From 0f106b591c7be48508821313a6b2a9566f8dca62 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E4=B8=89=E5=92=B2=E9=9B=85=20=C2=B7=20Misaki=20Masa?=
 <sxyazi@gmail.com>
Date: Sun, 18 Aug 2024 23:30:32 +0800
Subject: [PATCH] perf: new `image_delay` option debounces image previews to
 avoid lag caused by terminal image decoding during fast scrolling (#1512)

---
 yazi-config/preset/yazi.toml          |  1 +
 yazi-config/src/preview/preview.rs    |  4 ++++
 yazi-plugin/preset/plugins/font.lua   | 11 +++++------
 yazi-plugin/preset/plugins/image.lua  |  3 ++-
 yazi-plugin/preset/plugins/magick.lua | 11 +++++------
 yazi-plugin/preset/plugins/pdf.lua    | 11 +++++------
 yazi-plugin/preset/plugins/video.lua  | 11 +++++------
 7 files changed, 27 insertions(+), 25 deletions(-)

diff --git a/yazi-config/preset/yazi.toml b/yazi-config/preset/yazi.toml
index d21cfb07..e11aa703 100644
--- a/yazi-config/preset/yazi.toml
+++ b/yazi-config/preset/yazi.toml
@@ -21,6 +21,7 @@ tab_size        = 2
 max_width       = 600
 max_height      = 900
 cache_dir       = ""
+image_delay     = 30
 image_filter    = "triangle"
 image_quality   = 75
 sixel_fraction  = 15
diff --git a/yazi-config/src/preview/preview.rs b/yazi-config/src/preview/preview.rs
index 6f4be1c8..901d2e54 100644
--- a/yazi-config/src/preview/preview.rs
+++ b/yazi-config/src/preview/preview.rs
@@ -15,6 +15,7 @@ pub struct Preview {
 
 	pub cache_dir: PathBuf,
 
+	pub image_delay:    u8,
 	pub image_filter:   String,
 	pub image_quality:  u8,
 	pub sixel_fraction: u8,
@@ -63,6 +64,8 @@ impl FromStr for Preview {
 
 			cache_dir: Option<String>,
 
+			#[validate(range(min = 0, max = 100))]
+			image_delay:    u8,
 			image_filter:   String,
 			#[validate(range(min = 50, max = 90))]
 			image_quality:  u8,
@@ -87,6 +90,7 @@ impl FromStr for Preview {
 
 			cache_dir,
 
+			image_delay: preview.image_delay,
 			image_filter: preview.image_filter,
 			image_quality: preview.image_quality,
 			sixel_fraction: preview.sixel_fraction,
diff --git a/yazi-plugin/preset/plugins/font.lua b/yazi-plugin/preset/plugins/font.lua
index f94f6248..b0b648dc 100644
--- a/yazi-plugin/preset/plugins/font.lua
+++ b/yazi-plugin/preset/plugins/font.lua
@@ -3,15 +3,14 @@ local TEXT = "ABCDEFGHIJKLM\nNOPQRSTUVWXYZ\nabcdefghijklm\nnopqrstuvwxyz\n123456
 local M = {}
 
 function M:peek()
-	local cache = ya.file_cache(self)
-	if not cache then
+	local start, cache = os.clock(), ya.file_cache(self)
+	if not cache or self:preload() ~= 1 then
 		return
 	end
 
-	if self:preload() == 1 then
-		ya.image_show(cache, self.area)
-		ya.preview_widgets(self, {})
-	end
+	ya.sleep(math.max(0, PREVIEW.image_delay / 1000 + start - os.clock()))
+	ya.image_show(cache, self.area)
+	ya.preview_widgets(self, {})
 end
 
 function M:seek() end
diff --git a/yazi-plugin/preset/plugins/image.lua b/yazi-plugin/preset/plugins/image.lua
index 1a6a7707..a5a04b41 100644
--- a/yazi-plugin/preset/plugins/image.lua
+++ b/yazi-plugin/preset/plugins/image.lua
@@ -1,11 +1,12 @@
 local M = {}
 
 function M:peek()
-	local url = ya.file_cache(self)
+	local start, url = os.clock(), ya.file_cache(self)
 	if not url or not fs.cha(url) then
 		url = self.file.url
 	end
 
+	ya.sleep(math.max(0, PREVIEW.image_delay / 1000 + start - os.clock()))
 	ya.image_show(url, self.area)
 	ya.preview_widgets(self, {})
 end
diff --git a/yazi-plugin/preset/plugins/magick.lua b/yazi-plugin/preset/plugins/magick.lua
index dbe1aa9d..75586c14 100644
--- a/yazi-plugin/preset/plugins/magick.lua
+++ b/yazi-plugin/preset/plugins/magick.lua
@@ -1,15 +1,14 @@
 local M = {}
 
 function M:peek()
-	local cache = ya.file_cache(self)
-	if not cache then
+	local start, cache = os.clock(), ya.file_cache(self)
+	if not cache or self:preload() ~= 1 then
 		return
 	end
 
-	if self:preload() == 1 then
-		ya.image_show(cache, self.area)
-		ya.preview_widgets(self, {})
-	end
+	ya.sleep(math.max(0, PREVIEW.image_delay / 1000 + start - os.clock()))
+	ya.image_show(cache, self.area)
+	ya.preview_widgets(self, {})
 end
 
 function M:seek() end
diff --git a/yazi-plugin/preset/plugins/pdf.lua b/yazi-plugin/preset/plugins/pdf.lua
index de4f4ef8..b8a66a84 100644
--- a/yazi-plugin/preset/plugins/pdf.lua
+++ b/yazi-plugin/preset/plugins/pdf.lua
@@ -1,15 +1,14 @@
 local M = {}
 
 function M:peek()
-	local cache = ya.file_cache(self)
-	if not cache then
+	local start, cache = os.clock(), ya.file_cache(self)
+	if not cache or self:preload() ~= 1 then
 		return
 	end
 
-	if self:preload() == 1 then
-		ya.image_show(cache, self.area)
-		ya.preview_widgets(self, {})
-	end
+	ya.sleep(math.max(0, PREVIEW.image_delay / 1000 + start - os.clock()))
+	ya.image_show(cache, self.area)
+	ya.preview_widgets(self, {})
 end
 
 function M:seek(units)
diff --git a/yazi-plugin/preset/plugins/video.lua b/yazi-plugin/preset/plugins/video.lua
index 50ea9528..3bcf15c4 100644
--- a/yazi-plugin/preset/plugins/video.lua
+++ b/yazi-plugin/preset/plugins/video.lua
@@ -1,15 +1,14 @@
 local M = {}
 
 function M:peek()
-	local cache = ya.file_cache(self)
-	if not cache then
+	local start, cache = os.clock(), ya.file_cache(self)
+	if not cache or self:preload() ~= 1 then
 		return
 	end
 
-	if self:preload() == 1 then
-		ya.image_show(cache, self.area)
-		ya.preview_widgets(self, {})
-	end
+	ya.sleep(math.max(0, PREVIEW.image_delay / 1000 + start - os.clock()))
+	ya.image_show(cache, self.area)
+	ya.preview_widgets(self, {})
 end
 
 function M:seek(units)