MDL-56826 question: Add bootstrap styles to question preview

question/preview.php

@@ -255,13 +255,13 @@
 // Finish the question form.
 echo html_writer::start_tag('div', array('id' => 'previewcontrols', 'class' => 'controls'));
 echo html_writer::empty_tag('input', $restartdisabled + array('type' => 'submit',
-        'name' => 'restart', 'value' => get_string('restart', 'question')));
+        'name' => 'restart', 'value' => get_string('restart', 'question'), 'class' => 'btn btn-secondary'));
 echo html_writer::empty_tag('input', $finishdisabled  + array('type' => 'submit',
-        'name' => 'save',    'value' => get_string('save', 'question')));
+        'name' => 'save',    'value' => get_string('save', 'question'), 'class' => 'btn btn-secondary'));
 echo html_writer::empty_tag('input', $filldisabled    + array('type' => 'submit',
-        'name' => 'fill',    'value' => get_string('fillincorrect', 'question')));
+        'name' => 'fill',    'value' => get_string('fillincorrect', 'question'), 'class' => 'btn btn-secondary'));
 echo html_writer::empty_tag('input', $finishdisabled  + array('type' => 'submit',
-        'name' => 'finish',  'value' => get_string('submitandfinish', 'question')));
+        'name' => 'finish',  'value' => get_string('submitandfinish', 'question'), 'class' => 'btn btn-secondary'));
 echo html_writer::end_tag('div');
 echo html_writer::end_tag('form');
 

question/yui/build/moodle-question-preview/moodle-question-preview-debug.js

@@ -36,7 +36,7 @@ M.question.preview.init = function() {
     M.core_question_engine.init_form(Y, '#responseform');
 
     // Add a close button to the window.
-    var closebutton = Y.Node.create('<input type="button" />')
+    var closebutton = Y.Node.create('<input type="button" class="btn btn-secondary"/>')
             .set('value', M.util.get_string('closepreview', 'question'));
 
     closebutton.on('click', function() {

question/yui/build/moodle-question-preview/moodle-question-preview.js

@@ -36,7 +36,7 @@ M.question.preview.init = function() {
     M.core_question_engine.init_form(Y, '#responseform');
 
     // Add a close button to the window.
-    var closebutton = Y.Node.create('<input type="button" />')
+    var closebutton = Y.Node.create('<input type="button" class="btn btn-secondary"/>')
             .set('value', M.util.get_string('closepreview', 'question'));
 
     closebutton.on('click', function() {

question/yui/src/preview/js/preview.js

@@ -34,7 +34,7 @@ M.question.preview.init = function() {
     M.core_question_engine.init_form(Y, '#responseform');
 
     // Add a close button to the window.
-    var closebutton = Y.Node.create('<input type="button" />')
+    var closebutton = Y.Node.create('<input type="button" class="btn btn-secondary"/>')
             .set('value', M.util.get_string('closepreview', 'question'));
 
     closebutton.on('click', function() {