Systems 7: every page reads through page and follows

companion/src/main/java/com/github/minecraft_ta/totalDebugCompanion/catalog/KeyBindingLabels.java

@@ -1,5 +1,6 @@
 package com.github.minecraft_ta.totalDebugCompanion.catalog;
 
+import com.github.minecraft_ta.totalDebugCompanion.util.Signal;
 import com.github.minecraft_ta.totalDebugCompanion.change.ChangeLabels;
 import com.github.minecraft_ta.totalDebugCompanion.navigation.NavigationTarget;
 import com.github.minecraft_ta.totalDebugCompanion.storage.ChangeRecord;
@@ -22,8 +23,8 @@ public final class KeyBindingLabels implements ChangeLabels {
 
     /** A key rebound outside Companion, such as in the game, changes the key a row shows. */
     @Override
-    public Runnable follow(Runnable listener) {
-        return this.keys.assignmentsChanged().subscribe(listener);
+    public List<Signal> follows() {
+        return List.of(this.keys.assignmentsChanged());
     }
 
     public KeyBindingLabels(KeyBindingControl keys) {

companion/src/main/java/com/github/minecraft_ta/totalDebugCompanion/catalog/WorldReading.java

@@ -1,5 +1,6 @@
 package com.github.minecraft_ta.totalDebugCompanion.catalog;
 
+import java.util.Optional;
 import java.util.concurrent.CompletableFuture;
 import java.nio.file.attribute.FileTime;
 import com.github.minecraft_ta.totalDebugCompanion.util.FileWatch;
@@ -85,6 +86,13 @@ public Signal changed() {
         return this.changed;
     }
 
+    /** The name of the current world as read last, without reading; empty where none was read yet. */
+    public Optional<String> publishedName() {
+        Followed now = this.followed;
+        if (now.reading() == null) return Optional.empty();
+        return now.reading().published().map(read -> read.saved().name());
+    }
+
     /** The current world as read last; read now where it was not read yet. Blocking then. */
     public World value() {
         Followed now = this.followed;
@@ -128,8 +136,18 @@ private void follow() {
                 reading.close();
             };
             this.followed = new Followed(current, reading);
+            // Told once the new world's first read landed, so its followers find it published, as the tab its name.
+            Workers.files().execute(() -> {
+                try {
+                    reading.value();
+                } catch (IOException unreadable) {
+                    // The World page shows why.
+                }
+                this.changed.fire();
+            });
+            return;
         }
-        if (before.directory() != null || current != null) this.changed.fire();
+        if (before.directory() != null) this.changed.fire();
     }
 
     /** Watches the datapacks folder of {@code world}, which the game plays, or none; a change there reads it again. */

companion/src/main/java/com/github/minecraft_ta/totalDebugCompanion/change/ChangeLabels.java

@@ -1,5 +1,6 @@
 package com.github.minecraft_ta.totalDebugCompanion.change;
 
+import com.github.minecraft_ta.totalDebugCompanion.util.Signal;
 import com.github.minecraft_ta.totalDebugCompanion.catalog.CatalogIndex;
 import com.github.minecraft_ta.totalDebugCompanion.navigation.NavigationTarget;
 import com.github.minecraft_ta.totalDebugCompanion.storage.ChangeRecord;
@@ -88,11 +89,11 @@ record Rows(List<Row> rows, List<String> problems) {
     CompletableFuture<String> revert(List<ChangeRecord.Change> changes, CatalogIndex index);
 
     /**
-     * Runs {@code listener} when the values the category's rows show may have changed outside the change record, such as
-     * a key rebound in the game; returns its removal. Most categories' values change only through the record.
+     * The signals of values the category's rows show that change outside the change record, such as a key rebound in the
+     * game. Most categories' values change only through the record.
      */
-    default Runnable follow(Runnable listener) {
-        return () -> { };
+    default List<Signal> follows() {
+        return List.of();
     }
 
     /**

companion/src/main/java/com/github/minecraft_ta/totalDebugCompanion/model/ChangesView.java

@@ -17,11 +17,6 @@ public ChangesView(EditorContext context) {
                 context.navigation()::navigate);
     }
 
-    /** Reads the changed files again. */
-    public void refresh() {
-        this.panel.load();
-    }
-
     @Override
     public String getTitle() {
         return "Changes";

companion/src/main/java/com/github/minecraft_ta/totalDebugCompanion/model/DefinitionView.java

