feat(ui): decouple preview title position from input bar position and make it configurable (#144)

fixes #143 

## example
```toml
[ui]
input_bar_position = "top"
preview_title_position = "top"
```

<img width="2553" alt="Screenshot 2024-12-18 at 22 06 29"
src="https://github.com/user-attachments/assets/6c9ac842-e383-42a8-bdf4-d48c7a826df3"
/>

.config/config.toml

@@ -40,6 +40,8 @@ ui_scale = 100
 show_help_bar = true
 # Where to place the input bar in the UI (top or bottom)
 input_bar_position = "bottom"
+# Where to place the preview title in the UI (top or bottom)
+preview_title_position = "top"
 # The theme to use for the UI
 # A list of builtin themes can be found in the `themes` directory of the television
 # repository. You may also create your own theme by creating a new file in a `themes`

crates/television-screen/src/layout.rs

@@ -62,6 +62,24 @@ impl Display for InputPosition {
     }
 }
 
+#[derive(Debug, Clone, Copy, Deserialize, Default)]
+pub enum PreviewTitlePosition {
+    #[serde(rename = "top")]
+    #[default]
+    Top,
+    #[serde(rename = "bottom")]
+    Bottom,
+}
+
+impl Display for PreviewTitlePosition {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            PreviewTitlePosition::Top => write!(f, "top"),
+            PreviewTitlePosition::Bottom => write!(f, "bottom"),
+        }
+    }
+}
+
 pub struct Layout {
     pub help_bar: Option<HelpBarLayout>,
     pub results: Rect,
@@ -97,6 +115,7 @@ impl Layout {
         with_remote: bool,
         with_help_bar: bool,
         input_position: InputPosition,
+        preview_title_position: PreviewTitlePosition,
     ) -> Self {
         let main_block = centered_rect(dimensions.x, dimensions.y, area);
         // split the main block into two vertical chunks (help bar + rest)
@@ -172,16 +191,16 @@ impl Layout {
 
         let right_chunks = layout::Layout::default()
             .direction(Direction::Vertical)
-            .constraints(match input_position {
-                InputPosition::Top => {
+            .constraints(match preview_title_position {
+                PreviewTitlePosition::Bottom => {
                     preview_constraints.into_iter().rev().collect()
                 }
-                InputPosition::Bottom => preview_constraints,
+                PreviewTitlePosition::Top => preview_constraints,
             })
             .split(vt_chunks[1]);
-        let (preview_title, preview_window) = match input_position {
-            InputPosition::Bottom => (right_chunks[0], right_chunks[1]),
-            InputPosition::Top => (right_chunks[1], right_chunks[0]),
+        let (preview_title, preview_window) = match preview_title_position {
+            PreviewTitlePosition::Top => (right_chunks[0], right_chunks[1]),
+            PreviewTitlePosition::Bottom => (right_chunks[1], right_chunks[0]),
         };
 
         Self::new(

crates/television/config/ui.rs

@@ -2,7 +2,7 @@ use config::ValueKind;
 use serde::Deserialize;
 use std::collections::HashMap;
 
-use television_screen::layout::InputPosition;
+use television_screen::layout::{InputPosition, PreviewTitlePosition};
 
 use super::themes::DEFAULT_THEME;
 
@@ -15,6 +15,7 @@ pub struct UiConfig {
     pub show_help_bar: bool,
     #[serde(default)]
     pub input_bar_position: InputPosition,
+    pub preview_title_position: PreviewTitlePosition,
     pub theme: String,
 }
 
@@ -25,6 +26,7 @@ impl Default for UiConfig {
             ui_scale: DEFAULT_UI_SCALE,
             show_help_bar: true,
             input_bar_position: InputPosition::Bottom,
+            preview_title_position: PreviewTitlePosition::Top,
             theme: String::from(DEFAULT_THEME),
         }
     }
@@ -49,6 +51,10 @@ impl From<UiConfig> for ValueKind {
             String::from("input_position"),
             ValueKind::String(val.input_bar_position.to_string()).into(),
         );
+        m.insert(
+            String::from("preview_title_position"),
+            ValueKind::String(val.preview_title_position.to_string()).into(),
+        );
         m.insert(String::from("theme"), ValueKind::String(val.theme).into());
         ValueKind::Table(m)
     }

crates/television/television.rs

@@ -406,6 +406,7 @@ impl Television {
             !matches!(self.mode, Mode::Channel),
             self.config.ui.show_help_bar,
             self.config.ui.input_bar_position,
+            self.config.ui.preview_title_position,
         );
 
         // help bar (metadata, keymaps, logo)