From e0317611ef892cf58c34d26c66a4429c75eff448 Mon Sep 17 00:00:00 2001
From: Gokcehan <gokcehankara@gmail.com>
Date: Tue, 19 Jan 2021 01:47:09 +0300
Subject: [PATCH] avoid loading redundant previews for top/bottom

cc #531
---
 eval.go | 14 ++++++++------
 nav.go  | 12 ++++++++++--
 2 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/eval.go b/eval.go
index 020be46..789f41e 100644
--- a/eval.go
+++ b/eval.go
@@ -719,16 +719,18 @@ func (e *callExpr) eval(app *app, args []string) {
 		if app.ui.cmdPrefix != "" && app.ui.cmdPrefix != ">" {
 			normal(app)
 		}
-		app.nav.top()
-		app.ui.loadFile(app.nav, true)
-		app.ui.loadFileInfo(app.nav)
+		if app.nav.top() {
+			app.ui.loadFile(app.nav, true)
+			app.ui.loadFileInfo(app.nav)
+		}
 	case "bottom":
 		if app.ui.cmdPrefix != "" && app.ui.cmdPrefix != ">" {
 			normal(app)
 		}
-		app.nav.bottom()
-		app.ui.loadFile(app.nav, true)
-		app.ui.loadFileInfo(app.nav)
+		if app.nav.bottom() {
+			app.ui.loadFile(app.nav, true)
+			app.ui.loadFileInfo(app.nav)
+		}
 	case "toggle":
 		if len(e.args) == 0 {
 			app.nav.toggle()
diff --git a/nav.go b/nav.go
index 6c4b26f..2b25fbf 100644
--- a/nav.go
+++ b/nav.go
@@ -677,18 +677,26 @@ func (nav *nav) open() error {
 	return nil
 }
 
-func (nav *nav) top() {
+func (nav *nav) top() bool {
 	dir := nav.currDir()
 
+	old := dir.ind
+
 	dir.ind = 0
 	dir.pos = 0
+
+	return old != dir.ind
 }
 
-func (nav *nav) bottom() {
+func (nav *nav) bottom() bool {
 	dir := nav.currDir()
 
+	old := dir.ind
+
 	dir.ind = len(dir.files) - 1
 	dir.pos = min(dir.ind, nav.height-1)
+
+	return old != dir.ind
 }
 
 func (nav *nav) toggleSelection(path string) {