MDL-47494 ddmarker: DD markers, add help for the drop zones. #11029

question/type/ddmarker/edit_ddmarker_form.php

@@ -48,6 +48,8 @@ protected function definition_inner($mform) {
         $mform->addElement('advcheckbox', 'showmisplaced', ' ',
                                                 get_string('showmisplaced', 'qtype_ddmarker'));
         parent::definition_inner($mform);
+
+        $mform->addHelpButton('drops[0]', 'dropzones', 'qtype_ddmarker');
     }
 
     public function js_call() {

question/type/ddmarker/lang/en/qtype_ddmarker.php

@@ -39,6 +39,12 @@
 $string['dropbackground'] = 'Background image for dragging markers onto';
 $string['dropzone'] = 'Drop zone {$a}';
 $string['dropzoneheader'] = 'Drop zones';
+$string['dropzones'] = 'Drop zones';
+$string['dropzones_help'] = 'The drop zones are defined by typing co-ordinates. As you type, the preview above is immediately updated, so you can position things by trial and error.
+
+* Circle: centre_x, centre_y; radius<br>for example: `80, 100; 50`
+* Polygon: x1, y1; x2, y2; ...; xn, yn<br>for example: `20, 60; 100, 60; 20, 100`
+* Rectangle: left, top, width, height<br>for example: `20, 60; 80, 40`';
 $string['followingarewrong'] = 'The following markers have been placed in the wrong area : {$a}.';
 $string['followingarewrongandhighlighted'] = 'The following markers were incorrectly placed :  {$a}. Highlighted marker(s) are now shown with the correct placement(s).<br /> Click on the marker to highlight the allowed area.';
 $string['formerror_nobgimage'] = 'You need to select an image to use as the background for the drag and drop area.';