inputpanelv1window: fix showing and hiding

Instead of InputMethod directly calling showClient() on the input panel,
call methods that properly show or hide the panel as needed, with readyForPainting
set appropriately. This removes the cases where it's shown without being ready for
painting, which causes crashes.

BUG: 459404

src/inputmethod.cpp

@@ -139,16 +139,18 @@ void InputMethod::init()
 
 void InputMethod::show()
 {
+    m_shouldShowPanel = true;
     if (m_panel) {
-        m_panel->showClient();
+        m_panel->show();
         updateInputPanelState();
     }
 }
 
 void InputMethod::hide()
 {
+    m_shouldShowPanel = false;
     if (m_panel) {
-        m_panel->hideClient();
+        m_panel->hide();
         updateInputPanelState();
     }
 }
@@ -214,6 +216,10 @@ void InputMethod::setPanel(InputPanelV1Window *panel)
     Q_EMIT visibleChanged();
     updateInputPanelState();
     Q_EMIT panelChanged();
+
+    if (m_shouldShowPanel) {
+        show();
+    }
 }
 
 void InputMethod::setTrackedWindow(Window *trackedWindow)

src/inputmethod.h

@@ -138,6 +138,7 @@ private:
 
     bool m_hasPendingModifiers = false;
     bool m_activeClientSupportsTextInput = false;
+    bool m_shouldShowPanel = false;
 };
 
 }

src/inputpanelv1window.cpp

@@ -47,9 +47,11 @@ void InputPanelV1Window::showOverlayPanel()
 {
     setOutput(nullptr);
     m_mode = Overlay;
-    reposition();
+    if (m_shouldBeShown && surface()->isMapped()) {
-    showClient();
+        setReadyForPainting();
-    setReadyForPainting();
+        reposition();
+        showClient();
+    }
 }
 
 void InputPanelV1Window::showTopLevel(OutputInterface *output, InputPanelSurfaceV1Interface::Position position)
@@ -57,13 +59,39 @@ void InputPanelV1Window::showTopLevel(OutputInterface *output, InputPanelSurface
     Q_UNUSED(position);
     m_mode = Toplevel;
     setOutput(output);
-    showClient();
+    if (m_allowed && m_shouldBeShown && surface()->isMapped()) {
+        setReadyForPainting();
+        reposition();
+        showClient();
+    }
 }
 
 void InputPanelV1Window::allow()
 {
-    setReadyForPainting();
+    m_allowed = true;
-    reposition();
+    if (m_shouldBeShown && surface()->isMapped()) {
+        setReadyForPainting();
+        reposition();
+        showClient();
+    }
+}
+
+void InputPanelV1Window::show()
+{
+    m_shouldBeShown = true;
+    if (m_allowed && surface()->isMapped()) {
+        setReadyForPainting();
+        reposition();
+        showClient();
+    }
+}
+
+void InputPanelV1Window::hide()
+{
+    m_shouldBeShown = false;
+    if (readyForPainting()) {
+        hideClient();
+    }
 }
 
 void KWin::InputPanelV1Window::reposition()

src/inputpanelv1window.h

@@ -77,6 +77,8 @@ public:
         return m_mode;
     }
     void allow();
+    void show();
+    void hide();
 
 protected:
     void moveResizeInternal(const QRectF &rect, MoveResizeMode mode) override;
@@ -89,6 +91,8 @@ private:
 
     QPointer<Output> m_output;
     Mode m_mode = Toplevel;
+    bool m_allowed = false;
+    bool m_shouldBeShown = false;
     const QPointer<KWaylandServer::InputPanelSurfaceV1Interface> m_panelSurface;
 };