@@ -19,7 +19,7 @@ public DefinitionView(EditorContext context, SubjectRef.Definition subject) {
         this.subject = subject;
         this.panel = SubjectPanel.definition(subject, new DefinitionDetails.Services(context.project().catalog(),
                 () -> context.project().sources(), context.itemIcons(), context.navigation()::navigate,
-                context.project().packs().changed(ChangeRecord.PackSide.RESOURCES)::subscribe));
+                context.project().packs().changed(ChangeRecord.PackSide.RESOURCES)));
     }
 
     public SubjectRef.Definition subject() {

companion/src/main/java/com/github/minecraft_ta/totalDebugCompanion/model/InspectionView.java

@@ -23,7 +23,7 @@ public InspectionView(EditorContext context, InspectSubjectPayload subject, Runt
         this.subject = Objects.requireNonNull(subject, "subject");
         this.panel = SubjectPanel.occurrence(subject, context.snippets(), () -> context.project().scriptFiles(),
                 new DefinitionDetails.Services(context.project().catalog(), () -> context.project().sources(),
-                        context.itemIcons(), context.navigation()::navigate, context.project().packs().changed(ChangeRecord.PackSide.RESOURCES)::subscribe));
+                        context.itemIcons(), context.navigation()::navigate, context.project().packs().changed(ChangeRecord.PackSide.RESOURCES)));
     }
 
     public InspectSubjectPayload subject() {

companion/src/main/java/com/github/minecraft_ta/totalDebugCompanion/model/LogsView.java

@@ -18,10 +18,9 @@ public LogsView(EditorContext context) {
                 context.navigation()::navigate);
     }
 
-    /** Lists the logs and crash reports again, selecting {@code file} when it is not null. */
+    /** Selects {@code file} among the logs and crash reports when it is not null. */
     public void show(Path file) {
         this.panel.select(file);
-        this.panel.load();
     }
 
     @Override

companion/src/main/java/com/github/minecraft_ta/totalDebugCompanion/model/ModView.java

@@ -16,7 +16,7 @@ public final class ModView implements IEditorPanel {
     public ModView(EditorContext context, NavigationTarget.ModPage page) {
         this.panel = new ModPanel(page.modId(), context.project().catalog(), () -> context.project().sources(),
                 context.itemIcons(), context.project().profile().workspaceDirectory(), context.project().configSettings(),
-                context.project().keyBindings(), context.navigation()::navigate, context.project().packs().changed(ChangeRecord.PackSide.RESOURCES)::subscribe);
+                context.project().keyBindings(), context.navigation()::navigate, context.project().packs().changed(ChangeRecord.PackSide.RESOURCES));
         this.panel.show(page);
     }
 

companion/src/main/java/com/github/minecraft_ta/totalDebugCompanion/model/PackConfigurationView.java

@@ -18,9 +18,6 @@ public PackConfigurationView(EditorContext context) {
     }
 
     /** Reads the configuration files again. */
-    public void refresh() {
-        this.panel.load();
-    }
 
     @Override
     public String getTitle() {

companion/src/main/java/com/github/minecraft_ta/totalDebugCompanion/navigation/NavigationService.java

@@ -317,7 +317,7 @@ private CompletableFuture<Void> performNavigation(NavigationTarget target, Activ
                         PackConfigurationView.class,
                         view -> true,
                         () -> new PackConfigurationView(editors.get())
-                ).thenAccept(PackConfigurationView::refresh), activation);
+                ).thenAccept(view -> { }), activation);
                 case NavigationTarget.PackResources resources -> dispatchNavigation(() -> this.tabs.focusOrCreateIfAbsent(
                         PackResourcesView.class,
                         view -> true,
@@ -332,7 +332,7 @@ private CompletableFuture<Void> performNavigation(NavigationTarget target, Activ
                         ChangesView.class,
                         view -> true,
                         () -> new ChangesView(editors.get())
-                ).thenAccept(ChangesView::refresh), activation);
+                ).thenAccept(view -> { }), activation);
                 case NavigationTarget.Content content -> dispatchNavigation(() -> this.tabs.focusOrCreateIfAbsent(
                         ContentView.class,
                         view -> true,

companion/src/main/java/com/github/minecraft_ta/totalDebugCompanion/ui/components/PageLoader.java

