From bc8c35efff4659485aae1057b5397beaab67e7e0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20Kohlschu=CC=88tter?=
 <christian@kohlschutter.com>
Date: Tue, 7 May 2024 01:51:14 +0200
Subject: [PATCH] extensions: Add PlaceholdersExtension

---
 .../placeholders/PlaceholdersExtension.java   | 29 +++++++++++++++++++
 .../placeholders/webapp/css/placeholders.css  |  7 +++++
 .../placeholders/webapp/js/placeholders.js    |  6 ++++
 3 files changed, 42 insertions(+)
 create mode 100644 dumbo-extensions/src/main/java/com/kohlschutter/dumbo/placeholders/PlaceholdersExtension.java
 create mode 100644 dumbo-extensions/src/main/resources/com/kohlschutter/dumbo/placeholders/webapp/css/placeholders.css
 create mode 100644 dumbo-extensions/src/main/resources/com/kohlschutter/dumbo/placeholders/webapp/js/placeholders.js

diff --git a/dumbo-extensions/src/main/java/com/kohlschutter/dumbo/placeholders/PlaceholdersExtension.java b/dumbo-extensions/src/main/java/com/kohlschutter/dumbo/placeholders/PlaceholdersExtension.java
new file mode 100644
index 0000000..73cca5a
--- /dev/null
+++ b/dumbo-extensions/src/main/java/com/kohlschutter/dumbo/placeholders/PlaceholdersExtension.java
@@ -0,0 +1,29 @@
+/*
+ * Copyright 2022,2023 Christian Kohlschütter
+ * Copyright 2014,2015 Evernote Corporation.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.kohlschutter.dumbo.placeholders;
+
+import com.kohlschutter.dumbo.annotations.CSSResource;
+import com.kohlschutter.dumbo.annotations.JavaScriptResource;
+import com.kohlschutter.dumbo.api.DumboComponent;
+
+/**
+ * Improves handling of placeholder resources
+ */
+@CSSResource(value = "css/placeholders.css", group = "dumbo")
+@JavaScriptResource(value = "js/placeholders.js", group = "dumbo", async = true)
+public interface PlaceholdersExtension extends DumboComponent {
+}
diff --git a/dumbo-extensions/src/main/resources/com/kohlschutter/dumbo/placeholders/webapp/css/placeholders.css b/dumbo-extensions/src/main/resources/com/kohlschutter/dumbo/placeholders/webapp/css/placeholders.css
new file mode 100644
index 0000000..29823cf
--- /dev/null
+++ b/dumbo-extensions/src/main/resources/com/kohlschutter/dumbo/placeholders/webapp/css/placeholders.css
@@ -0,0 +1,7 @@
+BODY:not([class*=dumbo-ready]) .dumbo-placeholder {
+	opacity: 0;
+}
+
+BODY[class*=dumbo-ready]:not([class*=static-design-mode]) .dumbo-placeholder {
+    transition: opacity 0.33s ease-in;
+}
diff --git a/dumbo-extensions/src/main/resources/com/kohlschutter/dumbo/placeholders/webapp/js/placeholders.js b/dumbo-extensions/src/main/resources/com/kohlschutter/dumbo/placeholders/webapp/js/placeholders.js
new file mode 100644
index 0000000..4871ffc
--- /dev/null
+++ b/dumbo-extensions/src/main/resources/com/kohlschutter/dumbo/placeholders/webapp/js/placeholders.js
@@ -0,0 +1,6 @@
+Dumbo.whenReady(function() {
+    setTimeout(() => document.body.classList.add("dumbo-ready"), 0);
+});
+Dumbo.whenStatic(function() {
+    document.body.classList.add("dumbo-ready");
+});