allow setting a default text alignment for paragraphs in UiStyle
+- Made custom values of Element.Style persist when a new ui style is set
 
 Fixes
 - Fixed paragraph links having incorrect hover locations when using special text alignments
 
+Removals
+- Marked StyleProp equality members as obsolete
+
 ### MLEM.Extended
 Improvements
 - Preserve texture region names when converting between MLEM and MG.Extended

Demos/UiDemo.cs

@@ -81,7 +81,7 @@ namespace Demos {
             this.root.AddChild(new Button(Anchor.AutoCenter, new Vector2(1, 10), "Change Style") {
                 OnPressed = element => this.UiSystem.Style = this.UiSystem.Style == untexturedStyle ? style : untexturedStyle,
                 PositionOffset = new Vector2(0, 1),
-                Texture = this.testPatch
+                Style = untexturedStyle
             });
 
             this.root.AddChild(new VerticalSpace(3));

MLEM.Ui/Elements/Element.cs

@@ -32,22 +32,7 @@ namespace MLEM.Ui.Elements {
             internal set {
                 this.system = value;
                 this.Controls = value?.Controls;
-                this.Style = value?.Style;
-            }
-        }
-        /// <summary>
-        /// This Element's current <see cref="UiStyle"/>.
-        /// When this value is changed, <see cref="InitStyle"/> is called.
-        /// Note that this value is automatically set to the <see cref="UiSystem"/>'s ui style when it is changed.
-        /// </summary>
-        public UiStyle Style {
-            get => this.style;
-            set {
-                if (this.style != value) {
-                    this.style = value;
-                    if (value != null)
-                        this.InitStyle(value);
-                }
+                this.Style = this.Style.OrStyle(value?.Style);
             }
         }
         /// <summary>
@@ -261,6 +246,18 @@ namespace MLEM.Ui.Elements {
         /// </summary>
         public bool AreaDirty { get; private set; }
 
+        /// <summary>
+        /// This Element's current <see cref="UiStyle"/>.
+        /// When this property is set, <see cref="InitStyle"/> is called.
+        /// </summary>
+        public StyleProp<UiStyle> Style {
+            get => this.style;
+            set {
+                this.style = value;
+                if (this.style.HasValue())
+                    this.InitStyle(this.style);
+            }
+        }
         /// <summary>
         /// A style property that contains the selection indicator that is displayed on this element if it is the <see cref="RootElement.SelectedElement"/>
         /// </summary>
@@ -342,6 +339,10 @@ namespace MLEM.Ui.Elements {
         /// </summary>
         public GenericCallback OnAreaUpdated;
         /// <summary>
+        /// Event that is called when this element's <see cref="InitStyle"/> method is called while setting the <see cref="Style"/>.
+        /// </summary>
+        public GenericCallback OnStyleInit;
+        /// <summary>
         /// Event that is called when the element that is currently being moused changes within the ui system.
         /// Note that the event fired doesn't necessarily correlate to this specific element.
         /// </summary>
@@ -414,7 +415,7 @@ namespace MLEM.Ui.Elements {
         private RectangleF area;
         private bool isHidden;
         private int priority;
-        private UiStyle style;
+        private StyleProp<UiStyle> style;
         private StyleProp<Padding> childPadding;
 
         /// <summary>
@@ -1058,6 +1059,8 @@ 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.System?.InvokeOnElementStyleInit(this);
         }
 
         /// <summary>

MLEM.Ui/Elements/Paragraph.cs

@@ -90,7 +90,7 @@ namespace MLEM.Ui.Elements {
         /// <summary>
         /// The <see cref="TextAlignment"/> that this paragraph's text should be rendered with
         /// </summary>
-        public TextAlignment Alignment {
+        public StyleProp<TextAlignment> Alignment {
             get => this.alignment;
             set {
                 this.alignment = value;
@@ -99,7 +99,7 @@ namespace MLEM.Ui.Elements {
         }
 
         private string text;
-        private TextAlignment alignment;
+        private StyleProp<TextAlignment> alignment;
         private StyleProp<GenericFont> regularFont;
 
         /// <summary>
@@ -158,6 +158,7 @@ namespace MLEM.Ui.Elements {
             this.RegularFont = this.RegularFont.OrStyle(style.Font ?? throw new NotSupportedException("Paragraphs cannot use ui styles that don't have a font. Please supply a custom font by setting UiStyle.Font."));
             this.TextScale = this.TextScale.OrStyle(style.TextScale);
             this.TextColor = this.TextColor.OrStyle(style.TextColor);
+            this.Alignment = this.Alignment.OrStyle(style.TextAlignment);
         }
 
         /// <summary>
@@ -202,7 +203,7 @@ namespace MLEM.Ui.Elements {
         }
 
         private float GetAlignmentOffset() {
-            switch (this.Alignment) {
+            switch (this.Alignment.Value) {
                 case TextAlignment.Center:
                     return this.DisplayArea.Width / 2;
                 case TextAlignment.Right:

