add disabling of dialog primary button (#4503)

frappe/public/css/desk.css

@@ -475,6 +475,11 @@ fieldset[disabled] .form-control {
 .modal-title {
   margin-top: 5px;
 }
+.btn-primary.disabled {
+  background-color: #b1bdca;
+  color: #fff;
+  border-color: #b1bdca;
+}
 .form-control {
   position: relative;
 }

frappe/public/js/frappe/ui/dialog.js

@@ -86,6 +86,12 @@ frappe.ui.Dialog = frappe.ui.FieldGroup.extend({
 				click.apply(me, [values]);
 			});
 	},
+	disable_primary_action: function() {
+		this.get_primary_btn().addClass('disabled');
+	},
+	enable_primary_action: function() {
+		this.get_primary_btn().removeClass('disabled');
+	},
 	make_head: function() {
 		var me = this;
 		this.set_title(this.title);

frappe/public/less/desk.less

@@ -289,6 +289,12 @@ textarea.form-control {
 	margin-top: 5px;
 }
 
+.btn-primary.disabled {
+	background-color: #b1bdca;
+	color: #fff;
+	border-color: #b1bdca;
+}
+
 .form-control {
 	position: relative;