better implementation of the touch mousing from yesterday

MLEM.Ui/Elements/Element.cs

@@ -259,7 +259,7 @@ namespace MLEM.Ui.Elements {
         public float DrawAlpha = 1;
 
         /// <summary>
-        /// Stores whether this element is currently being moused over.
+        /// Stores whether this element is currently being moused over or touched.
         /// </summary>
         public bool IsMouseOver { get; protected set; }
         /// <summary>
@@ -300,6 +300,14 @@ namespace MLEM.Ui.Elements {
         /// </summary>
         public GenericCallback OnMouseExit;
         /// <summary>
+        /// Event that is called when this element starts being touched
+        /// </summary>
+        public GenericCallback OnTouchEnter;
+        /// <summary>
+        /// Event that is called when this element stops being touched
+        /// </summary>
+        public GenericCallback OnTouchExit;
+        /// <summary>
         /// Event that is called when text input is made.
         /// Note that this event is called for every element, even if it is not selected.
         /// Also note that if <see cref="TextInputWrapper.RequiresOnScreenKeyboard"/> is true, this event is never called.
@@ -315,6 +323,11 @@ namespace MLEM.Ui.Elements {
         /// </summary>
         public OtherElementCallback OnMousedElementChanged;
         /// <summary>
+        /// Event that is called when the element that is currently being touched changes within the ui system.
+        /// Note that the event fired doesn't necessarily correlate to this specific element.
+        /// </summary>
+        public OtherElementCallback OnTouchedElementChanged;
+        /// <summary>
         /// Event that is called when the element that is currently selected changes within the ui system.
         /// Note that the event fired doesn't necessarily correlate to this specific element.
         /// </summary>
@@ -362,6 +375,8 @@ namespace MLEM.Ui.Elements {
 
             this.OnMouseEnter += element => this.IsMouseOver = true;
             this.OnMouseExit += element => this.IsMouseOver = false;
+            this.OnTouchEnter += element => this.IsMouseOver = true;
+            this.OnTouchExit += element => this.IsMouseOver = false;
             this.OnSelected += element => this.IsSelected = true;
             this.OnDeselected += element => this.IsSelected = false;
             this.GetTabNextElement += (backward, next) => next;

MLEM.Ui/UiControls.cs

@@ -35,11 +35,15 @@ namespace MLEM.Ui {
         /// The <see cref="RootElement"/> that is currently active.
         /// The active root element is the one with the highest <see cref="RootElement.Priority"/> that whose <see cref="RootElement.CanSelectContent"/> property is true.
         /// </summary>
-        public RootElement ActiveRoot { get; private set; }
+        public RootElement ActiveRoot { get; protected set; }
         /// <summary>
         /// The <see cref="Element"/> that the mouse is currently over.
         /// </summary>
-        public Element MousedElement { get; private set; }
+        public Element MousedElement { get; protected set; }
+        /// <summary>
+        /// The <see cref="Element"/> that is currently touched.
+        /// </summary>
+        public Element TouchedElement { get; protected set; }
         private readonly Dictionary<string, Element> selectedElements = new Dictionary<string, Element>();
         /// <summary>
         /// The element that is currently selected.
@@ -141,14 +145,7 @@ namespace MLEM.Ui {
             // MOUSE INPUT
             if (this.HandleMouse) {
                 var mousedNow = this.GetElementUnderPos(this.Input.MousePosition.ToVector2());
-                if (mousedNow != this.MousedElement) {
+                this.SetMousedElement(mousedNow);
-                    if (this.MousedElement != null)
-                        this.System.OnElementMouseExit?.Invoke(this.MousedElement);
-                    if (mousedNow != null)
-                        this.System.OnElementMouseEnter?.Invoke(mousedNow);
-                    this.MousedElement = mousedNow;
-                    this.System.OnMousedElementChanged?.Invoke(mousedNow);
-                }
 
