provide an expert option to opt out from user zoom on mobile devices

boot.php

@@ -980,6 +980,10 @@ class App {
 
 	function build_pagehead() {
 
+		$user_scalable = ((local_user()) ? get_pconfig(local_user(),'system','user_scalable') : 1);
+		if ($user_scalable === false)
+			$user_scalable = 1;
+
 		$interval = ((local_user()) ? get_pconfig(local_user(),'system','update_interval') : 40000);
 		if($interval < 10000)
 			$interval = 40000;
@@ -993,6 +997,7 @@ class App {
 		 */
 		$tpl = get_markup_template('head.tpl');
 		$this->page['htmlhead'] = replace_macros($tpl, array(
+			'$user_scalable' => $user_scalable,
 			'$baseurl' => $this->get_baseurl(),
 			'$local_user' => local_user(),
 			'$generator' => RED_PLATFORM . ' ' . RED_VERSION,

mod/settings.php

@@ -135,6 +135,7 @@ function settings_post(&$a) {
 
 		$theme = ((x($_POST,'theme')) ? notags(trim($_POST['theme']))  : $a->channel['channel_theme']);
 		$mobile_theme = ((x($_POST,'mobile_theme')) ? notags(trim($_POST['mobile_theme']))  : '');
+		$user_scalable = ((x($_POST,'user_scalable')) ? intval($_POST['user_scalable'])  : 0);
 		$nosmile = ((x($_POST,'nosmile')) ? intval($_POST['nosmile'])  : 0);  
 		$browser_update   = ((x($_POST,'browser_update')) ? intval($_POST['browser_update']) : 0);
 		$browser_update   = $browser_update * 1000;
@@ -151,7 +152,7 @@ function settings_post(&$a) {
 		}
 
 //		$chanview_full = ((x($_POST,'chanview_full')) ? intval($_POST['chanview_full']) : 0);
-
+		set_pconfig(local_user(),'system','user_scalable',$user_scalable);
 		set_pconfig(local_user(),'system','update_interval', $browser_update);
 		set_pconfig(local_user(),'system','itemspage', $itemspage);
 		set_pconfig(local_user(),'system','no_smilies',$nosmile);
@@ -727,6 +728,9 @@ function settings_content(&$a) {
 		}
 		$theme_selected = (!x($_SESSION,'theme')? $default_theme : $_SESSION['theme']);
 		$mobile_theme_selected = (!x($_SESSION,'mobile_theme')? $default_mobile_theme : $_SESSION['mobile_theme']);
+
+		$user_scalable = get_pconfig(local_user(),'system','user_scalable');
+		$user_scalable = (($user_scalable===false)? '1': $user_scalable); // default if not set: 1
 		
 		$browser_update = intval(get_pconfig(local_user(), 'system','update_interval'));
 		$browser_update = (($browser_update == 0) ? 40 : $browser_update / 1000); // default if not set: 40 seconds
@@ -753,11 +757,13 @@ function settings_content(&$a) {
 		
 			'$theme'	=> array('theme', t('Display Theme:'), $theme_selected, '', $themes, 'preview'),
 			'$mobile_theme'	=> array('mobile_theme', t('Mobile Theme:'), $mobile_theme_selected, '', $mobile_themes, ''),
+			'$user_scalable' => array('user_scalable', t("Enable user zoom on mobile devices"), $user_scalable, ''),
 			'$ajaxint'   => array('browser_update',  t("Update browser every xx seconds"), $browser_update, t('Minimum of 10 seconds, no maximum')),
 			'$itemspage'   => array('itemspage',  t("Maximum number of conversations to load at any time:"), $itemspage, t('Maximum of 100 items')),
 			'$nosmile'	=> array('nosmile', t("Don't show emoticons"), $nosmile, ''),
 			'$layout_editor' => t('System Page Layout Editor - (advanced)'),
 			'$theme_config' => $theme_config,
+			'$expert' => feature_enabled(local_user(),'expert'),
 		));
 		
 		return $o;

view/tpl/head.tpl

@@ -1,6 +1,6 @@
 <meta http-equiv="Content-Type" content="text/html;charset=utf-8" />
 <base href="{{$baseurl}}/" />
-<meta name="viewport" content="width=device-width, height=device-height, initial-scale=1" />
+<meta name="viewport" content="width=device-width, height=device-height, initial-scale=1, user-scalable={{$user_scalable}}" />
 <meta name="generator" content="{{$generator}}" />
 
 <!--[if IE]>

view/tpl/settings_display.tpl

@@ -6,6 +6,9 @@
 
 {{include file="field_themeselect.tpl" field=$theme}}
 {{include file="field_themeselect.tpl" field=$mobile_theme}}
+{{if $expert}}
+{{include file="field_checkbox.tpl" field=$user_scalable}}
+{{/if}}
 {{include file="field_input.tpl" field=$ajaxint}}
 {{include file="field_input.tpl" field=$itemspage}}
 {{include file="field_checkbox.tpl" field=$nosmile}}