Update app.py

app.py

@@ -1,141 +1,128 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 """
-SVG → PNG 在线批量转换（Inkscape 版）
+SVG → PNG 批量转换（rsvg-convert ▸ Inkscape ▸ CairoSVG 三层保险版）
 作者: ChatGPT 示例
-运行环境: Python 3.9+ / Gradio 5.x / Inkscape ≥1.0
 """
 
-import os
-import shutil
-import subprocess
-import tempfile
-import zipfile
+import shutil, subprocess, tempfile, zipfile, gradio as gr
 from pathlib import Path
 from typing import List, Tuple
+import cairosvg   # 兜底
 
-import gradio as gr
-import cairosvg  # 纯 Python 兜底渲染
+DEFAULT_DPI = 300  # 默认分辨率
 
-# --------------------------- 全局配置 ---------------------------
-DEFAULT_DPI = 300  # 默认导出分辨率 (DPI)
+# ───────────────────────── 工具检测 ─────────────────────────
+def which(cmd: str) -> str | None:
+    """返回可执行文件完整路径，找不到则 None"""
+    return shutil.which(cmd)
 
-# --------------------------- 工具函数 ---------------------------
-def find_inkscape() -> str:
-    """在 PATH 中查找 inkscape 可执行文件；找不到则抛异常。"""
-    exe = shutil.which("inkscape")
-    if exe:
-        return exe
-    raise FileNotFoundError(
-        "未检测到 Inkscape，请确认 packages.txt 已包含 `inkscape`，"
-        "并在 Spaces 构建日志中检查安装是否成功。"
-    )
+RSVG = which("rsvg-convert")
+INKSCAPE = which("inkscape")
 
-
-INKSCAPE = None  # 运行期检测并缓存路径
-
-
-def svg_to_png(svg_path: Path, out_path: Path, dpi: int = DEFAULT_DPI):
+# ──────────────────────── 渲染核心函数 ───────────────────────
+def svg_to_png(svg: Path, png: Path, dpi: int = DEFAULT_DPI):
     """
-    以 Inkscape CLI 为主，将 SVG 转成 PNG。
-    - 优先使用新 CLI(--export-type)；失败后自动尝试旧 CLI(--export-png)。
-    - 若两者均失败，则回退到 CairoSVG。
+    依次尝试 rsvg-convert → Inkscape → CairoSVG。
+    任一成功即返回；全部失败则抛 RuntimeError。
     """
-    global INKSCAPE
-    if INKSCAPE is None:  # 首次调用时初始化
-        INKSCAPE = find_inkscape()
-
-    # Inkscape ≥1.0 推荐写法
-    cmd_new = [
-        INKSCAPE,
-        str(svg_path),
-        "--export-type=png",
-        f"--export-filename={out_path}",
-        f"--export-dpi={dpi}",
-    ]
+    errs = []
 
-    try:
-        subprocess.run(cmd_new, check=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
-    except subprocess.CalledProcessError as e_new:
-        # 兼容极旧版 (<1.0) 参数：--export-png
-        cmd_old = [
-            INKSCAPE,
-            str(svg_path),
-            f"--export-png={out_path}",
-            f"-d={dpi}",
-        ]
+    # 1) rsvg-convert（最快最稳，支持大部分特性）
+    if RSVG:
+        cmd = [RSVG, "-d", str(dpi), "-p", str(dpi), "-f", "png",
+               "-o", str(png), str(svg)]
+        try:
+            subprocess.run(cmd, check=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+            if png.stat().st_size > 2048:    # 简单判空
+                return
+        except subprocess.CalledProcessError as e:
+            errs.append(f"[rsvg-convert] {e.stderr.decode(errors='ignore')}")
+
+    # 2) Inkscape CLI（加 export-area-drawing 防止空白）
+    if INKSCAPE:
+        cmd_new = [INKSCAPE, str(svg),
+                   "--export-type=png",
+                   f"--export-filename={png}",
+                   f"--export-dpi={dpi}",
+                   "--export-area-drawing"]     # 关键参数
         try:
-            subprocess.run(cmd_old, check=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
-        except subprocess.CalledProcessError as e_old:
-            # Inkscape 全部失败 ➜ 回退 CairoSVG
+            subprocess.run(cmd_new, check=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+            if png.stat().st_size > 2048:
+                return
+        except subprocess.CalledProcessError as e_new:
+            # 极老版本 Inkscape (<1.0) 回退旧参数
+            cmd_old = [INKSCAPE, str(svg),
+                       f"--export-png={png}",
+                       f"-d={dpi}",
+                       "--export-area-drawing"]
             try:
-                cairosvg.svg2png(url=str(svg_path), write_to=str(out_path), dpi=dpi)
-            except Exception as cs_err:
-                # 抛出详细错误，方便前端提示
-                raise RuntimeError(
-                    f"Inkscape 新旧命令均失败：\n{e_new.stderr.decode(errors='ignore')}\n"
-                    f"{e_old.stderr.decode(errors='ignore')}\n"
-                    f"CairoSVG 也失败：{cs_err}"
-                ) from cs_err
-
-
-def batch_convert(files: List[gr.File], dpi: int = DEFAULT_DPI) -> Tuple[List[Tuple[str, str]], str]:
-    """Gradio 回调：批量转换并打包下载。"""
+                subprocess.run(cmd_old, check=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+                if png.stat().st_size > 2048:
+                    return
+            except subprocess.CalledProcessError as e_old:
+                errs.append(f"[Inkscape] {e_new.stderr.decode(errors='ignore')}\n"
+                            f"[Inkscape-old] {e_old.stderr.decode(errors='ignore')}")
+
+    # 3) CairoSVG 兜底
+    try:
+        cairosvg.svg2png(url=str(svg), write_to=str(png), dpi=dpi)
+        if png.stat().st_size > 2048:
+            return
+    except Exception as cs_err:
+        errs.append(f"[CairoSVG] {cs_err}")
+
+    raise RuntimeError("三种渲染器均失败：\n" + "\n".join(errs))
+
+# ───────────────────────── Gradio 回调 ───────────────────────
+def batch_convert(files: List[gr.File], dpi: int = DEFAULT_DPI
+                  ) -> Tuple[List[Tuple[str, str]], str]:
     if not files:
         raise gr.Error("请先上传至少一个 SVG 文件！")
 
