inputpanelv1window: polish window states

Do not markAsMapped an unpositioned panel, it would confuse the sliding
popups effect and force it to figure out its state in creative ways.
Mark the panel window as hidden as it gets destroyed.

src/inputpanelv1window.cpp

@@ -78,13 +78,9 @@ void InputPanelV1Window::hide()
     }
 }
 
-void InputPanelV1Window::reposition()
+void InputPanelV1Window::resetPosition()
 {
     Q_ASSERT(!isDeleted());
-    if (!readyForPainting()) {
-        return;
-    }
-
     switch (m_mode) {
     case Mode::None: {
         // should never happen
@@ -163,6 +159,15 @@ void InputPanelV1Window::reposition()
     }
 }
 
+void InputPanelV1Window::reposition()
+{
+    if (!readyForPainting()) {
+        return;
+    }
+
+    resetPosition();
+}
+
 void InputPanelV1Window::destroyWindow()
 {
     m_panelSurface->disconnect(this);
@@ -226,8 +231,8 @@ void InputPanelV1Window::maybeShow()
 {
     const bool shouldShow = m_mode == Mode::Overlay || (m_mode == Mode::VirtualKeyboard && m_allowed && m_virtualKeyboardShouldBeShown);
     if (shouldShow && !isDeleted() && surface()->isMapped()) {
+        resetPosition();
         markAsMapped();
-        reposition();
         setHidden(false);
     }
 }

src/inputpanelv1window.h

@@ -90,6 +90,7 @@ protected:
 private:
     void showTopLevel(OutputInterface *output, InputPanelSurfaceV1Interface::Position position);
     void showOverlayPanel();
+    void resetPosition();
     void reposition();
     void handleMapped();
     void maybeShow();