Add Icon API to WItemSlot (#119)

* Add Icon API to WItemSlot

* Fix checkstyle

* Clean up test description

3 files changed, 32 insertions, 0 deletions

diff --git a/GuiTest/src/main/java/io/github/cottonmc/test/TestDescription.java b/GuiTest/src/main/java/io/github/cottonmc/test/TestDescription.java
index e6c3564..ce579ae 100644
--- a/GuiTest/src/main/java/io/github/cottonmc/test/TestDescription.java
+++ b/GuiTest/src/main/java/io/github/cottonmc/test/TestDescription.java
@@ -4,6 +4,8 @@ import io.github.cottonmc.cotton.gui.SyncedGuiDescription;
 import io.github.cottonmc.cotton.gui.networking.NetworkSide;
 import io.github.cottonmc.cotton.gui.networking.ScreenNetworking;
 import io.github.cottonmc.cotton.gui.widget.*;
+import io.github.cottonmc.cotton.gui.widget.icon.TextureIcon;
+
 import net.minecraft.entity.player.PlayerInventory;
 import net.minecraft.screen.ScreenHandlerContext;
 import net.minecraft.screen.ScreenHandlerType;
@@ -38,6 +40,8 @@ public class TestDescription extends SyncedGuiDescription {
 		root.add(new WLabel(new LiteralText("Large slot:")), 0, 9);
 		root.add(WItemSlot.outputOf(blockInventory, 0), 4, 9);
 
+		root.add(WItemSlot.of(blockInventory, 7).setIcon(new TextureIcon(new Identifier("libgui-test", "saddle.png"))), 7, 9);
+
 		root.add(createPlayerInventoryPanel(), 0, 11);
 		System.out.println(root.toString());
 
diff --git a/GuiTest/src/main/resources/assets/libgui-test/saddle.png b/GuiTest/src/main/resources/assets/libgui-test/saddle.png
new file mode 100644
index 0000000..84394b9
--- /dev/null
+++ b/GuiTest/src/main/resources/assets/libgui-test/saddle.png
diff --git a/src/main/java/io/github/cottonmc/cotton/gui/widget/WItemSlot.java b/src/main/java/io/github/cottonmc/cotton/gui/widget/WItemSlot.java
index 1667bee..e1f0bce 100644
--- a/src/main/java/io/github/cottonmc/cotton/gui/widget/WItemSlot.java
+++ b/src/main/java/io/github/cottonmc/cotton/gui/widget/WItemSlot.java
@@ -12,6 +12,7 @@ import net.minecraft.screen.slot.SlotActionType;
 import io.github.cottonmc.cotton.gui.GuiDescription;
 import io.github.cottonmc.cotton.gui.ValidatedSlot;
 import io.github.cottonmc.cotton.gui.client.BackgroundPainter;
+import io.github.cottonmc.cotton.gui.widget.icon.Icon;
 import org.jetbrains.annotations.Nullable;
 
 import java.util.ArrayList;
@@ -62,6 +63,8 @@ public class WItemSlot extends WWidget {
 	@Nullable
 	@Environment(EnvType.CLIENT)
 	private BackgroundPainter backgroundPainter = null;
+	@Nullable
+	private Icon icon = null;
 	private Inventory inventory;
 	private int startIndex = 0;
 	private int slotsWide = 1;
@@ -149,6 +152,27 @@ public class WItemSlot extends WWidget {
 	}
 
 	/**
+	 * Sets the icon to this slot. Can be used for labeling slots for certain activities.
+	 *
+	 * @param icon the icon
+	 * @since 4.0.0
+	 */
+	public WItemSlot setIcon(@Nullable Icon icon) {
+		this.icon = icon;
+		return this;
+	}
+
+	/**
+	 *
+	 * @return icon if set, otherwise null
+	 * @since 4.0.0
+	 */
+	@Nullable
+	public Icon getIcon() {
+		return this.icon;
+	}
+
+	/**
 	 * Returns true if the contents of this {@code WItemSlot} can be modified by players.
 	 *
 	 * @return true if items can be inserted into or taken from this slot widget, false otherwise
@@ -330,6 +354,10 @@ public class WItemSlot extends WWidget {
 		if (backgroundPainter != null) {
 			backgroundPainter.paintBackground(matrices, x, y, this);
 		}
+
+		if (icon != null) {
+			icon.paint(matrices, x + 1, y + 1, 16);
+		}
 	}
 
 	@Nullable