feat(ui): add a World Backups icon to the title and pause screens

CHANGELOG.md

@@ -4,6 +4,9 @@
 
 ### Added
 
+- A World Backups icon sits at the far right of the square icons on the title
+  screen and on the pause screen. On the title screen it opens the list of
+  backed-up worlds; in a world it opens that world's backups.
 - The backup browser can select several backups at once. Ctrl or Cmd click
   toggles a row, Shift click extends the selection, and "Select all" picks
   every backup that matches the filter. One confirmation deletes all of them,

src/client/java/dev/ishaanko/worldarchive/WorldArchiveClient.java

@@ -3,6 +3,7 @@
 import dev.ishaanko.worldarchive.runtime.WorldArchiveRuntime;
 import dev.ishaanko.worldarchive.settings.ClientSettingsAccess;
 import dev.ishaanko.worldarchive.ui.EditWorldBackupIntegration;
+import dev.ishaanko.worldarchive.ui.IconRowBackupIntegration;
 import dev.ishaanko.worldarchive.ui.SelectWorldBackupIntegration;
 import net.fabricmc.api.ClientModInitializer;
 import org.slf4j.Logger;
@@ -17,6 +18,7 @@ public void onInitializeClient() {
         WorldArchiveRuntime runtime = WorldArchiveRuntime.initialize();
         SelectWorldBackupIntegration.register(() -> runtime);
         EditWorldBackupIntegration.register(() -> runtime);
+        IconRowBackupIntegration.register(() -> runtime, runtime::openBrowser);
         LOGGER.info("{} initialized.", WorldArchiveMetadata.MOD_NAME);
     }
 }

src/client/java/dev/ishaanko/worldarchive/runtime/RuntimeNavigation.java

@@ -72,10 +72,11 @@ void playRestoredWorld(Screen returnTo, RestoreBackupResult result) {
         transitionToRestoredWorld(returnTo, result, true);
     }
 
-    void openBrowser() {
+    /** Opens the live world's browser; false when no world is resolved or the runtime is not ready. */
+    boolean openBrowser() {
         BackupWorldContext world = runtime.currentLiveWorld();
         if (world == null || runtime.unavailable()) {
-            return;
+            return false;
         }
         Minecraft minecraft = runtime.services().minecraft();
         minecraft.execute(() -> {
@@ -86,6 +87,7 @@ void openBrowser() {
                         runtime));
             }
         });
+        return true;
     }
 
     boolean sourceDirectoryAvailable(BackupWorldContext world) {

src/client/java/dev/ishaanko/worldarchive/runtime/WorldArchiveRuntime.java

@@ -467,8 +467,9 @@ public void playRestoredWorld(Screen returnTo, RestoreBackupResult result) {
         clientFacade.playRestoredWorld(returnTo, result);
     }
 
-    public void openBrowser() {
-        navigation.openBrowser();
+    /** Opens the live world's backup browser; false when there is no resolved live world yet. */
+    public boolean openBrowser() {
+        return navigation.openBrowser();
     }
 
