diff --git a/VERSION b/VERSION
index bd195547..cf715db4 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-4.2.0.1364
+4.3.0.1365
diff --git a/configuration.ini.dist b/configuration.ini.dist
index e2203ebe..59e5d6a4 100644
--- a/configuration.ini.dist
+++ b/configuration.ini.dist
@@ -48,6 +48,7 @@
 #wiriseditorwindowattributes = width=570, height=450, scroll=no, resizable=yes
 #wiriseditorsetsize = false
 #wiriseditormodalwindow = false
+#wiriseditormodalwindowfullscreen = true
 #wirischemeditorenabled = true
 #wirisimageformat = png
 
diff --git a/core/core.js b/core/core.js
index 3430ceb1..b739b8a5 100644
--- a/core/core.js
+++ b/core/core.js
@@ -2184,7 +2184,7 @@ function wrs_openEditorWindow(language, target, isIframe) {
     }
 
     var title = wrs_int_getCustomEditorEnabled() != null ? wrs_int_getCustomEditorEnabled().title : 'WIRIS EDITOR math';
-    if (!_wrs_conf_modalWindow) {
+    if (_wrs_conf_modalWindow != 'undefined' && _wrs_conf_modalWindow === false) {
         _wrs_popupWindow = window.open(path, title, _wrs_conf_editorAttributes);
         return _wrs_popupWindow;
     }
@@ -2196,7 +2196,7 @@ function wrs_openEditorWindow(language, target, isIframe) {
             var fileref = document.createElement("link");
             fileref.setAttribute("rel", "stylesheet");
             fileref.setAttribute("type", "text/css");
-            fileref.setAttribute("href", wrs_concatenateUrl(window.parent._wrs_conf_path, '/core/modal.css'));
+            fileref.setAttribute("href", wrs_concatenateUrl(_wrs_conf_path, '/core/modal.css'));
             document.getElementsByTagName("head")[0].appendChild(fileref);
             _wrs_css_loaded = true;
         }
@@ -2700,7 +2700,7 @@ function wrs_createModalWindow() {
         var fileref = document.createElement("link");
         fileref.setAttribute("rel", "stylesheet");
         fileref.setAttribute("type", "text/css");
-        fileref.setAttribute("href", wrs_concatenateUrl(window.parent._wrs_conf_path, '/core/modal.css'));
+        fileref.setAttribute("href", wrs_concatenateUrl(_wrs_conf_path, '/core/modal.css'));
         document.getElementsByTagName("head")[0].appendChild(fileref);
         _wrs_css_loaded = true;
     }
@@ -3223,15 +3223,17 @@ function getMetricsFromSvgString(svgString) {
  */
 function wrs_int_getCustomEditorEnabled() {
     var customEditorEnabled = null;
-    Object.keys(_wrs_int_customEditors).forEach(function(key) {
+    for (var key in _wrs_int_customEditors) {
         if (_wrs_int_customEditors[key].enabled) {
-            customEditorEnabled = _wrs_int_customEditors[key]
+            customEditorEnabled = _wrs_int_customEditors[key];
+            break;
         }
-    });
+    }
 
     return customEditorEnabled;
 }
 
+
 /**
  * Disable all custom editors
  * @ignore
@@ -4122,50 +4124,84 @@ ModalWindow.prototype.create = function() {
     _wrs_popupWindow = this.iframe.contentWindow;
     this.properties.open = true;
     this.properties.created = true;
+
+    if (typeof _wrs_conf_modalWindow != "undefined" && _wrs_conf_modalWindow && _wrs_conf_modalWindowFullScreen) {
+        this.maximizeModalWindow();
+    }
+
 }
 
 ModalWindow.prototype.open = function() {
 
     this.hideKeyboard();
 
-    if (this.properties.open == true) {
-        this.iframe.contentWindow._wrs_modalWindowProperties.editor.setMathML(wrs_mathmlDecode(_wrs_temporalImage.getAttribute('data-mathml')));
-    } else if (this.properties.created) {
-
-        this.containerDiv.style.visibility = '';
-        this.overlayDiv.style.visibility = '';
-        this.containerDiv.style.display = '';
-        this.overlayDiv.style.display = '';
+    if (this.properties.open == true || this.properties.created) {
 
         var editor = this.iframe.contentWindow._wrs_modalWindowProperties.editor;
+        var update_toolbar = function() {
+            if (customEditor = wrs_int_getCustomEditorEnabled()) {
+                toolbar = customEditor.toolbar ? customEditor.toolbar : wrs_attributes['toolbar'];
+                if (typeof editor.params.toolbar == 'undefined' || editor.params.toolbar != toolbar) {
+                    editor.setParams({'toolbar' : toolbar});
+                    _wrs_modalWindow.setTitle(customEditor.title);
+                }
+            } else if (typeof editor.params.toolbar != 'undefined' && editor.params.toolbar != 'general') {
+                editor.setParams({'toolbar' : 'general'});
+                _wrs_modalWindow.setTitle('WIRIS EDITOR math');
+            }
+        };
 
