seperate adjust

src-tauri/src/lib.rs

@@ -106,6 +106,7 @@ struct ZcaResult {
 #[derive(serde::Deserialize)]
 struct ExportImageTask {
     path: String,
+    manual_position: Option<ManualPosition>,
 }
 
 #[derive(serde::Deserialize)]
@@ -116,8 +117,9 @@ struct WatermarkSettings {
     color: String, // Hex code e.g. "#FFFFFF"
     opacity: f64,
     scale: f64, // Font size relative to image height (e.g., 0.05 = 5% of height)
-    manual_override: bool,
-    manual_position: ManualPosition,
+    // Global manual override is deprecated in favor of per-task control, but kept for struct compatibility if needed
+    _manual_override: bool, 
+    _manual_position: ManualPosition,
 }
 
 #[derive(serde::Deserialize)]
@@ -169,9 +171,10 @@ async fn export_batch(images: Vec<ExportImageTask>, watermark: WatermarkSettings
             let final_scale = PxScale::from(scale_px);
             let (final_t_width, final_t_height) = imageproc::drawing::text_size(final_scale, &font, &watermark.text);
 
-            // 4. Determine Position (Center based)
-            let (pos_x_pct, pos_y_pct) = if watermark.manual_override {
-                 (watermark.manual_position.x, watermark.manual_position.y)
+            // 4. Determine Position (Task Specific > ZCA)
+            // If task has manual_position, use it. Otherwise calculate ZCA.
+            let (pos_x_pct, pos_y_pct) = if let Some(pos) = &task.manual_position {
+                 (pos.x, pos.y)
             } else {
                  match calculate_zca_internal(&dynamic_img) {
                      Ok(res) => (res.x, res.y),
@@ -231,7 +234,21 @@ async fn export_batch(images: Vec<ExportImageTask>, watermark: WatermarkSettings
             // Save
             let file_name = input_path.file_name().unwrap_or_default();
             let output_path = Path::new(&output_dir).join(file_name);
-            base_img.save(output_path).map_err(|e| e.to_string())?;
+            
+            // Handle format specific saving
+            // JPEG does not support Alpha channel. If we save Rgba8 to Jpeg, it might fail or look wrong.
+            let ext = output_path.extension().and_then(|s| s.to_str()).unwrap_or("").to_lowercase();
+            if ext == "jpg" || ext == "jpeg" {
+                // Convert to RGB8 (dropping alpha)
+                // Note: This simply drops alpha. If background was transparent, it becomes black.
+                // For photos (JPEGs) this is usually fine as they don't have alpha.
+                let rgb_img = image::DynamicImage::ImageRgba8(base_img).to_rgb8();
+                rgb_img.save(&output_path).map_err(|e| e.to_string())?;
+            } else {
+                // For PNG/WebP etc, keep RGBA
+                base_img.save(&output_path).map_err(|e| e.to_string())?;
+            }
+            
             Ok(())
         } else {
             Err(format!("Failed to open {}", task.path))