Add custom buttons support as $option param

[jojoob]

Provide an options array entry with "buttons" key and an array of "button arrays" with id, img, text, callback indexes to add custom buttons to the player.
Adapted download button init to this new flexible buttons feature.

Example:

$options['buttons'] = array(array(
    'id'=>'uniqueid',
    'img'=>'http://path/to/img.png',
    'text'=>'label',
    'callback'=>'M.plugin.callback'));

[kabalin]

Yeah, I see what you mean, but you already have M.filter_jwplayer context, just use it directly!

[kabalin]

This is how it can be modified, works for me.

diff --git a/filter/jwplayer/lib.php b/filter/jwplayer/lib.php
index 9ef5c70..7564128 100644
--- a/filter/jwplayer/lib.php
+++ b/filter/jwplayer/lib.php
@@ -190,7 +190,7 @@ class filter_jwplayer_media extends core_media_player {
                 $downloadbtn = array(
                     'img' => $CFG->wwwroot.'/filter/jwplayer/img/download.png',
                     'text' => get_string('videodownloadbtntttext', 'filter_jwplayer'),
-                    'callback' => 'M.filter_jwplayer.download',
+                    'callback' => 'download',
                     'id' => 'download'
                 );
                 $buttons[] = $downloadbtn;
diff --git a/filter/jwplayer/module.js b/filter/jwplayer/module.js
index 641927d..443f1bf 100644
--- a/filter/jwplayer/module.js
+++ b/filter/jwplayer/module.js
@@ -3,24 +3,14 @@ M.filter_jwplayer = {};
 M.filter_jwplayer.init = function(Y, playerid, setupdata, buttons) {
     jwplayer(playerid).setup(setupdata);

-    var executenamespacedFunction = function(namespacedFunctionName, args) {
-        var namespaces = namespacedFunctionName.split(".");
-        var fn = namespaces.pop();
-        var context = window;
-        for (var i = 0; i < namespaces.length; i++) {
-            context = context[namespaces[i]];
-        }
-        context[fn].apply(context, args);
-    };
-
-    function btncallback(i) {
+    function btncallback(callback) {
         return function() {
-            executenamespacedFunction(buttons[i].callback, [playerid]);
+            M.filter_jwplayer[callback](playerid);
         };
     }

     for (var i = 0; i < buttons.length; i++) {
-        jwplayer(playerid).addButton(buttons[i].img, buttons[i].text, btncallback(i), buttons[i].id);
+        jwplayer(playerid).addButton(buttons[i].img, buttons[i].text, btncallback(buttons[i].callback), buttons[i].id);
     }
 };

[jojoob]

But this will not work if you have a button callback outside of M.fitler_jwplayer workspace. And this would be the case if using the jwplayer with a custom button via the options param. For my mod_video plugin I create a button and the callback is declared in the mod_video namespace M.mod_video.

[kabalin]

Please resubmit pull request to JW7 branch, master branch will be deleted as per #37.