From 1211cda508054020de03c711563c00123e5edd84 Mon Sep 17 00:00:00 2001
From: Recrown <yunyangdeng@gmail.com>
Date: Fri, 26 Apr 2019 00:09:31 -0500
Subject: [PATCH] Hand scrolling moves scroll bars appropriately.

---
 .../UI/Modular/Modules/UIScrollable.cs        | 82 +++++++++++++++++--
 TestGame/TestGame.cs                          |  5 +-
 2 files changed, 80 insertions(+), 7 deletions(-)

diff --git a/RecrownedAthenaeum/UI/Modular/Modules/UIScrollable.cs b/RecrownedAthenaeum/UI/Modular/Modules/UIScrollable.cs
index c283b20..9fef5ce 100644
--- a/RecrownedAthenaeum/UI/Modular/Modules/UIScrollable.cs
+++ b/RecrownedAthenaeum/UI/Modular/Modules/UIScrollable.cs
@@ -20,10 +20,13 @@ namespace RecrownedAthenaeum.UI.Modular.Modules
         Color scrollBarColor;
         float opacityOfBar = 1;
         bool showingBars;
-        int shiftX, shiftY;
+        private bool mouseWasPressed;
+        private bool horizontalSelected;
+        private Vector2 mouseRelativePosition;
+        float shiftX, shiftY;
         int furthestX;
         int furthestY;
-        UIModule furthestXMod, furthestYMod;
+        UIModule furthestXModule, furthestYMod;
 
         bool horScrollAvailable, vertScrollAvailable;
 
@@ -154,7 +157,7 @@ namespace RecrownedAthenaeum.UI.Modular.Modules
         {
             if (hideScrollBars)
             {
-                if (!showingBars)
+                if (!showingBars && !mouseWasPressed)
                 {
                     if (opacityOfBar > 0f)
                     {
@@ -165,6 +168,7 @@ namespace RecrownedAthenaeum.UI.Modular.Modules
                 else
                 {
                     opacityOfBar = 1f;
+                    scrollBarColor = color * opacityOfBar;
                 }
             }
 
@@ -209,7 +213,7 @@ namespace RecrownedAthenaeum.UI.Modular.Modules
                 int mFurthestY = m.Boundaries.Y + m.Boundaries.Height;
                 if (mFurthestX > furthestX)
                 {
-                    furthestXMod = m;
+                    furthestXModule = m;
                     furthestX = mFurthestX;
                 }
                 if (mFurthestY > furthestY)
@@ -227,7 +231,7 @@ namespace RecrownedAthenaeum.UI.Modular.Modules
         {
             group.RemoveModule(module);
 
-            if (module == furthestXMod)
+            if (module == furthestXModule)
             {
                 furthestX = 0;
                 UIModule[] modules = group.GetCopyOfModules();
@@ -237,7 +241,7 @@ namespace RecrownedAthenaeum.UI.Modular.Modules
                     int mFurthestX = m.Boundaries.X + m.Boundaries.Width;
                     if (mFurthestX > furthestX)
                     {
-                        furthestXMod = m;
+                        furthestXModule = m;
                         furthestX = mFurthestX;
                     }
                 }
@@ -331,6 +335,17 @@ namespace RecrownedAthenaeum.UI.Modular.Modules
             }
         }
 
+
+        public override bool KeyboardStateChanged(KeyboardState state)
+        {
+            if (state.IsKeyDown(Keys.Right))
+            {
+                shiftX -= 20;
+            }
+
+            return base.KeyboardStateChanged(state);
+        }
+
         public override bool MouseStateChanged(MouseState state)
         {
             if (InputUtilities.MouseWithinBoundries(Boundaries))
@@ -341,7 +356,62 @@ namespace RecrownedAthenaeum.UI.Modular.Modules
             {
                 showingBars = false;
             }
+
+            if (InputUtilities.MouseWithinBoundries(horizontalScrollBarBounds))
+            {
+                if (state.LeftButton == ButtonState.Pressed)
+                {
+                    mouseWasPressed = true;
+                    horizontalSelected = true;
+                }
+                if (!mouseWasPressed)
+                {
+                    mouseRelativePosition.X = state.X - horizontalScrollBarBounds.X;
+                }
+            }
+
+            if (InputUtilities.MouseWithinBoundries(verticalScrollBarBounds))
+            {
+                if (state.LeftButton == ButtonState.Pressed)
+                {
+                    mouseWasPressed = true;
+                    horizontalSelected = false;
+                }
+                if (!mouseWasPressed)
+                {
+                    mouseRelativePosition.Y = state.Y - verticalScrollBarBounds.Y;
+                }
+            }
+
+            if (mouseWasPressed)
+            {
+                if (horizontalSelected)
+                {
+                    float latestPosition = state.X - mouseRelativePosition.X;
+                    shiftX = -(latestPosition / (Width - horizontalScrollBarBounds.Width)) * furthestX;
+                }
+                else
+                {
+                    float latestPosition = state.Y - mouseRelativePosition.Y;
+                    shiftY = -(latestPosition / (Height - verticalScrollBarBounds.Height)) * furthestY;
+                }
+
+                if (state.LeftButton == ButtonState.Released)
+                {
+                    mouseWasPressed = false;
+                }
+            }
             return base.MouseStateChanged(state);
         }
+
+        private void MoveHorizontalScrollBar(int position)
+        {
+            shiftX = -(int)(furthestX * ((float)position / Width));
+        }
+
+        private void MoveVerticalScrollBar(int position)
+        {
+            shiftY = (int)(furthestY * ((float)position / Height));
+        }
     }
 }
diff --git a/TestGame/TestGame.cs b/TestGame/TestGame.cs
index 55c8892..7b76ad3 100644
--- a/TestGame/TestGame.cs
+++ b/TestGame/TestGame.cs
@@ -1,6 +1,7 @@
 using Microsoft.Xna.Framework;
 using Microsoft.Xna.Framework.Graphics;
 using Microsoft.Xna.Framework.Input;
+using RecrownedAthenaeum.Input;
 using RecrownedAthenaeum.Render;
 using RecrownedAthenaeum.ScreenSystem;
 using RecrownedAthenaeum.SpecialTypes;
@@ -23,7 +24,7 @@ namespace TestGame
         Texture2D logo;
         Image logoImage;
         Skin skin;
-
+        
         public TestGame()
         {
             graphics = new GraphicsDeviceManager(this);
@@ -67,6 +68,7 @@ namespace TestGame
 
             logoImage = new Image(logo);
             uIScrollable.AddModules(logoImage);
+            InputUtilities.InputListeners.Add(uIScrollable);
             // TODO: use this.Content to load your game content here
         }
 
@@ -86,6 +88,7 @@ namespace TestGame
         /// <param name="gameTime">Provides a snapshot of timing values.</param>
         protected override void Update(GameTime gameTime)
         {
+            InputUtilities.Update();
             if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed || Keyboard.GetState().IsKeyDown(Keys.Escape))
                 Exit();
             uIScrollable.Update(gameTime);