tabbing, part 1!

Demos/UiDemo.cs

@@ -86,7 +86,8 @@ namespace Demos {
                 // (like above), these custom values don't get undone
                 HasCustomStyle = true,
                 Texture = this.testPatch,
-                HoveredColor = Color.LightGray
+                HoveredColor = Color.LightGray,
+                SelectionIndicator = style.SelectionIndicator
             });
 
             root.AddChild(new VerticalSpace(3));
@@ -129,7 +130,7 @@ namespace Demos {
             root.AddChild(new RadioButton(Anchor.AutoLeft, new Vector2(1, 10), "Radio button 2!") {PositionOffset = new Vector2(0, 1)});
 
             var tooltip = new Tooltip(50, "This is a test tooltip to see the window bounding") {IsHidden = true};
-            this.UiSystem.Add("TestTooltip", tooltip);
+            this.UiSystem.Add("TestTooltip", tooltip).CanSelectContent = false;
             root.AddChild(new VerticalSpace(3));
             root.AddChild(new Button(Anchor.AutoLeft, new Vector2(1, 10), "Toggle Test Tooltip") {
                 OnPressed = element => tooltip.IsHidden = !tooltip.IsHidden

MLEM.Ui/Elements/Element.cs

@@ -7,6 +7,7 @@ using Microsoft.Xna.Framework.Graphics;
 using Microsoft.Xna.Framework.Input;
 using MLEM.Extensions;
 using MLEM.Input;
+using MLEM.Textures;
 using MLEM.Ui.Style;
 
 namespace MLEM.Ui.Elements {
@@ -98,11 +99,11 @@ namespace MLEM.Ui.Elements {
                     this.InitStyle(this.system.Style);
             }
         }
-        protected InputHandler Input => this.System.InputHandler;
         protected UiControls Controls => this.System.Controls;
+        protected InputHandler Input => this.Controls.Input;
+        public Point MousePos => this.Input.MousePosition;
         public RootElement Root { get; private set; }
         public float Scale => this.Root.ActualScale;
-        public Point MousePos => this.Input.MousePosition;
         public Element Parent { get; private set; }
         public bool IsMouseOver { get; private set; }
         public bool IsSelected { get; private set; }
@@ -116,7 +117,8 @@ namespace MLEM.Ui.Elements {
                 this.SetAreaDirty();
             }
         }
-        public bool IgnoresMouse;
+        public bool CanBeSelected = true;
+        public bool CanBeMoused = true;
         public float DrawAlpha = 1;
         public bool HasCustomStyle;
         public bool SetHeightBasedOnChildren;
@@ -153,6 +155,7 @@ namespace MLEM.Ui.Elements {
         }
         private bool areaDirty;
         private bool sortedChildrenDirty;
+        public NinePatch SelectionIndicator;
 
         public Element(Anchor anchor, Vector2 size) {
             this.anchor = anchor;
@@ -422,6 +425,10 @@ namespace MLEM.Ui.Elements {
                 if (!child.IsHidden)
                     child.Draw(time, batch, alpha * child.DrawAlpha, offset);
             }
+
+            if (this.IsSelected && this.Controls.ShowSelectionIndicator && this.SelectionIndicator != null) {
+                batch.Draw(this.SelectionIndicator, this.DisplayArea.OffsetCopy(offset), Color.White * alpha);
+            }
         }
 
         public virtual void DrawEarly(GameTime time, SpriteBatch batch, float alpha, BlendState blendState = null, SamplerState samplerState = null) {
@@ -432,17 +439,18 @@ namespace MLEM.Ui.Elements {
         }
 
         public virtual Element GetMousedElement() {
-            if (this.IsHidden || this.IgnoresMouse)
+            if (this.IsHidden)
                 return null;
             for (var i = this.SortedChildren.Count - 1; i >= 0; i--) {
                 var element = this.SortedChildren[i].GetMousedElement();
                 if (element != null)
                     return element;
             }
-            return this.Area.Contains(this.MousePos) ? this : null;
+            return this.CanBeMoused && this.Area.Contains(this.MousePos) ? this : null;
         }
 
         protected virtual void InitStyle(UiStyle style) {
+            this.SelectionIndicator = style.SelectionIndicator;
         }
 
         public delegate void TextInputCallback(Element element, Keys key, char character);

