Add font family selector for watermark text

pixstrip-cli/src/main.rs

@@ -313,6 +313,7 @@ fn cmd_process(args: CmdProcessArgs) {
             font_size: 24.0,
             opacity: args.watermark_opacity,
             color: [255, 255, 255, 255],
+            font_family: None,
         });
     }
     if args.rename_prefix.is_some() || args.rename_suffix.is_some() || args.rename_template.is_some() {

pixstrip-core/src/operations/mod.rs

@@ -203,6 +203,7 @@ pub enum WatermarkConfig {
         font_size: f32,
         opacity: f32,
         color: [u8; 4],
+        font_family: Option<String>,
     },
     Image {
         path: std::path::PathBuf,

pixstrip-core/src/operations/watermark.rs

@@ -46,7 +46,8 @@ pub fn apply_watermark(
             font_size,
             opacity,
             color,
-        } => apply_text_watermark(img, text, *position, *font_size, *opacity, *color),
+            font_family,
+        } => apply_text_watermark(img, text, *position, *font_size, *opacity, *color, font_family.as_deref()),
         WatermarkConfig::Image {
             path,
             position,
@@ -56,7 +57,38 @@ pub fn apply_watermark(
     }
 }
 
-fn find_system_font() -> Result<Vec<u8>> {
+fn find_system_font(family: Option<&str>) -> Result<Vec<u8>> {
+    // If a specific font family was requested, try to find it via fontconfig
+    if let Some(name) = family {
+        if !name.is_empty() {
+            // Try common font paths with the family name
+            let search_dirs = [
+                "/usr/share/fonts",
+                "/usr/local/share/fonts",
+            ];
+            let name_lower = name.to_lowercase();
+            for dir in &search_dirs {
+                if let Ok(entries) = walkdir(std::path::Path::new(dir)) {
+                    for path in entries {
+                        let file_name = path.file_name()
+                            .and_then(|n| n.to_str())
+                            .unwrap_or("")
+                            .to_lowercase();
+                        if file_name.contains(&name_lower)
+                            && (file_name.ends_with(".ttf") || file_name.ends_with(".otf"))
+                            && (file_name.contains("regular") || !file_name.contains("bold") && !file_name.contains("italic"))
+                        {
+                            if let Ok(data) = std::fs::read(&path) {
+                                return Ok(data);
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    // Fall back to default system fonts
     let candidates = [
         "/usr/share/fonts/truetype/dejavu/DejaVuSans.ttf",
         "/usr/share/fonts/TTF/DejaVuSans.ttf",
@@ -78,6 +110,25 @@ fn find_system_font() -> Result<Vec<u8>> {
     })
 }
 
+/// Recursively walk a directory and collect file paths
+fn walkdir(dir: &std::path::Path) -> std::io::Result<Vec<std::path::PathBuf>> {
+    let mut results = Vec::new();
+    if dir.is_dir() {
+        for entry in std::fs::read_dir(dir)? {
+            let entry = entry?;
+            let path = entry.path();
+            if path.is_dir() {
+                if let Ok(sub) = walkdir(&path) {
+                    results.extend(sub);
+                }
+            } else {
+                results.push(path);
+            }
+        }
+    }
+    Ok(results)
+}
+
 fn apply_text_watermark(
     img: DynamicImage,
     text: &str,
@@ -85,8 +136,9 @@ fn apply_text_watermark(
     font_size: f32,
     opacity: f32,
     color: [u8; 4],
+    font_family: Option<&str>,
 ) -> Result<DynamicImage> {
-    let font_data = find_system_font()?;
+    let font_data = find_system_font(font_family)?;
     let font = ab_glyph::FontArc::try_from_vec(font_data).map_err(|_| {
         PixstripError::Processing {
             operation: "watermark".into(),

pixstrip-gtk/src/app.rs

@@ -66,6 +66,7 @@ pub struct JobConfig {
     pub watermark_opacity: f32,
     pub watermark_font_size: f32,
     pub watermark_color: [u8; 4],
+    pub watermark_font_family: String,
     pub watermark_use_image: bool,
     // Rename
     pub rename_enabled: bool,
@@ -360,6 +361,7 @@ fn build_ui(app: &adw::Application) {
             watermark_opacity: 0.5,
             watermark_font_size: 24.0,
             watermark_color: [255, 255, 255, 255],
+            watermark_font_family: String::new(),
             watermark_use_image: false,
             rename_enabled: if remember { sess_state.rename_enabled.unwrap_or(false) } else { false },
             rename_prefix: String::new(),
@@ -1666,6 +1668,7 @@ fn run_processing(_window: &adw::ApplicationWindow, ui: &WizardUi) {
                 font_size: cfg.watermark_font_size,
                 opacity: cfg.watermark_opacity,
                 color: cfg.watermark_color,
+                font_family: if cfg.watermark_font_family.is_empty() { None } else { Some(cfg.watermark_font_family.clone()) },
             });
         }
     }
@@ -2595,6 +2598,7 @@ fn build_preset_from_config(cfg: &JobConfig, name: &str) -> pixstrip_core::prese
                 font_size: cfg.watermark_font_size,
                 opacity: cfg.watermark_opacity,
                 color: cfg.watermark_color,
+                font_family: if cfg.watermark_font_family.is_empty() { None } else { Some(cfg.watermark_font_family.clone()) },
             })
         } else {
             None

pixstrip-gtk/src/steps/step_watermark.rs

@@ -61,7 +61,31 @@ pub fn build_watermark_page(state: &AppState) -> adw::NavigationPage {
         .adjustment(&gtk::Adjustment::new(cfg.watermark_font_size as f64, 8.0, 200.0, 1.0, 10.0, 0.0))
         .build();
 
+    // Font family picker
+    let font_row = adw::ActionRow::builder()
+        .title("Font Family")
+        .subtitle("Choose a typeface for the watermark text")
+        .build();
+
+    let font_dialog = gtk::FontDialog::builder()
+        .title("Choose Watermark Font")
+        .modal(true)
+        .build();
+    let font_button = gtk::FontDialogButton::builder()
+        .dialog(&font_dialog)
+        .valign(gtk::Align::Center)
+        .build();
+
+    // Set initial font if one was previously selected
+    if !cfg.watermark_font_family.is_empty() {
+        let desc = gtk::pango::FontDescription::from_string(&cfg.watermark_font_family);
+        font_button.set_font_desc(&desc);
+    }
+
+    font_row.add_suffix(&font_button);
+
     text_group.add(&text_row);
+    text_group.add(&font_row);
     text_group.add(&font_size_row);
     content.append(&text_group);
 
@@ -415,6 +439,16 @@ pub fn build_watermark_page(state: &AppState) -> adw::NavigationPage {
             jc.borrow_mut().watermark_font_size = row.value() as f32;
         });
     }
+    // Wire font family picker
+    {
+        let jc = state.job_config.clone();
+        font_button.connect_font_desc_notify(move |btn| {
+            let desc = btn.font_desc();
+            if let Some(family) = desc.family() {
+                jc.borrow_mut().watermark_font_family = family.to_string();
+            }
+        });
+    }
     // Wire position grid buttons
     for (i, btn) in buttons.iter().enumerate() {
         let jc = state.job_config.clone();