MLEM.Ui/Style/StyleProp.cs

@@ -75,6 +75,7 @@ namespace MLEM.Ui.Style {
         /// <summary>Indicates whether the current object is equal to another object of the same type.</summary>
         /// <param name="other">An object to compare with this object.</param>
         /// <returns>true if the current object is equal to the <paramref name="other">other</paramref> parameter; otherwise, false.</returns>
+        [Obsolete("StyleProp equality is ambiguous as it is not clear whether priority is taken into account. Compare Values instead.")]
         public bool Equals(StyleProp<T> other) {
             return EqualityComparer<T>.Default.Equals(this.Value, other.Value);
         }
@@ -82,12 +83,14 @@ namespace MLEM.Ui.Style {
         /// <summary>Indicates whether this instance and a specified object are equal.</summary>
         /// <param name="obj">The object to compare with the current instance.</param>
         /// <returns>true if <paramref name="obj">obj</paramref> and this instance are the same type and represent the same value; otherwise, false.</returns>
+        [Obsolete("StyleProp equality is ambiguous as it is not clear whether priority is taken into account. Compare Values instead.")]
         public override bool Equals(object obj) {
             return obj is StyleProp<T> other && this.Equals(other);
         }
 
         /// <summary>Returns the hash code for this instance.</summary>
         /// <returns>A 32-bit signed integer that is the hash code for this instance.</returns>
+        [Obsolete("StyleProp equality is ambiguous as it is not clear whether priority is taken into account. Compare Values instead.")]
         public override int GetHashCode() {
             return EqualityComparer<T>.Default.GetHashCode(this.Value);
         }
@@ -122,6 +125,7 @@ namespace MLEM.Ui.Style {
         /// <param name="left">The left style property.</param>
         /// <param name="right">The right style property.</param>
         /// <returns>Whether the two style properties are equal.</returns>
+        [Obsolete("StyleProp equality is ambiguous as it is not clear whether priority is taken into account. Compare Values instead.")]
         public static bool operator ==(StyleProp<T> left, StyleProp<T> right) {
             return left.Equals(right);
         }
@@ -132,6 +136,7 @@ namespace MLEM.Ui.Style {
         /// <param name="left">The left style property.</param>
         /// <param name="right">The right style property.</param>
         /// <returns>Whether the two style properties are not equal.</returns>
+        [Obsolete("StyleProp equality is ambiguous as it is not clear whether priority is taken into account. Compare Values instead.")]
         public static bool operator !=(StyleProp<T> left, StyleProp<T> right) {
             return !left.Equals(right);
         }

MLEM.Ui/Style/UiStyle.cs

@@ -199,6 +199,10 @@ namespace MLEM.Ui.Style {
         /// </summary>
         public Color TextColor = Color.White;
         /// <summary>
+        /// The <see cref="TextAlignment"/> that a <see cref="Paragraph"/> should use by default.
+        /// </summary>
+        public TextAlignment TextAlignment;
+        /// <summary>
         /// The <see cref="SoundEffectInfo"/> that should be played when an element's <see cref="Element.OnPressed"/> and <see cref="Element.OnSecondaryPressed"/> events are called.
         /// Note that this sound is only played if the callbacks have any subscribers.
         /// </summary>

MLEM.Ui/UiSystem.cs

@@ -153,6 +153,10 @@ namespace MLEM.Ui {
         /// </summary>
         public event Element.GenericCallback OnElementAreaUpdated;
         /// <summary>
+        /// Event that is called when an <see cref="Element"/>'s <see cref="Element.InitStyle"/> method is called while setting its <see cref="Element.Style"/>.
+        /// </summary>
+        public event Element.GenericCallback OnElementStyleInit;
+        /// <summary>
         /// Event that is invoked when the <see cref="Element"/> that the mouse is currently over changes
         /// </summary>
         public event Element.GenericCallback OnMousedElementChanged;
@@ -190,6 +194,7 @@ namespace MLEM.Ui {
         public UiSystem(Game game, UiStyle style, InputHandler inputHandler = null, bool automaticViewport = true) : base(game) {
             this.Controls = new UiControls(this, inputHandler);
             this.style = style;
+
             this.OnElementDrawn += (e, time, batch, alpha) => e.OnDrawn?.Invoke(e, time, batch, alpha);
             this.OnElementUpdated += (e, time) => e.OnUpdated?.Invoke(e, time);
             this.OnElementPressed += e => e.OnPressed?.Invoke(e);
@@ -201,6 +206,7 @@ namespace MLEM.Ui {
             this.OnElementTouchEnter += e => e.OnTouchEnter?.Invoke(e);
             this.OnElementTouchExit += e => e.OnTouchExit?.Invoke(e);
             this.OnElementAreaUpdated += e => e.OnAreaUpdated?.Invoke(e);
+            this.OnElementStyleInit += e => e.OnStyleInit?.Invoke(e);
             this.OnMousedElementChanged += e => this.ApplyToAll(t => t.OnMousedElementChanged?.Invoke(t, e));
             this.OnTouchedElementChanged += e => this.ApplyToAll(t => t.OnTouchedElementChanged?.Invoke(t, e));
             this.OnSelectedElementChanged += e => this.ApplyToAll(t => t.OnSelectedElementChanged?.Invoke(t, e));
@@ -216,6 +222,7 @@ namespace MLEM.Ui {
                 if (e.OnSecondaryPressed != null)
                     e.SecondActionSound.Value?.Play();
             };
+
             MlemPlatform.Current?.AddTextInputListener(game.Window, (sender, key, character) => this.ApplyToAll(e => e.OnTextInput?.Invoke(e, key, character)));
 
             if (automaticViewport) {
@@ -396,6 +403,10 @@ namespace MLEM.Ui {
             this.OnElementAreaUpdated?.Invoke(element);
         }
 
+        internal void InvokeOnElementStyleInit(Element element) {
+            this.OnElementStyleInit?.Invoke(element);
+        }
+
         internal void InvokeOnElementPressed(Element element) {
             this.OnElementPressed?.Invoke(element);
         }