From 3a55dda47c0031b6706d1b1c45092c7766047da4 Mon Sep 17 00:00:00 2001
From: Mike Frysinger <vapier@gentoo.org>
Date: Tue, 3 Sep 2013 14:18:17 -0400
Subject: [PATCH] only refresh metadata/playlist tabs when the underlying data
 has changed

This avoids rewriting a lot of HTML code upon a normal state refresh.
---
 js/mpc.js     |  2 ++
 main.js       | 91 ++++++++++++++++++++++++++-------------------------
 manifest.json |  2 +-
 3 files changed, 50 insertions(+), 45 deletions(-)

diff --git a/js/mpc.js b/js/mpc.js
index 1e3390b..84eea05 100644
--- a/js/mpc.js
+++ b/js/mpc.js
@@ -78,11 +78,13 @@ Mpc.prototype.recv_msg = function(lines) {
 				++i;
 		}
 		this.state.Playlist = playlist;
+		this.state.Playlist.lastUpdate = (new Date()).getTime();
 		this._cb_update_state(this.state);
 		break;
 
 	case 'currentsong':
 		this.state.Currentsong = this._parse_result(lines).state;
+		this.state.Currentsong.lastUpdate = (new Date()).getTime();
 		this._cb_update_state(this.state);
 		break;
 
diff --git a/main.js b/main.js
index 208f996..a5bf784 100644
--- a/main.js
+++ b/main.js
@@ -309,51 +309,54 @@ function update_ui(state, cmd) {
 		return;
 	}
 
-	/* Update the metadata tab. */
-	var currentsong = {};
-	if ('Currentsong' in state)
-		currentsong = state.Currentsong;
-	ui_mpc_metadata_album.innerText = currentsong.Album;
-	ui_mpc_metadata_artist.innerText = currentsong.Artist;
-	ui_mpc_metadata_title.innerText = currentsong.Title;
-	ui_mpc_metadata_date.innerText = currentsong.Date;
-	ui_mpc_metadata_file.innerText = currentsong.file;
-
-	/* Update the playlist tab. */
-	var playlist = [];
-	if ('Playlist' in state)
-		playlist = state.Playlist;
-	ui_mpc_playlist.innerHTML = '';
-	playlist.forEach(function(song) {
-		var cell, row = ui_mpc_playlist.insertRow(-1);
-		if (song.Pos == currentsong.Pos)
-			row.style.fontWeight = 'bold';
-
-		cell = row.insertCell(-1);
-		cell.id = 'playlist_del';
-		cell.innerHTML = '&#164;';
-		cell.song_id = song.Id;
-		cell.title = 'delete';
-		cell.onclick = playlist_del;
-
-		cell = row.insertCell(-1);
-		cell.innerText = song.Pos;
-		cell.style.textAlign = 'right';
-		cell.song_id = song.Id;
-		cell.title = 'play';
-		cell.onclick = playlist_play;
-
-		if ('Artist' in song) {
-			row.insertCell(-1).innerText = song.Artist;
-			row.insertCell(-1).innerText = song.Album;
-			row.insertCell(-1).innerText = song.Title;
-		} else {
+	/* Update the metadata tab only when things have changed. */
+	if ('Currentsong' in state && ui_mpc_metadata_file.lastUpdate != state.Currentsong.lastUpdate) {
+		var currentsong = state.Currentsong;
+		ui_mpc_metadata_album.innerText = currentsong.Album;
+		ui_mpc_metadata_artist.innerText = currentsong.Artist;
+		ui_mpc_metadata_title.innerText = currentsong.Title;
+		ui_mpc_metadata_date.innerText = currentsong.Date;
+		ui_mpc_metadata_file.innerText = currentsong.file;
+	}
+
+	/* Update the playlist tab only when things have changed. */
+	if ('Playlist' in state && ui_mpc_playlist.lastUpdate != state.Playlist.lastUpdate) {
+		var playlist = state.Playlist;
+
+		ui_mpc_playlist.innerHTML = '';
+		playlist.forEach(function(song) {
+			var cell, row = ui_mpc_playlist.insertRow(-1);
+			if (song.Pos == currentsong.Pos)
+				row.style.fontWeight = 'bold';
+
 			cell = row.insertCell(-1);
-			cell.innerText = song.file;
-			cell.colSpan = 3;
-		}
-		row.insertCell(-1).innerText = pretty_time(song.Time);
-	});
+			cell.id = 'playlist_del';
+			cell.innerHTML = '&#164;';
+			cell.song_id = song.Id;
+			cell.title = 'delete';
+			cell.onclick = playlist_del;
+
+			cell = row.insertCell(-1);
+			cell.innerText = song.Pos;
+			cell.style.textAlign = 'right';
+			cell.song_id = song.Id;
+			cell.title = 'play';
+			cell.onclick = playlist_play;
+
+			if ('Artist' in song) {
+				row.insertCell(-1).innerText = song.Artist;
+				row.insertCell(-1).innerText = song.Album;
+				row.insertCell(-1).innerText = song.Title;
+			} else {
+				cell = row.insertCell(-1);
+				cell.innerText = song.file;
+				cell.colSpan = 3;
+			}
+			row.insertCell(-1).innerText = pretty_time(song.Time);
+		});
+
+		ui_mpc_playlist.lastUpdate = playlist.lastUpdate;
+	}
 
 	/* Update the status tab. */
 	var time, percent;
diff --git a/manifest.json b/manifest.json
index 0e1073d..1ec8ed4 100644
--- a/manifest.json
+++ b/manifest.json
@@ -2,7 +2,7 @@
   "manifest_version": 2,
   "minimum_chrome_version": "24",
   "name": "Music Player Client",
-  "version": "3.0",
+  "version": "3.1",
   "description": "Control a Music Player Daemon (MPD)",
   "icons": {
     "128": "images/icon-128x128.png"
-- 
2.39.2