Markdown tables in preview pane

[maddes8cht]

Summary

The Markdown preview (Issue #15) should render tables in a readable format. Tkinter Text widget has no native column support, making table rendering complex.

Proposed interim solution

Tables are displayed in monospace font (TkFixedFont) — the same as code blocks. Most Markdown tables use ASCII alignment and are already somewhat readable in monospace. This avoids a placeholder like [Table] that would hide content.

Future full solution (tracked separately)

A proper table renderer would:

1. Parse pipe-delimited rows
2. Calculate column widths across all rows
3. Align cells using Text widget tabs or padding
4. Bold the header row

File

• core/markdown_renderer.py — _render_line handles table rows via TABLE_RE

Acceptance Criteria

• Lines starting with | are rendered in TkFixedFont
• Separator lines (| --- | --- |) are rendered but unobtrusive
• No external dependencies

[maddes8cht]

Plan for full table rendering (deferred)

1. Table-Parser (core/table_parser.py)

• Recognise table blocks (consecutive | lines, delimited by blank line or non-| line)
• Parse header row, separator row, data rows
• Calculate maximum column width across all rows

2. Integration in markdown_renderer.py

• Collect table lines in the main render loop (analogous to code_lines)
• After block end: call _render_table(w, rows, col_widths)

3. Tkinter rendering of a table

• Position columns using <Tab> stops (text_widget.tag_configure with tabs=), or
• Pad each cell to the computed column width using lmargin
• Bold the header row
• Render separator unobtrusively or dim it
• Still in TkFixedFont (monospace guarantees alignment)

4. Edge cases

• Table without header row
• Table without separator
• Uneven column count (pad shorter rows)
• Escaped pipes in cells (\|)

5. Tests

• test_table_parser for various table formats
• Integration test for rendered output

Note: The current interim solution (monospace fallback, TkFixedFont for |-lines) already satisfies the acceptance criteria in the issue. The full alignment solution is tracked here as a future enhancement.