Layers

Every drawable is a Layer added to a map with mappyng.Map.add(). Layers carry their data and parameters, validate themselves, and render into the map when it is built.

Base classes

class mappyng.layers.Layer(gdf=None, *, z_index=0, visible=True, **params)

Bases: ABC

Abstract description of a cartographic layer.

A layer holds its data (gdf) and parameters (params) and draws nothing until render() is called. It is validated at construction and at every update().

Parameters:

• gdf (GeoDataFrame, optional) – The layer data. Required for data layers (requires_gdf); ignored by reference layers such as the basemap.

• z_index (int, default 0) – Render order. Layers with equal z_index keep insertion order.

• visible (bool, default True) – Whether the layer is drawn.

• **params – Layer-specific parameters (see each concrete subclass).

id

Identifier, assigned by the map when the layer is added.

Type:

str or None

kind

Identifier prefix for the layer family (class attribute).

Type:

str

__init__(gdf=None, *, z_index=0, visible=True, **params)

classmethod from_dict(data, gdf=None)

Rebuild a layer from to_dict() output.

Parameters:

• data (dict) – A serialised layer.

• gdf (GeoDataFrame, optional) – Geometry to reattach (the serialised form does not carry it).

Return type:

Layer

kind: str = 'layer'

Identifier prefix for this layer family.

abstractmethod render(ctx)

Draw the layer into the map carried by ctx.

Called when the map is built. Implementations must set self._rendered = True once drawn.

Return type:

None

requires_gdf: bool = False

Whether a non-empty gdf is required at construction.

to_dict()

Serialise the layer’s intent (not its geometry).

The geometry is flagged by data['in_memory']; persisting it by reference or path is handled by serialisation.

Return type:

Dict[str, Any]

update(**kwargs)

Update parameters and re-validate. Returns self.

z_index and visible are treated as layer metadata; any other keyword updates params.

Raises:

LayerStateError – If the layer has already been rendered.

Return type:

Layer

validate()

Check internal consistency. Override in subclasses.

Raises in plain language (see errors.py convention) for structural problems such as a missing required parameter. Semiological advice is emitted as a warning, never an error.

Return type:

None

class mappyng.layers.RenderContext(map)

Bases: object

Carries what a Layer needs to render itself.

The context is the decoupling point between a layer and the map: a layer never reaches into Map directly, it goes through the context. It transports the host map (whose viewports, CRS, internal state and font scaling a layer reaches through).

Parameters:

map (Map) – The host map the layer draws into.

__init__(map)

exception mappyng.layers.LayerStateError

Bases: RuntimeError

Raised when a layer is mutated after it has been rendered.

A layer’s parameters describe an intent that is consumed at render time. Once rendered, changing them would silently desynchronise the object from the SVG already produced, so Layer.update() is refused.

Thematic layers

class mappyng.ChoroplethLayer(gdf=None, *, column=<unset>, cmap=<unset>, reverse=<unset>, method=<unset>, num_classes=<unset>, stroke=<unset>, stroke_width=<unset>, legend=<unset>, dissolve=<unset>, simplify=<unset>, on_zoom=<unset>, on_cartouches=<unset>, z_index=0, visible=True)

Bases: Layer

Choropleth (graduated colour) layer.

Maps a relative quantity (rate, ratio, density) to colour value.

Parameters:

• gdf (GeoDataFrame) – Polygons with a numeric column.

• column (str) – Column to classify (required).

• cmap (str or list, optional) – Colour ramp name or explicit list of hex colours (default from defaults). With "StdMean" a diverging ramp ("RdBu", "BrBG", "RdYlGn") reads the two sides of the mean apart; a sequential ramp raises a warning.

• reverse (bool, optional) – Reverse the colour order, so the lowest class takes the ramp’s last colour (default False). Applies to named ramps and explicit lists.

• method (str, optional) – Classification scheme: "Quantiles", "EqualInterval", "FisherJenks", "Q6", "StdMean" or "PrettyBreaks".

• num_classes (int, optional) – Number of classes, usually 4 to 7 (default 5). "StdMean" supports 5 or 7 (the central class straddles the mean, so the count is odd); any other count snaps to the nearest valid one with a warning. "Q6" always yields 6.

• stroke (str, optional) – Outline colour of each area as #RRGGBB (default from style).

• stroke_width (float, optional) – Outline width (default from style).

• legend (dict, optional) – Legend configuration (see ChoroplethLegendConfig), or a legend config instance.

