feat: style question inputs like Moodle

Adds bootstrap classes to question inputs to roughly emulate Moodle's look-and-feel.

Author: MHajoha

Diff for: classes/question_ui_renderer.php

@@ -216,6 +216,7 @@ private function render_part(DOMNode $part, question_attempt $qa, ?question_disp
             $this->hide_unwanted_feedback($xpath, $options);
             $this->set_input_values_and_readonly($xpath, $qa, $options);
             $this->shuffle_contents($xpath);
+            $this->add_bootstrap_classes($xpath);
             $this->mangle_ids_and_names($xpath, $qa);
             $this->clean_up($xpath);
             $this->resolve_placeholders($xpath);
@@ -449,4 +450,37 @@ private function resolve_placeholders(DOMXPath $xpath): void {
             }
         }
     }
+
+    private function add_bootstrap_classes(DOMXPath $xpath): void {
+        /** @var DOMElement $element */
+        foreach ($xpath->query("
+                //xhtml:input[@type != 'checkbox' and @type != 'radio' and @type != 'button' and @type != 'submit' and @type != 'reset'] 
+                | //xhtml:select | //xhtml:textarea
+                ") as $element) {
+            $this->add_class_names($element, "form-control", "qpy-input");
+        }
+
+        foreach ($xpath->query("//xhtml:input[@type = 'button' or @type = 'submit' or @type = 'reset'] | //xhtml:button") as $element) {
+            $this->add_class_names($element, "btn", "btn-primary", "qpy-input");
+        }
+
+        foreach ($xpath->query("//xhtml:input[@type = 'checkbox' or @type = 'radio']") as $element) {
+            $this->add_class_names($element, "qpy-input");
+        }
+    }
+
+    private function add_class_names(DOMElement $element, string ...$newclasses): void {
+        $classarray = [];
+        for ($class = strtok($element->getAttribute("class"), " \t\n"); $class; $class = strtok(" \t\n")) {
+            $classarray[] = $class;
+        }
+
+        foreach ($newclasses as $newclass) {
+            if (!in_array($newclass, $classarray)) {
+                $classarray[] = $newclass;
+            }
+        }
+
+        $element->setAttribute("class", implode(" ", $classarray));
+    }
 }

Diff for: styles.css

@@ -73,3 +73,10 @@
 .qpy-repetition-remove {
     margin: .5em;
 }
+
+.form-control.qpy-input {
+    /* Matches the styling used by most bundled question types. */
+    display: inline;
+    width: auto;
+    vertical-align: baseline;
+}