[Add] basic split

iota-cli/src/util/borders.rs

@@ -0,0 +1,63 @@
+use ratatui::layout::Rect;
+use ratatui::prelude::*;
+use ratatui::style::Style;
+use ratatui::widgets::Borders;
+
+fn set_join_char(frame: &mut Frame, x: u16, y: u16, c: char) {
+    frame
+        .buffer_mut()
+        .set_string(x, y, c.to_string(), Style::default());
+}
+
+pub fn draw_block_joins(frame: &mut Frame, area: Rect, borders: Borders, joins: Borders) {
+    let x0 = area.x;
+    let y0 = area.y;
+    let x1 = area.x + area.width - 1;
+    let y1 = area.y + area.height - 1;
+
+    if borders.contains(Borders::TOP) && borders.contains(Borders::LEFT) {
+        let top_left = match (joins.contains(Borders::TOP), joins.contains(Borders::LEFT)) {
+            (true, true) => '┼',
+            (true, false) => '├',
+            (false, true) => '┬',
+            (false, false) => '┌',
+        };
+        set_join_char(frame, x0, y0, top_left);
+    }
+
+    if borders.contains(Borders::TOP) && borders.contains(Borders::RIGHT) {
+        let top_right = match (joins.contains(Borders::TOP), joins.contains(Borders::RIGHT)) {
+            (true, true) => '┼',
+            (true, false) => '┤',
+            (false, true) => '┬',
+            (false, false) => '┐',
+        };
+        set_join_char(frame, x1, y0, top_right);
+    }
+
+    if borders.contains(Borders::BOTTOM) && borders.contains(Borders::LEFT) {
+        let bottom_left = match (
+            joins.contains(Borders::BOTTOM),
+            joins.contains(Borders::LEFT),
+        ) {
+            (true, true) => '┼',
+            (true, false) => '├',
+            (false, true) => '┴',
+            (false, false) => '└',
+        };
+        set_join_char(frame, x0, y1, bottom_left);
+    }
+
+    if borders.contains(Borders::BOTTOM) && borders.contains(Borders::RIGHT) {
+        let bottom_right = match (
+            joins.contains(Borders::BOTTOM),
+            joins.contains(Borders::RIGHT),
+        ) {
+            (true, true) => '┼',
+            (true, false) => '┤',
+            (false, true) => '┴',
+            (false, false) => '┘',
+        };
+        set_join_char(frame, x1, y1, bottom_right);
+    }
+}