1 files changed, 141 insertions, 0 deletions
diff --git a/idea_plugin/src/main/java/com/google/googlejavaformat/intellij/GoogleJavaFormatFormattingService.java b/idea_plugin/src/main/java/com/google/googlejavaformat/intellij/GoogleJavaFormatFormattingService.java
new file mode 100644
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+++ b/idea_plugin/src/main/java/com/google/googlejavaformat/intellij/GoogleJavaFormatFormattingService.java
@@ -0,0 +1,141 @@
+/*
+ * Copyright 2023 Google Inc. All Rights Reserved.
+ *
+ * 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.google.googlejavaformat.intellij;
+
+import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Range;
+import com.google.googlejavaformat.java.Formatter;
+import com.google.googlejavaformat.java.FormatterException;
+import com.google.googlejavaformat.java.JavaFormatterOptions;
+import com.google.googlejavaformat.java.JavaFormatterOptions.Style;
+import com.intellij.formatting.service.AsyncDocumentFormattingService;
+import com.intellij.formatting.service.AsyncFormattingRequest;
+import com.intellij.ide.highlighter.JavaFileType;
+import com.intellij.lang.ImportOptimizer;
+import com.intellij.openapi.project.Project;
+import com.intellij.openapi.util.TextRange;
+import com.intellij.psi.PsiFile;
+import java.util.Collection;
+import java.util.List;
+import java.util.Set;
+import org.jetbrains.annotations.NotNull;
+
+/** Uses {@code google-java-format} to reformat code. */
+public class GoogleJavaFormatFormattingService extends AsyncDocumentFormattingService {
+
+  public static final ImmutableSet<ImportOptimizer> IMPORT_OPTIMIZERS =
+      ImmutableSet.of(new GoogleJavaFormatImportOptimizer());
+
+  @Override
+  protected FormattingTask createFormattingTask(AsyncFormattingRequest request) {
+    Project project = request.getContext().getProject();
+
+    if (!JreConfigurationChecker.checkJreConfiguration(project)) {
+      return null;
+    }
+
+    Style style = GoogleJavaFormatSettings.getInstance(project).getStyle();
+    Formatter formatter = createFormatter(style, request.canChangeWhitespaceOnly());
+    return new GoogleJavaFormatFormattingTask(formatter, request);
+  }
+
+  @Override
+  protected String getNotificationGroupId() {
+    return Notifications.PARSING_ERROR_NOTIFICATION_GROUP;
+  }
+
+  @Override
+  protected String getName() {
+    return "google-java-format";
+  }
+
+  private static Formatter createFormatter(Style style, boolean canChangeWhiteSpaceOnly) {
+    JavaFormatterOptions.Builder optBuilder = JavaFormatterOptions.builder().style(style);
+    if (canChangeWhiteSpaceOnly) {
+      optBuilder.formatJavadoc(false).reorderModifiers(false);
+    }
+    return new Formatter(optBuilder.build());
+  }
+
+  @Override
+  public @NotNull Set<Feature> getFeatures() {
+    return Set.of(Feature.FORMAT_FRAGMENTS, Feature.OPTIMIZE_IMPORTS);
+  }
+
+  @Override
+  public boolean canFormat(@NotNull PsiFile file) {
+    return JavaFileType.INSTANCE.equals(file.getFileType())
+        && GoogleJavaFormatSettings.getInstance(file.getProject()).isEnabled();
+  }
+
+  @Override
+  public @NotNull Set<ImportOptimizer> getImportOptimizers(@NotNull PsiFile file) {
+    return IMPORT_OPTIMIZERS;
+  }
+
+  private static final class GoogleJavaFormatFormattingTask implements FormattingTask {
+    private final Formatter formatter;
+    private final AsyncFormattingRequest request;
+
+    private GoogleJavaFormatFormattingTask(Formatter formatter, AsyncFormattingRequest request) {
+      this.formatter = formatter;
+      this.request = request;
+    }
+
+    @Override
+    public void run() {
+      try {
+        String formattedText = formatter.formatSource(request.getDocumentText(), toRanges(request));
+        request.onTextReady(formattedText);
+      } catch (FormatterException e) {
+        request.onError(
+            Notifications.PARSING_ERROR_TITLE,
+            Notifications.parsingErrorMessage(request.getContext().getContainingFile().getName()));
+      }
+    }
+
+    private static Collection<Range<Integer>> toRanges(AsyncFormattingRequest request) {
+      if (isWholeFile(request)) {
+        // The IDE sometimes passes invalid ranges when the file is unsaved before invoking the
+        // formatter. So this is a workaround for that issue.
+        return ImmutableList.of(Range.closedOpen(0, request.getDocumentText().length()));
+      }
+      return request.getFormattingRanges().stream()
+          .map(textRange -> Range.closedOpen(textRange.getStartOffset(), textRange.getEndOffset()))
+          .collect(ImmutableList.toImmutableList());
+    }
+
+    private static boolean isWholeFile(AsyncFormattingRequest request) {
+      List<TextRange> ranges = request.getFormattingRanges();
+      return ranges.size() == 1
+          && ranges.get(0).getStartOffset() == 0
+          // using greater than or equal because ranges are sometimes passed inaccurately
+          && ranges.get(0).getEndOffset() >= request.getDocumentText().length();
+    }
+
+    @Override
+    public boolean isRunUnderProgress() {
+      return true;
+    }
+
+    @Override
+    public boolean cancel() {
+      return false;
+    }
+  }
+}