MDL-41438 core_renderer: Update the parameters for heading() and heading_with_help().

heading(), change the default value for classes from 'main' to null.
heading_with_help(), add 2 additional parameters for level and classnames. Default value of level is set to 2 and classnames is set to null.

With the changes for heading_with_help(), icon image vertical alignment needs to be adjusted, so it display in the middle of the heading.

Also added some notes in theme/upgrade.txt file.

lib/outputrenderers.php

@@ -2045,9 +2045,11 @@ class core_renderer extends renderer_base {
      * @param string $component component name
      * @param string|moodle_url $icon
      * @param string $iconalt icon alt text
+     * @param int $level The level of importance of the heading. Defaulting to 2
+     * @param string $classnames A space-separated list of CSS classes. Defaulting to null
      * @return string HTML fragment
      */
-    public function heading_with_help($text, $helpidentifier, $component = 'moodle', $icon = '', $iconalt = '') {
+    public function heading_with_help($text, $helpidentifier, $component = 'moodle', $icon = '', $iconalt = '', $level = 2, $classnames = null) {
         $image = '';
         if ($icon) {
             $image = $this->pix_icon($icon, $iconalt, $component, array('class'=>'icon'));
@@ -2058,7 +2060,7 @@ class core_renderer extends renderer_base {
             $help = $this->help_icon($helpidentifier, $component);
         }
 
-        return $this->heading($image.$text.$help, 2, 'main help');
+        return $this->heading($image.$text.$help, $level, $classnames);
     }
 
     /**
@@ -2669,11 +2671,11 @@ EOD;
      *
      * @param string $text The text of the heading
      * @param int $level The level of importance of the heading. Defaulting to 2
-     * @param string $classes A space-separated list of CSS classes
+     * @param string $classes A space-separated list of CSS classes. Defaulting to null
      * @param string $id An optional ID
      * @return string the HTML to output.
      */
-    public function heading($text, $level = 2, $classes = 'main', $id = null) {
+    public function heading($text, $level = 2, $classes = null, $id = null) {
         $level = (integer) $level;
         if ($level < 1 or $level > 6) {
             throw new coding_exception('Heading level must be an integer between 1 and 6.');

theme/base/style/core.css

@@ -97,10 +97,10 @@ img.resize {height: 1em;width: 1em;}
 .breadcrumb img.resize {height: 0.9em;width: 0.8em;}
 
 /* Icon styles */
-img.icon {height:16px;vertical-align:text-bottom;width:16px;padding-right: 6px;}
+img.icon {height:16px;vertical-align:middle;width:16px;padding-right: 6px;}
 .dir-rtl img.icon {padding-left: 6px; padding-right: 0; }
 img.iconsmall {height:12px;margin-right:3px;vertical-align:middle;width:12px;}
-img.iconhelp, .helplink img {height:16px; padding-left:3px;vertical-align:text-bottom;width:16px;}
+img.iconhelp, .helplink img {height:16px; padding-left:3px;vertical-align:middle;width:16px;}
 .dir-rtl img.iconhelp, .dir-rtl .helplink img {padding-right: 3px; padding-left: 0; }
 img.iconlarge {height: 24px; width: 24px; vertical-align:middle;}
 img.iconsort { vertical-align: text-bottom; padding-left: .3em; margin-bottom: .15em;}

theme/bootstrapbase/less/moodle/core.less

@@ -181,7 +181,7 @@ img.resize {
 /* Icon styles */
 img.icon {
     height: 16px;
-    vertical-align: text-bottom;
+    vertical-align: middle;
     width: 16px;
     padding-right: 6px;
 }
@@ -198,7 +198,7 @@ img.iconsmall {
 img.iconhelp, .helplink img {
     height: 16px;
     padding-left: 3px;
-    vertical-align: text-bottom;
+    vertical-align: middle;
     width: 16px;
 }
 .dir-rtl img.iconhelp, .dir-rtl .helplink img {

theme/upgrade.txt

@@ -1,5 +1,12 @@
 This files describes API changes in /theme/* themes,
 information provided here is intended especially for theme designer.
+=== 2.6 ===
+Notes:
+* The parameters value for the following functions have been modified: core_renderer::heading() and core_renderer::heading_with_help().
+  In core_renderer::heading(), the third param value for classname is set to null as default.
+  In core_renderer::heading_with_help(), additional parameters are added for heading level with default value set to 2,
+  and classname with default value set to null.
+
 === 2.6 ===
 Notes:
 * The file picker and activity chooser have been converted to use M.core.dialogue. This means the styles