Merge branch 'msw-font-dpi'

Various wxFont-related fixes and refactorings in preparation for adding
per-monitor DPI support.

Closes https://github.com/wxWidgets/wxWidgets/pull/1408

include/wx/fontutil.h

@@ -118,7 +118,20 @@ public:
     // set the XFLD
     void SetXFontName(const wxString& xFontName);
 #elif defined(__WXMSW__)
-    wxNativeFontInfo(const LOGFONT& lf_) : lf(lf_), pointSize(0.0f) { }
+    wxNativeFontInfo(const LOGFONT& lf_);
+
+    // MSW-specific: get the height value in pixels using LOGFONT convention
+    // (i.e. negative) corresponding to the given size in points and DPI.
+    static int GetLogFontHeightAtPPI(float size, int ppi)
+    {
+        return -wxRound(size * ppi / 72.0);
+    }
+
+    // And the same thing for the size of this font.
+    int GetLogFontHeightAtPPI(int ppi) const
+    {
+        return GetLogFontHeightAtPPI(pointSize, ppi);
+    }
 
     LOGFONT      lf;
 

include/wx/msw/private.h

@@ -961,10 +961,14 @@ extern const wxCursor *wxGetGlobalCursor(); // from msw/cursor.cpp
 WXDLLIMPEXP_CORE void wxGetCursorPosMSW(POINT* pt);
 
 WXDLLIMPEXP_CORE void wxGetCharSize(WXHWND wnd, int *x, int *y, const wxFont& the_font);
-WXDLLIMPEXP_CORE void wxFillLogFont(LOGFONT *logFont, const wxFont *font);
-WXDLLIMPEXP_CORE wxFont wxCreateFontFromLogFont(const LOGFONT *logFont);
 WXDLLIMPEXP_CORE wxFontEncoding wxGetFontEncFromCharSet(int charset);
 
+inline void wxSetWindowFont(HWND hwnd, const wxFont& font)
+{
+    ::SendMessage(hwnd, WM_SETFONT,
+                  (WPARAM)GetHfontOf(font), MAKELPARAM(TRUE, 0));
+}
+
 WXDLLIMPEXP_CORE void wxSliderEvent(WXHWND control, WXWORD wParam, WXWORD pos);
 WXDLLIMPEXP_CORE void wxScrollBarEvent(WXHWND hbar, WXWORD wParam, WXWORD pos);
 

include/wx/msw/subwin.h

@@ -113,14 +113,11 @@ public:
     // set font for all windows
     void SetFont(const wxFont& font)
     {
-        HFONT hfont = GetHfontOf(font);
-        wxCHECK_RET( hfont, wxT("invalid font") );
-
         for ( size_t n = 0; n < m_count; n++ )
         {
             if ( m_hwnds[n] )
             {
-                ::SendMessage(m_hwnds[n], WM_SETFONT, (WPARAM)hfont, 0);
+                wxSetWindowFont(m_hwnds[n], font);
 
                 // otherwise the window might not be redrawn correctly
                 ::InvalidateRect(m_hwnds[n], NULL, FALSE /* don't erase bg */);

src/msw/font.cpp

@@ -152,6 +152,16 @@ public:
         return m_hFont != 0;
     }
 
+    int GetLogFontHeight() const
+    {
+        return m_nativeFontInfo.lf.lfHeight;
+    }
+
+    int GetLogFontHeightAtPPI(int ppi) const
+    {
+        return m_nativeFontInfo.GetLogFontHeightAtPPI(ppi);
+    }
+
     // ... and setters: notice that all of them invalidate the currently
     // allocated HFONT, if any, so that the next call to GetHFONT() recreates a
     // new one
@@ -223,6 +233,13 @@ public:
         m_nativeFontInfo.SetEncoding(encoding);
     }
 
+    void SetLogFontHeight(int height)
+    {
+        Free();
+
+        m_nativeFontInfo.lf.lfHeight = height;
+    }
+
     const wxNativeFontInfo& GetNativeFontInfo() const
     {
         // we need to create the font now to get the corresponding LOGFONT if
@@ -385,6 +402,15 @@ void wxFontRefData::Free()
 // wxNativeFontInfo
 // ----------------------------------------------------------------------------
 
+wxNativeFontInfo::wxNativeFontInfo(const LOGFONT& lf_)
+    : lf(lf_)
+{
+    // Determine the size in points using the primary screen DPI as we don't
+    // have anything else here.
+    const float ppi = ::GetDeviceCaps(ScreenHDC(), LOGPIXELSY);
+    pointSize = 72.0f * abs(lf.lfHeight) / ppi;
+}
+
 void wxNativeFontInfo::Init()
 {
     wxZeroMemory(lf);
@@ -402,14 +428,7 @@ void wxNativeFontInfo::Init()
 
 float wxNativeFontInfo::GetFractionalPointSize() const
 {
-    if ( pointSize != 0.0f )
+    return pointSize;
-        return pointSize;
-
-    // FIXME: using the screen here results in incorrect font size calculation
-    //        for printing!
-    const int ppInch = ::GetDeviceCaps(ScreenHDC(), LOGPIXELSY);
-
-    return (72.0*abs(lf.lfHeight)) / (double) ppInch;
 }
 
 wxSize wxNativeFontInfo::GetPixelSize() const
@@ -490,17 +509,14 @@ wxFontEncoding wxNativeFontInfo::GetEncoding() const
     return wxGetFontEncFromCharSet(lf.lfCharSet);
 }
 