     private RuntimeState buildState(WorldArchiveConfig config) {

src/client/java/dev/ishaanko/worldarchive/ui/IconRowBackupIntegration.java

@@ -0,0 +1,145 @@
+package dev.ishaanko.worldarchive.ui;
+
+import java.util.ArrayList;
+import java.util.Comparator;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.function.BooleanSupplier;
+import java.util.function.Supplier;
+import java.util.stream.Collectors;
+import net.fabricmc.fabric.api.client.screen.v1.ScreenEvents;
+import net.fabricmc.fabric.api.client.screen.v1.Screens;
+import net.minecraft.client.Minecraft;
+import net.minecraft.client.gui.components.AbstractWidget;
+import net.minecraft.client.gui.components.Button;
+import net.minecraft.client.gui.components.FriendsButton;
+import net.minecraft.client.gui.screens.PauseScreen;
+import net.minecraft.client.gui.screens.Screen;
+import net.minecraft.client.gui.screens.TitleScreen;
+
+/**
+ * Adds the WorldArchive shortcut at the far right of the square-icon row on the title screen
+ * and the pause screen. On the title screen it opens the world list; in a world it opens
+ * that world's backups, or the world list while the live world is still being resolved.
+ */
+public final class IconRowBackupIntegration {
+    private static final int GAP = 4;
+
+    private static final AtomicBoolean REGISTERED = new AtomicBoolean();
+
+    private static volatile Supplier<? extends BackupClientFacade> facadeSupplier;
+
+    private static volatile BooleanSupplier openLiveWorldBackups;
+
+    private IconRowBackupIntegration() {
+    }
+
+    /**
+     * Registers the global Fabric screen hook. Repeated calls update the actions.
+     *
+     * @param facade supplies the facade the world list needs
+     * @param openLiveWorld opens the browser for the loaded world and reports whether it did
+     */
+    public static void register(
+            Supplier<? extends BackupClientFacade> facade,
+            BooleanSupplier openLiveWorld) {
+        facadeSupplier = Objects.requireNonNull(facade, "facade");
+        openLiveWorldBackups = Objects.requireNonNull(openLiveWorld, "openLiveWorld");
+        if (REGISTERED.compareAndSet(false, true)) {
+            ScreenEvents.AFTER_INIT.register(IconRowBackupIntegration::afterInit);
+        }
+    }
+
+    private static void afterInit(Minecraft minecraft, Screen screen, int width, int height) {
+        Button.OnPress action;
+        if (screen instanceof TitleScreen) {
+            action = ignored -> minecraft.setScreenAndShow(
+                    new BackupWorldsScreen(screen, currentFacade()));
+        } else if (screen instanceof PauseScreen && minecraft.hasSingleplayerServer()) {
+            action = ignored -> {
+                if (!currentLiveWorldAction().getAsBoolean()) {
+                    minecraft.setScreenAndShow(new BackupWorldsScreen(screen, currentFacade()));
+                }
+            };
+        } else {
+            return;
+        }
+        List<Button> iconRow = iconRow(Screens.getWidgets(screen));
+        if (iconRow.isEmpty()) {
+            // No icon row to join; stay out rather than guess a spot.
+            return;
+        }
+        int size = Math.max(WorldArchiveIconButton.SIZE, iconRow.getFirst().getHeight());
+        Button backups = WorldArchiveIconButton.create(0, iconRow.getFirst().getY(), size, action);
+        List<Button> row = new ArrayList<>(iconRow);
+        row.add(backups);
+        recenter(row, rowCenter(iconRow), iconRow.getFirst().getY(), width);
+        Screens.getWidgets(screen).add(backups);
+    }
+
+    /**
+     * Picks the square-icon row holding the Friends button, or the widest square-icon row
+     * without it. Any square button counts, so icons from other mods stay part of the row
+     * and the recentered layout cannot overlap them.
+     */
+    private static List<Button> iconRow(List<AbstractWidget> widgets) {
+        Map<Integer, List<Button>> rows = widgets.stream()
+                .filter(Button.class::isInstance)
+                .map(Button.class::cast)
+                .filter(IconRowBackupIntegration::isSquareIcon)
+                .collect(Collectors.groupingBy(Button::getY));
+        return rows.values().stream()
+                .max(Comparator
+                        .<List<Button>>comparingInt(row -> row.stream()
+                                .anyMatch(FriendsButton.class::isInstance) ? 1 : 0)
+                        .thenComparingInt(List::size)
+                        .thenComparingInt(row -> row.getFirst().getY()))
+                .map(row -> row.stream()
+                        .sorted(Comparator.comparingInt(Button::getX))
+                        .toList())
+                .orElse(List.of());
+    }
+
+    private static boolean isSquareIcon(Button button) {
+        return button.getWidth() == button.getHeight()
+                && button.getWidth() >= 16
+                && button.getWidth() <= 32;
+    }
+
+    private static int rowCenter(List<Button> iconRow) {
+        int left = iconRow.getFirst().getX();
+        Button last = iconRow.getLast();
+        return (left + last.getX() + last.getWidth()) / 2;
+    }
+
+    /** Lays the row out again around its old center so the new icon does not push off screen. */
+    private static void recenter(List<Button> row, int centerX, int y, int screenWidth) {
+        int totalWidth = row.stream().mapToInt(Button::getWidth).sum() + GAP * (row.size() - 1);
+        int x = Math.clamp(
+                centerX - totalWidth / 2,
+                GAP,
+                Math.max(GAP, screenWidth - totalWidth - GAP));
+        for (Button button : row) {
+            button.setPosition(x, y);
+            x += button.getWidth() + GAP;
+        }
+    }
+
+    private static BackupClientFacade currentFacade() {
+        Supplier<? extends BackupClientFacade> supplier = facadeSupplier;
+        if (supplier == null) {
+            throw new IllegalStateException("WorldArchive client facade has not been registered");
+        }
+        return Objects.requireNonNull(supplier.get(), "facadeSupplier result");
+    }
+
+    private static BooleanSupplier currentLiveWorldAction() {
+        BooleanSupplier action = openLiveWorldBackups;
+        if (action == null) {
+            throw new IllegalStateException("WorldArchive backup action has not been registered");
+        }
+        return action;
+    }
+}

src/client/java/dev/ishaanko/worldarchive/ui/WorldArchiveIconButton.java

@@ -0,0 +1,31 @@
+package dev.ishaanko.worldarchive.ui;
+
+import net.minecraft.client.gui.components.Button;
+import net.minecraft.client.gui.components.SpriteIconButton;
+import net.minecraft.network.chat.Component;
+import net.minecraft.resources.Identifier;
+
+/** Builds the compact WorldArchive shortcut used beside vanilla icon buttons. */
+final class WorldArchiveIconButton {
+    static final int SIZE = 20;
+
+    private static final Identifier SPRITE = Identifier.fromNamespaceAndPath(
+            "worldarchive",
+            "world_backups");
+
+    private WorldArchiveIconButton() {
+    }
+
+    static Button create(int x, int y, int size, Button.OnPress onPress) {
+        SpriteIconButton button = SpriteIconButton.builder(
+                        Component.translatable("screen.worldarchive.backups_button"),
+                        onPress,
+                        true)
+                .size(size, size)
+                .sprite(SPRITE, Math.min(16, size - 4), Math.min(16, size - 4))
+                .tooltip(Component.translatable("screen.worldarchive.backups_button"))
+                .build();
+        button.setRectangle(size, size, x, y);
+        return button;
+    }
+}

src/main/resources/assets/worldarchive/lang/en_us.json

@@ -1,5 +1,6 @@
 {
     "modmenu.descriptionTranslation.worldarchive": "Creates dependable local backups of your single-player worlds.",
+    "screen.worldarchive.backups_button": "World Backups",
     "screen.worldarchive.settings.archive_folder": "Archive folder",
     "screen.worldarchive.settings.back": "Back",
     "screen.worldarchive.settings.browse": "Browse...",