Method handleSelectionChange

src/mode/modeHandler.ts:173–416

* This is easily the worst function in VSCodeVim. * * We need to know when VSCode has updated our selection, so that we can sync * that internally. Unfortunately, VSCode has a habit of calling this * function at weird times, or or with incomplete information, so we have to * do a lot

(e: vscode.TextEditorSelectionChangeEvent)

   * cursor start position).
   */
  public async handleSelectionChange(e: vscode.TextEditorSelectionChangeEvent): Promise<void> {
    if (
      vscode.window.activeTextEditor === undefined ||
      e.textEditor.document !== vscode.window.activeTextEditor.document
    ) {
      // we don't care if there is no active editor
      // or user selection changed in a paneled window (e.g debug console/terminal)
      // This check is made before enqueuing this selection change, but sometimes
      // between the enqueueing and the actual calling of this function the editor
      // might close or change to other document
      return;
    }
    const selection = e.selections[0];
    Logger.debug(
      `Selection change: ${selection.anchor.toString()}, ${selection.active}, SelectionsLength: ${
        e.selections.length
      }`,
    );

    // If our previous cursors are not included on any of the current selections, then a snippet
    // must have been inserted.
    const isSnippetSelectionChange = () => {
      return e.selections.every((s) => {
        return this.vimState.cursors.every((c) => !s.contains(new vscode.Range(c.start, c.stop)));
      });
    };

    if (
      (e.selections.length !== this.vimState.cursors.length || this.vimState.isMultiCursor) &&
      this.vimState.currentMode !== Mode.VisualBlock
    ) {
      const allowedModes = [Mode.Normal];
      if (!isSnippetSelectionChange()) {
        allowedModes.push(Mode.Insert, Mode.Replace);
      }
      // Number of selections changed, make sure we know about all of them still
      this.vimState.cursors = e.textEditor.selections.map(
        (sel) =>
          new Cursor(
            // Adjust the cursor positions because cursors & selections don't match exactly
            sel.anchor.isAfter(sel.active) ? sel.anchor.getLeft() : sel.anchor,
            sel.active,
          ),
      );
      if (
        e.selections.some((s) => !s.anchor.isEqual(s.active)) &&
        allowedModes.includes(this.vimState.currentMode)
      ) {
        // If we got a visual selection and we are on normal, insert or replace mode, enter visual mode.
        // We shouldn't go to visual mode on any other mode, because the other visual modes are handled
        // very differently than vscode so only our extension will create them. And the other modes
        // like the plugin modes shouldn't be changed or else it might mess up the plugins actions.
        await this.setCurrentMode(Mode.Visual);
      }
      return this.updateView({ drawSelection: false, revealRange: false });
    }

    /**