fix: Don't show editing options that arent supported for the chosen image

Without this, after choosing one of the supported editing options for an
SVG image - the tab navigation at the top listing editing types shows
the ones that shouldn't be available - and if chosen, causes exceptions
to be encountered.

Author: aolley

imageclass.php

@@ -217,9 +217,11 @@ public function flip_image($direction) {
         return $fileinfo['filename'];
     }
 
-    private function get_editing_options() {
-        global $CFG;
-
+    /**
+     * Get the list of editing options allowed for this image.
+     * Not all editing types are supported for all image formats.
+     */
+    public function get_editing_options() {
         $options = [
             'caption',
             'delete',
@@ -238,6 +240,14 @@ private function get_editing_options() {
             ];
         }
 
+        return $options;
+    }
+
+    private function get_editing_options_form() {
+        global $CFG;
+
+        $options = $this->get_editing_options();
+
         $html = '<form action="'.$CFG->wwwroot.'/mod/lightboxgallery/imageedit.php" method="post"/>'.
                     '<input type="hidden" name="id" value="'.$this->cmid.'" />'.
                     '<input type="hidden" name="image" value="'.$this->storedfile->get_filename().'" />'.
@@ -305,7 +315,7 @@ public function get_image_display_html($editing = false) {
         }
         $html .= $this->gallery->extinfo ? '<div class="lightbox-gallery-image-extinfo">'.$timemodified.
                  '<br/>'.$filesize.'KB '.$this->width.'x'.$this->height.'px</div>' : '';
-        $html .= ($editing ? $this->get_editing_options() : '');
+        $html .= ($editing ? $this->get_editing_options_form() : '');
         $html .= '</div>'.
                     '</div>'.
                 '</div>';

imageedit.php

@@ -53,7 +53,13 @@
 $buttonurl = new moodle_url('/mod/lightboxgallery/view.php', array('id' => $id, 'editing' => 1, 'page' => $page));
 $PAGE->set_button($OUTPUT->single_button($buttonurl, get_string('backtogallery', 'lightboxgallery')));
 
-$edittypes = lightboxgallery_edit_types();
+$fs = get_file_storage();
+if (!$storedfile = $fs->get_file($context->id, 'mod_lightboxgallery', 'gallery_images', '0', '/', $image)) {
+    throw new \moodle_exception(get_string('errornofile', 'lightboxgallery', $image));
+}
+$imageclass = new lightboxgallery_image($storedfile, $gallery, $cm);
+
+$edittypes = lightboxgallery_edit_types(false, $imageclass);
 
 $tabs = array();
 foreach ($edittypes as $type => $name) {
@@ -75,11 +81,6 @@
 $editclass = 'edit_'.$tab;
 $editinstance = new $editclass($gallery, $cm, $image, $tab);
 
-$fs = get_file_storage();
-if (!$storedfile = $fs->get_file($context->id, 'mod_lightboxgallery', 'gallery_images', '0', '/', $image)) {
-    throw new \moodle_exception(get_string('errornofile', 'lightboxgallery', $image));
-}
-
 if ($editinstance->processing() && confirm_sesskey()) {
     $params = array(
         'context' => $context,
@@ -98,22 +99,20 @@
     redirect($CFG->wwwroot.'/mod/lightboxgallery/imageedit.php?id='.$cm->id.'&image='.$editinstance->image.'&tab='.$tab);
 }
 
-$image = new lightboxgallery_image($storedfile, $gallery, $cm);
-
 $table = new html_table();
 $table->width = '*';
 
 if ($editinstance->showthumb) {
     $table->attributes = array('style' => 'margin-left:auto;margin-right:auto;');
     $table->align = array('center', 'center');
     $table->size = array('*', '*');
-    $table->data[] = array('<img src="'.$image->get_thumbnail_url().
-                            '" alt="" /><br /><span title="'.$image->get_image_caption().'">'.
-                            $image->get_image_caption().'</span>', $editinstance->output($image->get_image_caption()));
+    $table->data[] = array('<img src="'.$imageclass->get_thumbnail_url().
+                            '" alt="" /><br /><span title="'.$imageclass->get_image_caption().'">'.
+                            $imageclass->get_image_caption().'</span>', $editinstance->output($imageclass->get_image_caption()));
 } else {
     $table->align = array('center');
     $table->size = array('*');
-    $table->data[] = array($editinstance->output($image->get_image_caption()));
+    $table->data[] = array($editinstance->output($imageclass->get_image_caption()));
 }
 
 echo $OUTPUT->header();

locallib.php

@@ -113,7 +113,7 @@ function lightboxgallery_config_defaults() {
     }
 }
 
-function lightboxgallery_edit_types($showall = false) {
+function lightboxgallery_edit_types($showall = false, $image = null) {
     $result = array();
 
     $disabledplugins = explode(',', get_config('lightboxgallery', 'disabledplugins'));
@@ -122,6 +122,9 @@ function lightboxgallery_edit_types($showall = false) {
     $disabledplugins[] = 'crop';
 
     $edittypes = get_list_of_plugins('mod/lightboxgallery/edit');
+    if ($image !== null && !$showall) {
+        $edittypes = array_intersect($image->get_editing_options(), $edittypes);
+    }
 
     foreach ($edittypes as $edittype) {
         if ($showall || !in_array($edittype, $disabledplugins)) {