v0.7.5e: added scroll wheel support

SPD-classes/src/main/java/com/watabou/input/ScrollEvent.java

@@ -0,0 +1,71 @@
+/*
+ * Pixel Dungeon
+ * Copyright (C) 2012-2015 Oleg Dolya
+ *
+ * Shattered Pixel Dungeon
+ * Copyright (C) 2014-2019 Evan Debenham
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ */
+
+package com.watabou.input;
+
+import com.watabou.utils.PointF;
+import com.watabou.utils.Signal;
+
+import java.util.ArrayList;
+
+public class ScrollEvent {
+	
+	public PointF pos;
+	public int amount;
+	
+	public ScrollEvent(PointF mousePos, int amount){
+		this.amount = amount;
+		this.pos = mousePos;
+	}
+	
+	// **********************
+	// *** Static members ***
+	// **********************
+	
+	private static Signal<ScrollEvent> scrollSignal = new Signal<>( true );
+	
+	public static void addScrollListener( Signal.Listener<ScrollEvent> listener ){
+		scrollSignal.add(listener);
+	}
+	
+	public static void removeScrollListener( Signal.Listener<ScrollEvent> listener ){
+		scrollSignal.remove(listener);
+	}
+	
+	public static void clearListeners(){
+		scrollSignal.removeAll();
+	}
+	
+	//Accumulated key events
+	private static ArrayList<ScrollEvent> scrollEvents = new ArrayList<>();
+	
+	public static synchronized void addScrollEvent( ScrollEvent event ){
+		scrollEvents.add( event );
+	}
+	
+	public static synchronized void processScrollEvents(){
+		for (ScrollEvent k : scrollEvents){
+			scrollSignal.dispatch(k);
+		}
+		scrollEvents.clear();
+	}
+	
+}