Add sub-widget focusing and item slot focusing

Widgets can now have inner parts of themselves focused that will be cycled.
This is basically the panel focusing system without the pivot.

5 files changed, 100 insertions, 10 deletions

diff --git a/src/main/java/io/github/cottonmc/cotton/gui/client/BackgroundPainter.java b/src/main/java/io/github/cottonmc/cotton/gui/client/BackgroundPainter.java
index fa51754..f95d816 100644
--- a/src/main/java/io/github/cottonmc/cotton/gui/client/BackgroundPainter.java
+++ b/src/main/java/io/github/cottonmc/cotton/gui/client/BackgroundPainter.java
@@ -47,6 +47,7 @@ public interface BackgroundPainter {
 			WItemSlot slot = (WItemSlot)panel;
 			for(int x = 0; x < slot.getWidth()/18; ++x) {
 				for(int y = 0; y < slot.getHeight()/18; ++y) {
+					int index = x + y * (slot.getWidth() / 18);
 					int lo = 0xB8000000;
 					int bg = 0x4C000000;
 					//this will cause a slightly discolored bottom border on vanilla backgrounds but it's necessary for color support, it shouldn't be *too* visible unless you're looking for it
@@ -54,9 +55,25 @@ public interface BackgroundPainter {
 					if (slot.isBigSlot()) {
 						ScreenDrawing.drawBeveledPanel((x * 18) + left - 3, (y * 18) + top - 3, 26, 26,
 								lo, bg, hi);
+						if (slot.getFocusedSlot() == index) {
+							int sx = (x * 18) + left - 3;
+							int sy = (y * 18) + top - 3;
+							ScreenDrawing.coloredRect(sx,          sy,          26,     1,      0xFF_FFFFA0);
+							ScreenDrawing.coloredRect(sx,          sy + 1,      1,      26 - 1, 0xFF_FFFFA0);
+							ScreenDrawing.coloredRect(sx + 26 - 1, sy + 1,      1,      26 - 1, 0xFF_FFFFA0);
+							ScreenDrawing.coloredRect(sx + 1,      sy + 26 - 1, 26 - 1, 1,      0xFF_FFFFA0);
+						}
 					} else {
 						ScreenDrawing.drawBeveledPanel((x * 18) + left, (y * 18) + top, 16+2, 16+2,
 								lo, bg, hi);
+						if (slot.getFocusedSlot() == index) {
+							int sx = (x * 18) + left;
+							int sy = (y * 18) + top;
+							ScreenDrawing.coloredRect(sx,          sy,          18,     1,      0xFF_FFFFA0);
+							ScreenDrawing.coloredRect(sx,          sy + 1,      1,      18 - 1, 0xFF_FFFFA0);
+							ScreenDrawing.coloredRect(sx + 18 - 1, sy + 1,      1,      18 - 1, 0xFF_FFFFA0);
+							ScreenDrawing.coloredRect(sx + 1,      sy + 18 - 1, 18 - 1, 1,      0xFF_FFFFA0);
+						}
 					}
 				}
 			}
diff --git a/src/main/java/io/github/cottonmc/cotton/gui/impl/FocusHandler.java b/src/main/java/io/github/cottonmc/cotton/gui/impl/FocusHandler.java
index df0ef32..61cffa6 100644
--- a/src/main/java/io/github/cottonmc/cotton/gui/impl/FocusHandler.java
+++ b/src/main/java/io/github/cottonmc/cotton/gui/impl/FocusHandler.java
@@ -14,8 +14,7 @@ public final class FocusHandler {
 		if (focus == null) {
 			result = cycleFocus(host, lookForwards, host.getRootPanel(), null);
 		} else {
-			WPanel parent = focus.getParent();
-			result = cycleFocus(host, lookForwards, parent != null ? parent : host.getRootPanel(), focus);
+			result = cycleFocus(host, lookForwards, focus, null);
 		}
 
 		if (!result) {
@@ -24,15 +23,18 @@ public final class FocusHandler {
 		}
 	}
 
-	private static boolean cycleFocus(GuiDescription host, boolean lookForwards, WPanel panel, WWidget pivot) {
-		WWidget next = panel.cycleFocus(lookForwards, pivot);
+	private static boolean cycleFocus(GuiDescription host, boolean lookForwards, WWidget widget, WWidget pivot) {
+		WWidget next = widget instanceof WPanel
+				? ((WPanel) widget).cycleFocus(lookForwards, pivot)
+				: widget.cycleFocus(lookForwards);
+
 		if (next != null) {
 			host.requestFocus(next);
 			return true;
 		} else {
-			WPanel parent = panel.getParent();
+			WPanel parent = widget.getParent();
 			if (parent != null) {
-				return cycleFocus(host, lookForwards, parent, panel);
+				return cycleFocus(host, lookForwards, parent, widget);
 			}
 		}
 
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 d173ae2..ec1bf9c 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
@@ -8,8 +8,11 @@ import io.github.cottonmc.cotton.gui.ValidatedSlot;
 import io.github.cottonmc.cotton.gui.client.BackgroundPainter;
 import net.fabricmc.api.EnvType;
 import net.fabricmc.api.Environment;
+import net.minecraft.client.MinecraftClient;
 import net.minecraft.client.util.math.MatrixStack;
 import net.minecraft.inventory.Inventory;
+import net.minecraft.screen.ScreenHandler;
+import net.minecraft.screen.slot.SlotActionType;
 
 import javax.annotation.Nullable;
 