• dissolve (bool, optional) – Merge adjacent areas that share a class before drawing (default False).

• simplify (None, str or float, optional) – Geometry simplification: None (default, no simplification), "auto" (half a pixel at the render scale) or a tolerance in the data CRS units.

• on_zoom (bool, optional) – Draw on the zoom viewport (default True).

• on_cartouches (bool, optional) – Draw on cartouche viewports (default True).

• z_index (int, optional) – Render order (default 0).

• visible (bool, optional) – Whether the layer is drawn (default True).

Examples

>>> m.add(ChoroplethLayer(gdf, column="density", method="FisherJenks"))

__init__(gdf=None, *, column=<unset>, cmap=<unset>, reverse=<unset>, method=<unset>, num_classes=<unset>, stroke=<unset>, stroke_width=<unset>, legend=<unset>, dissolve=<unset>, simplify=<unset>, on_zoom=<unset>, on_cartouches=<unset>, z_index=0, visible=True)

kind: str = 'choropleth'

Identifier prefix for this layer family.

render(ctx)

Draw the layer into the map carried by ctx.

Called when the map is built. Implementations must set self._rendered = True once drawn.

Return type:

None

requires_gdf: bool = True

Whether a non-empty gdf is required at construction.

validate()

Check internal consistency. Override in subclasses.

Raises in plain language (see errors.py convention) for structural problems such as a missing required parameter. Semiological advice is emitted as a warning, never an error.

Return type:

None

class mappyng.ProportionalLayer(gdf=None, *, column=<unset>, fill=<unset>, fill_opacity=<unset>, stroke=<unset>, stroke_width=<unset>, max_radius=<unset>, reference_value=<unset>, reference_radius=<unset>, legend=<unset>, on_zoom=<unset>, on_cartouches=<unset>, z_index=0, visible=True)

Bases: Layer

Proportional symbols layer.

Maps an absolute quantity (stock) to symbol size, preserving magnitude where colour value would flatten it.

Parameters:

• gdf (GeoDataFrame) – Geometries with a numeric column.

• column (str) – Column driving symbol size (required).

• fill (str, optional) – Symbol fill colour as #RRGGBB (default from defaults).

• fill_opacity (float, optional) – Symbol fill opacity in [0, 1] (default from defaults).

• stroke (str, optional) – Symbol outline colour (default from defaults).

• stroke_width (float, optional) – Symbol outline width (default from defaults).

• max_radius (float, optional) – Radius in pixels of the largest symbol (default from defaults).

• reference_value (float, optional) – Value mapped to reference_radius for the legend. Defaults to the data maximum.

• reference_radius (float, optional) – Radius in pixels for reference_value. Defaults to max_radius.

• legend (dict, optional) – Legend configuration (see ProportionalLegendConfig).

• on_zoom (bool, optional) – Draw on the zoom viewport (default True).

• on_cartouches (bool, optional) – Draw on cartouche viewports (default True).

• z_index (int, optional) – Render order (default 0).

• visible (bool, optional) – Whether the layer is drawn (default True).

Examples

>>> m.add(ProportionalLayer(gdf, column="population", max_radius=30))

__init__(gdf=None, *, column=<unset>, fill=<unset>, fill_opacity=<unset>, stroke=<unset>, stroke_width=<unset>, max_radius=<unset>, reference_value=<unset>, reference_radius=<unset>, legend=<unset>, on_zoom=<unset>, on_cartouches=<unset>, z_index=0, visible=True)

kind: str = 'proportional'

Identifier prefix for this layer family.

render(ctx)

Draw the layer into the map carried by ctx.

Called when the map is built. Implementations must set self._rendered = True once drawn.

Return type:

None

requires_gdf: bool = True

Whether a non-empty gdf is required at construction.

validate()

Check internal consistency. Override in subclasses.

Raises in plain language (see errors.py convention) for structural problems such as a missing required parameter. Semiological advice is emitted as a warning, never an error.

Return type:

None

class mappyng.SituationLayer(gdf=None, *, column=<unset>, symbol=<unset>, marker=<unset>, fill=<unset>, size=<unset>, stroke=<unset>, stroke_width=<unset>, fill_opacity=<unset>, inner_fill=<unset>, inner_stroke=<unset>, label=<unset>, legend=<unset>, on_zoom=<unset>, on_cartouches=<unset>, z_index=0, visible=True)

Bases: Layer

Situation (qualitative point/area) layer.

