Support #rrggbbaa, #rgb and #rgba colors syntax

Add support for alpha channel in the #rrggbbaa format to
wxColour::GetAsString() and FromString(). This syntax is introduced in
CSS4 spec draft (see https://drafts.csswg.org/css-color/#hex-notation)
and already used by Pango for markup as well.

Also recognize #rgb and #rgba shorter variants in FromString().
This commit is contained in:
Václav Slavík
2016-11-20 12:12:38 +01:00
parent 4aacaa88b7
commit fb27932e4c

View File

@@ -158,16 +158,42 @@ bool wxColourBase::FromString(const wxString& str)
(unsigned char)wxClip(blue, 0, 255),
(unsigned char)wxClip(alpha, 0, 255));
}
else if ( str[0] == wxT('#') && wxStrlen(str) == 7 )
else if ( str[0] == wxT('#') )
{
// hexadecimal prefixed with # (HTML syntax)
// hexadecimal prefixed with # ("HTML syntax")
// see https://drafts.csswg.org/css-color/#hex-notation
size_t len = wxStrlen(str) - 1;
unsigned long tmp;
if (wxSscanf(str.wx_str() + 1, wxT("%lx"), &tmp) != 1)
return false;
Set((unsigned char)(tmp >> 16),
(unsigned char)(tmp >> 8),
(unsigned char)tmp);
switch ( len )
{
case 6: // #rrggbb
tmp = (tmp << 8) + wxALPHA_OPAQUE;
wxFALLTHROUGH;
case 8: // #rrggbbaa
Set((unsigned char)((tmp >> 24) & 0xFF),
(unsigned char)((tmp >> 16) & 0xFF),
(unsigned char)((tmp >> 8) & 0xFF),
(unsigned char)( tmp & 0xFF));
break;
case 3: // #rgb
tmp = (tmp << 4) + 0xF;
wxFALLTHROUGH;
case 4: // #rgba
Set((unsigned char)(((tmp >> 12) & 0xF) * 0x11),
(unsigned char)(((tmp >> 8) & 0xF) * 0x11),
(unsigned char)(((tmp >> 4) & 0xF) * 0x11),
(unsigned char)(( tmp & 0xF) * 0x11));
break;
default:
return false; // unrecognized
}
}
else if (wxTheColourDatabase) // a colour name ?
{
@@ -195,7 +221,8 @@ wxString wxColourBase::GetAsString(long flags) const
{
wxString colName;
const bool isOpaque = Alpha() == wxALPHA_OPAQUE;
const int alpha = Alpha();
const bool isOpaque = alpha == wxALPHA_OPAQUE;
// we can't use the name format if the colour is not opaque as the alpha
// information would be lost
@@ -208,8 +235,8 @@ wxString wxColourBase::GetAsString(long flags) const
if ( colName.empty() )
{
const int red = Red(),
blue = Blue(),
green = Green();
green = Green(),
blue = Blue();
if ( flags & wxC2S_CSS_SYNTAX )
{
@@ -222,15 +249,16 @@ wxString wxColourBase::GetAsString(long flags) const
{
colName.Printf(wxT("rgba(%d, %d, %d, %s)"),
red, green, blue,
wxString::FromCDouble(Alpha() / 255., 3));
wxString::FromCDouble(alpha / 255., 3));
}
}
else if ( flags & wxC2S_HTML_SYNTAX )
{
wxASSERT_MSG( isOpaque, "alpha is lost in HTML syntax" );
// no name for this colour; return it in HTML syntax
if ( isOpaque )
colName.Printf(wxT("#%02X%02X%02X"), red, green, blue);
else
colName.Printf(wxT("#%02X%02X%02X%02X"), red, green, blue, alpha);
}
}