@@ -25,6 +28,7 @@ public class WItemSlot extends WWidget {
 	private boolean big = false;
 	private boolean insertingAllowed = true;
 	private boolean takingAllowed = true;
+	private int focusedSlot = -1;
 
 	public WItemSlot(Inventory inventory, int startIndex, int slotsWide, int slotsHigh, boolean big) {
 		this.inventory = inventory;
@@ -92,6 +96,11 @@ public class WItemSlot extends WWidget {
 		return slotsHigh * 18;
 	}
 
+	@Override
+	public boolean canFocus() {
+		return true;
+	}
+
 	public boolean isBigSlot() {
 		return big;
 	}
@@ -166,6 +175,16 @@ public class WItemSlot extends WWidget {
 		return this;
 	}
 
+	/**
+	 * Gets the currently focused slot index.
+	 *
+	 * @return the currently focused slot, or -1 if this widget isn't focused
+	 * @since 2.0.0
+	 */
+	public int getFocusedSlot() {
+		return focusedSlot;
+	}
+
 	@Override
 	public void createPeers(GuiDescription c) {
 		super.createPeers(c);
@@ -185,6 +204,18 @@ public class WItemSlot extends WWidget {
 		}
 	}
 
+	@Environment(EnvType.CLIENT)
+	@Override
+	public void onKeyPressed(int ch, int key, int modifiers) {
+		if (isActivationKey(ch) && host instanceof ScreenHandler && focusedSlot >= 0) {
+			ScreenHandler handler = (ScreenHandler) host;
+			MinecraftClient client = MinecraftClient.getInstance();
+
+			ValidatedSlot peer = peers.get(focusedSlot);
+			client.interactionManager.clickSlot(handler.syncId, peer.id, 0, SlotActionType.PICKUP, client.player);
+		}
+	}
+
 	/**
 	 * Creates a slot peer for this slot widget.
 	 *
@@ -228,4 +259,26 @@ public class WItemSlot extends WWidget {
 			backgroundPainter.paintBackground(x, y, this);
 		}
 	}
+
+	@Nullable
+	@Override
+	public WWidget cycleFocus(boolean lookForwards) {
+		if (focusedSlot < 0) {
+			focusedSlot = lookForwards ? 0 : (slotsWide * slotsHigh - 1);
+			return this;
+		}
+
+		if (lookForwards) {
+			focusedSlot++;
+			if (focusedSlot >= slotsWide * slotsHigh) {
+				focusedSlot = -1;
+				return null;
+			} else {
+				return this;
+			}
+		} else {
+			focusedSlot--;
+			return focusedSlot >= 0 ? this : null;
+		}
+	}
 }
\ No newline at end of file
diff --git a/src/main/java/io/github/cottonmc/cotton/gui/widget/WPanel.java b/src/main/java/io/github/cottonmc/cotton/gui/widget/WPanel.java
index 987248f..3002fc2 100644
--- a/src/main/java/io/github/cottonmc/cotton/gui/widget/WPanel.java
+++ b/src/main/java/io/github/cottonmc/cotton/gui/widget/WPanel.java
@@ -199,6 +199,12 @@ public abstract class WPanel extends WWidget {
 		for(WWidget child : children) child.tick();
 	}
 
+	@Nullable
+	@Override
+	public WWidget cycleFocus(boolean lookForwards) {
+		return cycleFocus(lookForwards, null);
+	}
+
 	/**
 	 * Cycles the focus inside this panel.
 	 *
@@ -253,10 +259,8 @@ public abstract class WPanel extends WWidget {
 
 	@Nullable
 	private WWidget checkFocusCycling(boolean lookForwards, WWidget child) {
-		if (child.canFocus()) {
-			return child;
-		} else if (child instanceof WPanel) {
-			return ((WPanel) child).cycleFocus(lookForwards, null);
+		if (child.canFocus() || child instanceof WPanel) {
+			return child.cycleFocus(lookForwards);
 		}
 
 		return null;
diff --git a/src/main/java/io/github/cottonmc/cotton/gui/widget/WWidget.java b/src/main/java/io/github/cottonmc/cotton/gui/widget/WWidget.java
index 11387e2..7476c71 100644
--- a/src/main/java/io/github/cottonmc/cotton/gui/widget/WWidget.java
+++ b/src/main/java/io/github/cottonmc/cotton/gui/widget/WWidget.java
@@ -387,6 +387,20 @@ public class WWidget {
 	public void tick() {}
 
 	/**
+	 * Cycles the focus inside this widget.
+	 *
+	 * <p>If this widget is not focusable, returns null.
+	 *
+	 * @param lookForwards whether this should cycle forwards (true) or backwards (false)
+	 * @return the next focused widget, or null if should exit to the parent panel
+	 * @since 2.0.0
+	 */
+	@Nullable
+	public WWidget cycleFocus(boolean lookForwards) {
+		return canFocus() ? (isFocused() ? null : this) : null;
+	}
+
+	/**
 	 * Tests if the provided key code is an activation key for widgets.
 	 *
 	 * <p>The activation keys are Enter, keypad Enter, and Space.