Parameters:

• gdf (GeoDataFrame) – Geometries to draw.

• column (str, optional) – Category column. When set together with symbol, each category gets its own marker.

• symbol (dict, optional) – Mapping of category value to a per-category marker style.

• marker (str, optional) – Marker shape used in uniform mode (default "circle").

• fill (str, optional) – Marker fill colour as #RRGGBB (default "#e31a1c").

• size (float, optional) – Marker size in pixels (default 8).

• stroke (str, optional) – Marker outline colour (default "#ffffff").

• stroke_width (float, optional) – Marker outline width (default 0.5).

• fill_opacity (float, optional) – Marker fill opacity in [0, 1] (default 1).

• inner_fill (str, optional) – Fill colour of an inner marker, for layered symbols.

• inner_stroke (str, optional) – Outline colour of the inner marker.

• label (str, optional) – Column holding a short text drawn next to each marker.

• legend (dict, optional) – Legend configuration (see SituationLegendConfig).

• on_zoom (bool, optional) – Draw on the zoom viewport (default True).

• on_cartouches (bool, optional) – Draw on cartouche viewports (default True).

• z_index (int, optional) – Render order (default 0).

• visible (bool, optional) – Whether the layer is drawn (default True).

Examples

>>> m.add(SituationLayer(gdf, marker="square", fill="#1f78b4"))

__init__(gdf=None, *, column=<unset>, symbol=<unset>, marker=<unset>, fill=<unset>, size=<unset>, stroke=<unset>, stroke_width=<unset>, fill_opacity=<unset>, inner_fill=<unset>, inner_stroke=<unset>, label=<unset>, legend=<unset>, on_zoom=<unset>, on_cartouches=<unset>, z_index=0, visible=True)

kind: str = 'situation'

Identifier prefix for this layer family.

render(ctx)

Draw the layer into the map carried by ctx.

Called when the map is built. Implementations must set self._rendered = True once drawn.

Return type:

None

requires_gdf: bool = True

Whether a non-empty gdf is required at construction.

validate()

Check internal consistency. Override in subclasses.

Raises in plain language (see errors.py convention) for structural problems such as a missing required parameter. Semiological advice is emitted as a warning, never an error.

Return type:

None

class mappyng.LabelLayer(gdf=None, *, column=<unset>, target=<unset>, font_size=<unset>, font_family=<unset>, font_weight=<unset>, color=<unset>, halo_color=<unset>, halo_width=<unset>, priority_col=<unset>, min_priority=<unset>, max_labels=<unset>, initial_position=<unset>, candidate_positions=<unset>, label_offset=<unset>, max_displacement=<unset>, avoid_overlap=<unset>, allow_hide=<unset>, leader_lines=<unset>, leader_threshold=<unset>, leader_color=<unset>, leader_width=<unset>, wrap=<unset>, wrap_max_chars=<unset>, numbered_above=<unset>, numbered_legend_position=<unset>, numbered_circle_r=<unset>, numbered_circle_fill=<unset>, numbered_circle_stroke=<unset>, numbered_legend_bg=<unset>, numbered_legend_bg_opacity=<unset>, numbered_legend_border=<unset>, numbered_legend_title=<unset>, n_sweeps=<unset>, initial_temperature=<unset>, final_temperature=<unset>, seed=<unset>, w_LL=<unset>, w_LO=<unset>, w_LC=<unset>, w_LA=<unset>, w_D=<unset>, w_OR=<unset>, w_OOB=<unset>, z_index=0, visible=True)

Bases: Layer

Text label layer placed by simulated annealing.

Parameters:

• gdf (GeoDataFrame) – Geometries to label.

• column (str) – Column holding the label text (required).

• target (str, optional) – Viewport to place labels on: "main" (default), "zoom" or "cartouche:<index>".

• font_size (float, optional) – Label font size in pixels (default 10).

• font_family (str, optional) – Font family (default "sans-serif").

• font_weight (str, optional) – Font weight (default "normal").

• color (str, optional) – Text colour as #RRGGBB (default "#000000").

• halo_color (str or None, optional) – Halo (outline) colour; None disables the halo.

• halo_width (float, optional) – Halo width in pixels (default 2).

• priority_col (str, optional) – Column ranking which labels are placed first (higher first).

• min_priority (float, optional) – Skip rows whose priority is below this threshold.

• max_labels (int, optional) – Hard cap on the number of labels placed.