MLEM.Ui/Elements/ElementHelper.cs

@@ -7,10 +7,7 @@ namespace MLEM.Ui.Elements {
 
         public static Button ImageButton(Anchor anchor, Vector2 size, TextureRegion texture, string text = null, string tooltipText = null, float tooltipWidth = 50, int imagePadding = 2) {
             var button = new Button(anchor, size, text, tooltipText, tooltipWidth);
-            var image = new Image(Anchor.CenterLeft, Vector2.One, texture) {
+            var image = new Image(Anchor.CenterLeft, Vector2.One, texture) {Padding = new Point(imagePadding)};
-                Padding = new Point(imagePadding),
-                IgnoresMouse = true
-            };
             button.OnAreaUpdated += e => image.Size = new Vector2(e.Area.Height, e.Area.Height) / e.Scale;
             button.AddChild(image, 0);
             return button;

MLEM.Ui/Elements/Group.cs

@@ -5,6 +5,7 @@ namespace MLEM.Ui.Elements {
 
         public Group(Anchor anchor, Vector2 size, bool setHeightBasedOnChildren = true) : base(anchor, size) {
             this.SetHeightBasedOnChildren = setHeightBasedOnChildren;
+            this.CanBeSelected = false;
         }
 
     }

MLEM.Ui/Elements/Image.cs

@@ -15,6 +15,7 @@ namespace MLEM.Ui.Elements {
         public Image(Anchor anchor, Vector2 size, TextureRegion texture, bool scaleToImage = false) : base(anchor, size) {
             this.Texture = texture;
             this.ScaleToImage = scaleToImage;
+            this.CanBeSelected = false;
         }
 
         protected override Point CalcActualSize(Rectangle parentArea) {

MLEM.Ui/Elements/Panel.cs

@@ -19,6 +19,7 @@ namespace MLEM.Ui.Elements {
             this.SetHeightBasedOnChildren = setHeightBasedOnChildren;
             this.scrollOverflow = scrollOverflow;
             this.ChildPadding = new Point(5);
+            this.CanBeSelected = false;
 
             if (scrollOverflow) {
                 var scrollSize = scrollerSize ?? Point.Zero;

MLEM.Ui/Elements/Paragraph.cs

@@ -45,7 +45,8 @@ namespace MLEM.Ui.Elements {
         public Paragraph(Anchor anchor, float width, string text, bool centerText = false) : base(anchor, new Vector2(width, 0)) {
             this.text = text;
             this.AutoAdjustWidth = centerText;
-            this.IgnoresMouse = true;
+            this.CanBeSelected = false;
+            this.CanBeMoused = false;
         }
 
         protected override Point CalcActualSize(Rectangle parentArea) {

MLEM.Ui/Elements/ScrollBar.cs

@@ -43,14 +43,15 @@ namespace MLEM.Ui.Elements {
             this.maxValue = maxValue;
             this.Horizontal = horizontal;
             this.ScrollerSize = new Point(horizontal ? scrollerSize : size.X.Floor(), !horizontal ? scrollerSize : size.Y.Floor());
+            this.CanBeSelected = false;
         }
 
         public override void Update(GameTime time) {
             base.Update(time);
-            var moused = this.System.MousedElement;
+            var moused = this.Controls.MousedElement;
-            if (moused == this && this.Controls.MainButton(this.Input)) {
+            if (moused == this && this.Controls.Input.IsMouseButtonDown(MouseButton.Left)) {
                 this.isMouseHeld = true;
-            } else if (this.isMouseHeld && this.Controls.MainButton(this.Input)) {
+            } else if (this.isMouseHeld && !this.Controls.Input.IsMouseButtonDown(MouseButton.Left)) {
                 this.isMouseHeld = false;
             }
 
@@ -65,7 +66,7 @@ namespace MLEM.Ui.Elements {
             }
 
             if (!this.Horizontal && moused != null && (moused == this.Parent || moused.GetParentTree().Contains(this.Parent))) {
-                var scroll = this.Controls.Scroll(this.Input);
+                var scroll = this.Input.LastScrollWheel - this.Input.ScrollWheel;
                 if (scroll != 0)
                     this.CurrentValue += this.StepPerScroll * Math.Sign(scroll);
             }