-        this.properties.open = true;
-        if (customEditor = wrs_int_getCustomEditorEnabled()) {
-            toolbar = customEditor.toolbar ? customEditor.toolbar : wrs_attributes['toolbar'];
-            if (typeof editor.params.toolbar == 'undefined' || editor.params.toolbar != toolbar) {
-                editor.setParams({'toolbar' : toolbar});
+        if (this.properties.open == true) {
+            var customEditorClass = _wrs_temporalImage.getAttribute('data-custom-editor');
+            if (customEditorClass) {
+                wrs_int_enableCustomEditor(customEditorClass);
+            }
+            else {
+                wrs_int_disableCustomEditors();
             }
-        } else if (typeof editor.params.toolbar != 'undefined' && editor.params.toolbar != 'general') {
-            editor.setParams({'toolbar' : 'general'});
+            update_toolbar();
+            this.iframe.contentWindow._wrs_modalWindowProperties.editor.setMathML(wrs_mathmlDecode(_wrs_temporalImage.getAttribute('data-mathml')));
         }
+        else {
+            this.containerDiv.style.visibility = '';
+            this.overlayDiv.style.visibility = '';
+            this.containerDiv.style.display = '';
+            this.overlayDiv.style.display = '';
 
-        if (_wrs_isNewElement) {
-            if (this.properties.deviceProperties.isAndroid || this.properties.deviceProperties.isIOS) {
-                editor.setMathML('<math><semantics><annotation encoding="application/json">[]</annotation></semantics></math>"');
+            this.properties.open = true;
+
+            if (_wrs_isNewElement) {
+                if (this.properties.deviceProperties.isAndroid || this.properties.deviceProperties.isIOS) {
+                    editor.setMathML('<math><semantics><annotation encoding="application/json">[]</annotation></semantics></math>"');
+                } else {
+                    editor.setMathML('<math/>');
+                }
+                update_toolbar();
             } else {
-                editor.setMathML('<math/>');
+                var customEditorClass = _wrs_temporalImage.getAttribute('data-custom-editor');
+                if (customEditorClass) {
+                    wrs_int_enableCustomEditor(customEditorClass);
+                }
+                else {
+                    wrs_int_disableCustomEditors();
+                }
+                update_toolbar();
+                editor.setMathML(wrs_mathmlDecode(_wrs_temporalImage.getAttribute('data-mathml')));
+            }
+
+            editor.focus();
+            if (!this.properties.deviceProperties.isAndroid && !this.properties.deviceProperties.isIOS) {
+                this.stackModalWindow();
             }
-        } else {
-            editor.setMathML(wrs_mathmlDecode(_wrs_temporalImage.getAttribute('data-mathml')));
         }
 
-        editor.focus();
-        if (!this.properties.deviceProperties.isAndroid && !this.properties.deviceProperties.isIOS) {
-            this.stackModalWindow();
+        if (typeof _wrs_conf_modalWindow != "undefined" && _wrs_conf_modalWindow && _wrs_conf_modalWindowFullScreen) {
+            this.maximizeModalWindow();
         }
     } else {
         this.create();
     }
+
 }
 
 /**
@@ -4497,5 +4533,8 @@ ModalWindow.prototype.hideKeyboard = function() {
 
           }, 200);
     };
+    // ...focus function changes scroll value, so we need to restore it.
+    var keepScroll = scrollY;
     field.focus();
+    window.scrollTo(0, keepScroll);
 }
diff --git a/version.php b/version.php
index 88f25d49..8598b230 100644
--- a/version.php
+++ b/version.php
@@ -25,9 +25,9 @@
 
 defined('MOODLE_INTERNAL') || die();
 
-$plugin->version   = 2017040600;
-$plugin->release = '4.2.0.1364';
+$plugin->version   = 2017050800;
+$plugin->release = '4.3.0.1365';
 $plugin->requires  = 2014050800;
 $plugin->component = 'atto_wiris';
-$plugin->dependencies = array ('filter_wiris' => 2017040600);
+$plugin->dependencies = array ('filter_wiris' => 2017050800);
 $plugin->maturity = MATURITY_STABLE;
diff --git a/yui/src/button/js/button.js b/yui/src/button/js/button.js
index a5721f2b..212ae6b1 100644
--- a/yui/src/button/js/button.js
+++ b/yui/src/button/js/button.js
@@ -113,6 +113,7 @@ Y.namespace('M.atto_wiris').Button = Y.Base.create('button', Y.M.editor_atto.Edi
         var host = this.get('host');
         var wirisplugin = this;
         window._wrs_int_currentPlugin = this;
+        window._wrs_int_editors_elements = typeof window._wrs_int_editors_elements == "undefined" ? {} : window._wrs_int_editors_elements;
         // Update textarea value on change.
         host.on('change', function() {
             wirisplugin._unparseContent();
@@ -257,9 +258,8 @@ Y.namespace('M.atto_wiris').Button = Y.Base.create('button', Y.M.editor_atto.Edi
                     wrs_int_enableCustomEditor(customEditor);
                 }
             }
-            // We need to call global variable (can't call this._editorButton())
-            // out of context.
-            window._wrs_int_currentPlugin._editorButton();
+
+            window._wrs_int_editors_elements[target.id]._editorButton();
         }
     },
     /**
@@ -277,6 +277,7 @@ Y.namespace('M.atto_wiris').Button = Y.Base.create('button', Y.M.editor_atto.Edi
     _updateEditorImgHandlers: function() {
         // Add doubleclick event to editable div.
         wrs_addElementEvents(this.get('host').editor.getDOMNode(),this._handleElementDoubleclick);
+        window._wrs_int_editors_elements[this.get("host").editor.getDOMNode().id] = this;
     },
     /**
      * Reset event handlers for cas images.