                 if (this.Input.IsMouseButtonPressed(MouseButton.Left)) {
                     this.IsAutoNavMode = false;
@@ -200,6 +197,19 @@ namespace MLEM.Ui {
                     this.SelectElement(this.ActiveRoot, held);
                     if (held != null && held.CanBePressed)
                         this.System.OnElementSecondaryPressed?.Invoke(held);
+                } else if (this.Input.TouchState.Count <= 0) {
+                    this.SetTouchedElement(null);
+                } else {
+                    foreach (var location in this.Input.TouchState) {
+                        var element = this.GetElementUnderPos(location.Position);
+                        if (location.State == TouchLocationState.Pressed) {
+                            // start touching an element if we just touched down on it
+                            this.SetTouchedElement(element);
+                        } else if (element != this.TouchedElement) {
+                            // if we moved off of the touched element, we stop touching
+                            this.SetTouchedElement(null);
+                        }
+                    }
                 }
             }
 
@@ -269,6 +279,36 @@ namespace MLEM.Ui {
                 this.IsAutoNavMode = autoNav.Value;
         }
 
+        /// <summary>
+        /// Sets the <see cref="MousedElement"/> to the given value, calling the appropriate events.
+        /// </summary>
+        /// <param name="element">The element to set as moused</param>
+        public void SetMousedElement(Element element) {
+            if (element != this.MousedElement) {
+                if (this.MousedElement != null)
+                    this.System.OnElementMouseExit?.Invoke(this.MousedElement);
+                if (element != null)
+                    this.System.OnElementMouseEnter?.Invoke(element);
+                this.MousedElement = element;
+                this.System.OnMousedElementChanged?.Invoke(element);
+            }
+        }
+
+        /// <summary>
+        /// Sets the <see cref="TouchedElement"/> to the given value, calling the appropriate events.
+        /// </summary>
+        /// <param name="element">The element to set as touched</param>
+        public void SetTouchedElement(Element element) {
+            if (element != this.TouchedElement) {
+                if (this.TouchedElement != null)
+                    this.System.OnElementTouchExit?.Invoke(this.TouchedElement);
+                if (element != null)
+                    this.System.OnElementTouchEnter?.Invoke(element);
+                this.TouchedElement = element;
+                this.System.OnTouchedElementChanged?.Invoke(element);
+            }
+        }
+
         /// <summary>
         /// Returns the selected element for the given root element.
         /// A property equivalent to this method is <see cref="RootElement.SelectedElement"/>.

MLEM.Ui/UiSystem.cs

@@ -141,6 +141,14 @@ namespace MLEM.Ui {
         /// </summary>
         public Element.GenericCallback OnElementMouseExit = e => e.OnMouseExit?.Invoke(e);
         /// <summary>
+        /// Event that is invoked when an <see cref="Element"/> starts being touched
+        /// </summary>
+        public Element.GenericCallback OnElementTouchEnter = e => e.OnTouchEnter?.Invoke(e);
+        /// <summary>
+        /// Event that is invoked when an <see cref="Element"/> stops being touched
+        /// </summary>
+        public Element.GenericCallback OnElementTouchExit = e => e.OnTouchExit?.Invoke(e);
+        /// <summary>
         /// Event that is invoked when an <see cref="Element"/>'s display area changes
         /// </summary>
         public Element.GenericCallback OnElementAreaUpdated = e => e.OnAreaUpdated?.Invoke(e);
@@ -149,6 +157,10 @@ namespace MLEM.Ui {
         /// </summary>
         public Element.GenericCallback OnMousedElementChanged;
         /// <summary>
+        /// Event that is invoked when the <see cref="Element"/> that is being touched changes
+        /// </summary>
+        public Element.GenericCallback OnTouchedElementChanged;
+        /// <summary>
         /// Event that is invoked when the selected <see cref="Element"/> changes, either through automatic navigation, or by pressing on an element with the mouse
         /// </summary>
         public Element.GenericCallback OnSelectedElementChanged;
@@ -184,6 +196,7 @@ namespace MLEM.Ui {
 
             TextInputWrapper.Current.AddListener(window, (sender, key, character) => this.ApplyToAll(e => e.OnTextInput?.Invoke(e, key, character)));
             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));
             this.OnSelectedElementDrawn = (element, time, batch, alpha) => {
                 if (this.Controls.IsAutoNavMode && element.SelectionIndicator.HasValue()) {