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