Make ItemDrawable return widget of size 16 (#73)

Author: miozune

src/main/java/com/cleanroommc/modularui/drawable/ItemDrawable.java

@@ -5,6 +5,7 @@
 import com.cleanroommc.modularui.theme.WidgetTheme;
 import com.cleanroommc.modularui.utils.GameObjectHelper;
 import com.cleanroommc.modularui.utils.JsonHelper;
+import com.cleanroommc.modularui.widget.Widget;
 
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.renderer.GlStateManager;
@@ -40,6 +41,11 @@ public void draw(GuiContext context, int x, int y, int width, int height, Widget
         GuiDraw.drawItem(this.item, x, y, width, height);
     }
 
+    @Override
+    public Widget<?> asWidget() {
+        return IDrawable.super.asWidget().size(16);
+    }
+
     @Override
     public Icon asIcon() {
         return IDrawable.super.asIcon().size(16);