feat: Add support for PDF line, curve, and rectangle elements

- Implement placeholder methods for handling LTLine, LTCurve, and LTRect elements
- Add logging warnings for unsupported curve and rectangle elements
- Update converter to route line, curve, and rectangle elements to respective handlers

babeldoc/converter.py

@@ -506,6 +506,7 @@ def vflag(font: str, char: str):    # 匹配公式（和角标）字体
                 self.il_creater.on_pdf_figure(child)
                 pass
             elif isinstance(child, LTLine):     # 线条
+                self.il_creater.on_ltline(child)
                 continue
                 layout = self.layout[ltpage.pageid]
                 # ltpage.height 可能是 fig 里面的高度，这里统一用 layout.shape
@@ -518,8 +519,10 @@ def vflag(font: str, char: str):    # 匹配公式（和角标）字体
                 else:                           # 全局线条
                     lstk.append(child)
             elif isinstance(child, LTCurve):
+                self.il_creater.on_ltcurve(child)
                 pass
             elif isinstance(child, LTRect):
+                self.il_creater.on_ltrect(child)
                 pass
             else:
                 pass

babeldoc/document_il/frontend/il_creater.py

@@ -5,7 +5,10 @@
 import pdfminer.pdfinterp
 import pymupdf
 from pdfminer.layout import LTChar
+from pdfminer.layout import LTCurve
 from pdfminer.layout import LTFigure
+from pdfminer.layout import LTLine
+from pdfminer.layout import LTRect
 from pdfminer.pdffont import PDFCIDFont
 from pdfminer.pdffont import PDFFont
 from pdfminer.psparser import PSLiteral
@@ -353,3 +356,12 @@ def on_pdf_figure(self, figure: LTFigure):
             figure.bbox[3],
         )
         self.current_page.pdf_figure.append(il_version_1.PdfFigure(box=box))
+
+    def on_ltline(self, line: LTLine):
+        pass
+
+    def on_ltcurve(self, curve: LTCurve):
+        logger.warning("curve is not supported yet")
+
+    def on_ltrect(self, rect: LTRect):
+        logger.warning("rect is not supported yet")