-void wxNativeFontInfo::SetFractionalPointSize(float pointsize)
+void wxNativeFontInfo::SetFractionalPointSize(float pointSizeNew)
 {
-    // Store it to be able to return it from GetFractionalPointSize() later
+    // We don't have the correct DPI to use here, so use that of the
-    // exactly.
+    // primary screen.
-    pointSize = pointsize;
+    const int ppi = ::GetDeviceCaps(ScreenHDC(), LOGPIXELSY);
+    lf.lfHeight = GetLogFontHeightAtPPI(pointSizeNew, ppi);
 
-    // FIXME: using the screen here results in incorrect font size calculation
+    pointSize = pointSizeNew;
-    //        for printing!
-    const int ppInch = ::GetDeviceCaps(ScreenHDC(), LOGPIXELSY);
-
-    lf.lfHeight = -wxRound(pointsize*((double)ppInch)/72.0);
 }
 
 void wxNativeFontInfo::SetPixelSize(const wxSize& pixelSize)
@@ -516,6 +532,11 @@ void wxNativeFontInfo::SetPixelSize(const wxSize& pixelSize)
     // versions by passing a negative value explicitly itself.
     lf.lfHeight = -abs(pixelSize.GetHeight());
     lf.lfWidth = pixelSize.GetWidth();
+
+    // We don't have the right DPI to use here neither, but we need to update
+    // the point size too, so fall back to the default.
+    const float ppi = ::GetDeviceCaps(ScreenHDC(), LOGPIXELSY);
+    pointSize = 72.0f * pixelSize.GetHeight() / ppi;
 }
 
 void wxNativeFontInfo::SetStyle(wxFontStyle style)
@@ -855,7 +876,6 @@ void wxFont::SetFractionalPointSize(float pointSize)
 {
     AllocExclusive();
 
-    M_FONTDATA->Free();
     M_FONTDATA->SetFractionalPointSize(pointSize);
 }
 

src/msw/fontdlg.cpp

@@ -36,6 +36,8 @@
     #include "wx/math.h"
 #endif
 
+#include "wx/fontutil.h"
+
 #include <stdlib.h>
 #include <string.h>
 
@@ -118,7 +120,7 @@ int wxFontDialog::ShowModal()
     if ( m_fontData.m_initialFont.IsOk() )
     {
         flags |= CF_INITTOLOGFONTSTRUCT;
-        wxFillLogFont(&logFont, &m_fontData.m_initialFont);
+        logFont = m_fontData.m_initialFont.GetNativeFontInfo()->lf;
     }
 
     if ( m_fontData.m_fontColour.IsOk() )
@@ -150,7 +152,7 @@ int wxFontDialog::ShowModal()
     if ( ChooseFont(&chooseFontStruct) != 0 )
     {
         wxRGBToColour(m_fontData.m_fontColour, chooseFontStruct.rgbColors);
-        m_fontData.m_chosenFont = wxCreateFontFromLogFont(&logFont);
+        m_fontData.m_chosenFont = wxFont(wxNativeFontInfo(logFont));
         m_fontData.EncodingInfo().facename = logFont.lfFaceName;
         m_fontData.EncodingInfo().charset = logFont.lfCharSet;
 

src/msw/fontutil.cpp

@@ -264,35 +264,3 @@ wxFontEncoding wxGetFontEncFromCharSet(int cs)
 
     return fontEncoding;
 }
-
-// ----------------------------------------------------------------------------
-// wxFont <-> LOGFONT conversion
-// ----------------------------------------------------------------------------
-
-void wxFillLogFont(LOGFONT *logFont, const wxFont *font)
-{
-    wxNativeFontInfo fi;
-
-    // maybe we already have LOGFONT for this font?
-    const wxNativeFontInfo *pFI = font->GetNativeFontInfo();
-    if ( !pFI )
-    {
-        // use wxNativeFontInfo methods to build a LOGFONT for this font
-        fi.InitFromFont(*font);
-
-        pFI = &fi;
-    }
-
-    // transfer all the data to LOGFONT
-    *logFont = pFI->lf;
-}
-
-wxFont wxCreateFontFromLogFont(const LOGFONT *logFont)
-{
-    wxNativeFontInfo info;
-
-    info.lf = *logFont;
-
-    return wxFont(info);
-}
-

src/msw/listctrl.cpp

@@ -620,8 +620,7 @@ bool wxListCtrl::SetHeaderAttr(const wxItemAttr& attr)
 
             // We need to tell the header about its new font to let it compute
             // its new height.
-            ::SendMessage(hwndHdr, WM_SETFONT,
+            wxSetWindowFont(hwndHdr, font);
-                          (WPARAM)GetHfontOf(font), MAKELPARAM(TRUE, 0));
         }
 
