add forceFullscreen

README.md

@@ -78,6 +78,7 @@ simplemde.value("This text will appear in the editor");
   - **code** Can be set to  ```` ``` ```` or `~~~`.  Defaults to ```` ``` ````.
   - **italic** Can be set to `*` or `_`. Defaults to `*`.
 - **element**: The DOM element for the textarea to use. Defaults to the first textarea on the page.
+- **forceFullscreen**: If set to `true`, force enter fullscreen mode when toggle side by side mode. Defaults to `false`.
 - **forceSync**: If set to `true`, force text changes made in SimpleMDE to be immediately stored in original textarea. Defaults to `false`.
 - **hideIcons**: An array of icon names to hide. Can be used to hide specific icons shown by default without completely customizing the toolbar.
 - **indentWithTabs**: If set to `false`, indent using spaces instead of tabs. Defaults to `true`.

src/js/simplemde.js

@@ -693,6 +693,7 @@ function toggleSideBySide(editor) {
 	var preview = wrapper.nextSibling;
 	var toolbarButton = editor.toolbarElements["side-by-side"];
 	var useSideBySideListener = false;
+	var options = editor.options;
 	if(/editor-preview-active-side/.test(preview.className)) {
 		preview.className = preview.className.replace(
 			/\s*editor-preview-active-side\s*/g, ""
@@ -703,8 +704,9 @@ function toggleSideBySide(editor) {
 		// When the preview button is clicked for the first time,
 		// give some time for the transition from editor.css to fire and the view to slide from right to left,
 		// instead of just appearing.
+		forceFullscreen = (options.forceFullscreen != undefined) ? options.forceFullscreen : true;
 		setTimeout(function() {
-			if(!cm.getOption("fullScreen"))
+			if(forceFullscreen && !cm.getOption("fullScreen"))
 				toggleFullScreen(editor);
 			preview.className += " editor-preview-active-side";
 		}, 1);