Allow any window to be bounds-checked (#4802)

Co-authored-by: Rasmus Karlsson <rasmus.karlsson@pajlada.com>

src/util/WidgetHelpers.hpp

@@ -0,0 +1,29 @@
+#pragma once
+
+class QWidget;
+class QPoint;
+class QScreen;
+
+namespace chatterino::widgets {
+
+enum class BoundsChecking {
+    /// Don't do any bounds checking (equivalent to `QWidget::move`).
+    Off,
+
+    /// Attempt to keep the window within bounds of the screen the cursor is on.
+    CursorPosition,
+
+    /// Attempt to keep the window within bounds of the screen the desired position is on.
+    DesiredPosition,
+};
+
+/// Moves the `window` to the (global) `position`
+/// while doing bounds-checking according to `mode` to ensure the window stays on one screen.
+///
+/// @param window The window to move.
+/// @param position The global position to move the window to.
+/// @param mode The desired bounds checking.
+void moveWindowTo(QWidget *window, QPoint position,
+                  BoundsChecking mode = BoundsChecking::DesiredPosition);
+
+}  // namespace chatterino::widgets