add text/plain content type support

src/app/browser/window/tab/item/page/content/text/plain.rs

@@ -0,0 +1,22 @@
+use gtk::{TextBuffer, TextView};
+
+pub trait Plain {
+    fn plain(data: &str) -> Self;
+}
+
+impl Plain for TextView {
+    fn plain(data: &str) -> Self {
+        const MARGIN: i32 = 8;
+        TextView::builder()
+            .bottom_margin(MARGIN)
+            .cursor_visible(false)
+            .buffer(&TextBuffer::builder().text(data).build())
+            .editable(false)
+            .left_margin(MARGIN)
+            .monospace(true)
+            .right_margin(MARGIN)
+            .top_margin(MARGIN)
+            .vexpand(true)
+            .build()
+    }
+}

src/app/browser/window/tab/item/page/content/text/plain/reader.rs

@@ -1,33 +0,0 @@
-use gtk::{Align, Label};
-
-pub struct Reader {
-    widget: Label,
-}
-
-impl Default for Reader {
-    fn default() -> Self {
-        Self::new()
-    }
-}
-
-impl Reader {
-    // Construct
-    pub fn new() -> Self {
-        Self {
-            widget: Label::builder()
-                .halign(Align::Start)
-                .valign(Align::Start)
-                .margin_start(8)
-                .margin_end(8)
-                .wrap(true)
-                .selectable(true)
-                .use_markup(true)
-                .build(),
-        }
-    }
-
-    // Getters
-    pub fn widget(&self) -> &Label {
-        &self.widget
-    }
-}