`; finalPreviewContainer.innerHTML = html; }; const downloadPDF = async () => { const contentToPrint = document.getElementById('pdf-content'); if (!contentToPrint) { displayError("No content to download."); return; } if (typeof window.jspdf === 'undefined' || typeof window.html2canvas === 'undefined') { displayError("PDF generation library is not available."); return; } try { const { jsPDF } = window.jspdf; const pdfCanvas = await html2canvas(contentToPrint, { backgroundColor: '#ffffff', scale: 2 }); const imgData = pdfCanvas.toDataURL('image/png'); const pdf = new jsPDF({ orientation: 'portrait', unit: 'pt', format: 'a4' }); const pdfWidth = pdf.internal.pageSize.getWidth(); const imgProps = pdf.getImageProperties(imgData); const pdfHeight = (imgProps.height * pdfWidth) / imgProps.width; pdf.addImage(imgData, 'PNG', 0, 0, pdfWidth, pdfHeight); pdf.save(`${courseData.title || 'course-outline'}.pdf`); } catch(err) { console.error("PDF generation failed:", err); displayError("An error occurred while creating the PDF."); } }; const displayError = (message) => { errorDiv.textContent = message; errorDiv.classList.remove('hidden'); }; const hideError = () => errorDiv.classList.add('hidden'); // --- Event Listeners --- tabButtons.forEach(button => { button.addEventListener('click', () => { // This direct navigation is disabled in favor of Next/Prev // but could be enabled if desired. // currentTab = parseInt(button.dataset.tab); // updateTabs(); }); }); nextBtn.addEventListener('click', () => navigate(1)); prevBtn.addEventListener('click', () => navigate(-1)); addModuleBtn.addEventListener('click', addModule); addLessonBtn.addEventListener('click', addLesson); pdfBtn.addEventListener('click', downloadPDF); // Initial setup updateTabs(); updateModuleSelect(); });