Revert "Simplify the HUD API"

Positioners actually have another use case -- centering widgets.
Centering is not possible with just x/y as it also needs
the widget and the height.

This reverts commit 5b23e67.

src/main/java/io/github/cottonmc/cotton/gui/client/CottonHud.java

@@ -20,46 +20,64 @@ public enum CottonHud implements HudRenderCallback {
 		HudRenderCallback.EVENT.register(INSTANCE);
 	}
 
-	private final Map<WWidget, Position> widgets = new HashMap<>();
+	private final Set<WWidget> widgets = new HashSet<>();
+	private final Map<WWidget, Positioner> positioners = new HashMap<>();
 
 	/**
-	 * Adds a new widget to the HUD at the specified offsets.
+	 * Adds a new widget to the HUD.
 	 *
-	 * <p>The offsets wrap around the screen. Use negative values for bottom/right edges.
+	 * @param widget the widget
+	 */
+	public void add(WWidget widget) {
+		widgets.add(widget);
+	}
+
+	/**
+	 * Adds a new widget to the HUD at the specified offsets.
 	 *
 	 * @param widget the widget
 	 * @param x the x offset
 	 * @param y the y offset
+	 * @see Positioner#of documentation about the offsets
 	 */
 	public void add(WWidget widget, int x, int y) {
-		widgets.put(widget, new Position(x, y));
+		add(widget, Positioner.of(x, y));
 	}
 
 	/**
 	 * Adds a new widget to the HUD at the specified offsets and resizes it.
 	 *
-	 * <p>The offsets wrap around the screen. Use negative values for bottom/right edges.
-	 *
 	 * @param widget the widget
 	 * @param x the x offset
 	 * @param y the y offset
 	 * @param width the width of the widget
-	 * @param height the height of the widget
+	 * @param height the heigh of the widget
+	 * @see Positioner#of documentation about the offsets
 	 */
 	public void add(WWidget widget, int x, int y, int width, int height) {
-		add(widget, x, y);
+		add(widget, Positioner.of(x, y));
 		widget.setSize(width, height);
 	}
 
+	/**
+	 * Adds a new widget to the HUD with a custom positioner.
+	 *
+	 * @param widget the widget
+	 * @param positioner the positioner
+	 */
+	public void add(WWidget widget, Positioner positioner) {
+		widgets.add(widget);
+		setPositioner(widget, positioner);
+	}
+
 	/**
 	 * Sets the positioner of the widget.
 	 *
 	 * @param widget the widget
+	 * @param positioner the positioner
 	 */
-	public void setPosition(WWidget widget, int x, int y) {
-		Position pos = widgets.get(widget);
-		pos.x = x;
-		pos.y = y;
+	public void setPositioner(WWidget widget, Positioner positioner) {
+		positioners.put(widget, positioner);
 	}
 
 	/**
@@ -76,21 +94,43 @@ public void onHudRender(float tickDelta) {
 		Window window = MinecraftClient.getInstance().getWindow();
 		int hudWidth = window.getScaledWidth();
 		int hudHeight = window.getScaledHeight();
-		for (Map.Entry<WWidget, Position> entry : widgets.entrySet()) {
-			WWidget widget = entry.getKey();
-			Position pos = entry.getValue();
-			widget.setLocation((hudWidth + pos.x) % hudWidth, (hudHeight + pos.y) % hudHeight);
+		for (WWidget widget : widgets) {
+			Positioner positioner = positioners.get(widget);
+			if (positioner != null) {
+				positioner.reposition(widget, hudWidth, hudHeight);
+			}
+
 			widget.paintBackground(widget.getX(), widget.getY(), -1, -1);
 		}
 	}
 
-	private static final class Position {
-		int x;
-		int y;
+	/**
+	 * Positioners can be used to change the position of a widget based on the window dimensions.
+	 */
+	@FunctionalInterface
+	public interface Positioner {
+		/**
+		 * Repositions the widget according to the HUD dimensions.
+		 *
+		 * @param widget the widget
+		 * @param hudWidth the width of the HUD
+		 * @param hudHeight the height of the HUD
+		 */
+		void reposition(WWidget widget, int hudWidth, int hudHeight);
 
-		Position(int x, int y) {
-			this.x = x;
-			this.y = y;
+		/**
+		 * Creates a new positioner that offsets widgets.
+		 *
+		 * <p>If an offset is negative, the offset is subtracted from the HUD dimension on that axis.
+		 *
+		 * @param x the x offset
+		 * @param y the y offset
+		 * @return an offsetting positioner
+		 */
+		static Positioner of(int x, int y) {
+			return (widget, hudWidth, hudHeight) -> {
+				widget.setLocation((hudWidth + x) % hudWidth, (hudHeight + y) % hudHeight);
+			};
 		}
 	}
 }