+ * Tries to test an attribute of one style in the given window @win. The library
+ * may not be able to determine the attribute; if not, this returns %FALSE (0).
+ * If it can, it returns %TRUE (1) and stores the value in the location pointed
+ * at by @result.
+ * <note><para>
+ * As usual, it is legal for @result to be %NULL, although fairly pointless.
+ * </para></note>
+ *
+ * The meaning of the value depends on the hint which was tested:
+ * <variablelist>
+ * <varlistentry>
+ * <term>%stylehint_Indentation, %stylehint_ParaIndentation</term>
+ * <listitem><para>The indentation and paragraph indentation. These are in a
+ * metric which is platform-dependent.</para>
+ * <note><para>Most likely either characters or pixels.</para></note>
+ * </listitem>
+ * </varlistentry>
+ * <varlistentry>
+ * <term>%stylehint_Justification</term>
+ * <listitem><para>One of the constants %stylehint_just_LeftFlush,
+ * %stylehint_just_LeftRight, %stylehint_just_Centered, or
+ * %stylehint_just_RightFlush.</para></listitem>
+ * </varlistentry>
+ * <varlistentry>
+ * <term>%stylehint_Size</term>
+ * <listitem><para>The font size. Again, this is in a platform-dependent
+ * metric.</para>
+ * <note><para>Pixels, points, or simply 1 if the library does not support
+ * varying font sizes.</para></note>
+ * </listitem>
+ * </varlistentry>
+ * <varlistentry>
+ * <term>%stylehint_Weight</term>
+ * <listitem><para>1 for heavy-weight fonts (boldface), 0 for normal weight,
+ * and -1 for light-weight fonts.</para></listitem>
+ * </varlistentry>
+ * <varlistentry>
+ * <term>%stylehint_Oblique</term>
+ * <listitem><para>1 for oblique fonts (italic), or 0 for normal angle.</para>
+ * </listitem>
+ * </varlistentry>
+ * <varlistentry>
+ * <term>%stylehint_Proportional</term>
+ * <listitem><para>1 for proportional-width fonts, or 0 for fixed-width.
+ * </para></listitem>
+ * </varlistentry>
+ * <varlistentry>
+ * <term>%stylehint_TextColor, %stylehint_BackColor</term>
+ * <listitem><para>These are values from 0x00000000 to 0x00FFFFFF, encoded as
+ * described in <link
+ * linkend="chimara-Suggesting-the-Appearance-of-Styles">Suggesting the
+ * Appearance of Styles</link>.</para></listitem>
+ * </varlistentry>
+ * <varlistentry>
+ * <term>%stylehint_ReverseColor</term>
+ * <listitem><para>0 for normal printing, 1 if the foreground and background
+ * colors are reversed.</para></listitem>
+ * </varlistentry>
+ * </variablelist>
+ *
+ * Returns: TRUE upon successul retrieval, otherwise FALSE.