Add focus management to UI components

This commit introduces focus handling capabilities to UI components, providing methods for components to gain or lose focus. The changes include updating the handling of keyboard events to streamline focus management and integrating focus functions into the existing `BasePLScreen` and `VanillaUIComponent` classes. These enhancements improve user interaction by ensuring that UI components correctly respond to focus changes.

common-testmod/src/main/java/me/pandamods/test/client/screen/TestScreen.java

@@ -18,6 +18,7 @@
 import me.pandamods.pandalib.client.screen.layouts.StackContainer;
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.gui.components.Button;
+import net.minecraft.client.gui.components.EditBox;
 import net.minecraft.network.chat.Component;
 
 public class TestScreen extends BasePLScreen<StackContainer> {
@@ -31,9 +32,12 @@ protected void build(StackContainer rootComponent) {
 				button -> System.out.println("Test click"))
 				.width(200)
 				.build());
-
 		vanillaTestButton.mount(rootComponent);
 
+		EditBox editBox = new EditBox(Minecraft.getInstance().font, 0, 0, 200, 20, Component.literal("Test TextField"));
+		VanillaUIComponent vanillaTestTextField = VanillaUIComponent.of(editBox);
+		vanillaTestTextField.mount(rootComponent);
+
 		TextUIComponent textUIComponent = new TextUIComponent(Minecraft.getInstance().font, Component.literal("Test Text"));
 		textUIComponent.mount(rootComponent);
 	}

common/src/main/java/me/pandamods/pandalib/client/screen/BasePLScreen.java

@@ -62,25 +62,19 @@ public boolean mouseScrolled(double mouseX, double mouseY, double scrollX, doubl
 
 	@Override
 	public boolean keyPressed(int keyCode, int scanCode, int modifiers) {
-		FocusHandler focusHandler = this.rootComponent.getFocusHandler();
-		if (focusHandler != null && focusHandler.isFocusing() && focusHandler.getFocusedComponent().keyPressed(keyCode, scanCode, modifiers))
-			return true;
+		if (this.rootComponent.keyPressed(keyCode, scanCode, modifiers)) return true;
 		return super.keyPressed(keyCode, scanCode, modifiers);
 	}
 
 	@Override
 	public boolean keyReleased(int keyCode, int scanCode, int modifiers) {
-		FocusHandler focusHandler = this.rootComponent.getFocusHandler();
-		if (focusHandler != null && focusHandler.isFocusing() && focusHandler.getFocusedComponent().keyReleased(keyCode, scanCode, modifiers))
-			return true;
+		if (this.rootComponent.keyReleased(keyCode, scanCode, modifiers)) return true;
 		return super.keyReleased(keyCode, scanCode, modifiers);
 	}
 
 	@Override
 	public boolean charTyped(char codePoint, int modifiers) {
-		FocusHandler focusHandler = this.rootComponent.getFocusHandler();
-		if (focusHandler != null && focusHandler.isFocusing() && focusHandler.getFocusedComponent().charTyped(codePoint, modifiers))
-			return true;
+		if (this.rootComponent.charTyped(codePoint, modifiers)) return true;
 		return super.charTyped(codePoint, modifiers);
 	}
 }

common/src/main/java/me/pandamods/pandalib/client/screen/BaseParentUIComponent.java

@@ -19,15 +19,16 @@
 import org.jetbrains.annotations.Nullable;
 
 public abstract class BaseParentUIComponent extends BaseUIComponent implements ParentUIComponent {
-	private FocusHandler focusHandler = new FocusHandler(this);
+	protected FocusHandler focusHandler = new FocusHandler(this);
 
 	@Override
 	public void render(RenderContext context, int mouseX, int mouseY, float partialTicks) {
 		Runnable renderChildren = () -> renderChildren(context, mouseX, mouseY, partialTicks);
-		if (this.isOverflowAllowed())
+		if (this.isOverflowAllowed()) {
 			renderChildren.run();
-		else
+		}else {
 			context.scissor(this.getX(), this.getY(), this.getX() + this.getWidth(), this.getY() + this.getHeight(), renderChildren);
+		}
 	}
 
 	protected void renderChildren(RenderContext context, int mouseX, int mouseY, float partialTicks) {
@@ -53,12 +54,4 @@ public void updateChildState(UIComponent uiComponent) {
 
 	protected abstract void addChild(UIComponent UIComponent);
 	protected abstract void removeChild(UIComponent UIComponent);
-
-	@Override
-	public @Nullable FocusHandler getFocusHandler() {
-		FocusHandler focusHandler = super.getFocusHandler();
-		if (focusHandler == null)
-			focusHandler = this.focusHandler;
-		return focusHandler;
-	}
 }

common/src/main/java/me/pandamods/pandalib/client/screen/BaseUIComponent.java

@@ -14,7 +14,6 @@
 
 import me.pandamods.pandalib.client.screen.core.ParentUIComponent;
 import me.pandamods.pandalib.client.screen.core.UIComponent;
-import me.pandamods.pandalib.client.screen.utils.FocusHandler;
 import org.jetbrains.annotations.Nullable;
 
 public abstract class BaseUIComponent implements UIComponent {
@@ -43,11 +42,6 @@ public void dismount() {
 		mount(null);
 	}
 
-	@Override
-	public @Nullable FocusHandler getFocusHandler() {
-		return this.hasParent() ? this.getParent().getFocusHandler() : null;
-	}
-
 	@Override
 	public void setX(int x) {
 		this.x = x;

common/src/main/java/me/pandamods/pandalib/client/screen/components/VanillaUIComponent.java

