Use iframe loader for loading frame content on Prev/Next button use

skins/elastic/styles/styles.less

@@ -84,8 +84,6 @@ a:hover {
     color: @color-link-hover;
 }
 
-@import "layout";
-
 
 /*** Font-icons ***/
 
@@ -137,87 +135,12 @@ a:hover {
     animation: fa-spin 2s infinite linear;
 }
 
-/*** Common sizing variables ***/
-
-@listing-line-height:           2.5rem;
-@listing-touch-line-height:     3.6rem;
-
-
-/*** Common UI elements ***/
-
-.hidden,
-.voice {
-    display: none !important;
-}
-
-#rcmdraglayer {
-    min-width: 260px;
-    width: auto !important;
-    width: 260px;
-    background: @color-drag-layer-background;
-    z-index: 250;
-    color: @color-drag-layer;
-    white-space: nowrap;
-    opacity: .92;
-}
-
-.listbox .scroller {
-    width: 100%;
-    overflow-x: hidden;
-    overflow-y: auto;
-}
-
-
-#folder-selector {
-    overflow-y: auto;
 
-    li a.virtual {
-        opacity: .2;
-    }
-}
-
-#layout > .content .watermark {
-    background: url(../images/watermark.jpg) center no-repeat;
-    width: 100%;
-    height: 100%;
-}
-
-.noselect {
-    user-select: none;
-    -moz-user-select: none;
-    -khtml-user-select: none;
-    -ms-user-select: none;
-    -webkit-user-select: none;
-}
-
-.iframe-loader {
-    width: 100%;
-    height: 100%;
-    position: absolute;
-    top: 0;
-    background-color: rgba(255, 255, 255, .95);
-    display: flex;
-    align-items: center;
-    justify-content: center;
-
-    .spinner {
-        position: relative;
-        display: inline-block;
-        width: 7rem;
-        height: 7rem;
-        overflow: hidden;
-        text-indent: -999em;
-        color: @color-spinner-circle;
-        border: 1rem solid;
-        border-color: currentColor @color-spinner-item currentColor currentColor;
-        border-radius: 50%;
-        -webkit-animation: fa-spin 1s infinite linear;
-        animation: fa-spin 1s infinite linear;
-    }
-}
+@import "layout";
 
 /*** Widgets ***/
 
+@import "widgets/common";
 @import "widgets/buttons";
 @import "widgets/jqueryui";
 @import "widgets/dialogs";

skins/elastic/styles/widgets/common.less

@@ -0,0 +1,94 @@
+/**
+ * Roundcube webmail styles for the Elastic skin
+ *
+ * Copyright (c) 2017, The Roundcube Dev Team
+ *
+ * The contents are subject to the Creative Commons Attribution-ShareAlike
+ * License. It is allowed to copy, distribute, transmit and to adapt the work
+ * by keeping credits to the original authors in the README.md file.
+ * See http://creativecommons.org/licenses/by-sa/3.0/ for details.
+ */
+
+/*** Common sizing variables ***/
+
+@listing-line-height:           2.5rem;
+@listing-touch-line-height:     3.6rem;
+
+
+/*** Common UI elements ***/
+
+.hidden,
+.voice {
+    display: none !important;
+}
+
+#rcmdraglayer {
+    min-width: 260px;
+    width: auto !important;
+    width: 260px;
+    background: @color-drag-layer-background;
+    z-index: 250;
+    color: @color-drag-layer;
+    white-space: nowrap;
+    opacity: .92;
+}
+
+.listbox .scroller {
+    width: 100%;
+    overflow-x: hidden;
+    overflow-y: auto;
+}
+
+
+#folder-selector {
+    overflow-y: auto;
+
+    li a.virtual {
+        opacity: .2;
+    }
+}
+
+#layout > .content .watermark {
+    background: url(../images/watermark.jpg) center no-repeat;
+    width: 100%;
+    height: 100%;
+}
+
+.noselect {
+    user-select: none;
+    -moz-user-select: none;
+    -khtml-user-select: none;
+    -ms-user-select: none;
+    -webkit-user-select: none;
+}
+
+.iframe-loader {
+    width: 100%;
+    position: absolute;
+    top: 0;
+    bottom: 0;
+    background-color: rgba(255, 255, 255, .95);
+    display: flex;
+    align-items: center;
+    justify-content: center;
+
+    .spinner {
+        position: relative;
+        display: inline-block;
+        width: 7rem;
+        height: 7rem;
+        overflow: hidden;
+        text-indent: -999em;
+        color: @color-spinner-circle;
+        border: 1rem solid;
+        border-color: currentColor @color-spinner-item currentColor currentColor;
+        border-radius: 50%;
+        -webkit-animation: fa-spin 1s infinite linear;
+        animation: fa-spin 1s infinite linear;
+    }
+}
+
+.footer.toolbar + .iframe-loader {
+    top: @layout-header-height;
+    bottom: @layout-header-height;
+}

skins/elastic/ui.js

@@ -646,7 +646,7 @@ function rcube_elastic_ui()
             }
         }
 
-        // TODO: Add "message X of Y" text between buttons
+        // TODO: Add "message X of Y" text between buttons?
 
         if (!env.frame_nav) {
             env.frame_nav = $('<div class="footer toolbar content-frame-navigation">')
@@ -657,6 +657,7 @@ function rcube_elastic_ui()
         }
 
         var prev, next, found = false,
+            frame = $('#' + rcmail.env.contentframe),
             next_button = $('a.button.next', env.frame_nav).off('click').addClass('disabled'),
             prev_button = $('a.button.prev', env.frame_nav).off('click').addClass('disabled'),
             span = $('span', env.frame_nav).text('');
@@ -665,6 +666,8 @@ function rcube_elastic_ui()
             found = true;
             next_button.removeClass('disabled').on('click', function() {
                 env.content_lock = true;
+                iframe_loader(frame);
+
                 if (next) {
                     list.select(next);
                 }
@@ -679,6 +682,8 @@ function rcube_elastic_ui()
             found = true;
             prev_button.removeClass('disabled').on('click', function() {
                 env.content_lock = true;
+                iframe_loader(frame);
+
                 if (prev) {
                     list.select(prev);
                 }
@@ -1023,6 +1028,12 @@ function rcube_elastic_ui()
      */
     function message_displayed(p)
     {
+        if (p.type == 'loading' && $('.iframe-loader:visible').length) {
+            // hide original message object, we don't need two "loaders"
+            rcmail.hide_message(p.object);
+            return;
+        }
+
         alert_style(p.object, p.type);
         $(p.object).attr('role', 'alert');
         $('a', p.object).addClass('alert-link');