Update app.py

app.py

@@ -339,16 +339,18 @@ def pdf_to_image(pdf_bytes):
         st.error(f"Failed to render PDF preview: {e}")
         return None
 
-# PDF creation and linking function
-WORDS = ["one", "two", "three", "four", "five", "six", "seven", "eight", "nine", "ten"]
+# PDF creation and linking functions
+WORDS_10 = ["one", "two", "three", "four", "five", "six", "seven", "eight", "nine", "ten"]
+WORDS_20 = ["one", "two", "three", "four", "five", "six", "seven", "eight", "nine", "ten",
+            "eleven", "twelve", "thirteen", "fourteen", "fifteen", "sixteen", "seventeen", "eighteen", "nineteen", "twenty"]
 
-def create_and_link_pdfs(source_pdf="TestSource.pdf", target_pdf="TestTarget.pdf"):
-    """Create two PDFs with numbered lists, add links and bookmarks."""
+def create_crossfile_pdfs(source_pdf="TestSource.pdf", target_pdf="TestTarget.pdf"):
+    """Create two PDFs with cross-file linking."""
     def create_base_pdf(filename):
         buffer = io.BytesIO()
         c = canvas.Canvas(buffer)
         c.setFont("Helvetica", 12)
-        for i, word in enumerate(WORDS, 1):
+        for i, word in enumerate(WORDS_10, 1):
             y = 800 - (i * 20)
             c.drawString(50, y, f"{i}. {word}")
         c.showPage()
@@ -386,7 +388,6 @@ def create_and_link_pdfs(source_pdf="TestSource.pdf", target_pdf="TestTarget.pdf
         text_pdf = PdfReader(buffer)
         page = writer.pages[0]
         page.merge_page(text_pdf.pages[0])
-        # Correctly include url parameter
         link = Link(
             rect=(90, seven_y - 10, 150, seven_y + 10),
             url=f"file://{os.path.abspath(target)}#page=1"
@@ -420,6 +421,69 @@ def create_and_link_pdfs(source_pdf="TestSource.pdf", target_pdf="TestTarget.pdf
     add_internal_link(target_pdf)
     return source_pdf, target_pdf
 
+def create_selflinking_pdf(pdf_file="SelfLinking.pdf"):
+    """Create a PDF with a TOC on page 1 linking to a 1-20 list starting on page 2."""
+    buffer = io.BytesIO()
+    c = canvas.Canvas(buffer)
+    
+    # Page 1: Table of Contents
+    c.setFont("Helvetica", 14)
+    c.drawString(50, 800, "Table of Contents")
+    c.setFont("Helvetica", 12)
+    toc_y_positions = []
+    for i, word in enumerate(WORDS_10, 1):
+        y = 760 - (i * 20)
+        c.drawString(50, y, f"{word}")
+        toc_y_positions.append(y)
+    c.showPage()
+    
+    # Page 2: Numbered list 1-20
+    c.setFont("Helvetica", 12)
+    list_y_positions = []
+    for i, word in enumerate(WORDS_20, 1):
+        y = 800 - (i * 20)
+        c.drawString(50, y, f"{i}. {word}")
+        list_y_positions.append(y)
+    c.showPage()
+    
+    # Save the initial PDF
+    c.save()
+    buffer.seek(0)
+    with open(pdf_file, "wb") as f:
+        f.write(buffer.getvalue())
+    buffer.close()
+
+    # Add outlines and links
+    reader = PdfReader(pdf_file)
+    writer = PdfWriter()
+    for page in reader.pages:
+        writer.add_page(page)
+
+    # Add outline entries
+    toc_page = writer.pages[0]
+    list_page = writer.pages[1]
+    writer.add_outline_item("Table of Contents", 0, fit=Fit(fit_type="/Fit"))
+    for i, word in enumerate(WORDS_10, 1):
+        y = list_y_positions[i-1]
+        writer.add_outline_item(word, 1, fit=Fit(fit_type="/XYZ", fit_args=[50, y, 0]))
+
+    # Add TOC links from page 1 to page 2
+    for i, word in enumerate(WORDS_10):
+        toc_y = toc_y_positions[i]
+        list_y = list_y_positions[i]
+        link = Link(
+            rect=(50, toc_y - 10, 150, toc_y + 10),
+            target_page_index=1,
+            fit=Fit(fit_type="/XYZ", fit_args=[50, list_y, 0])
+        )
+        writer.add_annotation(page_number=0, annotation=link)
+
+    # Save the modified PDF
+    with open(pdf_file, "wb") as f:
+        writer.write(f)
+
+    return pdf_file
+
 # Streamlit UI
 md_files = [f for f in glob.glob("*.md") if os.path.basename(f) != "README.md"]
 md_options = [os.path.splitext(os.path.basename(f))[0] for f in md_files]
@@ -516,9 +580,9 @@ with st.sidebar:
             mime="audio/mpeg"
         )
     
-    if st.button("📑 Create Linked PDFs"):
-        with st.spinner("Creating and linking PDFs..."):
-            source_pdf, target_pdf = create_and_link_pdfs()
+    if st.button("📑 Create CrossFile PDFs"):
+        with st.spinner("Creating cross-file linked PDFs..."):
+            source_pdf, target_pdf = create_crossfile_pdfs()
             st.success(f"Created {source_pdf} and {target_pdf}")
             for pdf_file in [source_pdf, target_pdf]:
                 with open(pdf_file, "rb") as f:
@@ -529,25 +593,24 @@ with st.sidebar:
                         mime="application/pdf"
                     )
     
-    if st.button("🧪 Test PDFs"):
-        with st.spinner("Generating and testing PDFs..."):
-            source_pdf, target_pdf = create_and_link_pdfs()
-            st.success(f"Generated {source_pdf} and {target_pdf}")
-            for pdf_file in [source_pdf, target_pdf]:
-                with open(pdf_file, "rb") as f:
-                    pdf_bytes = f.read()
-                images = pdf_to_image(pdf_bytes)
-                if images:
-                    st.subheader(f"Preview of {pdf_file}")
-                    for img in images:
-                        st.image(img, caption=f"{pdf_file} Page", use_container_width=True)
-                with open(pdf_file, "rb") as f:
-                    st.download_button(
-                        label=f"💾 Download {pdf_file}",
-                        data=f.read(),
-                        file_name=pdf_file,
-                        mime="application/pdf"
-                    )
+    if st.button("🧪 Create SelfLinking PDF"):
+        with st.spinner("Generating self-linking PDF with TOC..."):
+            pdf_file = create_selflinking_pdf()
+            st.success(f"Generated {pdf_file}")
+            with open(pdf_file, "rb") as f:
+                pdf_bytes = f.read()
+            images = pdf_to_image(pdf_bytes)
+            if images:
+                st.subheader(f"Preview of {pdf_file}")
+                for i, img in enumerate(images):
+                    st.image(img, caption=f"{pdf_file} Page {i+1}", use_container_width=True)
+            with open(pdf_file, "rb") as f:
+                st.download_button(
+                    label=f"💾 Download {pdf_file}",
+                    data=f.read(),
+                    file_name=pdf_file,
+                    mime="application/pdf"
+                )
 
 with st.spinner("Generating PDF..."):
     pdf_bytes = create_pdf(st.session_state.markdown_content, base_font_size, render_with_bold, auto_bold_numbers, enlarge_numbered, num_columns, add_space_before_numbered, headings_to_fonts)