-    tmp_dir = Path(tempfile.mkdtemp(prefix="svg2png_"))
-    png_dir = tmp_dir / "png"
-    png_dir.mkdir(exist_ok=True)
+    tmp = Path(tempfile.mkdtemp(prefix="svg2png_"))
+    out_dir = tmp / "png"; out_dir.mkdir()
 
-    gallery_items = []
+    gallery, errs = [], []
     for f in files:
-        svg_path = Path(f.name)
-        out_path = png_dir / f"{svg_path.stem}.png"
-        svg_to_png(svg_path, out_path, dpi)
-        # Gallery 需要 (标题, 路径)
-        gallery_items.append((out_path.name, str(out_path)))
-
-    # 打包 ZIP
-    zip_path = tmp_dir / "result.zip"
-    with zipfile.ZipFile(zip_path, "w", zipfile.ZIP_DEFLATED) as zf:
-        for p in png_dir.iterdir():
-            zf.write(p, arcname=p.name)
-
-    return gallery_items, str(zip_path)
-
-# --------------------------- Gradio UI ---------------------------
-with gr.Blocks(title="SVG → PNG (Inkscape 版)", theme="soft") as demo:
-    gr.Markdown(
-        """
-# 🌈 SVG → PNG 在线转换器（Inkscape 引擎）  
-- **批量上传** + **DPI 可调** + **透明背景**  
-- 首选 Inkscape CLI，高质量矢量光栅化  
-- 若 Inkscape 不可用自动回退 CairoSVG  
-        """
-    )
+        svg = Path(f.name)
+        out = out_dir / f"{svg.stem}.png"
+        try:
+            svg_to_png(svg, out, dpi)
+            gallery.append((out.name, str(out)))
+        except Exception as e:
+            errs.append(f"{svg.name} 转换失败：{e}")
 
+    # 打包 zip
+    zip_path = tmp / "result.zip"
+    with zipfile.ZipFile(zip_path, "w", zipfile.ZIP_DEFLATED) as zf:
+        for p in out_dir.iterdir():
+            zf.write(p, p.name)
+
+    if errs:
+        # 收敛为单条 Warning，避免打断流程
+        gr.Warning("\n".join(errs))
+
+    return gallery, str(zip_path)
+
+# ────────────────────────── Gradio UI ────────────────────────
+with gr.Blocks(title="SVG → PNG 在线转换", theme="soft") as demo:
+    gr.Markdown("""
+# 🖼️ SVG → PNG 转换器  
+- **rsvg-convert ▸ Inkscape ▸ CairoSVG** 三层保险  
+- 支持批量上传，DPI 可调，默认导出实际绘图区域  
+""")
     with gr.Row():
-        uploader = gr.File(
-            label="上传 SVG（可多选）", file_count="multiple", file_types=[".svg"]
-        )
-        dpi_slider = gr.Slider(
-            72, 600, step=1, value=DEFAULT_DPI,
-            label="输出 DPI", info="数值越大越清晰，文件体积也越大"
-        )
-
-    convert_btn = gr.Button("🚀 开始转换")
-    gallery = gr.Gallery(label="PNG 预览", show_label=True, height="auto")
-    zip_file = gr.File(label="下载全部 PNG (ZIP)")
-
-    convert_btn.click(
-        batch_convert,
-        inputs=[uploader, dpi_slider],
-        outputs=[gallery, zip_file],
-        api_name="convert",
-        queue=True,
-    )
+        uploader = gr.File(file_count="multiple", file_types=[".svg"],
+                           label="上传 SVG 文件（可多选）")
+        dpi_slider = gr.Slider(72, 600, value=DEFAULT_DPI, step=1,
+                               label="输出 DPI", info="分辨率越高越清晰")
+    btn = gr.Button("🚀 开始转换")
+    gallery = gr.Gallery(label="PNG 预览")
+    zip_out = gr.File(label="下载全部 PNG (ZIP)")
+
+    btn.click(batch_convert, [uploader, dpi_slider], [gallery, zip_out],
+              api_name="convert", queue=True)
 
 if __name__ == "__main__":
-    # 在 HF Spaces 中启动时会忽略 share 参数；本地调试可设 share=True
-    demo.launch(share=False)
+    demo.launch(share=False)   # 本地调试可改 True