webmusic.js: replace ifs with switch

webmusic.js

@@ -21,37 +21,47 @@ window.onload = function () {
 };
 
 window.onkeyup = function (event) {
-    if (event.key === " " || event.key === "p") {
-        if (gstate !== "idle") {
-            togglePlayback();
-        } else {
-            playSong(queue[0])
-        }
-    }
-    else if (event.key === "r") {
-        toggleRepeat();
-    }
-    else if (event.key === "c") {
-        toggleContinue();
-    }
-    else if (event.key === "ArrowUp") {
-        previousTrack();
-    }
-    else if (event.key === "ArrowDown") {
-        nextTrack();
-    }
-    else if (event.key === "ArrowLeft") {
-        if (sound.seek() < 10) {
-            sound.seek(0);
-        } else {
-            sound.seek(sound.seek()-10);
-        }
-    }
-    else if (event.key === "ArrowRight") {
-        sound.seek(sound.seek()+10);
-    }
-    else if (event.key === "Escape") {
-        document.getElementById("back").click();
+    switch (event.key) {
+        case " ":
+        case "p":
+            if (gstate == "idle" && total !== 0) {
+                playSong(queue[0])
+            } else {
+                togglePlayback();
+            }
+            break;
+
+        case "r":
+            toggleRepeat();
+            break;
+
+        case "c":
+            toggleContinue();
+            break;
+
+        case "ArrowUp":
+            previousTrack();
+            break;
+
+        case "ArrowDown":
+            nextTrack();
+            break;
+
+        case "ArrowLeft":
+            if (sound.seek() < 10) {
+                sound.seek(0);
+            } else {
+                sound.seek(sound.seek()-10);
+            }
+            break;
+
+        case "ArrowRight":
+            sound.seek(sound.seek()+10);
+            break;
+
+        case "Escape":
+            document.getElementById("back").click();
+            break;
     }
 };