feat: Add PDF Download option (#56)

.devcontainer/packages.txt

@@ -2,6 +2,7 @@ git
 gdal-bin
 libgdal-dev
 build-essential
+libcairo2
 libgl1
 libglib2.0-0
 tk

.devcontainer/requirements.txt

@@ -1,3 +1,4 @@
+cairosvg==2.7.1
 dem-stitcher==2.5.5
 dnspython==2.6.1
 geopy==2.4.1

.vscode/.mypy.ini

@@ -18,6 +18,9 @@ ignore_missing_imports = True
 [mypy-tqdm.*]
 ignore_missing_imports = True
 
+[mypy-cairosvg.*]
+ignore_missing_imports = True
+
 [mypy-cv2.*]
 ignore_missing_imports = True
 

pretty_gpx/ui/pages/template/ui_manager.py

@@ -2,6 +2,7 @@
 """Ui Manager."""
 from dataclasses import dataclass
 from typing import Generic
+from typing import Literal
 from typing import TypeVar
 
 from nicegui import events
@@ -119,7 +120,9 @@ def __init__(self, cache: T) -> None:
                         self.subclass_column = ui.column(align_items="center")
                         col_3 = ui.column(align_items="center")
 
-                    ui.button('Download', on_click=self.on_click_download)
+                    with ui.row(align_items="center"):
+                        ui.button('Download SVG', on_click=self.on_click_download_svg)
+                        ui.button('Download PDF', on_click=self.on_click_download_pdf)
                 self.params_to_hide.visible = False
 
         ###
@@ -209,13 +212,22 @@ def on_dark_mode_switch_change(self, e: events.ValueChangeEventArguments) -> Non
         else:
             self.theme = self.theme.change(LightTheme.get_mapping())
 
-    async def on_click_download(self) -> None:
+    async def on_click_download_svg(self) -> None:
         """Asynchronously render the high resolution poster and download it as SVG."""
         svg_bytes = await self.render_download_svg_bytes()
+        self.download(svg_bytes, "svg")
 
+    async def on_click_download_pdf(self) -> None:
+        """Asynchronously render the high resolution poster and download it as PDF."""
+        svg_bytes = await self.render_download_svg_bytes()
+        pdf_bytes = await self.plot.svg_to_pdf_bytes(svg_bytes)
+        self.download(pdf_bytes, "pdf")
+
+    def download(self, data: bytes, ext: Literal["svg", "pdf"]) -> None:
+        """Download the high resolution poster."""
         basename = "poster"
         title = self.title.value
         if title:
             basename += f"_{sanitize_filename(title.replace(' ', '_'))}"
-        ui.download(svg_bytes, f'{basename}.svg')
-        logger.info("Poster Downloaded")
+        ui.download(data, f'{basename}.{ext}')
+        logger.info(f"{ext.upper()} Poster Downloaded")

pretty_gpx/ui/pages/template/ui_plot.py

@@ -1,10 +1,12 @@
 #!/usr/bin/python3
 """Ui Plot."""
 import base64
+import io
 from collections.abc import Callable
 from io import BytesIO
 from typing import TypeVar
 
+import cairosvg
 import matplotlib
 import matplotlib.pyplot as plt
 from matplotlib.axes import Axes
@@ -39,6 +41,7 @@ def __init__(self, visible: bool) -> None:
         with ui.card().classes(f'w-[{W_DISPLAY_PIX}px]').style(f'{BOX_SHADOW_STYLE};') as self.card:
             self.img = ui.image()
         self.card.visible = visible
+        self.svg_bytes: bytes | None = None
 
     @staticmethod
     @profile_parallel
@@ -61,19 +64,37 @@ def draw_svg(func: Callable[[Figure, Axes, T], None], data: T) -> bytes:
 
     async def update_preview(self, draw_func: Callable[[Figure, Axes, T], None], data: T) -> None:
         """Draw the figure and rasterize it to update the preview."""
+        self.svg_bytes = None
         with UiWaitingModal("Updating Preview"):
             self.img.source = await run_cpu_bound(UiPlot.draw_png, draw_func, data)
 
     async def render_svg(self, draw_func: Callable[[Figure, Axes, T], None], data: T) -> bytes:
         """Draw the figure and return the SVG bytes."""
-        with UiWaitingModal("Rendering SVG"):
-            return await run_cpu_bound(UiPlot.draw_svg, draw_func, data)
+        if self.svg_bytes is None:
+            with UiWaitingModal("Rendering Vectorized Poster"):
+                self.svg_bytes = await run_cpu_bound(UiPlot.draw_svg, draw_func, data)
+
+        return self.svg_bytes
+
+    async def svg_to_pdf_bytes(self, svg_bytes: bytes) -> bytes:
+        """Convert SVG bytes to PDF bytes."""
+        with UiWaitingModal("Converting to PDF"):
+            return await run_cpu_bound(svg_to_pdf_bytes, svg_bytes)
 
     def make_visible(self) -> None:
         """Make the layout visible."""
         self.card.visible = True
 
 
+@profile_parallel
+def svg_to_pdf_bytes(svg_bytes: bytes) -> bytes:
+    """Convert SVG bytes to PDF bytes."""
+    pdf_bytes = io.BytesIO()
+    cairosvg.svg2pdf(bytestring=svg_bytes, write_to=pdf_bytes)
+    pdf_bytes.seek(0)
+    return pdf_bytes.read()
+
+
 @profile
 def fig_to_rasterized_base64(fig: Figure, dpi: int) -> str:
     """Convert a Matplotlib figure to a rasterized PNG in base64."""