ggsql 0.4.1

A declarative visualization language that extends SQL with powerful data visualization capabilities.
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//! Path geom implementation

use super::types::POSITION_VALUES;
use super::{
    densify_edges, needs_projection, project_position_columns, DefaultAesthetics,
    DefaultParamValue, GeomTrait, GeomType, ParamConstraint, ParamDefinition,
};
use crate::plot::projection::Projection;
use crate::plot::types::DefaultAestheticValue;
use crate::reader::SqlDialect;
use crate::{Mappings, Result};

/// Path geom - connected line segments in order
#[derive(Debug, Clone, Copy)]
pub struct Path;

impl GeomTrait for Path {
    fn geom_type(&self) -> GeomType {
        GeomType::Path
    }

    fn aesthetics(&self) -> DefaultAesthetics {
        DefaultAesthetics {
            defaults: &[
                ("pos1", DefaultAestheticValue::Required),
                ("pos2", DefaultAestheticValue::Required),
                ("stroke", DefaultAestheticValue::String("black")),
                ("linewidth", DefaultAestheticValue::Number(1.5)),
                ("opacity", DefaultAestheticValue::Number(1.0)),
                ("linetype", DefaultAestheticValue::String("solid")),
            ],
        }
    }

    fn default_params(&self) -> &'static [ParamDefinition] {
        const PARAMS: &[ParamDefinition] = &[ParamDefinition {
            name: "position",
            default: DefaultParamValue::String("identity"),
            constraint: ParamConstraint::string_option(POSITION_VALUES),
        }];
        PARAMS
    }

    fn apply_projection(
        &self,
        query: &str,
        projection: &Projection,
        dialect: &dyn SqlDialect,
        mappings: &mut Mappings,
        partition_by: &mut Vec<String>,
        _parameters: &mut std::collections::HashMap<String, crate::plot::types::ParameterValue>,
    ) -> Result<String> {
        if !needs_projection(projection) {
            return Ok(query.to_string());
        }
        let columns = crate::util::set_union(mappings.column_names(), partition_by);
        let densified = densify_edges(
            query,
            dialect,
            &columns,
            partition_by,
            None,
            false,
            1.0,
            360,
        );
        project_position_columns(&densified, projection, dialect, &columns)
    }
}

impl std::fmt::Display for Path {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(f, "path")
    }
}