Allow to set a customized placeholder for ajax tabs in scrollable mode

images/placeholders/skeleton-dashboard.svg

@@ -0,0 +1,79 @@
+<svg
+        role="img"
+        aria-labelledby="loading-aria"
+        viewBox="0 0 540 100"
+        preserveAspectRatio="none"
+>
+  <rect
+          x="0"
+          y="0"
+          width="100%"
+          height="100%"
+          clip-path="url(#dashboard-clip-path)"
+          style='fill: url("#dashboard-fill");'
+  ></rect>
+  <defs>
+    <clipPath id="dashboard-clip-path">
+        <circle cx="231" cy="30" r="30" /> 
+        <rect x="8" y="6" rx="2" ry="2" width="140" height="10" /> 
+        <rect x="8" y="28" rx="2" ry="2" width="20" height="10" /> 
+        <rect x="397" y="4" rx="2" ry="2" width="20" height="20" /> 
+        <rect x="38" y="28" rx="2" ry="2" width="20" height="10" /> 
+        <rect x="68" y="28" rx="2" ry="2" width="20" height="10" /> 
+        <rect x="98" y="28" rx="2" ry="2" width="20" height="10" /> 
+        <rect x="8" y="60" rx="2" ry="2" width="130" height="10" /> 
+        <rect x="8" y="80" rx="2" ry="2" width="40" height="10" /> 
+        <rect x="274" y="14" rx="3" ry="3" width="61" height="6" /> 
+        <rect x="274" y="24" rx="3" ry="3" width="61" height="6" /> 
+        <rect x="274" y="34" rx="3" ry="3" width="61" height="6" /> 
+        <rect x="204" y="70" rx="0" ry="0" width="30" height="10" /> 
+        <rect x="204" y="90" rx="0" ry="0" width="150" height="10" /> 
+        <rect x="425" y="9" rx="0" ry="0" width="120" height="10" /> 
+        <rect x="402" y="90" rx="2" ry="2" width="20" height="11" /> 
+        <rect x="432" y="40" rx="2" ry="2" width="20" height="60" /> 
+        <rect x="462" y="70" rx="2" ry="2" width="20" height="30" /> 
+        <rect x="492" y="60" rx="2" ry="2" width="20" height="40" />
+    </clipPath>
+    <linearGradient id="dashboard-fill">
+      <stop
+              offset="0.599964"
+              stop-color="#f3f3f3"
+              stop-opacity="1"
+      >
+        <animate
+                attributeName="offset"
+                values="-2; -2; 1"
+                keyTimes="0; 0.25; 1"
+                dur="2s"
+                repeatCount="indefinite"
+        ></animate>
+      </stop>
+      <stop
+              offset="1.59996"
+              stop-color="#ecebeb"
+              stop-opacity="1"
+      >
+        <animate
+                attributeName="offset"
+                values="-1; -1; 2"
+                keyTimes="0; 0.25; 1"
+                dur="2s"
+                repeatCount="indefinite"
+        ></animate>
+      </stop>
+      <stop
+              offset="2.59996"
+              stop-color="#f3f3f3"
+              stop-opacity="1"
+      >
+        <animate
+                attributeName="offset"
+                values="0; 0; 3"
+                keyTimes="0; 0.25; 1"
+                dur="2s"
+                repeatCount="indefinite"
+        ></animate>
+      </stop>
+    </linearGradient>
+  </defs>
+</svg>