From 725c3d5608f6e1f81ee70e3efdd553b60d476e82 Mon Sep 17 00:00:00 2001
From: Vadim Zeitlin <vadim@wxwidgets.org>
Date: Sun, 7 Nov 2021 16:06:55 +0000
Subject: [PATCH] Update images when DPI changes in wxBookCtrlBase-derived
 classes

Just pretend that the images themselves have changed, this should be
enough to recreate wxImageList from the bundle using the new scale
factor in UpdateImageListIfNecessary().
---
 include/wx/bookctrl.h   |  4 ++++
 src/common/bookctrl.cpp | 12 ++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/include/wx/bookctrl.h b/include/wx/bookctrl.h
index f77f277ca6..1fc4d0edd6 100644
--- a/include/wx/bookctrl.h
+++ b/include/wx/bookctrl.h
@@ -360,6 +360,10 @@ private:
     // common part of all ctors
     void Init();
 
+    // update the images if we use them on DPI change
+    void WXHandleDPIChanged(wxDPIChangedEvent& event);
+
+
     // internal border
     unsigned int m_internalBorder;
 
diff --git a/src/common/bookctrl.cpp b/src/common/bookctrl.cpp
index fe09f7e031..52cc3f4333 100644
--- a/src/common/bookctrl.cpp
+++ b/src/common/bookctrl.cpp
@@ -41,6 +41,8 @@ wxBEGIN_EVENT_TABLE(wxBookCtrlBase, wxControl)
 #if wxUSE_HELP
     EVT_HELP(wxID_ANY, wxBookCtrlBase::OnHelp)
 #endif // wxUSE_HELP
+
+    EVT_DPI_CHANGED(wxBookCtrlBase::WXHandleDPIChanged)
 wxEND_EVENT_TABLE()
 
 // ----------------------------------------------------------------------------
@@ -291,6 +293,16 @@ wxSize wxBookCtrlBase::GetControllerSize() const
 // miscellaneous stuff
 // ----------------------------------------------------------------------------
 
+void wxBookCtrlBase::WXHandleDPIChanged(wxDPIChangedEvent& event)
+{
+    if ( HasImages() )
+    {
+        OnImagesChanged();
+    }
+
+    event.Skip();
+}
+
 #if wxUSE_HELP
 
 void wxBookCtrlBase::OnHelp(wxHelpEvent& event)