From 9befd0645da8eea809d2b47455e0f8fa7e6faedd Mon Sep 17 00:00:00 2001
From: Jinzhou Zhang <lotabout@gmail.com>
Date: Wed, 8 Apr 2020 15:49:39 +0800
Subject: [PATCH] fix #291: hide scroll info when content fit

- Do not show the pager if the content could fit the window.
- Show the pager otherwise.
---
 src/previewer.rs | 32 ++++++++++++++++++++------------
 1 file changed, 20 insertions(+), 12 deletions(-)

diff --git a/src/previewer.rs b/src/previewer.rs
index 39b33fe9..98cea7e7 100644
--- a/src/previewer.rs
+++ b/src/previewer.rs
@@ -190,6 +190,12 @@ impl Previewer {
     }
 
     fn act_scroll_down(&mut self, diff: i32) {
+        let content_len = self.content_lines.lock().len();
+        if content_len <= self.height.load(Ordering::SeqCst) {
+            // don't scroll if content could be filled
+            return;
+        }
+
         if diff > 0 {
             self.vscroll_offset += diff as usize;
         } else {
@@ -261,18 +267,20 @@ impl Draw for Previewer {
             .unwrap();
         printer.print_lines(canvas, &content);
 
-        // print the vscroll info
-        let status = format!("{}/{}", self.vscroll_offset + 1, content.len());
-        let col = max(status.len() + 1, self.width.load(Ordering::Relaxed)) - status.len() - 1;
-        canvas.print_with_attr(
-            0,
-            col,
-            &status,
-            Attr {
-                effect: Effect::REVERSE,
-                ..Attr::default()
-            },
-        )?;
+        // print the vscroll info (only if content could not fit in one page)
+        if content.len() > self.height.load(Ordering::SeqCst) {
+            let status = format!("{}/{}", self.vscroll_offset + 1, content.len());
+            let col = max(status.len() + 1, self.width.load(Ordering::SeqCst)) - status.len() - 1;
+            canvas.print_with_attr(
+                0,
+                col,
+                &status,
+                Attr {
+                    effect: Effect::REVERSE,
+                    ..Attr::default()
+                },
+            )?;
+        }
 
         Ok(())
     }