Fix: Ctrl+C respects text selection instead of always copying full markdown

[Copilot]

The global keydown handler unconditionally intercepted Ctrl+C and copied the entire markdown content, breaking standard copy behavior whenever a user had text selected in the editor or preview pane.

Changes

• script.js — keydown handler: Guard the full-markdown copy behind two conditions; only trigger when no text is selected and focus is not in a text control (<textarea>/<input>).

// Before
if ((e.ctrlKey || e.metaKey) && e.key === "c") {
  e.preventDefault();
  copyMarkdownButton.click();
}

// After
if ((e.ctrlKey || e.metaKey) && e.key === "c") {
  const activeEl = document.activeElement;
  const isTextControl = activeEl && (activeEl.tagName === "TEXTAREA" || activeEl.tagName === "INPUT");
  const hasSelection = window.getSelection && window.getSelection().toString().trim().length > 0;
  if (!isTextControl && !hasSelection) {
    e.preventDefault();
    copyMarkdownButton.click();
  }
}

Behavior matrix:

Context	Ctrl+C result
Text selected in editor or preview	Browser copies selection (native behavior restored)
Focused in <textarea> / <input>	Browser copies selection (native behavior restored)
No selection, no text-control focus	Copies full markdown (existing behavior preserved)

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Bug: Ctrl+C global shortcut copies full markdown instead of selected text</issue_title>
<issue_description>Description
The application currently intercepts the Ctrl+C (copy) keyboard shortcut at the document level and prevents the default browser behavior:

• In script.js, a keydown handler uses e.preventDefault() and invokes the copy-markdown button when Ctrl+C is pressed. (code link)
• The copy handler copies markdownEditor.value (the entire markdown content) via copyToClipboard, so pressing Ctrl+C always copies the full markdown instead of just the user's selection.

Expected behavior

• When the user has a text selection (in the preview or editor), Ctrl+C should copy only the selected text (standard browser behavior).
• The full markdown copy action should only run when there is no selection, or via a separate shortcut (e.g., Ctrl+Shift+C).

Suggested fix

• Modify the keydown handler to check for a selection (window.getSelection().toString()) and/or whether the focused element is a text control before calling e.preventDefault() and triggering the copy action.
• Alternatively, use a different shortcut for "copy full markdown" to avoid colliding with Ctrl+C.

This issue can negatively affect usability for users who frequently copy selected text from the editor or preview.

References

• script.js keydown handler
• copyToClipboard implementation

</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Bug: Ctrl+C global shortcut copies full markdown instead of selected text #31

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Project	Deployment	Actions	Updated (UTC)
markdown-viwer	Ready	Preview, Comment	Mar 4, 2026 1:46pm

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