@@ -1,6 +1,7 @@
 package com.github.minecraft_ta.totalDebugCompanion.ui.components;
 
 import com.github.minecraft_ta.totalDebugCompanion.util.Signal;
+import com.github.minecraft_ta.totalDebugCompanion.util.Workers;
 
 import javax.swing.JComponent;
 import javax.swing.SwingUtilities;
@@ -17,7 +18,6 @@
 import java.util.concurrent.CompletionException;
 import java.util.function.BooleanSupplier;
 import java.util.function.Consumer;
-import java.util.function.Function;
 
 /**
  * Reads what a page shows off the Swing thread and shows it on that thread (docs/SYSTEMS.md, section 3). One read runs
@@ -29,10 +29,8 @@
  * first shown, and after a followed signal fires, at once while the page is shown, otherwise once it is shown again. A
  * page shown again with nothing changed reads nothing, unless its last read failed. While the page holds its reads
  * ({@link #hold}), as during a save, signals wait in the same way. The page never reads in its constructor or because a
- * navigation showed it.</p>
- *
- * <p>Pages not moved to {@link #page} yet use the older modes {@link #whenShown}, {@link #waitsWhileHidden} and
- * {@link #readsWhenShown} with {@link #follow}, and read in their constructors; the last of them to move deletes those.</p>
+ * navigation showed it. A page whose files others write and only it reads, such as the logs, reads whenever it is shown
+ * ({@link #readsWhenShown}); work that only redraws from memory waits the same way ({@link #updates}).</p>
  */
 public final class PageLoader<T> {
     /** What to read: prepared on the Swing thread, where the page's state is captured, then run off it. */
@@ -78,6 +76,11 @@ public interface Read<T> {
      */
     private boolean showReadQueued;
 
+    /** A loader for {@code page}, which reads nothing and only redraws from memory ({@link #updates}). */
+    public static PageLoader<Void> redraws(JComponent page) {
+        return new PageLoader<Void>(() -> null, nothing -> { }, failure -> { }).page(page);
+    }
+
     /** {@code show} and {@code fail} run on the Swing thread with what a read returned or why it failed. */
     public PageLoader(Read<T> read, Consumer<T> show, Consumer<Throwable> fail) {
         this.read = Objects.requireNonNull(read, "read");
@@ -125,24 +128,6 @@ public boolean fired(Signal signal) {
         return this.fired.contains(signal);
     }
 
-    /**
-     * Waits while {@code page} is hidden and reads every time it is shown, since what it shows may have changed while it
-     * was hidden without a source telling, such as a file the game writes.
-     */
-    public PageLoader<T> whenShown(JComponent page) {
-        this.page = Objects.requireNonNull(page, "page");
-        return readsWhenShown(page);
-    }
-
-    /**
-     * Waits while {@code page} is hidden: a followed change then reads once the page is shown again, and not at all when
-     * none came. For pages whose sources tell every change.
-     */
-    public PageLoader<T> waitsWhileHidden(JComponent page) {
-        this.page = Objects.requireNonNull(page, "page");
-        return watch(page, false);
-    }
-
     /**
      * Reads every time {@code component} is shown, such as a tab listing files that change without telling. It may be a
      * part of the page, which then reads when that part is chosen.
@@ -169,11 +154,39 @@ private PageLoader<T> watch(JComponent component, boolean always) {
     }
 
     /**
-     * Loads whenever a source changes, or once the page is shown again. {@code subscribe} adds a listener to the source
-     * and returns what removes it, as {@code catalog.changed()::subscribe} does; the listener may be called on any thread.
+     * Runs {@code update}, which only redraws from memory, such as icons again after new ones came, when {@code signal}
+     * fires: at once while the page is shown, otherwise once it is shown again, once however often it fired. Swing thread.
      */
-    public PageLoader<T> follow(Function<Runnable, Runnable> subscribe) {
-        this.unsubscribe.add(subscribe.apply(() -> SwingUtilities.invokeLater(() -> changed(ALWAYS))));
+    public PageLoader<T> updates(Signal signal, Runnable update) {
+        Objects.requireNonNull(update, "update");
+        boolean[] missed = {false};
+        this.unsubscribe.add(signal.subscribe(() -> SwingUtilities.invokeLater(() -> {
+            if (this.disposed) return;
+            if (this.page != null && !this.page.isShowing()) missed[0] = true;
+            else update.run();
+        })));
+        if (this.page != null) {
+            JComponent shown = this.page;
+            HierarchyListener listener = event -> {
+                if ((event.getChangeFlags() & HierarchyEvent.SHOWING_CHANGED) == 0 || !shown.isShowing() || !missed[0]) return;
+                missed[0] = false;
+                if (!this.disposed) update.run();
+            };
+            shown.addHierarchyListener(listener);
+            this.unwatch.add(() -> shown.removeHierarchyListener(listener));
+        }
+        return this;
+    }
+
+    /**
+     * Runs {@code redraw} on the Swing thread whenever {@code signal} fires, shown or not, for what shows outside the page
+     * from memory, such as the title of its tab.
+     */
+    public PageLoader<T> retitles(Signal signal, Runnable redraw) {
+        Objects.requireNonNull(redraw, "redraw");
+        this.unsubscribe.add(signal.subscribe(() -> SwingUtilities.invokeLater(() -> {
+            if (!this.disposed) redraw.run();
+        })));
         return this;
     }
 