MLEM.Ui/Elements/Tooltip.cs

@@ -13,9 +13,10 @@ namespace MLEM.Ui.Elements {
             base(Anchor.TopLeft, width, text) {
             this.AutoAdjustWidth = true;
             this.Padding = new Point(2);
+            this.CanBeSelected = false;
 
             if (elementToHover != null) {
-                elementToHover.OnMouseEnter += element => element.System.Add(element.GetType().Name + "Tooltip", this);
+                elementToHover.OnMouseEnter += element => element.System.Add(element.GetType().Name + "Tooltip", this).CanSelectContent = false;
                 elementToHover.OnMouseExit += element => element.System.Remove(element.GetType().Name + "Tooltip");
             }
         }

MLEM.Ui/Elements/VerticalSpace.cs

@@ -4,6 +4,7 @@ namespace MLEM.Ui.Elements {
     public class VerticalSpace : Element {
 
         public VerticalSpace(int height) : base(Anchor.AutoCenter, new Vector2(1, height)) {
+            this.CanBeSelected = false;
         }
 
     }

MLEM.Ui/Style/UiStyle.cs

@@ -5,6 +5,7 @@ using MLEM.Textures;
 namespace MLEM.Ui.Style {
     public class UiStyle {
 
+        public NinePatch SelectionIndicator;
         public NinePatch ButtonTexture;
         public NinePatch ButtonHoveredTexture;
         public Color ButtonHoveredColor;
@@ -28,5 +29,6 @@ namespace MLEM.Ui.Style {
         public IGenericFont BoldFont;
         public IGenericFont ItalicFont;
         public float TextScale = 1;
+
     }
 }

MLEM.Ui/Style/UntexturedStyle.cs

@@ -9,6 +9,7 @@ namespace MLEM.Ui.Style {
     public class UntexturedStyle : UiStyle {
 
         public UntexturedStyle(SpriteBatch batch) {
+            this.SelectionIndicator = GenerateTexture(batch, Color.Transparent, Color.Red);
             this.ButtonTexture = GenerateTexture(batch, Color.CadetBlue);
             this.ButtonHoveredColor = Color.LightGray;
             this.PanelTexture = GenerateTexture(batch, Color.Gray);
@@ -27,12 +28,13 @@ namespace MLEM.Ui.Style {
             this.Font = new EmptyFont();
         }
 
-        private static NinePatch GenerateTexture(SpriteBatch batch, Color color) {
+        private static NinePatch GenerateTexture(SpriteBatch batch, Color color, Color? outlineColor = null) {
+            var outli = outlineColor ?? Color.Black;
             var tex = new Texture2D(batch.GraphicsDevice, 3, 3);
             tex.SetData(new[] {
-                Color.Black, Color.Black, Color.Black,
+                outli, outli, outli,
-                Color.Black, color, Color.Black,
+                outli, color, outli,
-                Color.Black, Color.Black, Color.Black
+                outli, outli, outli
             });
             batch.Disposing += (sender, args) => {
                 if (tex != null) {

MLEM.Ui/UiControls.cs

@@ -1,15 +1,116 @@
+using System;
+using System.Linq;
+using Microsoft.Xna.Framework;
+using Microsoft.Xna.Framework.Input;
 using MLEM.Input;
+using MLEM.Ui.Elements;
 
 namespace MLEM.Ui {
     public class UiControls {
 
-        public BoolQuery MainButton = h => h.IsMouseButtonPressed(MouseButton.Left);
+        public readonly InputHandler Input;
-        public BoolQuery SecondaryButton = h => h.IsMouseButtonPressed(MouseButton.Right);
+        private readonly bool isInputOurs;
-        public FloatQuery Scroll = h => h.LastScrollWheel - h.ScrollWheel;
+        private readonly UiSystem system;
 
-        public delegate bool BoolQuery(InputHandler handler);
+        public Element MousedElement { get; private set; }
+        public Element SelectedElement { get; private set; }
+        public bool ShowSelectionIndicator;
 
