From 9a578b9c8f50972a1d46755b63878a004a2e6311 Mon Sep 17 00:00:00 2001
From: Vadim Zeitlin <vadim@wxwidgets.org>
Date: Mon, 27 Sep 2021 18:41:45 +0100
Subject: [PATCH] Update bitmap size automatically on DPI change in wxMSW
 wxToolBar

Remove the now unnecessary wxEVT_DPI_CHANGED event handler in the
sample.
---
 samples/toolbar/toolbar.cpp | 12 ------------
 src/msw/toolbar.cpp         |  4 ++++
 2 files changed, 4 insertions(+), 12 deletions(-)

diff --git a/samples/toolbar/toolbar.cpp b/samples/toolbar/toolbar.cpp
index 22490a3b6b..d002567538 100644
--- a/samples/toolbar/toolbar.cpp
+++ b/samples/toolbar/toolbar.cpp
@@ -111,7 +111,6 @@ public:
     void OnAbout(wxCommandEvent& event);
 
     void OnSize(wxSizeEvent& event);
-    void OnDPIChanged(wxDPIChangedEvent& event);
 
     void OnToggleToolbar(wxCommandEvent& event);
     void OnToggleAnotherToolbar(wxCommandEvent& event);
@@ -242,7 +241,6 @@ enum
 
 wxBEGIN_EVENT_TABLE(MyFrame, wxFrame)
     EVT_SIZE(MyFrame::OnSize)
-    EVT_DPI_CHANGED(MyFrame::OnDPIChanged)
 
     EVT_MENU(wxID_EXIT, MyFrame::OnQuit)
     EVT_MENU(wxID_HELP, MyFrame::OnAbout)
@@ -698,16 +696,6 @@ void MyFrame::OnSize(wxSizeEvent& event)
     }
 }
 
-void MyFrame::OnDPIChanged(wxDPIChangedEvent& event)
-{
-    event.Skip();
-
-    // We check the DPI scaling factor when the toolbar is created, so just
-    // recreate it whenever DPI changes. We could also just update the tools
-    // bitmaps, but this is simpler and doesn't have any significant drawbacks.
-    RecreateToolbar();
-}
-
 void MyFrame::OnToggleToolbar(wxCommandEvent& WXUNUSED(event))
 {
     wxToolBar *tbar = GetToolBar();
diff --git a/src/msw/toolbar.cpp b/src/msw/toolbar.cpp
index 36d5840058..fe7b8f49d2 100644
--- a/src/msw/toolbar.cpp
+++ b/src/msw/toolbar.cpp
@@ -1949,6 +1949,10 @@ void wxToolBar::RealizeHelper()
 
 void wxToolBar::OnDPIChanged(wxDPIChangedEvent& event)
 {
+    // Ensure that when Realize() is called, the bitmaps size corresponding to
+    // the new resolution will be used.
+    SetToolBitmapSize(event.Scale(wxSize(m_defaultWidth, m_defaultHeight)));
+
     // Manually scale the size of the controls. Even though the font has been
     // updated, the internal size of the controls does not.
     wxToolBarToolsList::compatibility_iterator node;