Make logic dealing with converting offsets more robust. (#3635)

Only use the converted offsets when the file and the converted
offsets disagree. This avoids bugs where we sometimes converted
offsets that shouldn't be converted on windows.

Author: jacob314

src/io/flutter/editor/OutlineLocation.java

@@ -61,7 +61,7 @@ public OutlineLocation(
     int column,
     int indent,
     VirtualFile file,
-    DartAnalysisServerService analysisService
+    WidgetIndentsHighlightingPass pass
   ) {
     this.line = line;
     this.column = column;
@@ -76,8 +76,8 @@ public OutlineLocation(
     assert (column >= indent);
     assert (line >= 0);
     this.indent = indent;
-    this.offset = analysisService.getConvertedOffset(file, node.getOffset());
-    this.endOffset = analysisService.getConvertedOffset(file, node.getOffset() + node.getLength());
+    this.offset = pass.getConvertedOffset(node);
+    this.endOffset = pass.getConvertedOffset(node.getOffset() + node.getLength());
   }
 
   public void dispose() {

src/io/flutter/editor/WidgetIndentsHighlightingPass.java

@@ -425,12 +425,14 @@ public void paint(@NotNull Editor editor, @NotNull RangeHighlighter highlighter,
   private final Document myDocument;
   private final Project myProject;
   private final VirtualFile myFile;
+  private final boolean convertOffsets;
 
-  WidgetIndentsHighlightingPass(@NotNull Project project, @NotNull EditorEx editor) {
+  WidgetIndentsHighlightingPass(@NotNull Project project, @NotNull EditorEx editor, boolean convertOffsets) {
     this.myDocument = editor.getDocument();
     this.myEditor = editor;
     this.myProject = project;
     this.myFile = editor.getVirtualFile();
+    this.convertOffsets = convertOffsets;
   }
 
   private static void drawVerticalLineHelper(
@@ -524,8 +526,8 @@ public static void cleanupHighlighters(Editor editor) {
     setIndentsPassData(editor, null);
   }
 
-  public static void run(@NotNull Project project, @NotNull EditorEx editor, @NotNull FlutterOutline outline) {
-    final WidgetIndentsHighlightingPass widgetIndentsHighlightingPass = new WidgetIndentsHighlightingPass(project, editor);
+  public static void run(@NotNull Project project, @NotNull EditorEx editor, @NotNull FlutterOutline outline, boolean convertOffsets) {
+    final WidgetIndentsHighlightingPass widgetIndentsHighlightingPass = new WidgetIndentsHighlightingPass(project, editor, convertOffsets);
     widgetIndentsHighlightingPass.setOutline(outline);
   }
 
@@ -671,10 +673,28 @@ DartAnalysisServerService getAnalysisService() {
     return DartAnalysisServerService.getInstance(myProject);
   }
 
+  /**
+   * All calls to convert offsets for indent highlighting must go through this
+   * method.
+   *
+   * Sometimes we need to use the raw offsets and sometimes we need
+   * to use the converted offsets depending on whether the FlutterOutline
+   * matches the current document or the expectations given by the
+   * @param node
+   * @return
+   */
+  int getConvertedOffset(FlutterOutline node) {
+    return getConvertedOffset(node.getOffset());
+  }
+
+  int getConvertedOffset(int offset) {
+    return convertOffsets ? getAnalysisService().getConvertedOffset(myFile, offset) : offset;
+  }
+
   private OutlineLocation computeLocation(FlutterOutline node) {
     assert (myDocument != null);
     final int documentLength = myDocument.getTextLength();
-    final int rawOffset = getAnalysisService().getConvertedOffset(myFile, node.getOffset());
+    final int rawOffset = getConvertedOffset(node);
     final int nodeOffset = min(rawOffset, documentLength);
     final int line = myDocument.getLineNumber(nodeOffset);
     final int lineStartOffset = myDocument.getLineStartOffset(line);
@@ -692,7 +712,7 @@ private OutlineLocation computeLocation(FlutterOutline node) {
       }
     }
 
-    return new OutlineLocation(node, line, column, indent, myFile, getAnalysisService());
+    return new OutlineLocation(node, line, column, indent, myFile, this);
   }
 
   private void buildWidgetDescriptors(

src/io/flutter/editor/WidgetIndentsHighlightingPassFactory.java

@@ -21,12 +21,12 @@
 import com.intellij.openapi.editor.ex.DocumentEx;
 import com.intellij.openapi.editor.ex.EditorEx;
 import com.intellij.openapi.fileEditor.*;
-import com.intellij.openapi.fileEditor.impl.FileOffsetsManager;
 import com.intellij.openapi.progress.ProgressIndicator;
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.util.io.FileUtil;
 import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.psi.PsiFile;
+import com.jetbrains.lang.dart.analyzer.DartAnalysisServerService;
 import io.flutter.FlutterUtils;
 import io.flutter.dart.FlutterDartAnalysisServer;
 import io.flutter.dart.FlutterOutlineListener;
@@ -230,7 +230,6 @@ private void syncSettings(FlutterSettings settings) {
       isShowBuildMethodGuides = settings.isShowBuildMethodGuides();
       updateActiveEditors();
     }
-
     isShowMultipleChildrenGuides = settings.isShowMultipleChildrenGuides() && isShowBuildMethodGuides;
   }
 
@@ -290,7 +289,7 @@ public TextEditorHighlightingPass createHighlightingPass(@NotNull PsiFile file,
   }
 
   void runWidgetIndentsPass(EditorEx editor, @NotNull FlutterOutline outline) {
-    if (editor.isDisposed()) {
+    if (editor.isDisposed() || project.isDisposed()) {
       // The editor might have been disposed before we got a new FlutterOutline.
       // It is safe to ignore it as it isn't relevant.
       return;
@@ -302,18 +301,25 @@ void runWidgetIndentsPass(EditorEx editor, @NotNull FlutterOutline outline) {
     }
     // If the editor and the outline have different lengths then
     // the outline is out of date and cannot safely be displayed.
-    final FileOffsetsManager offsetManager = FileOffsetsManager.getInstance();
     final DocumentEx document = editor.getDocument();
-    if (document.getTextLength() != offsetManager.getConvertedOffset(file, outline.getLength())) {
+    final int documentLength = document.getTextLength();
+    final int outlineLength = outline.getLength();
+    // TODO(jacobr): determine why we sometimes have to check against both the
+    // raw outlineLength and the converted outline length for things to work
+    // correctly on windows.
+    if (documentLength != outlineLength &&
+        documentLength != DartAnalysisServerService.getInstance(project).getConvertedOffset(file, outlineLength)) {
       // Outline is out of date. That is ok. Ignore it for now.
       // An up to date outline will probably arive shortly. Showing an
       // outline from data inconsistent with the current
       // content will show annoying flicker. It is better to
       // instead
       return;
     }
-
-    WidgetIndentsHighlightingPass.run(project, editor, outline);
+    // We only need to convert offsets when the document and outline disagree
+    // on the document length.
+    final boolean convertOffsets = documentLength != outlineLength;
+    WidgetIndentsHighlightingPass.run(project, editor, outline, convertOffsets);
   }
 
   @Override