-        public delegate float FloatQuery(InputHandler handler);
+        public UiControls(UiSystem system, InputHandler inputHandler = null) {
+            this.system = system;
+            this.Input = inputHandler ?? new InputHandler();
+            this.isInputOurs = inputHandler == null;
+        }
+
+        public void Update() {
+            if (this.isInputOurs)
+                this.Input.Update();
+
+            var mousedNow = this.GetMousedElement();
+            // mouse new element
+            if (mousedNow != this.MousedElement) {
+                if (this.MousedElement != null)
+                    this.MousedElement.OnMouseExit?.Invoke(this.MousedElement);
+                if (mousedNow != null)
+                    mousedNow.OnMouseEnter?.Invoke(mousedNow);
+                this.MousedElement = mousedNow;
+            }
+
+            if (this.Input.IsMouseButtonPressed(MouseButton.Left)) {
+                // select element
+                var selectedNow = mousedNow != null && mousedNow.CanBeSelected ? mousedNow : null;
+                if (this.SelectedElement != selectedNow)
+                    this.SelectElement(selectedNow, false);
+
+                // first action on element
+                if (mousedNow != null)
+                    mousedNow.OnPressed?.Invoke(mousedNow);
+            } else if (this.Input.IsMouseButtonPressed(MouseButton.Right)) {
+                // secondary action on element
+                if (mousedNow != null)
+                    mousedNow.OnSecondaryPressed?.Invoke(mousedNow);
+            } else if (this.Input.IsKeyPressed(Keys.Enter) || this.Input.IsKeyPressed(Keys.Space)) {
+                if (this.SelectedElement != null) {
+                    if (this.Input.IsModifierKeyDown(ModifierKey.Shift)) {
+                        // secondary action on element using space or enter
+                        this.SelectedElement.OnSecondaryPressed?.Invoke(this.SelectedElement);
+                    } else {
+                        // first action on element using space or enter
+                        this.SelectedElement.OnPressed?.Invoke(this.SelectedElement);
+                    }
+                }
+            } else if (this.Input.IsKeyPressed(Keys.Tab)) {
+                // tab or shift-tab to next or previous element
+                this.SelectElement(this.GetNextElement(this.Input.IsModifierKeyDown(ModifierKey.Shift)), true);
+            }
+        }
+
+        public void SelectElement(Element element, bool show) {
+            if (this.SelectedElement != null)
+                this.SelectedElement.OnDeselected?.Invoke(this.SelectedElement);
+            if (element != null)
+                element.OnSelected?.Invoke(element);
+            this.SelectedElement = element;
+            this.ShowSelectionIndicator = show;
+        }
+
+        public Element GetMousedElement() {
+            foreach (var root in this.system.GetRootElements()) {
+                var moused = root.Element.GetMousedElement();
+                if (moused != null)
+                    return moused;
+            }
+            return null;
+        }
+
+        private Element GetNextElement(bool backward) {
+            var currRoot = this.system.GetRootElements().FirstOrDefault(root => root.CanSelectContent);
+            if (currRoot == null)
+                return null;
+            var children = currRoot.Element.GetChildren(regardChildrensChildren: true);
+            if (this.SelectedElement == null || this.SelectedElement.Root != currRoot) {
+                return backward ? children.LastOrDefault(c => c.CanBeSelected) : children.FirstOrDefault(c => c.CanBeSelected);
+            } else {
+                var foundCurr = false;
+                Element lastFound = null;
+                foreach (var child in children) {
+                    if (!child.CanBeSelected)
+                        continue;
+                    if (child == this.SelectedElement) {
+                        // when going backwards, return the last element found before the current one
+                        if (backward)
+                            return lastFound;
+                        foundCurr = true;
+                    } else {
+                        // when going forwards, return the element after the current one
+                        if (!backward && foundCurr)
+                            return child;
+                    }
+                    lastFound = child;
+                }
+                return null;
+            }
+        }
 
     }
 }

MLEM.Ui/UiSystem.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using Microsoft.Xna.Framework;
 using Microsoft.Xna.Framework.Graphics;
 using MLEM.Extensions;
@@ -14,8 +15,6 @@ namespace MLEM.Ui {
         public readonly GraphicsDevice GraphicsDevice;
         public Rectangle Viewport { get; private set; }
         private readonly List<RootElement> rootElements = new List<RootElement>();
-        public readonly InputHandler InputHandler;
-        private readonly bool isInputOurs;
 
         public bool AutoScaleWithScreen;
         public Point AutoScaleReferenceSize;
@@ -33,8 +32,6 @@ namespace MLEM.Ui {
                     root.Element.ForceUpdateArea();
             }
         }
-        public Element MousedElement { get; private set; }
-        public Element SelectedElement { get; private set; }
         private UiStyle style;
         public UiStyle Style {
             get => this.style;
@@ -49,12 +46,11 @@ namespace MLEM.Ui {
         public float DrawAlpha = 1;
         public BlendState BlendState;
         public SamplerState SamplerState = SamplerState.PointClamp;
-        public UiControls Controls = new UiControls();
+        public UiControls Controls;
 
