+/// ensure correct mode, possibly by opening \ensuremath or \lyxmathsym
+bool ensureMath(WriteStream & os, bool needs_mathmode = true,
+ bool macro = false, bool textmode_macro = false);
+
+/// ensure the requested mode, possibly by closing \ensuremath or \lyxmathsym
+int ensureMode(WriteStream & os, InsetMath::mode_type mode, bool locked, bool ascii);
+
+
+/**
+ * MathEnsurer - utility class for ensuring math mode
+ *
+ * A local variable of this type can be used to either ensure math mode
+ * or delay the writing of a pending brace when outputting LaTeX.
+ * A LyX MathMacro is always assumed needing a math mode environment, while
+ * no assumption is made for macros defined through \newcommand or \def.
+ *
+ * Example 1:
+ *
+ * MathEnsurer ensurer(os);
+ *
+ * If not already in math mode, inserts an \ensuremath command followed
+ * by an open brace. This brace will be automatically closed when exiting
+ * math mode. Math mode is automatically exited when writing something
+ * that doesn't explicitly require math mode.
+ *
+ * Example 2:
+ *
+ * MathEnsurer ensurer(os, false);
+ *
+ * Simply suspend writing a closing brace until the end of ensurer's scope.
+ *
+ * Example 3:
+ *
+ * MathEnsurer ensurer(os, needs_mathmode, true, textmode_macro);
+ *
+ * This form is mainly used for math macros as they are treated specially.
+ * In essence, the macros defined in the lib/symbols file and tagged as
+ * textmode will be enclosed in \lyxmathsym if they appear in a math mode
+ * environment, while macros defined in the preamble or ERT are left as is.
+ * The third parameter must be set to true and the fourth parameter has also
+ * to be specified. Only the following 3 different cases are handled.
+ *
+ * When the needs_mathmode parameter is true the behavior is as in Example 1.
+ * This is the case for a LyX MathMacro or a macro not tagged as textmode.
+ *
+ * When the needs_mathmode and textmode_macro parameters are both false the
+ * macro is left in the same (text or math mode) environment it was entered.
+ * This is because it is assumed that the macro was designed for that mode
+ * and we have no way to tell the contrary.
+ * This is the case for macros defined by using \newcommand or \def in ERT.
+ *
+ * When the needs_mathmode parameter is false while textmode_macro is true the
+ * macro will be enclosed in \lyxmathsym if it appears in a math mode environment.
+ * This is the case for the macros tagged as textmode in lib/symbols.
+ */
+class MathEnsurer
+{
+public:
+ ///
+ explicit MathEnsurer(WriteStream & os, bool needs_mathmode = true,
+ bool macro = false, bool textmode_macro = false)
+ : os_(os), brace_(ensureMath(os, needs_mathmode, macro, textmode_macro)) {}
+ ///
+ ~MathEnsurer() { os_.pendingBrace(brace_); }
+private:
+ ///
+ WriteStream & os_;
+ ///
+ bool brace_;
+};
+
+
+/**
+ * ModeSpecifier - utility class for specifying a given mode (math or text)
+ *
+ * A local variable of this type can be used to specify that a command or
+ * environment works in a given mode. For example, \mbox works in text
+ * mode, but \boxed works in math mode. Note that no mode changing commands
+ * are needed, but we have to track the current mode, hence this class.
+ * This is only used when exporting to latex and helps determining whether
+ * the mode needs being temporarily switched when a command would not work
+ * in the current mode. As there are cases where this switching is to be
+ * avoided, the optional third parameter can be used to lock the mode.
+ * When the mode is locked, the optional fourth parameter specifies whether
+ * strings are to be output by using a suitable ascii representation.
+ *
+ * Example 1:
+ *
+ * ModeSpecifier specifier(os, TEXT_MODE);
+ *
+ * Sets the current mode to text mode and allows mode switching.
+ *
+ * Example 2:
+ *
+ * ModeSpecifier specifier(os, TEXT_MODE, true);
+ *
+ * Sets the current mode to text mode and disallows mode switching.
+ *
+ * Example 3:
+ *
+ * ModeSpecifier specifier(os, TEXT_MODE, true, true);
+ *
+ * Sets the current mode to text mode, disallows mode switching, and outputs
+ * strings as ascii only.
+ *
+ * At the end of specifier's scope the mode is reset to its previous value.
+ */
+class ModeSpecifier
+{
+public:
+ ///
+ explicit ModeSpecifier(WriteStream & os, InsetMath::mode_type mode,
+ bool locked = false, bool ascii = false)
+ : os_(os), oldmodes_(ensureMode(os, mode, locked, ascii)) {}
+ ///
+ ~ModeSpecifier()
+ {
+ os_.textMode(oldmodes_ & 0x01);
+ os_.lockedMode(oldmodes_ & 0x02);
+ os_.asciiOnly(oldmodes_ & 0x04);
+ }
+private:
+ ///
+ WriteStream & os_;
+ ///
+ int oldmodes_;
+};
+