1 files changed, 72 insertions, 0 deletions
diff --git a/tools/language-server/src/plugins/css/StyleAttributeDocument.ts b/tools/language-server/src/plugins/css/StyleAttributeDocument.ts
new file mode 100644
index 000000000..e00398037
--- /dev/null
+++ b/tools/language-server/src/plugins/css/StyleAttributeDocument.ts
@@ -0,0 +1,72 @@
+import { Stylesheet } from 'vscode-css-languageservice';
+import { Position } from 'vscode-languageserver';
+import { getLanguageService } from './service';
+import { Document, DocumentMapper, ReadableDocument } from '../../core/documents';
+
+const PREFIX = '__ {';
+const SUFFIX = '}';
+
+export class StyleAttributeDocument extends ReadableDocument implements DocumentMapper {
+  readonly version = this.parent.version;
+
+  public stylesheet: Stylesheet;
+  public languageId = 'css';
+
+  constructor(private readonly parent: Document, private readonly attrStart: number, private readonly attrEnd: number) {
+    super();
+
+    this.stylesheet = getLanguageService(this.languageId).parseStylesheet(this);
+  }
+
+  /**
+   * Get the fragment position relative to the parent
+   * @param pos Position in fragment
+   */
+  getOriginalPosition(pos: Position): Position {
+    const parentOffset = this.attrStart + this.offsetAt(pos) - PREFIX.length;
+    return this.parent.positionAt(parentOffset);
+  }
+
+  /**
+   * Get the position relative to the start of the fragment
+   * @param pos Position in parent
+   */
+  getGeneratedPosition(pos: Position): Position {
+    const fragmentOffset = this.parent.offsetAt(pos) - this.attrStart + PREFIX.length;
+    return this.positionAt(fragmentOffset);
+  }
+
+  /**
+   * Returns true if the given parent position is inside of this fragment
+   * @param pos Position in parent
+   */
+  isInGenerated(pos: Position): boolean {
+    const offset = this.parent.offsetAt(pos);
+    return offset >= this.attrStart && offset <= this.attrEnd;
+  }
+
+  /**
+   * Get the fragment text from the parent
+   */
+  getText(): string {
+    return PREFIX + this.parent.getText().slice(this.attrStart, this.attrEnd) + SUFFIX;
+  }
+
+  /**
+   * Returns the length of the fragment as calculated from the start and end position
+   */
+  getTextLength(): number {
+    return PREFIX.length + this.attrEnd - this.attrStart + SUFFIX.length;
+  }
+
+  /**
+   * Return the parent file path
+   */
+  getFilePath(): string | null {
+    return this.parent.getFilePath();
+  }
+
+  getURL() {
+    return this.parent.getURL();
+  }
+}