qrcode_render/
plugin.rs

1//! Built-in renderer plugins backed by `qrcode-render`.
2
3use alloc::{boxed::Box, string::String};
4use qrcode_core::{
5    Color, DynRenderer, ModuleSource, ModuleStorage, PluginError, PluginRegistry, PostProcessor, QrPlugin,
6    RenderConfig, RenderOutput, RendererFactory,
7};
8
9/// Built-in plugin that registers the plain-text renderer.
10#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
11pub struct PlainTextRendererPlugin;
12
13impl PlainTextRendererPlugin {
14    /// Renderer name registered by this plugin.
15    pub const RENDERER_NAME: &'static str = "plain-text";
16}
17
18impl QrPlugin for PlainTextRendererPlugin {
19    fn name(&self) -> &str {
20        "qrcode-render/plain-text"
21    }
22
23    fn version(&self) -> &str {
24        env!("CARGO_PKG_VERSION")
25    }
26
27    fn register(&self, registry: &mut PluginRegistry) {
28        registry.register_renderer(Self::RENDERER_NAME, Box::new(PlainTextRendererFactory));
29    }
30}
31
32/// Built-in plugin that registers [`InvertModulesPostProcessor`].
33#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
34pub struct InvertModulesPlugin;
35
36impl QrPlugin for InvertModulesPlugin {
37    fn name(&self) -> &str {
38        "qrcode-render/invert-modules"
39    }
40
41    fn version(&self) -> &str {
42        env!("CARGO_PKG_VERSION")
43    }
44
45    fn register(&self, registry: &mut PluginRegistry) {
46        registry.register_postprocessor(Box::new(InvertModulesPostProcessor));
47    }
48}
49
50/// Postprocessor that flips every module from dark to light, or light to dark.
51#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
52pub struct InvertModulesPostProcessor;
53
54impl PostProcessor for InvertModulesPostProcessor {
55    fn process(&self, modules: &mut dyn ModuleStorage) -> Result<(), PluginError> {
56        for y in 0..modules.height() {
57            for x in 0..modules.width() {
58                modules.set(x, y, !modules.get(x, y));
59            }
60        }
61        Ok(())
62    }
63}
64
65/// Factory for [`PlainTextRenderer`].
66#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
67pub struct PlainTextRendererFactory;
68
69impl RendererFactory for PlainTextRendererFactory {
70    fn build(&self, config: &RenderConfig) -> Box<dyn DynRenderer> {
71        let dark = config_char(config, "dark", '#');
72        let light = config_char(config, "light", ' ');
73        let quiet_zone = config_u32(config, "quiet_zone", 4);
74        Box::new(PlainTextRenderer { dark, light, quiet_zone })
75    }
76}
77
78/// Object-safe plain-text renderer.
79#[derive(Clone, Copy, Debug, PartialEq, Eq)]
80pub struct PlainTextRenderer {
81    dark: char,
82    light: char,
83    quiet_zone: u32,
84}
85
86impl DynRenderer for PlainTextRenderer {
87    fn render(&self, code: &dyn ModuleSource) -> Result<RenderOutput, PluginError> {
88        qrcode_core::Renderer::render(self, code).map(RenderOutput::Text)
89    }
90}
91
92impl<Code> qrcode_core::Renderer<Code> for PlainTextRenderer
93where
94    Code: ModuleSource + ?Sized,
95{
96    type Output = String;
97    type Error = PluginError;
98
99    fn render(&self, code: &Code) -> Result<Self::Output, Self::Error> {
100        validate_module_source(code)?;
101        Ok(render_plain_text(code, self.dark, self.light, self.quiet_zone))
102    }
103}
104
105fn validate_module_source<Code>(code: &Code) -> Result<(), PluginError>
106where
107    Code: ModuleSource + ?Sized,
108{
109    let width = code.width();
110    let height = code.height();
111    match width.checked_mul(height) {
112        Some(len) if width != 0 && width == height && len == code.modules().len() => Ok(()),
113        _ => Err(PluginError::InvalidModuleGrid),
114    }
115}
116
117fn render_plain_text<Code>(code: &Code, dark: char, light: char, quiet_zone: u32) -> String
118where
119    Code: ModuleSource + ?Sized,
120{
121    let width = code.width();
122    let quiet_zone = quiet_zone as usize;
123    let total_width = width + 2 * quiet_zone;
124    let mut output = String::with_capacity(total_width * total_width + total_width.saturating_sub(1));