• initial_position (str, optional) – Starting candidate position (default "NE").

• candidate_positions (list of str, optional) – Candidate positions tried around each anchor.

• label_offset (float, optional) – Distance from anchor to label edge in pixels (default 4).

• max_displacement (float, optional) – Maximum displacement before a label is hidden (default 40).

• avoid_overlap (bool, optional) – Enable label-label overlap avoidance (default True).

• allow_hide (bool, optional) – Allow hiding labels that cannot be placed (default True).

• leader_lines (bool, optional) – Draw leader lines for displaced labels (default True).

• leader_threshold (float, optional) – Displacement (in label heights) that triggers a leader line.

• leader_color (str, optional) – Leader line colour (default "#666666").

• leader_width (float, optional) – Leader line width (default 0.5).

• wrap (bool, optional) – Wrap long labels at dashes (default True).

• wrap_max_chars (int, optional) – Maximum characters per line before wrapping (default 12).

• numbered_above (int, optional) – Switch to numbered-circle mode past this label count.

• numbered_legend_position (dict, optional) – Legend placement {"x": frac, "y": frac} in figure fractions.

• numbered_circle_r (float, optional) – Numbered circle radius in pixels (default 5).

• numbered_circle_fill (str, optional) – Numbered circle fill colour (default "#ffffff").

• numbered_circle_stroke (str, optional) – Numbered circle outline colour (default "#333333").

• numbered_legend_bg (str, optional) – Numbered legend background colour (default "white").

• numbered_legend_bg_opacity (float, optional) – Numbered legend background opacity (default 0.88).

• numbered_legend_border (str, optional) – Numbered legend border colour (default "#cccccc").

• numbered_legend_title (str, optional) – Numbered legend title text.

• n_sweeps (int, optional) – Number of annealing sweeps (default 50).

• initial_temperature (float, optional) – Annealing start temperature (default 1.0).

• final_temperature (float, optional) – Annealing end temperature (default 0.01).

• seed (int, optional) – Random seed for reproducible placement. Defaults to the map seed.

• w_LL, w_LO, w_LC, w_LA, w_D, w_OR, w_OOB (float, optional) – Energy weights tuning the placement: label-label, label-obstacle, label-chrome, label-anchor, distance, orientation bias and out-of-bounds penalties.

• z_index (int, optional) – Render order (default 0).

• visible (bool, optional) – Whether the layer is drawn (default True).

Examples

>>> m.add(LabelLayer(gdf, column="name", priority_col="population",
...                  max_labels=20, font_size=9))

__init__(gdf=None, *, column=<unset>, target=<unset>, font_size=<unset>, font_family=<unset>, font_weight=<unset>, color=<unset>, halo_color=<unset>, halo_width=<unset>, priority_col=<unset>, min_priority=<unset>, max_labels=<unset>, initial_position=<unset>, candidate_positions=<unset>, label_offset=<unset>, max_displacement=<unset>, avoid_overlap=<unset>, allow_hide=<unset>, leader_lines=<unset>, leader_threshold=<unset>, leader_color=<unset>, leader_width=<unset>, wrap=<unset>, wrap_max_chars=<unset>, numbered_above=<unset>, numbered_legend_position=<unset>, numbered_circle_r=<unset>, numbered_circle_fill=<unset>, numbered_circle_stroke=<unset>, numbered_legend_bg=<unset>, numbered_legend_bg_opacity=<unset>, numbered_legend_border=<unset>, numbered_legend_title=<unset>, n_sweeps=<unset>, initial_temperature=<unset>, final_temperature=<unset>, seed=<unset>, w_LL=<unset>, w_LO=<unset>, w_LC=<unset>, w_LA=<unset>, w_D=<unset>, w_OR=<unset>, w_OOB=<unset>, z_index=0, visible=True)

kind: str = 'labels'

Identifier prefix for this layer family.

render(ctx)

Draw the layer into the map carried by ctx.

Called when the map is built. Implementations must set self._rendered = True once drawn.

Return type:

None

requires_gdf: bool = True

Whether a non-empty gdf is required at construction.

validate()

Check internal consistency. Override in subclasses.

Raises in plain language (see errors.py convention) for structural problems such as a missing required parameter. Semiological advice is emitted as a warning, never an error.

