Add html.rs viewer

src/viewer/html.rs

@@ -0,0 +1,28 @@
+//! HTML 檢視器
+
+use anyhow::Result;
+
+pub struct HtmlViewer {
+    content: Option<String>,
+}
+
+impl HtmlViewer {
+    pub fn new() -> Self {
+        Self { content: None }
+    }
+
+    pub fn load_file(&mut self, path: &str) -> Result<String> {
+        let content = std::fs::read_to_string(path)?;
+        self.content = Some(content.clone());
+        Ok(content)
+    }
+
+    pub fn load_content(&mut self, html: &str) -> String {
+        self.content = Some(html.to_string());
+        html.to_string()
+    }
+
+    pub fn get_content(&self) -> Option<&str> {
+        self.content.as_deref()
+    }
+}