Added Mouse Scroll Wheel Support

.gitignore

@@ -14,4 +14,5 @@ bin
 **/Thumbs.db
 
 # Ignore MacOS
-**/.DS_Store
+**/.DS_Store
+.idea/

src/main/java/ru/windcorp/optica/client/graphics/backend/InputHandler.java

@@ -25,6 +25,31 @@ import ru.windcorp.optica.client.graphics.input.*;
 public class InputHandler {
 	
 	private static final EventBus INPUT_EVENT_BUS = new EventBus("Input");
+
+	// ScrollEvent Start
+
+	private static class ModifiableWheelScrollEvent extends WheelScrollEvent {
+
+		public void initialize(double xoffset, double yoffset) {
+			this.xoffset = xoffset;
+			this.yoffset = yoffset;
+		}
+
+	}
+
+	private static final ModifiableWheelScrollEvent THE_SCROLL_EVENT = new ModifiableWheelScrollEvent();
+
+	static void handleMouseWheel(
+			long window,
+			double xoffset,
+			double yoffset
+	) {
+		if (GraphicsBackend.getWindowHandle() != window) return;
+		THE_SCROLL_EVENT.initialize(xoffset, yoffset);
+		dispatch(THE_SCROLL_EVENT);
+	}
+
+	// KeyEvent Start
 	
 	private static class ModifiableKeyEvent extends KeyEvent {
 		
@@ -36,7 +61,7 @@ public class InputHandler {
 		}
 		
 	}
-	
+
 	private static final ModifiableKeyEvent THE_KEY_EVENT = new ModifiableKeyEvent();
 	
 	static void handleKeyInput(
@@ -50,6 +75,8 @@ public class InputHandler {
 		THE_KEY_EVENT.initialize(key, scancode, action, mods);
 		dispatch(THE_KEY_EVENT);
 	}
+
+	// CursorEvent Start
 	
 	private static class ModifiableCursorMoveEvent extends CursorMoveEvent {
 		

src/main/java/ru/windcorp/optica/client/graphics/backend/LWJGLInitializer.java

@@ -86,12 +86,14 @@ class LWJGLInitializer {
 
 	private static void setupWindowCallbacks() {
 		long handle = GraphicsBackend.getWindowHandle();
-		
+
 		glfwSetFramebufferSizeCallback(handle,
 				GraphicsBackend::onFramebufferResized);
 		
 		glfwSetKeyCallback(handle, InputHandler::handleKeyInput);
 		glfwSetCursorPosCallback(handle, InputHandler::handleMouseMoveInput);
+
+		glfwSetScrollCallback(handle, InputHandler::handleMouseWheel);
 	}
 
 }

src/main/java/ru/windcorp/optica/client/graphics/flat/LayerTestUI.java

@@ -39,12 +39,14 @@ public class LayerTestUI extends AssembledFlatLayer {
 	}
 	
 	private boolean flag = false;
-	
+
+	private static int width = 512 + 256;
+	private static final int height = 64;
+	private static final int border = 5;
+
 	@Override
 	protected void assemble(RenderTarget target) {
-		final int width = 512 + 256;
+
-		final int height = 64;
-		final int border = 5;
 		
 		final int boxColor = flag ? 0xEE8888 : 0xEEEE88;
 		final int borderColor = flag ? 0xAA4444 : 0xAAAA44;

src/main/java/ru/windcorp/optica/client/graphics/input/KeyEvent.java

@@ -27,7 +27,6 @@ public class KeyEvent extends InputEvent {
 	protected int mods;
 
 	protected KeyEvent(int key, int scancode, int action, int mods) {
-		this();
 		this.key = key;
 		this.scancode = scancode;
 		this.action = action;

src/main/java/ru/windcorp/optica/client/graphics/input/WheelEvent.java

@@ -0,0 +1,7 @@
+package ru.windcorp.optica.client.graphics.input;
+
+public abstract class WheelEvent extends InputEvent {
+
+    @Override
+    public abstract WheelEvent snapshot();
+}

src/main/java/ru/windcorp/optica/client/graphics/input/WheelScrollEvent.java

@@ -0,0 +1,56 @@
+package ru.windcorp.optica.client.graphics.input;
+
+import glm.vec._2.d.Vec2d;
+
+public class WheelScrollEvent extends WheelEvent {
+
+    protected double xoffset;
+    protected double yoffset;
+
+    protected WheelScrollEvent(double xoffset, double yoffset) {
+        this.xoffset = xoffset;
+        this.yoffset = yoffset;
+    }
+
+    protected WheelScrollEvent() {}
+
+    public boolean isUp() { return yoffset > 0; }
+
+    public boolean isDown() { return yoffset < 0; }
+
+    public boolean isRight() { return xoffset > 0; }
+
+    public boolean isLeft() { return xoffset < 0; }
+
+    public boolean hasVerticalMovement() { return yoffset != 0; }
+
+    public boolean hasHorizontalMovement() { return xoffset != 0; }
+
+    public double getX() { return xoffset; }
+
+    public double getY() { return yoffset; }
+
+    @Override
+    public WheelEvent snapshot() {
+        return new StaticWheelScrollEvent(xoffset, yoffset, getTime());
+    }
+
+    private class StaticWheelScrollEvent extends WheelScrollEvent {
+
+        private final double time;
+
+        public StaticWheelScrollEvent(double xoffset, double yoffset, double time) {
+            super(xoffset, yoffset);
+            this.time = time;
+        }
+
+        @Override
+        public double getTime() { return time; }
+
+        @Override
+        public WheelEvent snapshot() {
+            return this;
+        }
+
+    }
+}