Add support for scrolling in new GUI API

src/main/java/de/johni0702/minecraft/gui/container/AbstractGuiOverlay.java

@@ -38,6 +38,7 @@ import net.minecraftforge.client.event.RenderGameOverlayEvent;
 import net.minecraftforge.common.MinecraftForge;
 import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
 import net.minecraftforge.fml.common.gameevent.TickEvent;
+import org.lwjgl.input.Mouse;
 import org.lwjgl.util.Dimension;
 import org.lwjgl.util.Point;
 import org.lwjgl.util.ReadableDimension;
@@ -235,6 +236,14 @@ public abstract class AbstractGuiOverlay<T extends AbstractGuiOverlay<T>> extend
             forEach(Tickable.class).tick();
         }
 
+        @Override
+        public void handleMouseInput() throws IOException {
+            super.handleMouseInput();
+            if (Mouse.hasWheel() && Mouse.getEventDWheel() != 0) {
+                forEach(Scrollable.class).scroll(MouseUtils.getMousePos(), Mouse.getEventDWheel());
+            }
+        }
+
         @Override
         public void onGuiClosed() {
             mouseVisible = false;

src/main/java/de/johni0702/minecraft/gui/container/AbstractGuiScreen.java

@@ -32,10 +32,12 @@ import de.johni0702.minecraft.gui.function.*;
 import eu.crushedpixel.replaymod.utils.MouseUtils;
 import lombok.Getter;
 import lombok.Setter;
+import net.minecraft.client.gui.ScaledResolution;
 import net.minecraft.crash.CrashReport;
 import net.minecraft.crash.CrashReportCategory;
 import net.minecraft.util.ReportedException;
 import org.lwjgl.input.Keyboard;
+import org.lwjgl.input.Mouse;
 import org.lwjgl.util.Dimension;
 import org.lwjgl.util.Point;
 import org.lwjgl.util.ReadableDimension;
@@ -194,6 +196,14 @@ public abstract class AbstractGuiScreen<T extends AbstractGuiScreen<T>> extends
             forEach(Tickable.class).tick();
         }
 
+        @Override
+        public void handleMouseInput() throws IOException {
+            super.handleMouseInput();
+            if (Mouse.hasWheel() && Mouse.getEventDWheel() != 0) {
+                forEach(Scrollable.class).scroll(MouseUtils.getMousePos(), Mouse.getEventDWheel());
+            }
+        }
+
         @Override
         public void onGuiClosed() {
             forEach(Closeable.class).close();

src/main/java/de/johni0702/minecraft/gui/function/Scrollable.java

@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2015 johni0702
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package de.johni0702.minecraft.gui.function;
+
+import org.lwjgl.util.ReadablePoint;
+
+public interface Scrollable {
+    /**
+     * Called when the user scrolled.
+     * @param mousePosition Global position of the mouse.
+     * @param dWheel Wheel movement (positive is upwards, negative is downwards)
+     * @return {@code true} if this event should be consumed,
+     *          {@code false} if it should be delivered to other elements as well
+     */
+    boolean scroll(ReadablePoint mousePosition, int dWheel);
+}