qml: Add ProgressIndicator control

Github-Pull: bitcoin-core#69
Rebased-From: 455b2f8

Author: promag

src/qml/BitcoinApp/Controls/CMakeLists.txt

@@ -9,4 +9,5 @@ qt6_add_qml_module(bitcoin_qml_controls
   RESOURCE_PREFIX /qt/qml/
   QML_FILES
     OptionButton.qml
+    ProgressIndicator.qml
 )

src/qml/BitcoinApp/Controls/ProgressIndicator.qml

@@ -0,0 +1,33 @@
+// Copyright (c) 2021 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+import QtQuick
+import QtQuick.Controls
+
+Control {
+    property real progress: 0
+    Behavior on progress {
+        NumberAnimation {
+            easing.type: Easing.Bezier
+            easing.bezierCurve: [0.5, 0.0, 0.2, 1, 1, 1]
+            duration: 250
+        }
+    }
+    contentItem: Rectangle {
+        implicitHeight: 6
+        radius: Math.floor(height / 2)
+        color: "#404040"
+        Item {
+            width: Math.round(progress * contentItem.width)
+            height: parent.height
+            clip: true
+            Rectangle {
+                width: contentItem.width
+                height: contentItem.height
+                radius: contentItem.radius
+                color: "orange"
+            }
+        }
+    }
+}