@@ -253,7 +266,7 @@ public void load() {
             } catch (Exception exception) {
                 throw new CompletionException(exception);
             }
-        }).whenComplete((value, failure) -> {
+        }, Workers.files()).whenComplete((value, failure) -> {
             // Completed off the Swing thread, so a wait on the Swing thread does not block what it waits for.
             finished.complete(null);
             SwingUtilities.invokeLater(() -> showRead(value, failure));

companion/src/main/java/com/github/minecraft_ta/totalDebugCompanion/ui/components/catalog/ChangesPanel.java

@@ -223,9 +223,10 @@ public ChangesPanel(PackCatalogService catalog, ChangeRecord record, List<Change
 
         this.loader = new PageLoader<>(this::prepareLoad, this::show,
                 failure -> setStatus("Could not read the changes: " + failure.getMessage()))
-                .whenShown(this).follow(this.record.changed()::subscribe).follow(this.catalog.changed()::subscribe);
-        for (ChangeLabels labels : categories) this.loader.follow(labels::follow);
-        load();
+                .page(this).follows(this.record.changed()).follows(this.catalog.changed())
+                // Until the owners notice values put back outside Companion, the labels read the files whenever shown.
+                .readsWhenShown(this);
+        for (ChangeLabels labels : categories) labels.follows().forEach(this.loader::follows);
     }
 
     public void load() {

companion/src/main/java/com/github/minecraft_ta/totalDebugCompanion/ui/components/catalog/ConfigFilePanel.java

@@ -49,8 +49,7 @@ public ConfigFilePanel(Path file, ConfigSources.Owner owner, ConfigSettings conf
         add(bar, BorderLayout.NORTH);
         add(this.editor.component(), BorderLayout.CENTER);
         this.loader = new PageLoader<>(() -> this::readFile, this.editor::load,
-                failure -> setStatus("Could not read " + this.file.getFileName() + ": " + failure.getMessage())).whenShown(this);
-        load();
+                failure -> setStatus("Could not read " + this.file.getFileName() + ": " + failure.getMessage())).page(this).readsWhenShown(this);
     }
 
     public Path file() {

companion/src/main/java/com/github/minecraft_ta/totalDebugCompanion/ui/components/catalog/ConfigPanel.java

@@ -107,15 +107,15 @@ final class ConfigPanel extends JPanel {
         this.navigator = Objects.requireNonNull(navigator, "navigator");
         this.values = new PageLoader<>(this::prepareValues, read -> show(read.file(), read.values(),
                 read.values() == null ? "" : read.values().text(), read.problem()),
-                failure -> showFailure("Could not read the file: " + failure.getMessage())).whenShown(this);
+                failure -> showFailure("Could not read the file: " + failure.getMessage())).page(this).readsWhenShown(this);
         this.sources = new PageLoader<>(this::prepareSources, read -> showSources(read.file(), read.found(), true),
                 failure -> showFailure("Could not list the worlds' copies: " + failure.getMessage()))
                 // A server configuration is shown from the world the game has open first; it follows the game to another
                 // world, unless its text has unsaved changes, which stay with the file they were made in.
-                .follow(listener -> this.location.playingChanged().subscribe(() -> SwingUtilities.invokeLater(() -> {
+                .page(this).follows(this.location.playingChanged(), () -> {
                     PackCatalog.ConfigFile file = selectedFile();
-                    if (file != null && file.type() == PackCatalog.ConfigType.SERVER && !this.textEditor.modified()) listener.run();
-                })));
+                    return file != null && file.type() == PackCatalog.ConfigType.SERVER && !this.textEditor.modified();
+                });
         configureFiles();
         this.content.add(toolbar(), BorderLayout.NORTH);
         JPanel settings = new JPanel(new BorderLayout());