125
126    for y in 0..total_width {
127        if y > 0 {
128            output.push('\n');
129        }
130
131        let row = (quiet_zone..quiet_zone + width).contains(&y).then(|| code.row(y - quiet_zone));
132        for x in 0..total_width {
133            let color = row
134                .filter(|_| (quiet_zone..quiet_zone + width).contains(&x))
135                .map_or(Color::Light, |row| row[x - quiet_zone]);
136            output.push(color.select(dark, light));
137        }
138    }
139
140    output
141}
142
143fn config_char(config: &RenderConfig, key: &str, default: char) -> char {
144    config.option(key).and_then(|value| value.chars().next()).unwrap_or(default)
145}
146
147fn config_u32(config: &RenderConfig, key: &str, default: u32) -> u32 {
148    config.option(key).and_then(|value| value.parse().ok()).unwrap_or(default)
149}
150
151#[cfg(test)]
152mod tests {
153    use super::{InvertModulesPlugin, InvertModulesPostProcessor, PlainTextRendererFactory, PlainTextRendererPlugin};
154    use qrcode_core::{
155        Color, ModuleGrid, ModuleSource, PluginError, PluginRegistry, PostProcessor, QrPlugin, RenderConfig,
156        RenderOutput, Renderer as CoreRenderer, RendererFactory,
157    };
158
159    struct BadSource {
160        modules: [Color; 4],
161    }
162
163    impl ModuleSource for BadSource {
164        fn get(&self, x: usize, y: usize) -> Color {
165            self.modules[y * self.width() + x]
166        }
167
168        fn width(&self) -> usize {
169            3
170        }
171
172        fn height(&self) -> usize {
173            2
174        }
175
176        fn modules(&self) -> &[Color] {
177            &self.modules
178        }
179    }
180
181    #[test]
182    fn plugin_registers_plain_text_renderer() {
183        let mut registry = PluginRegistry::new();
184        PlainTextRendererPlugin.register(&mut registry);
185
186        assert!(registry.renderer(PlainTextRendererPlugin::RENDERER_NAME).is_some());
187    }
188
189    #[test]
190    fn invert_modules_plugin_registers_postprocessor() {
191        let mut registry = PluginRegistry::new();
192        InvertModulesPlugin.register(&mut registry);
193
194        assert_eq!(registry.postprocessors().len(), 1);
195    }
196
197    #[test]
198    fn invert_modules_postprocessor_flips_all_modules() {
199        let mut modules =
200            ModuleGrid::new(alloc::vec![Color::Dark, Color::Light, Color::Light, Color::Dark], 2, 2).unwrap();
201
202        InvertModulesPostProcessor.process(&mut modules).unwrap();
203
204        assert_eq!(modules.modules(), [Color::Light, Color::Dark, Color::Dark, Color::Light]);
205    }
206
207    #[test]
208    fn plain_text_renderer_uses_configured_colors_and_quiet_zone() {
209        let modules = ModuleGrid::new(alloc::vec![Color::Dark, Color::Light, Color::Light, Color::Dark], 2, 2).unwrap();
210        let renderer = PlainTextRendererFactory.build(
211            &RenderConfig::new().with_option("dark", "X").with_option("light", ".").with_option("quiet_zone", "0"),
212        );
213
214        assert_eq!(renderer.render(&modules).unwrap(), RenderOutput::Text("X.\n.X".into()));
215    }
216
217    #[test]
218    fn plain_text_core_renderer_matches_dyn_renderer() {
219        let modules = ModuleGrid::new(alloc::vec![Color::Dark, Color::Light, Color::Light, Color::Dark], 2, 2).unwrap();
220        let renderer = super::PlainTextRenderer { dark: 'X', light: '.', quiet_zone: 0 };
221
222        let core_output = CoreRenderer::render(&renderer, &modules).unwrap();
223        let dyn_output = qrcode_core::DynRenderer::render(&renderer, &modules).unwrap();
224
225        assert_eq!(core_output, "X.\n.X");
226        assert_eq!(dyn_output, RenderOutput::Text(core_output));
227    }
228
229    #[test]
230    fn plain_text_renderer_reports_invalid_module_source() {
231        let renderer = PlainTextRendererFactory.build(&RenderConfig::new());
232
233        assert_eq!(renderer.render(&BadSource { modules: [Color::Dark; 4] }), Err(PluginError::InvalidModuleGrid));
234    }
235}
qrcode_render/plugin.rs

qrcode_render/
plugin.rs
