text: add metrics and dynamic height

src/pango.rs

@@ -85,6 +85,7 @@ extern "C" {
         ink_rect: *mut PangoRectangle,
         logical_rect: *mut PangoRectangle,
     );
+    fn pango_layout_get_baseline(layout: *mut PangoLayout_) -> c::c_int;
 
     fn pango_extents_to_pixels(inclusive: *mut PangoRectangle, nearest: *mut PangoRectangle);
 }
@@ -104,6 +105,7 @@ pub enum PangoError {
 }
 
 #[repr(C)]
+#[derive(Default)]
 struct PangoRectangle {
     x: c::c_int,
     y: c::c_int,
@@ -111,6 +113,8 @@ struct PangoRectangle {
     height: c::c_int,
 }
 
+const PANGO_SCALE: i32 = 1024;
+
 pub struct CairoImageSurface {
     s: *mut cairo_surface_t,
 }
@@ -325,18 +329,29 @@ impl PangoLayout {
 
     pub fn inc_pixel_rect(&self) -> Rect {
         unsafe {
-            let mut rect = PangoRectangle {
-                x: 0,
-                y: 0,
-                width: 0,
-                height: 0,
-            };
+            let mut rect = PangoRectangle::default();
             pango_layout_get_extents(self.l, &mut rect, ptr::null_mut());
             pango_extents_to_pixels(&mut rect, ptr::null_mut());
             Rect::new_sized(rect.x, rect.y, rect.width, rect.height).unwrap()
         }
     }
 
+    pub fn logical_pixel_rect(&self) -> Rect {
+        unsafe {
+            let mut rect = PangoRectangle::default();
+            pango_layout_get_extents(self.l, ptr::null_mut(), &mut rect);
+            pango_extents_to_pixels(&mut rect, ptr::null_mut());
+            Rect::new_sized(rect.x, rect.y, rect.width, rect.height).unwrap()
+        }
+    }
+
+    pub fn pixel_baseline(&self) -> i32 {
+        unsafe {
+            let res = pango_layout_get_baseline(self.l);
+            (res as i32 + PANGO_SCALE - 1) / PANGO_SCALE
+        }
+    }
+
     pub fn show_layout(&self) {
         unsafe {
             pango_cairo_show_layout(self.c.c.c, self.l);

src/text.rs

@@ -76,14 +76,21 @@ pub fn measure(
     text: &str,
     markup: bool,
     scale: Option<f64>,
-) -> Result<Rect, TextError> {
+    full: bool,
+) -> Result<TextMeasurement, TextError> {
     let data = create_data(font, 1, 1, scale)?;
     if markup {
         data.layout.set_markup(text);
     } else {
         data.layout.set_text(text);
     }
-    Ok(data.layout.inc_pixel_rect())
+    let mut res = TextMeasurement::default();
+    res.ink_rect = data.layout.inc_pixel_rect();
+    if full {
+        res.logical_rect = data.layout.logical_pixel_rect();
+        res.baseline = data.layout.pixel_baseline();
+    }
+    Ok(res)
 }
 
 pub fn render(
@@ -96,13 +103,14 @@ pub fn render(
     scale: Option<f64>,
 ) -> Result<Rc<Texture>, TextError> {
     render2(
-        ctx, 1, width, height, 1, font, text, color, true, false, scale,
+        ctx, 1, None, width, height, 1, font, text, color, true, false, scale,
     )
 }
 
 fn render2(
     ctx: &Rc<RenderContext>,
     x: i32,
+    y: Option<i32>,
     width: i32,
     height: i32,
     padding: i32,
@@ -128,8 +136,8 @@ fn render2(
     data.cctx.set_operator(CAIRO_OPERATOR_SOURCE);
     data.cctx
         .set_source_rgba(color.r as _, color.g as _, color.b as _, color.a as _);
-    data.cctx
-        .move_to(x as f64, ((height - font_height) / 2) as f64);
+    let y = y.unwrap_or((height - font_height) / 2);
+    data.cctx.move_to(x as f64, y as f64);
     data.layout.show_layout();
     data.image.flush();
     let bytes = match data.image.data() {
@@ -144,19 +152,44 @@ fn render2(
 
 pub fn render_fitting(
     ctx: &Rc<RenderContext>,
-    height: i32,
+    height: Option<i32>,
     font: &str,
     text: &str,
     color: Color,
     markup: bool,
     scale: Option<f64>,
 ) -> Result<Rc<Texture>, TextError> {
-    let rect = measure(font, text, markup, scale)?;
-    render2(
+    render_fitting2(ctx, height, font, text, color, markup, scale, false).map(|(a, _)| a)
+}
+
+#[derive(Debug, Copy, Clone, Default)]
+pub struct TextMeasurement {
+    pub ink_rect: Rect,
+    pub logical_rect: Rect,
+    pub baseline: i32,
+}
+
+pub fn render_fitting2(
+    ctx: &Rc<RenderContext>,
+    height: Option<i32>,
+    font: &str,
+    text: &str,
+    color: Color,
+    markup: bool,
+    scale: Option<f64>,
+    include_measurements: bool,
+) -> Result<(Rc<Texture>, TextMeasurement), TextError> {
+    let measurement = measure(font, text, markup, scale, include_measurements)?;
+    let y = match height {
+        Some(_) => None,
+        _ => Some(measurement.ink_rect.y1().neg()),
+    };
+    let res = render2(
         ctx,
-        rect.x1().neg(),
-        rect.width(),
-        height,
+        measurement.ink_rect.x1().neg(),
+        y,
+        measurement.ink_rect.width(),
+        height.unwrap_or(measurement.ink_rect.height()),
         0,
         font,
         text,
@@ -164,5 +197,6 @@ pub fn render_fitting(
         false,
         markup,
         scale,
-    )
+    );
+    res.map(|r| (r, measurement))
 }

src/tree/output.rs

@@ -168,7 +168,7 @@ impl OutputNode {
                     };
                     let title = match text::render_fitting(
                         &ctx,
-                        texture_height,
+                        Some(texture_height),
                         &font,
                         &ws.name,
                         tc,
@@ -219,14 +219,21 @@ impl OutputNode {
                 break 'set_status;
             }
             let tc = self.state.theme.colors.bar_text.get();
-            let title =
-                match text::render_fitting(&ctx, texture_height, &font, &status, tc, true, scale) {
-                    Ok(t) => t,
-                    Err(e) => {
-                        log::error!("Could not render status {}: {}", status, ErrorFmt(e));
-                        break 'set_status;
-                    }
-                };
+            let title = match text::render_fitting(
+                &ctx,
+                Some(texture_height),
+                &font,
+                &status,
+                tc,
+                true,
+                scale,
+            ) {
+                Ok(t) => t,
+                Err(e) => {
+                    log::error!("Could not render status {}: {}", status, ErrorFmt(e));
+                    break 'set_status;
+                }
+            };
             let mut width = title.width();
             if let Some(scale) = scale {
                 width = (width as f64 / scale).round() as _;

src/tree/placeholder.rs

@@ -61,7 +61,7 @@ impl PlaceholderNode {
                     let font = format!("monospace {}", width / 10);
                     match text::render_fitting(
                         &ctx,
-                        height,
+                        Some(height),
                         &font,
                         "Fullscreen",
                         self.toplevel.state.theme.colors.unfocused_title_text.get(),