Added refresh option for plugin list.

This fixes the issue that if you don't have internet connection on first start of the browser, you'd need a reboot of cura to get the list.

CURA-3856

plugins/PluginBrowser/PluginBrowser.py

@@ -66,7 +66,9 @@ class PluginBrowser(QObject, Extension):
             self._createDialog()
         self._dialog.show()
 
+    @pyqtSlot()
     def requestPluginList(self):
+        Logger.log("i", "Requesting plugin list")
         url = QUrl(self._api_url + "plugins")
         self._plugin_list_request = QNetworkRequest(url)
         self._plugin_list_request.setRawHeader(*self._request_header)
@@ -181,7 +183,6 @@ class PluginBrowser(QObject, Extension):
 
     def _onRequestFinished(self, reply):
         reply_url = reply.url().toString()
-
         if reply.error() == QNetworkReply.TimeoutError:
             Logger.log("w", "Got a timeout.")
             # Reset everything.
@@ -191,6 +192,11 @@ class PluginBrowser(QObject, Extension):
                 self._download_plugin_reply.downloadProgress.disconnect(self._onDownloadPluginProgress)
                 self._download_plugin_reply.abort()
                 self._download_plugin_reply = None
+            return
+        elif reply.error() == QNetworkReply.HostNotFoundError:
+            Logger.log("w", "Unable to reach server.")
+            return
+
         if reply.operation() == QNetworkAccessManager.GetOperation:
             if reply_url == self._api_url + "plugins":
                 try:

plugins/PluginBrowser/PluginBrowser.qml

@@ -14,6 +14,11 @@ UM.Dialog
     Item
     {
         anchors.fill: parent
+        Item
+        {
+            id: topBar
+            height: childrenRect.height;
+            width: parent.width
             Label
             {
                 id: introText
@@ -21,10 +26,19 @@ UM.Dialog
                 width: parent.width
                 height: 30
             }
+
+            Button
+            {
+                id: refresh
+                text: catalog.i18nc("@action:button", "Refresh")
+                onClicked: manager.requestPluginList()
+                anchors.right: parent.right
+            }
+        }
         ScrollView
         {
             width: parent.width
-            anchors.top: introText.bottom
+            anchors.top: topBar.bottom
             anchors.bottom: progressbar.top
             anchors.bottomMargin: UM.Theme.getSize("default_margin").height
             frameVisible: true