/// <devdoc>
/// Selects the specified object into the dc. If the specified object is the same as the one currently selected
/// in the dc, the object is not set and a null value is returned.
/// </devdoc>
public IntPtr SelectFont(WindowsFont font)
{
// Fonts are one of the most expensive objects to select in an hdc and in many cases we are passed a Font that is the
// same as the one already selected in the dc so to avoid a perf hit we get the hdc font's log font and compare it
// with the one passed in before selecting it in the hdc.
// Also, we avoid performing GDI operations that if done on an enhanced metafile DC would add an entry to it, hence
// reducing the size of the metafile.
if (font.Equals(this.Font))
{
return(IntPtr.Zero);
}
IntPtr result = SelectObject(font.Hfont, GdiObjectType.Font);
WindowsFont previousFont = selectedFont;
selectedFont = font;
hCurrentFont = font.Hfont;
// the measurement DC always leaves fonts selected for pref reasons.
// in this case, we need to diposse the font since the original
// creator didn't fully dispose.
if (previousFont != null)
{
#if DEBUG
//Disabling this assert until DevDiv Bugs 95968 gets fixed
//Debug.Assert(previousFont.Hfont != IntPtr.Zero, "A font has been disposed before it was unselected from the DC. This will leak a GDI handle on Win9x! Call ResetFont()");
#endif
if (MeasurementDCInfo.IsMeasurementDC(this))
{
previousFont.Dispose();
}
}
#if OPTIMIZED_MEASUREMENTDC
// once we've changed the font, update the last used font.
if (MeasurementDCInfo.IsMeasurementDC(this))
{
if (result != IntPtr.Zero)
{
MeasurementDCInfo.LastUsedFont = font;
}
else
{
// there was an error selecting the Font into the DC, we dont know anything about it.
MeasurementDCInfo.Reset();
}
}
#endif
return(result);
}
/// <devdoc>
/// Selects the specified object into the dc. If the specified object is the same as the one currently selected
/// in the dc, the object is not set and a null value is returned.
/// </devdoc>
public IntPtr SelectFont( WindowsFont font )
{
// Fonts are one of the most expensive objects to select in an hdc and in many cases we are passed a Font that is the
// same as the one already selected in the dc so to avoid a perf hit we get the hdc font's log font and compare it
// with the one passed in before selecting it in the hdc.
// Also, we avoid performing GDI operations that if done on an enhanced metafile DC would add an entry to it, hence
// reducing the size of the metafile.
if( font.Equals( this.Font ))
{
return IntPtr.Zero;
}
IntPtr result = SelectObject( font.Hfont, GdiObjectType.Font);
WindowsFont previousFont = selectedFont;
selectedFont = font;
hCurrentFont = font.Hfont;
// the measurement DC always leaves fonts selected for pref reasons.
// in this case, we need to diposse the font since the original
// creator didn't fully dispose.
if (previousFont != null) {
#if DEBUG
//Disabling this assert until DevDiv Bugs 95968 gets fixed
//Debug.Assert(previousFont.Hfont != IntPtr.Zero, "A font has been disposed before it was unselected from the DC. This will leak a GDI handle on Win9x! Call ResetFont()");
#endif
if (MeasurementDCInfo.IsMeasurementDC(this)) {
previousFont.Dispose();
}
}
#if OPTIMIZED_MEASUREMENTDC
// once we've changed the font, update the last used font.
if (MeasurementDCInfo.IsMeasurementDC(this))
{
if (result != IntPtr.Zero)
{
MeasurementDCInfo.LastUsedFont = font;
}
else
{
// there was an error selecting the Font into the DC, we dont know anything about it.
MeasurementDCInfo.Reset();
}
}
#endif
return result;
}
