continuation

(cherry picked from commit 36dd886f35c6d39ae4a6134e5ecc23bd369950fb)

platform/vcs-api/src/com/intellij/openapi/vcs/changes/BackgroundFromStartOption.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2000-2009 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.intellij.openapi.vcs.changes;
+
+import com.intellij.openapi.progress.PerformInBackgroundOption;
+
+public class BackgroundFromStartOption implements PerformInBackgroundOption {
+  private final static BackgroundFromStartOption ourInstance = new BackgroundFromStartOption();
+
+  public static PerformInBackgroundOption getInstance() {
+    return ourInstance;
+  }
+
+  public boolean shouldStartInBackground() {
+    return true;
+  }
+
+  public void processSentToBackground() {
+  }
+
+}

platform/vcs-api/src/com/intellij/util/continuation/Continuation.java

@@ -0,0 +1,101 @@
+/*
+ * Copyright 2000-2010 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.intellij.util.continuation;
+
+import com.intellij.openapi.application.ApplicationManager;
+import com.intellij.openapi.progress.ProgressIndicator;
+import com.intellij.openapi.progress.ProgressManager;
+import com.intellij.openapi.progress.Task;
+import com.intellij.openapi.project.Project;
+import com.intellij.openapi.vcs.CalledInAwt;
+import com.intellij.openapi.vcs.changes.BackgroundFromStartOption;
+import com.intellij.util.Consumer;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+public class Continuation {
+  private GeneralConsumer myGeneralConsumer;
+
+  public Continuation(final Project project, final boolean cancellable) {
+    myGeneralConsumer = new GeneralConsumer(project, cancellable);
+  }
+
+  public void run(final TaskDescriptor task) {
+    if (! ApplicationManager.getApplication().isDispatchThread()) {
+      ApplicationManager.getApplication().invokeLater(new Runnable() {
+        public void run() {
+          myGeneralConsumer.consume(task);
+        }
+      });
+    } else {
+      myGeneralConsumer.consume(task);
+    }
+  }
+
+  private static class TaskWrapper extends Task.Backgroundable {
+    private final TaskDescriptor myTaskDescriptor;
+    private TaskDescriptor myResult;
+    private final Consumer<TaskDescriptor> myGeneralRunner;
+
+    private TaskWrapper(@Nullable Project project,
+                       @NotNull String title,
+                       boolean canBeCancelled,
+                       TaskDescriptor taskDescriptor,
+                       Consumer<TaskDescriptor> generalRunner) {
+      super(project, title, canBeCancelled, BackgroundFromStartOption.getInstance());
+      myTaskDescriptor = taskDescriptor;
+      myGeneralRunner = generalRunner;
+    }
+
+    @Override
+    public void run(@NotNull ProgressIndicator indicator) {
+      myResult = myTaskDescriptor.run();
+    }
+
+    @Override
+    public void onSuccess() {
+      if (myResult != null) {
+        myGeneralRunner.consume(myResult);
+      }
+    }
+  }
+
+  private static class GeneralConsumer implements Consumer<TaskDescriptor> {
+    private final Project myProject;
+    private final boolean myCancellable;
+
+    private GeneralConsumer(final Project project, boolean cancellable) {
+      myProject = project;
+      myCancellable = cancellable;
+    }
+
+    @CalledInAwt
+    public void consume(TaskDescriptor taskDescriptor) {
+      ApplicationManager.getApplication().assertIsDispatchThread();
+
+      TaskDescriptor current = taskDescriptor;
+      while (current != null) {
+        if (Where.AWT.equals(current.getWhere())) {
+          current = current.run();
+        } else {
+          // dont forget cases here if more than 2 instances of Where
+          ProgressManager.getInstance().run(new TaskWrapper(myProject, current.getName(), myCancellable, current, this));
+          return;
+        }
+      }
+    }
+  }
+}

platform/vcs-api/src/com/intellij/util/continuation/TaskDescriptor.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2000-2010 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.intellij.util.continuation;
+
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+public abstract class TaskDescriptor {
+  private final String myName;
+  @NotNull
+  private final Where myWhere;
+
+  public TaskDescriptor(final String name, @NotNull final Where where) {
+    myName = name;
+    myWhere = where;
+  }
+
+  @Nullable
+  public abstract TaskDescriptor run();
+
+  public String getName() {
+    return myName;
+  }
+
+  @NotNull
+  public Where getWhere() {
+    return myWhere;
+  }
+}

platform/vcs-api/src/com/intellij/util/continuation/Where.java

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2000-2010 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.intellij.util.continuation;
+
+public enum Where {
+  AWT,
+  POOLED
+}