From fd2cf1f4e282e6b834458b372f1b3217dab17bd5 Mon Sep 17 00:00:00 2001
From: Maarten Bent <MaartenBent@users.noreply.github.com>
Date: Thu, 10 Jan 2019 21:54:16 +0100
Subject: [PATCH] Fix wx[Check]ListBox font and margin on DPI change

These control are drawn using a wxDC. When the DPI changes, call SetFont
to update the font of the wxDC. First call wxListBoxBase::SetFont() so
m_font is updated to the new DPI, then use this font in the wxDC.
For wxCheckListBox update the margins to fit the changed checkbox size.
---
 include/wx/msw/checklst.h |  2 ++
 include/wx/msw/listbox.h  |  2 ++
 src/msw/checklst.cpp      | 15 ++++++++++++++-
 src/msw/listbox.cpp       | 16 ++++++++++++----
 4 files changed, 30 insertions(+), 5 deletions(-)

diff --git a/include/wx/msw/checklst.h b/include/wx/msw/checklst.h
index 8fa50253ba..91180c6a3e 100644
--- a/include/wx/msw/checklst.h
+++ b/include/wx/msw/checklst.h
@@ -81,6 +81,8 @@ protected:
         ProcessCommand(event);
     }
 
+    virtual void MSWUpdateFontOnDPIChange(const wxSize& newDPI) wxOVERRIDE;
+
     wxSize DoGetBestClientSize() const wxOVERRIDE;
 
     wxDECLARE_EVENT_TABLE();
diff --git a/include/wx/msw/listbox.h b/include/wx/msw/listbox.h
index 3ba0175320..3c910e325e 100644
--- a/include/wx/msw/listbox.h
+++ b/include/wx/msw/listbox.h
@@ -181,6 +181,8 @@ protected:
         return wxSize(w, h);
     }
 
+    virtual void MSWUpdateFontOnDPIChange(const wxSize& newDPI) wxOVERRIDE;
+
     // free memory (common part of Clear() and dtor)
     void Free();
 
diff --git a/src/msw/checklst.cpp b/src/msw/checklst.cpp
index 753bccc335..911dd1cb86 100644
--- a/src/msw/checklst.cpp
+++ b/src/msw/checklst.cpp
@@ -255,7 +255,20 @@ bool wxCheckListBox::MSWOnMeasure(WXMEASUREITEMSTRUCT *item)
     }
 
     return false;
-  }
+}
+
+void wxCheckListBox::MSWUpdateFontOnDPIChange(const wxSize& newDPI)
+{
+    wxCheckListBoxBase::MSWUpdateFontOnDPIChange(newDPI);
+
+    wxSize size = wxRendererNative::Get().GetCheckBoxSize(this);
+    size.x += 2 * CHECKMARK_EXTRA_SPACE + CHECKMARK_LABEL_SPACE;
+
+    for ( unsigned int i = 0; i < GetCount(); ++i )
+    {
+        GetItem(i)->SetMarginWidth(size.GetWidth());
+    }
+}
 
 // check items
 // -----------
diff --git a/src/msw/listbox.cpp b/src/msw/listbox.cpp
index 02f2ecb9e5..128f679d2c 100644
--- a/src/msw/listbox.cpp
+++ b/src/msw/listbox.cpp
@@ -190,6 +190,14 @@ WXDWORD wxListBox::MSWGetStyle(long style, WXDWORD *exstyle) const
     return msStyle;
 }
 
+void wxListBox::MSWUpdateFontOnDPIChange(const wxSize& newDPI)
+{
+    wxListBoxBase::MSWUpdateFontOnDPIChange(newDPI);
+
+    if ( m_font.IsOk() )
+        SetFont(m_font);
+}
+
 void wxListBox::OnInternalIdle()
 {
     wxWindow::OnInternalIdle();
@@ -695,22 +703,22 @@ bool wxListBox::MSWCommand(WXUINT param, WXWORD WXUNUSED(id))
 
 bool wxListBox::SetFont(const wxFont &font)
 {
+    wxListBoxBase::SetFont(font);
+
     if ( HasFlag(wxLB_OWNERDRAW) )
     {
         const unsigned count = m_aItems.GetCount();
         for ( unsigned i = 0; i < count; i++ )
-            m_aItems[i]->SetFont(font);
+            m_aItems[i]->SetFont(m_font);
 
         // Non owner drawn list boxes update the item height on their own, but
         // we need to do it manually in the owner drawn case.
         wxClientDC dc(this);
-        dc.SetFont(font);
+        dc.SetFont(m_font);
         SendMessage(GetHwnd(), LB_SETITEMHEIGHT, 0,
                     dc.GetCharHeight() + 2 * LISTBOX_EXTRA_SPACE);
     }
 
-    wxListBoxBase::SetFont(font);
-
     return true;
 }