show retry link when failed to fetch version list

HMCLCore/src/main/java/org/jackhuang/hmcl/download/DefaultGameBuilder.java

@@ -62,7 +62,7 @@ public class DefaultGameBuilder extends GameBuilder {
                     downloadGameAsync(gameVersion, version),
                     new GameLibrariesTask(dependencyManager, version) // Game libraries will be downloaded for multiple times partly, this time is for vanilla libraries.
             ).with(new VersionJsonSaveTask(dependencyManager.getGameRepository(), version)); // using [with] because download failure here are tolerant.
-            
+
             if (toolVersions.containsKey("forge"))
                 result = result.then(libraryTaskHelper(gameVersion, "forge"));
             if (toolVersions.containsKey("liteloader"))
@@ -70,12 +70,9 @@ public class DefaultGameBuilder extends GameBuilder {
             if (toolVersions.containsKey("optifine"))
                 result = result.then(libraryTaskHelper(gameVersion, "optifine"));
             return result;
-        }).finalized(new Task() {
-            @Override
-            public void execute() {
-                if (!isDependentsSucceeded())
-                    dependencyManager.getGameRepository().getVersionRoot(name).delete();
-            }
+        }).finalized((variables, isDependentsSucceeded) -> {
+            if (!isDependentsSucceeded)
+                dependencyManager.getGameRepository().getVersionRoot(name).delete();
         });
     }
 

HMCLCore/src/main/java/org/jackhuang/hmcl/task/FinalizedCallback.java

@@ -0,0 +1,24 @@
+/*
+ * Hello Minecraft! Launcher.
+ * Copyright (C) 2017  huangyuhui <huanghongxun2008@126.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see {http://www.gnu.org/licenses/}.
+ */
+package org.jackhuang.hmcl.task;
+
+import org.jackhuang.hmcl.util.AutoTypingMap;
+
+public interface FinalizedCallback {
+    void execute(AutoTypingMap<String> variables, boolean isDependentsSucceeded) throws Exception;
+}

HMCLCore/src/main/java/org/jackhuang/hmcl/task/FinalizedTask.java

@@ -0,0 +1,78 @@
+/*
+ * Hello Minecraft! Launcher.
+ * Copyright (C) 2017  huangyuhui <huanghongxun2008@126.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see {http://www.gnu.org/licenses/}.
+ */
+package org.jackhuang.hmcl.task;
+
+import org.jackhuang.hmcl.util.AutoTypingMap;
+import org.jackhuang.hmcl.util.ExceptionalFunction;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.LinkedList;
+import java.util.List;
+
+/**
+ * A task that combines two tasks and make sure [pred] runs before succ.
+ *
+ * @author huangyuhui
+ */
+final class FinalizedTask extends Task {
+
+    private final Collection<Task> dependents;
+    private final FinalizedCallback callback;
+    private final Scheduler scheduler;
+
+    /**
+     * A task that combines two tasks and make sure pred runs before succ.
+     *
+     * @param pred the task that runs before succ.
+     * @param callback a callback that returns the task runs after pred, succ will be executed asynchronously. You can do something that relies on the result of pred.
+     */
+    public FinalizedTask(Task pred, Scheduler scheduler, FinalizedCallback callback) {
+        this.dependents = Collections.singleton(pred);
+        this.scheduler = scheduler;
+        this.callback = callback;
+
+        setSignificance(TaskSignificance.MODERATE);
+        setName(callback.toString());
+    }
+
+    @Override
+    public Scheduler getScheduler() {
+        return scheduler;
+    }
+
+    @Override
+    public void execute() throws Exception {
+        setName(callback.toString());
+        callback.execute(getVariables(), isDependentsSucceeded());
+
+        if (!isDependentsSucceeded())
+            throw new SilentException();
+    }
+
+    @Override
+    public Collection<Task> getDependents() {
+        return dependents;
+    }
+
+    @Override
+    public boolean isRelyingOnDependents() {
+        return false;
+    }
+}
+

HMCLCore/src/main/java/org/jackhuang/hmcl/task/Task.java

@@ -260,12 +260,12 @@ public abstract class Task {
         return new CoupleTask<>(this, b, false, false);
     }
 
-    public final Task finalized(Task b) {
-        return finalized(convert(b));
+    public final Task finalized(FinalizedCallback b) {
+        return finalized(Schedulers.defaultScheduler(), b);
     }
 
-    public final Task finalized(ExceptionalFunction<AutoTypingMap<String>, Task, ?> b) {
-        return new CoupleTask<>(this, b, false, true);
+    public final Task finalized(Scheduler scheduler, FinalizedCallback b) {
+        return new FinalizedTask(this, scheduler, b);
     }
 
     public static Task empty() {