Fix scroll

pulse-ui/src/render.rs

@@ -42,6 +42,10 @@ impl RenderTextResult {
 
 impl RenderScope {
     pub fn draw_text<P: Into<Point>, T: Display>(&mut self, at: P, text: T) -> u16 {
+        if self.rect.width == 0 || self.rect.height == 0 {
+            return 0;
+        }
+
         let point: Point = at.into();
 
         let text = text.to_string();
@@ -140,6 +144,10 @@ impl RenderScope {
             match inst {
                 Instr::DrawText(point, text) => {
                     for (i, line) in text.lines().enumerate() {
+                        if i as u16 + point.y >= self.rect.height {
+                            continue;
+                        }
+
                         print_at(
                             self.rect.x + point.x,
                             self.rect.y + point.y + i as u16,

pulse-ui/src/widget/scroll.rs

@@ -12,16 +12,15 @@ impl Widget for ScrollText {
     fn render(&self, scope: &mut crate::render::RenderScope) {
         let title_lines = scope.draw_text(0, &self.title);
 
-        let mut y = title_lines as u16;
-
-        for line in self
+        let text = self
             .text
             .lines()
             .skip(self.scroll)
-            .take((scope.rect.height - title_lines) as usize)
-        {
-            y += scope.draw_text((0, y), line);
-        }
+            .map(|v| v.trim_end())
+            .collect::<Vec<_>>()
+            .join("\n");
+
+        scope.draw_text((0, title_lines), text);
     }
 }