X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/c7a49742ec6b4effe012dc7204db307e1267bf6a..14722c43c30918cd8fbba956b50ac3426d2fe339:/src/gtk/font.cpp

diff --git a/src/gtk/font.cpp b/src/gtk/font.cpp
index 1ae79d7eb7..06260392d9 100644
--- a/src/gtk/font.cpp
+++ b/src/gtk/font.cpp
@@ -487,3 +487,66 @@ wxGDIRefData* wxFont::CloneGDIRefData(const wxGDIRefData* data) const
 {
     return new wxFontRefData(*static_cast<const wxFontRefData*>(data));
 }
+
+bool wxFont::GTKSetPangoAttrs(PangoLayout* layout) const
+{
+    if (!IsOk() || !(GetUnderlined() || GetStrikethrough()))
+        return false;
+
+    PangoAttrList* attrs = pango_attr_list_new();
+    PangoAttribute* a;
+
+    if (wx_pango_version_check(1,16,0))
+    {
+        // a PangoLayout which has leading/trailing spaces with underlined font
+        // is not correctly drawn by this pango version: Pango won't underline the spaces.
+        // This can be a problem; e.g. wxHTML rendering of underlined text relies on
+        // this behaviour. To workaround this problem, we use a special hack here
+        // suggested by pango maintainer Behdad Esfahbod: we prepend and append two
+        // empty space characters and give them a dummy colour attribute.
+        // This will force Pango to underline the leading/trailing spaces, too.
+
+        const char* text = pango_layout_get_text(layout);
+        const size_t n = strlen(text);
+        if ((n > 0 && text[0] == ' ') || (n > 1 && text[n - 1] == ' '))
+        {
+            wxCharBuffer buf(n + 6);
+            // copy the leading U+200C ZERO WIDTH NON-JOINER encoded in UTF8 format
+            memcpy(buf.data(), "\342\200\214", 3);
+            // copy the user string
+            memcpy(buf.data() + 3, text, n);
+            // copy the trailing U+200C ZERO WIDTH NON-JOINER encoded in UTF8 format
+            memcpy(buf.data() + 3 + n, "\342\200\214", 3);
+
+            pango_layout_set_text(layout, buf, n + 6);
+
+            // Add dummy attributes (use colour as it's invisible anyhow for 0
+            // width spaces) to ensure that the spaces in the beginning/end of the
+            // string are underlined too.
+            a = pango_attr_foreground_new(0x0057, 0x52A9, 0xD614);
+            a->start_index = 0;
+            a->end_index = 3;
+            pango_attr_list_insert(attrs, a);
+
+            a = pango_attr_foreground_new(0x0057, 0x52A9, 0xD614);
+            a->start_index = n + 3;
+            a->end_index = n + 6;
+            pango_attr_list_insert(attrs, a);
+        }
+    }
+    if (GetUnderlined())
+    {
+        a = pango_attr_underline_new(PANGO_UNDERLINE_SINGLE);
+        pango_attr_list_insert(attrs, a);
+    }
+    if (GetStrikethrough())
+    {
+        a = pango_attr_strikethrough_new(true);
+        pango_attr_list_insert(attrs, a);
+    }
+
+    pango_layout_set_attributes(layout, attrs);
+    pango_attr_list_unref(attrs);
+
+    return true;
+}