Add image preview box; serve PDF preview via iframe /file=; hook image render after run; fix merge markers

app.py

@@ -499,6 +499,59 @@ def _pdf_to_iframe_html(pdf_path: Path, width="100%", height="900px") -> str:
     except Exception:
         return ""
 
+def _pdf_to_iframe_file(pdf_path: Path, width="100%", height="900px") -> str:
+    """Build an iframe HTML that references the served file path, avoiding data: URIs."""
+    try:
+        from urllib.parse import quote
+        p = str(pdf_path)
+        src = f"/file={quote(p)}"
+        return (
+            f"<div style='border:1px solid #ddd;border-radius:8px;overflow:hidden'>"
+            f"<iframe src='{src}' width='{width}' height='{height}' style='border:0'></iframe>"
+            f"</div>"
+        )
+    except Exception:
+        return ""
+
+def preview_image_from_pdf(pdf_file):
+    """Render first page of PDF to PNG for image preview. Returns path or None."""
+    try:
+        # Accept path str or gradio File-like
+        path = pdf_file
+        if hasattr(pdf_file, 'name'):
+            path = pdf_file.name
+        if not path:
+            return None
+        pdf_path = Path(path)
+        out_png = pdf_path.parent / "poster_preview.png"
+        # Prefer PyMuPDF
+        try:
+            import fitz  # PyMuPDF
+            doc = fitz.open(str(pdf_path))
+            if doc.page_count == 0:
+                return None
+            page = doc.load_page(0)
+            mat = fitz.Matrix(2, 2)
+            pix = page.get_pixmap(matrix=mat, alpha=False)
+            pix.save(str(out_png))
+            return str(out_png) if out_png.exists() else None
+        except Exception:
+            pass
+        # Fallback: pypdfium2
+        try:
+            import pypdfium2 as pdfium
+            pdf = pdfium.PdfDocument(str(pdf_path))
+            if len(pdf) == 0:
+                return None
+            page = pdf[0]
+            pil = page.render(scale=2).to_pil()
+            pil.save(out_png)
+            return str(out_png) if out_png.exists() else None
+        except Exception:
+            return None
+    except Exception:
+        return None
+
 def _compile_tex_to_pdf(tex_path: Path, logs):
     """Generic TeX compile helper for a .tex file. Returns Path to PDF or None."""
     try:
@@ -1161,7 +1214,7 @@ def run_pipeline(arxiv_url, pdf_file, openai_key, logo_files, meeting_logo_file,
     try:
         pdf_path = _compile_poster_pdf(OUTPUT_DIR, logs)
         if pdf_path and pdf_path.exists():
-            pdf_html = _pdf_to_iframe_html(pdf_path)
+            pdf_html = _pdf_to_iframe_file(pdf_path)
             compiled_pdf_file = str(pdf_path)
             logs.append("🖨️ PDF ready for preview in UI.")
     except Exception as e:
@@ -1267,6 +1320,7 @@ The framework builds upon [CAMEL-ai](https://github.com/camel-ai/camel).
             with gr.Accordion("Output", open=True):
                 logs_out     = gr.Textbox(label="🧾 Logs (8–10 minutes)", lines=30, max_lines=50)
                 pdf_out      = gr.HTML(label="📄 Poster (PDF Preview)")
+                img_out      = gr.Image(label="🖼️ Poster (Image Preview)", interactive=False)
                 pdf_file_out = gr.File(label="📄 Download Poster (PDF)")
                 zip_out      = gr.File(label="📦 Download Results (.zip)")
                 overleaf_out = gr.HTML(label="Open in Overleaf")
@@ -1274,11 +1328,12 @@ The framework builds upon [CAMEL-ai](https://github.com/camel-ai/camel).
                 debug_zip_out= gr.HTML(label="🐞 Real Output Preview")
                 debug_last_btn= gr.Button("🐞 Test last pipeline zip", variant="secondary")
                 debug_last_out= gr.HTML(label="🐞 Last Pipeline Preview")
-    run_btn.click(
+    _run_evt = run_btn.click(
         fn=run_pipeline,
         inputs=[arxiv_in, pdf_in, key_in, inst_logo_in, conf_logo_in, theme_in],
         outputs=[logs_out, pdf_out, pdf_file_out, zip_out, overleaf_out],
     )
+    _run_evt.then(fn=preview_image_from_pdf, inputs=[pdf_file_out], outputs=[img_out])
     debug_zip_btn.click(fn=debug_compile_output_zip, inputs=[], outputs=[debug_zip_out])
     debug_last_btn.click(fn=debug_compile_last_pipeline_zip, inputs=[], outputs=[debug_last_out])