         public UiSystem(GameWindow window, GraphicsDevice device, UiStyle style, InputHandler inputHandler = null) {
+            this.Controls = new UiControls(this, inputHandler);
             this.GraphicsDevice = device;
-            this.InputHandler = inputHandler ?? new InputHandler();
-            this.isInputOurs = inputHandler == null;
             this.style = style;
             this.Viewport = device.Viewport.Bounds;
             this.AutoScaleReferenceSize = this.Viewport.Size;
@@ -71,37 +67,7 @@ namespace MLEM.Ui {
         }
 
         public void Update(GameTime time) {
-            if (this.isInputOurs)
+            this.Controls.Update();
-                this.InputHandler.Update();
-
-            var mousedNow = this.GetMousedElement();
-            // mouse new element
-            if (mousedNow != this.MousedElement) {
-                if (this.MousedElement != null)
-                    this.MousedElement.OnMouseExit?.Invoke(this.MousedElement);
-                if (mousedNow != null)
-                    mousedNow.OnMouseEnter?.Invoke(mousedNow);
-                this.MousedElement = mousedNow;
-            }
-
-            if (this.Controls.MainButton(this.InputHandler)) {
-                // select element
-                if (this.SelectedElement != mousedNow) {
-                    if (this.SelectedElement != null)
-                        this.SelectedElement.OnDeselected?.Invoke(this.SelectedElement);
-                    if (mousedNow != null)
-                        mousedNow.OnSelected?.Invoke(mousedNow);
-                    this.SelectedElement = mousedNow;
-                }
-
-                // first action on element
-                if (mousedNow != null)
-                    mousedNow.OnPressed?.Invoke(mousedNow);
-            } else if (this.Controls.SecondaryButton(this.InputHandler)) {
-                // secondary action on element
-                if (mousedNow != null)
-                    mousedNow.OnSecondaryPressed?.Invoke(mousedNow);
-            }
 
             foreach (var root in this.rootElements)
                 root.Element.Update(time);
@@ -158,13 +124,9 @@ namespace MLEM.Ui {
             return this.rootElements.FindIndex(element => element.Name == name);
         }
 
-        private Element GetMousedElement() {
+        public IEnumerable<RootElement> GetRootElements() {
-            for (var i = this.rootElements.Count - 1; i >= 0; i--) {
+            for (var i = this.rootElements.Count - 1; i >= 0; i--)
-                var moused = this.rootElements[i].Element.GetMousedElement();
+                yield return this.rootElements[i];
-                if (moused != null)
-                    return moused;
-            }
-            return null;
         }
 
     }
@@ -185,6 +147,7 @@ namespace MLEM.Ui {
             }
         }
         public float ActualScale => this.System.GlobalScale * this.Scale;
+        public bool CanSelectContent = true;
 
         public RootElement(string name, Element element, UiSystem system) {
             this.Name = name;

MLEM/Input/InputHandler.cs

@@ -77,6 +77,19 @@ namespace MLEM.Input {
             return this.WasKeyUp(key) && this.IsKeyDown(key);
         }
 
+        public bool IsModifierKeyDown(ModifierKey modifier) {
+            switch (modifier) {
+                case ModifierKey.Shift:
+                    return this.IsKeyDown(Keys.LeftShift) || this.IsKeyDown(Keys.RightShift);
+                case ModifierKey.Control:
+                    return this.IsKeyDown(Keys.LeftControl) || this.IsKeyDown(Keys.RightControl);
+                case ModifierKey.Alt:
+                    return this.IsKeyDown(Keys.LeftAlt) || this.IsKeyDown(Keys.RightAlt);
+                default:
+                    throw new ArgumentException(nameof(modifier));
+            }
+        }
+
         public bool IsMouseButtonDown(MouseButton button) {
             return GetState(this.MouseState, button) == ButtonState.Pressed;
         }
@@ -145,4 +158,12 @@ namespace MLEM.Input {
         Extra2
 
     }
+
+    public enum ModifierKey {
+
+        Shift,
+        Control,
+        Alt
+
+    }
 }