Return type:

None

class mappyng.VectorLayer(gdf=None, *, position=<unset>, z=<unset>, fill=<unset>, stroke=<unset>, stroke_width=<unset>, fill_opacity=<unset>, stroke_opacity=<unset>, stroke_linecap=<unset>, stroke_dasharray=<unset>, on_zoom=<unset>, on_cartouches=<unset>, z_index=0, visible=True)

Bases: Layer

Raw vector layer drawn with explicit styling.

Parameters:

• gdf (GeoDataFrame) – Geometries to draw.

• position (str, optional) – "background" (default) or "top" relative to the data.

• z (int, optional) – Explicit stacking order, overriding position.

• fill (str, optional) – Fill colour as #RRGGBB (default "none").

• stroke (str, optional) – Stroke colour (default from style).

• stroke_width (float, optional) – Stroke width (default from style).

• fill_opacity (float, optional) – Fill opacity in [0, 1].

• stroke_opacity (float, optional) – Stroke opacity in [0, 1]. A wide faint stroke under a thin bright one fakes a glowing line.

• stroke_linecap (str, optional) – "butt", "round" or "square".

• stroke_dasharray (str, optional) – SVG dash pattern, e.g. "4 2".

• on_zoom (bool, optional) – Draw on the zoom viewport (default False).

• on_cartouches (bool, optional) – Draw on cartouche viewports (default False).

• z_index (int, optional) – Render order among layers (default 0).

• visible (bool, optional) – Whether the layer is drawn (default True).

Examples

>>> m.add(VectorLayer(gdf, stroke="#333", stroke_width=0.4,
...                  position="top"))

__init__(gdf=None, *, position=<unset>, z=<unset>, fill=<unset>, stroke=<unset>, stroke_width=<unset>, fill_opacity=<unset>, stroke_opacity=<unset>, stroke_linecap=<unset>, stroke_dasharray=<unset>, on_zoom=<unset>, on_cartouches=<unset>, z_index=0, visible=True)

kind: str = 'vector'

Identifier prefix for this layer family.

render(ctx)

Draw the layer into the map carried by ctx.

Called when the map is built. Implementations must set self._rendered = True once drawn.

Return type:

None

requires_gdf: bool = True

Whether a non-empty gdf is required at construction.

Reference layers

class mappyng.BasemapLayer(gdf=None, *, fill=<unset>, stroke=<unset>, stroke_width=<unset>, z_index=0, visible=True)

Bases: Layer

Plain background drawn from the map’s main GeoDataFrame.

Parameters:

• fill (str, optional) – Fill colour as #RRGGBB (default from style or the map’s basemap colour override).

• stroke (str, optional) – Outline colour (default from style).

• stroke_width (float, optional) – Outline width (default from style).

• z_index (int, optional) – Render order (default 0).

• visible (bool, optional) – Whether the layer is drawn (default True).

Examples

>>> m.add(BasemapLayer(fill="#f2efe9", stroke="#999999"))

__init__(gdf=None, *, fill=<unset>, stroke=<unset>, stroke_width=<unset>, z_index=0, visible=True)

kind: str = 'basemap'

Identifier prefix for this layer family.

render(ctx)

Draw the layer into the map carried by ctx.

Called when the map is built. Implementations must set self._rendered = True once drawn.

Return type:

None

requires_gdf: bool = False

Whether a non-empty gdf is required at construction.

class mappyng.GraticuleLayer(gdf=None, *, step=<unset>, stroke=<unset>, opacity=<unset>, stroke_width=<unset>, dash=<unset>, position=<unset>, z=<unset>, z_index=0, visible=True)

Bases: Layer

Latitude/longitude grid.

Parameters:

• step (float, optional) – Spacing between lines in degrees (default 10).

• stroke (str, optional) – Line colour as #RRGGBB (default "#aaaaaa").

• opacity (float, optional) – Stroke opacity in [0, 1] (default 0.5).

• stroke_width (float, optional) – Line width (default 0.5).

• dash (str, optional) – SVG dash pattern (default "4 2").

• position (str, optional) – "background" (default) draws the grid above the ocean but below the data; "top" draws it over everything, which suits globe-style maps.

• z (int, optional) – Explicit stacking order, overriding position.

• z_index (int, optional) – Render order among layers (default 0).

• visible (bool, optional) – Whether the layer is drawn (default True).

Examples

>>> m.add(GraticuleLayer(step=5.0, stroke="#888888", opacity=0.4))

__init__(gdf=None, *, step=<unset>, stroke=<unset>, opacity=<unset>, stroke_width=<unset>, dash=<unset>, position=<unset>, z=<unset>, z_index=0, visible=True)

kind: str = 'graticule'

Identifier prefix for this layer family.

render(ctx)

Draw the layer into the map carried by ctx.