         // Refreshing the listview makes it notice the change in height of its

src/msw/renderer.cpp

@@ -552,7 +552,8 @@ int wxRendererMSW::GetHeaderButtonHeight(wxWindow * win)
         font = win->GetFont();
     if ( !font.IsOk() )
         wxSystemSettings::GetFont(wxSYS_DEFAULT_GUI_FONT);
-    ::SendMessage(hwndHeader, WM_SETFONT, (WPARAM)GetHfontOf(font), 0);
+
+    wxSetWindowFont(hwndHeader, font);
 
     // initialize the struct filled with the values by Header_Layout()
     RECT parentRect = { 0, 0, 100, 100 };

src/msw/settings.cpp

@@ -345,7 +345,7 @@ extern wxFont wxGetCCDefaultFont()
                 0
            ) )
     {
-        return wxFont(wxCreateFontFromLogFont(&lf));
+        return wxFont(lf);
     }
     else
     {

src/msw/spinctrl.cpp

@@ -564,8 +564,7 @@ bool wxSpinCtrl::SetFont(const wxFont& font)
         return false;
     }
 
-    WXHANDLE hFont = GetFont().GetResourceHandle();
+    wxSetWindowFont(GetBuddyHwnd(), GetFont());
-    (void)::SendMessage(GetBuddyHwnd(), WM_SETFONT, (WPARAM)hFont, TRUE);
 
     return true;
 }

src/msw/textctrl.cpp

@@ -40,6 +40,7 @@
     #include "wx/wxcrtvararg.h"
 #endif
 
+#include "wx/fontutil.h"
 #include "wx/scopedptr.h"
 #include "wx/stack.h"
 #include "wx/sysopt.h"
@@ -2829,14 +2830,13 @@ bool wxTextCtrl::MSWSetCharFormat(const wxTextAttr& style, long start, long end)
                      CFM_ITALIC | CFM_BOLD | CFM_UNDERLINE | CFM_STRIKEOUT;
 
         // fill in data from LOGFONT but recalculate lfHeight because we need
-        // the real height in twips and not the negative number which
+        // the real height in twips and not the negative number used inside
-        // wxFillLogFont() returns (this is correct in general and works with
+        // LOGFONT returns (this is correct in general and works with
         // the Windows font mapper, but not here)
 
         wxFont font(style.GetFont());
 
-        LOGFONT lf;
+        LOGFONT lf = font.GetNativeFontInfo()->lf;
-        wxFillLogFont(&lf, &font);
         cf.yHeight = 20*font.GetPointSize(); // 1 pt = 20 twips
         cf.bCharSet = lf.lfCharSet;
         cf.bPitchAndFamily = lf.lfPitchAndFamily;
@@ -3126,8 +3126,9 @@ bool wxTextCtrl::GetStyle(long position, wxTextAttr& style)
     LOGFONT lf;
     // Convert the height from the units of 1/20th of the point in which
     // CHARFORMAT stores it to pixel-based units used by LOGFONT.
-    const wxCoord ppi = wxClientDC(this).GetPPI().y;
+    // Note that RichEdit seems to always use standard DPI of 96, even when the
-    lf.lfHeight = -MulDiv(cf.yHeight/20, ppi, 72);
+    // window is a monitor using a higher DPI.
+    lf.lfHeight = wxNativeFontInfo::GetLogFontHeightAtPPI(cf.yHeight/20.0f, 96);
     lf.lfWidth = 0;
     lf.lfCharSet = ANSI_CHARSET; // FIXME: how to get correct charset?
     lf.lfClipPrecision = 0;
@@ -3160,7 +3161,7 @@ bool wxTextCtrl::GetStyle(long position, wxTextAttr& style)
     else
         lf.lfWeight = FW_NORMAL;
 
-    wxFont font = wxCreateFontFromLogFont(& lf);
+    wxFont font(lf);
     if (font.IsOk())
     {
         style.SetFont(font);

src/msw/window.cpp

@@ -827,11 +827,7 @@ bool wxWindowMSW::SetFont(const wxFont& font)
         // just been reset and in this case we need to change the font used by
         // the native window to the default for this class, i.e. exactly what
         // GetFont() returns
-        WXHANDLE hFont = GetFont().GetResourceHandle();
+        wxSetWindowFont(hWnd, GetFont());
-
-        wxASSERT_MSG( hFont, wxT("should have valid font") );
-
-        ::SendMessage(hWnd, WM_SETFONT, (WPARAM)hFont, MAKELPARAM(TRUE, 0));
     }
 
     return true;
@@ -7425,7 +7421,12 @@ static TEXTMETRIC wxGetTextMetrics(const wxWindowMSW *win)
 
 #if !wxDIALOG_UNIT_COMPATIBILITY
     // and select the current font into it
-    HFONT hfont = GetHfontOf(win->GetFont());
+
+    // Note that it's important to extend the lifetime of the possibly
+    // temporary wxFont returned by GetFont() to ensure that its HFONT remains
+    // valid.
+    const wxFont& f(win->GetFont());
+    HFONT hfont = GetHfontOf(f);
     if ( hfont )
     {
         hfont = (HFONT)::SelectObject(hdc, hfont);