Merge branch 'underline-improvements' of https://github.com/MaartenBent/wxWidgets

Add support for different underline types and colour to wxTextCtrl.

See https://github.com/wxWidgets/wxWidgets/pull/1406

Closes #17124.

interface/wx/textctrl.h

@@ -219,6 +219,19 @@ enum wxTextAttrLineSpacing
 };
 
 
+/**
+    Underline types that can be used in wxTextAttr::SetFontUnderline().
+
+    @since 3.1.3
+*/
+enum wxTextAttrUnderlineType
+{
+     wxTEXT_ATTR_UNDERLINE_NONE,
+     wxTEXT_ATTR_UNDERLINE_SOLID,
+     wxTEXT_ATTR_UNDERLINE_DOUBLE,
+     wxTEXT_ATTR_UNDERLINE_SPECIAL
+};
+
 /**
     Describes the possible return values of wxTextCtrl::HitTest().
 
@@ -422,6 +435,20 @@ public:
     */
     bool GetFontUnderlined() const;
 
+    /**
+        Returns the underline type, which is one of the @wxTextAttrUnderlineType values.
+
+        @since 3.1.3
+    */
+    wxTextAttrUnderlineType GetUnderlineType() const;
+
+    /**
+        Returns the underline color used. wxNullColour when the text colour is used.
+
+        @since 3.1.3
+    */
+    const wxColour& GetUnderlineColour() const;
+
     /**
         Returns the font weight.
     */
@@ -803,10 +830,34 @@ public:
     void SetFontStyle(wxFontStyle fontStyle);
 
     /**
-        Sets the font underlining.
+        Sets the font underlining (solid line, text colour).
     */
     void SetFontUnderlined(bool underlined);
 
+    /**
+        Sets the font underlining.
+
+        @param type Type of underline.
+
+        @param colour Colour to use for underlining, text colour is used by
+        default.
+
+        @note On wxMSW, wxTEXT_ATTR_UNDERLINE_DOUBLE is shown as
+        wxTEXT_ATTR_UNDERLINE_SOLID. There is only a limited number of colours
+        supported, the RGB values are listed
+        <a href="https://docs.microsoft.com/en-us/windows/win32/api/tom/nf-tom-itextdocument2-geteffectcolor">here</a>.
+        wxTEXT_ATTR_UNDERLINE_SPECIAL is shown as a waved line.
+
+        @note On wxGTK, underline colour is only supported by wxGTK3.
+        wxTEXT_ATTR_UNDERLINE_SPECIAL is shown as a waved line. GTK might
+        overrule the colour of wxTEXT_ATTR_UNDERLINE_SPECIAL.
+
+        @note On wxOSX, wxTEXT_ATTR_UNDERLINE_SPECIAL is shown as a dotted line.
+
+        @since 3.1.3
+    */
+    void SetFontUnderlined(wxTextAttrUnderlineType type, const wxColour& colour = wxNullColour);
+
     /**
         Sets the font weight.
     */