Check if gtk is initialised in get_monitors before assuming so in get_monitors

CHANGELOG.md

@@ -99,6 +99,7 @@ You can find its changes [documented below](#070---2021-01-01).
 - X11 backend now uses the platform locale ([#1756] by [@Maan2003])
 - `Either` and `Tab` widgets were still propagating events to hidden widgets ([#1860] by [@lisael])
 - RichText: Invalidate layout on Env change ([#1907] by [@Maan2003])
+- GTK: fix using gdk before initialising it ([#1946] by [@JAicewizard])
 
 ### Visual
 
@@ -784,6 +785,7 @@ Last release without a changelog :(
 [#1886]: https://github.com/linebender/druid/pull/1886
 [#1907]: https://github.com/linebender/druid/pull/1907
 [#1929]: https://github.com/linebender/druid/pull/1929
+[#1947]: https://github.com/linebender/druid/pull/1947
 
 [Unreleased]: https://github.com/linebender/druid/compare/v0.7.0...master
 [0.7.0]: https://github.com/linebender/druid/compare/v0.6.0...v0.7.0

druid-shell/src/backend/gtk/screen.rs

@@ -37,6 +37,12 @@ fn translate_gdk_monitor(mon: gtk::gdk::Monitor) -> Monitor {
 }
 
 pub(crate) fn get_monitors() -> Vec<Monitor> {
+    if !gtk::is_initialized() {
+        if let Err(err) = gtk::init() {
+            tracing::error!("{}", err.message);
+            return Vec::new();
+        }
+    }
     DisplayManager::get()
         .list_displays()
         .iter()