Update app.py

app.py

@@ -1,102 +1,57 @@
-# gallery_viewer.py
+# pdf_viewer_app.py
 import base64
-import pathlib
+from pathlib import Path
+from typing import Union, BinaryIO
 import gradio as gr
 
 
-def files_to_b64(files):
-    """支持 Gradio NamedString / FileData / 纯路径字符串"""
-    out = []
-    for f in files:
-        # ① Gradio 4.x 的 FileData / NamedString
-        if hasattr(f, "data"):                    # NamedString / FileData
-            raw = f.data                         # bytes
-            suffix = pathlib.Path(f.name).suffix[1:]
-        # ② 早期 gr.File 可能直接给文件路径字符串
-        else:
-            path = pathlib.Path(f)
-            raw = path.read_bytes()
-            suffix = path.suffix[1:]
+def pdf_to_html(
+    pdf: Union[str, Path, bytes, BinaryIO],
+    scale: float = 1.0,
+    height: int = 800,
+) -> str:
+    """把 PDF 转成可嵌入浏览器的 HTML 片段（<iframe> + Blob URL）"""
+    # 读取二进制
+    if isinstance(pdf, (str, Path)):
+        raw = Path(pdf).read_bytes()
+    elif isinstance(pdf, bytes):
+        raw = pdf
+    else:  # file-like
+        raw = pdf.read()
+
+    b64 = base64.b64encode(raw).decode()
+    zoom = int(scale * 100)  # 转百分比
+
+    return f"""
+<div style="width:100%;height:{height}px;">
+  <iframe id="pdf_view" style="width:100%;height:100%;border:none;"></iframe>
+</div>
+<script>
+const bytes = Uint8Array.from(atob("{b64}"), c => c.charCodeAt(0));
+const blob  = new Blob([bytes], {{type:"application/pdf"}});
+const url   = URL.createObjectURL(blob);
+document.getElementById("pdf_view").src = url + "#zoom={zoom}";
+</script>
+"""
+
+
+def show_pdf(file_obj, scale):
+    if file_obj is None:
+        return "<p style='color:gray'>请先上传 PDF 文件</p>"
+    return pdf_to_html(file_obj, scale)
+
+
+with gr.Blocks(title="自定义 PDF 预览") as demo:
+    gr.Markdown("## 📄 PDF 预览 Demo（Blob URL + iframe）")
 
-        b64 = base64.b64encode(raw).decode()
-        out.append(f"data:image/{suffix};base64,{b64}")
-    return out
-
-
-def render_img(b64_list, idx, scale):
-    """根据当前索引 idx 和缩放倍数 scale 渲染 HTML。"""
-    if not b64_list:
-        return "<p style='color:gray'>请先上传图片</p>"
-    idx %= len(b64_list)  # 防止越界
-    src = b64_list[idx]
-    return (
-        f'<div style="overflow:auto;border:1px solid #ccc;'
-        f'width:100%;height:800px;text-align:center">'
-        f'<img src="{src}" '
-        f'style="transform:scale({scale});transform-origin:0 0;" />'
-        f'</div>'
-    )
-
-
-with gr.Blocks(title="多图预览 + 缩放 + 翻页") as demo:
-    gr.Markdown("## 🖼️ 多张图片翻页预览 Demo")
-
-    # 用户上传
-    uploader = gr.File(
-        file_types=[".png", ".jpg", ".jpeg"],
-        file_count="multiple",
-        label="上传多张图片",
-    )
-
-    # 缩放 & 翻页 控件
     with gr.Row():
-        prev_btn = gr.Button("⬅️ 上一张")
-        next_btn = gr.Button("下一张 ➡️")
+        uploader = gr.File(label="上传 PDF", file_types=[".pdf"])
         zoom = gr.Slider(0.5, 3, value=1, step=0.1, label="缩放倍数")
 
-    # HTML 容器
-    viewer = gr.HTML()
-
-    # ---- 状态变量 ----
-    img_list_state = gr.State([])   # base64 列表
-    idx_state = gr.State(0)         # 当前索引
-
-    # ---- 事件逻辑 ----
-    def upload_handler(files):
-        b64s = files_to_b64(files)
-        return b64s, 0, render_img(b64s, 0, 1)
-
-    uploader.change(
-        upload_handler,
-        inputs=uploader,
-        outputs=[img_list_state, idx_state, viewer],
-    )
-
-    def show_prev(b64s, idx, scale):
-        idx -= 1
-        return idx, render_img(b64s, idx, scale)
-
-    prev_btn.click(
-        show_prev,
-        inputs=[img_list_state, idx_state, zoom],
-        outputs=[idx_state, viewer],
-    )
-
-    def show_next(b64s, idx, scale):
-        idx += 1
-        return idx, render_img(b64s, idx, scale)
-
-    next_btn.click(
-        show_next,
-        inputs=[img_list_state, idx_state, zoom],
-        outputs=[idx_state, viewer],
-    )
+    html_out = gr.HTML(sanitize=False)  # 关闭净化，允许 <script>
 
-    # 缩放滑块变化
-    zoom.change(
-        lambda b64s, idx, scale: render_img(b64s, idx, scale),
-        inputs=[img_list_state, idx_state, zoom],
-        outputs=viewer,
-    )
+    # 事件绑定
+    uploader.change(show_pdf, [uploader, zoom], html_out)
+    zoom.change(show_pdf, [uploader, zoom], html_out)
 
-demo.launch(share=True)
+demo.launch()