1 files changed, 149 insertions, 0 deletions
diff --git a/src/text.rs b/src/text.rs
new file mode 100644
index 0000000..eefbd48
--- /dev/null
+++ b/src/text.rs
@@ -0,0 +1,149 @@
+use crate::color::Color;
+use pango::{EllipsizeMode, FontDescription};
+use pangocairo::{cairo, pango};
+use serde::Deserialize;
+
+#[derive(Clone, Debug, PartialEq)]
+pub struct RenderOptions {
+    pub x_offset: f64,
+    pub bar_height: f64,
+    pub fg_color: Color,
+    pub bg_color: Option<Color>,
+}
+
+#[derive(Clone, Debug, PartialEq)]
+pub struct Attributes {
+    pub font: FontDescription,
+    pub padding_left: f64,
+    pub padding_right: f64,
+    pub min_width: Option<f64>,
+    pub align: Align,
+    pub markup: bool,
+}
+
+#[derive(Deserialize, Debug, Clone, Copy, PartialEq, Eq)]
+#[serde(rename_all = "lowercase")]
+pub enum Align {
+    Right,
+    Left,
+    Center,
+}
+
+impl Default for Align {
+    fn default() -> Self {
+        Self::Left
+    }
+}
+
+fn create_pango_layout(cairo_context: &cairo::Context) -> pango::Layout {
+    pangocairo::create_layout(cairo_context).unwrap()
+}
+
+fn show_pango_layout(cairo_context: &cairo::Context, layout: &pango::Layout) {
+    pangocairo::show_layout(cairo_context, layout);
+}
+
+#[derive(Clone, Debug, PartialEq)]
+pub struct Text {
+    pub attr: Attributes,
+    pub text: String,
+}
+
+impl Text {
+    pub fn compute(mut self, context: &cairo::Context) -> ComputedText {
+        let (mut width, height) = {
+            let layout = create_pango_layout(context);
+            layout.set_font_description(Some(&self.attr.font));
+            if self.attr.markup {
+                layout.set_markup(&self.text);
+            } else {
+                layout.set_text(&self.text);
+            }
+
+            let (text_width, text_height) = layout.pixel_size();
+            let width = f64::from(text_width) + self.attr.padding_right + self.attr.padding_right;
+            let height = f64::from(text_height);
+            (width, height)
+        };
+
+        if let Some(min_width) = self.attr.min_width {
+            if width < min_width {
+                let d = min_width - width;
+                width = min_width;
+                match self.attr.align {
+                    Align::Right => self.attr.padding_left += d,
+                    Align::Left => self.attr.padding_right += d,
+                    Align::Center => {
+                        self.attr.padding_left += d * 0.5;
+                        self.attr.padding_right += d * 0.5;
+                    }
+                }
+            }
+        }
+
+        ComputedText {
+            text: self,
+            width,
+            height,
+        }
+    }
+}
+
+#[derive(Clone, Debug, PartialEq)]
+pub struct ComputedText {
+    pub text: Text,
+    pub width: f64,
+    pub height: f64,
+}
+
+impl ComputedText {
+    pub fn render(&self, context: &cairo::Context, options: RenderOptions) {
+        let text = &self.text;
+        let layout = create_pango_layout(context);
+        layout.set_font_description(Some(&text.attr.font));
+        if text.attr.markup {
+            layout.set_markup(&text.text);
+        } else {
+            layout.set_text(&text.text);
+        }
+
+        context.save().unwrap();
+        context.translate(options.x_offset, 0.0);
+
+        // Set the width/height on the Pango layout so that it word-wraps/ellipises.
+        let text_width = self.width - text.attr.padding_left - text.attr.padding_right;
+        let text_height = self.height;
+        layout.set_ellipsize(EllipsizeMode::End);
+        layout.set_width(text_width as i32 * pango::SCALE);
+        layout.set_height(text_height as i32 * pango::SCALE);
+
+        if let Some(bg) = options.bg_color {
+            bg.apply(&context);
+            context.rectangle(0.0, 0.0, self.width, options.bar_height);
+            context.fill().unwrap();
+        }
+
+        options.fg_color.apply(&context);
+        context.translate(
+            text.attr.padding_left,
+            (options.bar_height - self.height) * 0.5,
+        );
+        show_pango_layout(context, &layout);
+        context.restore().unwrap();
+    }
+}
+
+pub fn width_of(text: &str, context: &cairo::Context, markup: bool, font: &FontDescription) -> f64 {
+    let text = Text {
+        text: text.into(),
+        attr: Attributes {
+            font: font.clone(),
+            padding_left: 0.0,
+            padding_right: 0.0,
+            min_width: None,
+            align: Default::default(),
+            markup,
+        },
+    };
+    text.compute(context).width
+}