Called when the map is built. Implementations must set self._rendered = True once drawn.

Return type:

None

requires_gdf: bool = False

Whether a non-empty gdf is required at construction.

class mappyng.TileLayer(gdf=None, *, source=<unset>, zoom=<unset>, zoom_offset=<unset>, opacity=<unset>, z_order=<unset>, timeout=<unset>, cache=<unset>, cache_dir=<unset>, on_cartouches=<unset>, on_zoom=<unset>, max_tiles=<unset>, warp_scale=<unset>, extra_zoom_levels=<unset>, z_index=0, visible=True)

Bases: Layer

XYZ raster tile backdrop.

Parameters:

• source (str, optional) – Provider alias (e.g. "cartodb_positron", "osm", "satellite") or a URL template with {x}, {y}, {z} placeholders.

• zoom (int or str, optional) – Zoom level, or "auto" (default) to derive it from the bbox.

• zoom_offset (int, optional) – Added to the auto-calculated zoom (e.g. -1 for lighter tiles).

• opacity (float, optional) – Tile opacity in [0, 1] (default 1).

• z_order (int, optional) – SVG stacking order (default below the basemap).

• timeout (float, optional) – HTTP request timeout in seconds (default 10).

• cache (bool, optional) – Cache tiles on disk (default True).

• cache_dir (str, optional) – Cache directory (default ~/.cache/mappyng/tiles).

• on_cartouches (bool, optional) – Draw on cartouche viewports (default True).

• on_zoom (bool, optional) – Draw on the zoom viewport (default True).

• max_tiles (int, optional) – Safety cap on tiles downloaded per viewport (default 64).

• warp_scale (float, optional) – Output resolution relative to the content area (default 1.5).

• extra_zoom_levels (int, optional) – Number of coarser zoom levels to also fetch and blend (default 0).

• z_index (int, optional) – Render order among layers (default 0).

• visible (bool, optional) – Whether the layer is drawn (default True).

Examples

>>> m.add(TileLayer())
>>> m.add(TileLayer(source="satellite", opacity=0.7))

__init__(gdf=None, *, source=<unset>, zoom=<unset>, zoom_offset=<unset>, opacity=<unset>, z_order=<unset>, timeout=<unset>, cache=<unset>, cache_dir=<unset>, on_cartouches=<unset>, on_zoom=<unset>, max_tiles=<unset>, warp_scale=<unset>, extra_zoom_levels=<unset>, z_index=0, visible=True)

kind: str = 'tile'

Identifier prefix for this layer family.

render(ctx)

Draw the layer into the map carried by ctx.

Called when the map is built. Implementations must set self._rendered = True once drawn.

Return type:

None

requires_gdf: bool = False

Whether a non-empty gdf is required at construction.

class mappyng.RasterLayer(gdf=None, *, paths=<unset>, opacity=<unset>, on_zoom=<unset>, on_cartouches=<unset>, z_index=0, visible=True)

Bases: Layer

Raster image overlay.

Parameters:

• paths (dict) – Mapping of region name to GeoTIFF path (required). Each viewport picks the raster whose footprint overlaps its bbox.

• opacity (float, optional) – Raster opacity in [0, 1] (default 1).

• on_zoom (bool, optional) – Draw on the zoom viewport (default True).

• on_cartouches (bool, optional) – Draw on cartouche viewports (default True).

• z_index (int, optional) – Render order among layers (default 0).

• visible (bool, optional) – Whether the layer is drawn (default True).

Examples

>>> m.add(RasterLayer(paths={"metropole": "data/dem.tif"}, opacity=0.8))

__init__(gdf=None, *, paths=<unset>, opacity=<unset>, on_zoom=<unset>, on_cartouches=<unset>, z_index=0, visible=True)

kind: str = 'raster'

Identifier prefix for this layer family.

render(ctx)

Draw the layer into the map carried by ctx.

Called when the map is built. Implementations must set self._rendered = True once drawn.

Return type:

None

requires_gdf: bool = False

Whether a non-empty gdf is required at construction.

validate()

Check internal consistency. Override in subclasses.

Raises in plain language (see errors.py convention) for structural problems such as a missing required parameter. Semiological advice is emitted as a warning, never an error.

Return type:

None