@@ -111,4 +111,14 @@ public boolean mouseReleased(double mouseX, double mouseY, int button) {
 	public boolean mouseScrolled(double mouseX, double mouseY, double scrollX, double scrollY) {
 		return this.widget.mouseScrolled(mouseX, mouseY, scrollX, scrollY);
 	}
+
+	@Override
+	public void onFocusGained() {
+		this.widget.setFocused(true);
+	}
+
+	@Override
+	public void onFocusLost() {
+		this.widget.setFocused(false);
+	}
 }

common/src/main/java/me/pandamods/pandalib/client/screen/core/ParentUIComponent.java

@@ -12,6 +12,8 @@
 
 package me.pandamods.pandalib.client.screen.core;
 
+import me.pandamods.pandalib.client.screen.utils.FocusHandler;
+
 import java.util.List;
 
 public interface ParentUIComponent extends UIComponent {
@@ -36,21 +38,16 @@ default UIComponent getChildAt(int x, int y) {
 		return isInBoundingBox(x, y) ? this : null;
 	}
 
-	@Override
-	default boolean keyPressed(int keyCode, int scanCode, int modifiers) {
-		return UIComponent.super.keyPressed(keyCode, scanCode, modifiers);
-	}
-
-	@Override
-	default boolean keyReleased(int keyCode, int scanCode, int modifiers) {
-		return UIComponent.super.keyReleased(keyCode, scanCode, modifiers);
-	}
-
 	@Override
 	default boolean mousePressed(double mouseX, double mouseY, int button) {
 		for (UIComponent child : getChildren()) {
 			if (!child.isInBoundingBox(getX() + mouseX, getY() + mouseY)) continue;
-			if (child.mousePressed(mouseX, mouseY, button)) return true;
+			if (child.mousePressed(mouseX, mouseY, button)) {
+				FocusHandler focusHandler = getFocusHandler();
+				if (focusHandler != null)
+					focusHandler.focus(child);
+				return true;
+			}
 		}
 
 		return UIComponent.super.mousePressed(mouseX, mouseY, button);

common/src/main/java/me/pandamods/pandalib/client/screen/core/UIComponent.java

@@ -12,9 +12,10 @@
 
 package me.pandamods.pandalib.client.screen.core;
 
+import me.pandamods.pandalib.client.screen.BasePLScreen;
 import me.pandamods.pandalib.client.screen.utils.FocusHandler;
 import me.pandamods.pandalib.client.screen.utils.RenderContext;
-import org.jetbrains.annotations.Nullable;
+import net.minecraft.client.Minecraft;
 
 public interface UIComponent {
 	void render(RenderContext context, int mouseX, int mouseY, float partialTicks);
@@ -28,13 +29,19 @@ default boolean hasParent() {
 	void mount(ParentUIComponent parent);
 	void dismount();
 
+	default boolean isMounted() {
+		return this.hasParent();
+	}
+
 	default ParentUIComponent root() {
 		ParentUIComponent root = this.getParent();
 		while (root.hasParent()) root = root.getParent();
 		return root;
 	}
 
-	@Nullable FocusHandler getFocusHandler();
+	default FocusHandler getFocusHandler() {
+		return this.hasParent() ? this.getParent().getFocusHandler() : null;
+	}
 
 	void setX(int x);
 	void setY(int y);
@@ -56,6 +63,7 @@ default void position(int x, int y) {
 		setX(x);
 		setY(y);
 	}
+
 	default void size(int width, int height) {
 		setWidth(width);
 		setHeight(height);
@@ -87,4 +95,7 @@ default boolean mouseReleased(double mouseX, double mouseY, int button) {
 	default boolean mouseScrolled(double mouseX, double mouseY, double scrollX, double scrollY) {
 		return false;
 	}
+
+	default void onFocusGained() {}
+	default void onFocusLost() {}
 }

common/src/main/java/me/pandamods/pandalib/client/screen/utils/FocusHandler.java

@@ -12,30 +12,41 @@
 
 package me.pandamods.pandalib.client.screen.utils;
 
+import me.pandamods.pandalib.client.screen.BaseParentUIComponent;
 import me.pandamods.pandalib.client.screen.core.ParentUIComponent;
 import me.pandamods.pandalib.client.screen.core.UIComponent;
-import org.jetbrains.annotations.Contract;
 import org.jetbrains.annotations.Nullable;
 
 public class FocusHandler {
-	protected final ParentUIComponent root;
+	private final ParentUIComponent root;
 
-	protected UIComponent focusedComponent;
+	@Nullable
+	protected UIComponent focused;
 
 	public FocusHandler(ParentUIComponent root) {
 		this.root = root;
 	}
 
-	public void setFocused(UIComponent component) {
-		this.focusedComponent = component;
+	public void focus(UIComponent focused) {
+		if (this.focused != null) this.focused.onFocusLost();
+		this.focused = focused;
+		if (this.focused != null) this.focused.onFocusGained();
+	}
+
+	public void clearFocus() {
+		focus(null);
 	}
 
 	@Nullable
-	public UIComponent getFocusedComponent() {
-		return focusedComponent;
+	public UIComponent getFocused() {
+		return focused;
+	}
+
+	public boolean isFocused(UIComponent component) {
+		return focused == component;
 	}
 
-	public boolean isFocusing() {
-		return getFocusedComponent() != null;
+	public ParentUIComponent getRoot() {
+		return root;
 	}
 }