Add support for fractional font scaling to wxGTK3

Respect the system font scaling parameter (e.g. "Fonts->Scaling Factor"
in Gnome Tweaks, "Force font DPI" in KDE System Settings or
GDK_DPI_SCALE environment variable) when drawing text using wxFont.

This ensures that generic widgets have their text scaled appropriately
to be consistent with native widgets.

Closes https://github.com/wxWidgets/wxWidgets/pull/1635
This commit is contained in:
iwbnwif
2019-11-04 20:04:12 +00:00
committed by Vadim Zeitlin
parent 33da780ecf
commit fbc75ec8e0

View File

@@ -526,6 +526,9 @@ protected:
WindowHDC m_mswWindowHDC;
int m_mswStateSavedDC;
#endif
#ifdef __WXGTK__
float m_fontScalingFactor;
#endif
private:
cairo_t* m_context;
@@ -2360,6 +2363,14 @@ wxCairoContext::~wxCairoContext()
void wxCairoContext::Init(cairo_t *context)
{
#ifdef __WXGTK__
// Attempt to find the system font scaling parameter (e.g. "Fonts->Scaling
// Factor" in Gnome Tweaks, "Force font DPI" in KDE System Settings or
// GDK_DPI_SCALE environment variable).
GdkScreen* screen = gdk_screen_get_default();
m_fontScalingFactor = screen ? gdk_screen_get_resolution(screen) / 96.0 : 1.0;
#endif
m_context = context;
if ( m_context )
{
@@ -2660,9 +2671,12 @@ void wxCairoContext::DoDrawText(const wxString& str, wxDouble x, wxDouble y)
fontData->Apply(this);
#ifdef __WXGTK__
const wxFont& font = fontData->GetFont();
wxFont font = fontData->GetFont();
if ( font.IsOk() )
{
// Apply GDK font scaling factor.
font.Scale(m_fontScalingFactor);
wxGtkObject<PangoLayout> layout(pango_cairo_create_layout (m_context));
pango_layout_set_font_description(layout, font.GetNativeFontInfo()->description);
pango_layout_set_text(layout, data, data.length());
@@ -2710,7 +2724,7 @@ void wxCairoContext::GetTextExtent( const wxString &str, wxDouble *width, wxDoub
#ifdef __WXGTK__
// Use Pango instead of Cairo toy font API if we have the font.
const wxFont& font = fontData->GetFont();
wxFont font = fontData->GetFont();
if ( font.IsOk() )
{
// Note that there is no need to call Apply() at all in this case, it
@@ -2718,6 +2732,9 @@ void wxCairoContext::GetTextExtent( const wxString &str, wxDouble *width, wxDoub
// measuring its extent.
int w, h;
// Apply GDK font scaling factor.
font.Scale(m_fontScalingFactor);
wxGtkObject<PangoLayout> layout(pango_cairo_create_layout (m_context));
pango_layout_set_font_description(layout, font.GetNativeFontInfo()->description);
const wxCharBuffer data = str.utf8_str();
@@ -2787,7 +2804,11 @@ void wxCairoContext::GetPartialTextExtents(const wxString& text, wxArrayDouble&
if (data.length())
{
wxGtkObject<PangoLayout> layout(pango_cairo_create_layout(m_context));
const wxFont& font = static_cast<wxCairoFontData*>(m_font.GetRefData())->GetFont();
wxFont font = static_cast<wxCairoFontData*>(m_font.GetRefData())->GetFont();
// Apply GDK font scaling factor.
font.Scale(m_fontScalingFactor);
pango_layout_set_font_description(layout, font.GetNativeFontInfo()->description);
pango_layout_set_text(layout, data, data.length());
PangoLayoutIter* iter = pango_layout_get_iter(layout);