Add the component header that I miss in a previous commit

Contributes to CURA-5941.

resources/qml/ExpandableComponentHeader.qml

@@ -0,0 +1,68 @@
+// Copyright (c) 2018 Ultimaker B.V.
+// Cura is released under the terms of the LGPLv3 or higher.
+
+import QtQuick 2.7
+import QtQuick.Controls 2.3
+
+import UM 1.2 as UM
+import Cura 1.0 as Cura
+
+// Header of the popup
+Cura.RoundedRectangle
+{
+    id: header
+
+    property alias headerTitle: headerLabel.text
+
+    height: UM.Theme.getSize("expandable_component_content_header").height
+    color: UM.Theme.getColor("secondary")
+    cornerSide: Cura.RoundedRectangle.Direction.Up
+    border.width: UM.Theme.getSize("default_lining").width
+    border.color: UM.Theme.getColor("lining")
+    radius: UM.Theme.getSize("default_radius").width
+
+    Label
+    {
+        id: headerLabel
+        text: "Title"
+        font: UM.Theme.getFont("default")
+        renderType: Text.NativeRendering
+        verticalAlignment: Text.AlignVCenter
+        color: UM.Theme.getColor("small_button_text")
+        height: parent.height
+
+        anchors
+        {
+            topMargin: UM.Theme.getSize("default_margin").height
+            left: parent.left
+            leftMargin: UM.Theme.getSize("default_margin").height
+        }
+    }
+
+    Button
+    {
+        id: closeButton
+        width: UM.Theme.getSize("message_close").width
+        height: UM.Theme.getSize("message_close").height
+        hoverEnabled: true
+
+        anchors
+        {
+            right: parent.right
+            rightMargin: UM.Theme.getSize("default_margin").width
+            verticalCenter: parent.verticalCenter
+        }
+
+        contentItem: UM.RecolorImage
+        {
+            anchors.fill: parent
+            sourceSize.width: width
+            color: closeButton.hovered ? UM.Theme.getColor("small_button_text_hover") : UM.Theme.getColor("small_button_text")
+            source: UM.Theme.getIcon("cross1")
+        }
+
+        background: Item {}
+
+        onClicked: toggleContent() // Will hide the popup item
+    }
+}