****************************************************************************/
int ReverseFind(
const wxString &tstr,
- const wxString &str)
+ const wxString &str,
+ int start = -1)
{
wxASSERT( str.GetStringData()->IsValid() );
// TODO could be made much quicker than that
int p = tstr.Len()-str.Len()-1;
+ int p2 = start-str.Len();
+
+ // if the user supplied a valid start point, use it
+ if (start != -1 && p > p2) p = p2;
while ( p >= 0 ) {
if ( wxStrncmp(tstr.c_str() + p, str.c_str(), str.Len()) == 0 )
return p;
return -1;
}
+/****************************************************************************
+PARAMETERS:
+str - text of #if statement
+
+RETURNS:
+true or false depending on how it evaluated
+
+REMARKS:
+
+SEE ALSO:
+wxIfElseVariable
+****************************************************************************/
+bool ParseIfStatementValue(wxString &str) {
+
+ // Find out if the tag has parenthesis
+ // recursive to parse the text within the parenthesis,
+ // replacing the text with 1 or 0, (hardcoded true or false)
+ int b;
+ while ((b = str.Find('(')) != -1) {
+ int e;
+ // Find the matching parenthesis
+ int nextbeg, nextend;
+ int parencount = 1, min = b+1;
+ do {
+
+ nextbeg = str.find('(', min);
+ nextend = str.find(')', min);
+ if (nextbeg < nextend && nextbeg != wxString::npos) {
+ parencount++;
+ min = nextbeg+1;
+ }
+ else {
+ parencount--;
+ min = nextend+1;
+ }
+
+ if (nextend == wxString::npos) {
+ #ifdef CHECKED
+ wxMessageBox("wxHTML #if\\else error: Unmatched parenthesis in #if expression.","Error",wxICON_ERROR);
+ #endif
+ return true;
+ }
+ // once parencount reaches 0 again we have found our matchin )
+ } while (parencount > 0);
+
+ e = nextend;
+
+ // Extract the expression from the parenthesis block and recurse
+ // to solve it.
+ wxString tag;
+ tag = str.Mid(b+1, e-b-1);
+ bool val = ParseIfStatementValue(tag);
+ // Add extra spaces just in case of NOT(VAL)
+ if (val) str = str.Mid(0, b) + " 1" + str.Mid(e+1);
+ else str = str.Mid(0, b) + " 0" + str.Mid(e+1);
+
+ }
+
+ // Remove spaces from left and right
+ str.Trim(false);
+ str.Trim(true);
+
+ // Convert text method of operators "AND" and "OR" to c style
+ // this makes only one special case necessary for each later on
+ str.Replace(" AND ", "&&");
+ str.Replace(" OR ", "||");
+
+ // We use ReverseFind so that the whole left expression gets evaluated agains
+ // the right single item, creating a left -> right evaluation
+ // Search for || operators, recurse to solve (so we don't have to handle special cases here)
+ int and, or;
+ and = ReverseFind(str, "&&");
+ or = ReverseFind(str, "||");
+ if ( (and != -1) || (or != -1) ) {
+ wxString tag1, tag2;
+ // handle the rightmost first to force left->right evaluation
+ if (and > or) {
+ return (
+ ParseIfStatementValue(tag2 = str.Mid(and+2)) &&
+ ParseIfStatementValue(tag1 = str.Mid(0, and)) );
+ }
+ else {
+ return (
+ ParseIfStatementValue(tag2 = str.Mid(or+2)) ||
+ ParseIfStatementValue(tag1 = str.Mid(0, or)) );
+ }
+
+ }
+
+ // By the time we get to this place in the function we are guarenteed to have a single
+ // variable operation, perhaps with a NOT or ! operator
+ bool notval = false;
+
+ // search for a NOT or ! operator
+ if (str.Mid(0, 1) == "!") {
+ str.Remove(0, 1);
+ str.Trim(false); // trim spaces from left
+ notval = true;
+ }
+ else if (str.Mid(0,4).CmpNoCase("NOT ") == 0) {
+ str.Remove(0, 4);
+ str.Trim(false); // trim any extra spaces from left
+ notval = true;
+ }
+
+ // now all we have left is the name of the class or a hardcoded 0 or 1
+
+ if (str == "") {
+ #ifdef CHECKED
+ wxMessageBox("wxHTML #if\\else error: Empty expression in #if\\#elif statement.","Error",wxICON_ERROR);
+ #endif
+ return true;
+ }
+
+ // check for hardcoded 0 and 1 cases, (these are used by parenthesis catcher)
+ // this just decomplicates the recursion algorithm
+ if (str == "0") return notval;
+ if (str == "1") return !notval;
+
+ // Grab the value from the variable class identified by cname
+ bool value = wxIfElseVariable::FindValue(str);
+ if (notval) value = !value;
+ return value;
+
+}
/****************************************************************************
PARAMETERS:
text - HTML to process for if/else blocks
The string containing the processed HTML
REMARKS:
-This function replaces #if, #else, and #endif directives with the text
+This function replaces #if, #else, #elif, and #endif directives with the text
contained within the blocks, dependant on the value of the given boolean
variable. The variable is created by making a sub class of wxIfElseVariable.
Dynamic class construction is used at run time internally to create an instance
{
int b;
char ft[] = "<!--#if ";
+ char ftend[] = "<!--#endif-->";
+ char ftelse[] = "<!--#else-->";
+ char ftnot[] = "<!--#if not ";
+ char ftnot2[] = "<!--#if !";
+
+ char ftelif[] = "<!--#elif ";
- // make a copy so we can replace text as we go without affecting the original
+ // make a copy so we can replace text as we go without affecting the original
wxString output = text;
+
+ // Avoid duplication of our parsing code by turning any #elif blocks into appropriate
+ // else/if blocks
+ while ((b = ReverseFind(output.Lower(), ftelif)) != -1) {
+ int e;
+ // Replace beginning of block
+ e = output.find("-->", b + strlen(ftelif));
+
+ if (e == wxString::npos) {
+ #ifdef CHECKED
+ wxMessageBox("wxHTML #elif error: Premature end of file while parsing #elif.","Error",wxICON_ERROR);
+ #endif
+ break;
+ }
+
+ // Convert to lower case so find is easy, grab everything after #elif tag
+ wxString remains = (output.Mid(e+strlen("-->"))).Lower();
+
+ // find matching else or endif
+ int nextif, nextendif;
+ int ifcount = 1, min = 0;
+ do {
+ nextif = remains.find(ft, min);
+ nextendif = remains.find(ftend, min);
+ if (nextif < nextendif && nextif != wxString::npos) {
+ ifcount++;
+ min = nextif+1;
+ }
+ else {
+ ifcount--;
+ min = nextendif+1;
+ }
+
+ if (nextendif == wxString::npos) {
+ #ifdef CHECKED
+ wxMessageBox("wxHTML #elif error: Premature end of file before finding #endif.","Error",wxICON_ERROR);
+ #endif
+ break;
+ }
+ // once ifcount reaches 0 again we have found our matchin #endif
+ } while (ifcount > 0);
+
+ // If it couldn't be found die gracefully
+ if (nextendif == wxString::npos) {
+ // We already displayed a message, just break all the way out
+ break;
+ }
+
+ int elifsize = e - (b + strlen(ftelif)) + strlen("-->");
+ // Create the #if/else block, removing the #elif code
+ output = output.Mid(0, b) +
+ wxString(wxString(ftelse)+wxString(ft)) +
+ output.Mid(b+strlen(ftelif), elifsize+nextendif) +
+ wxString(ftend) +
+ output.Mid(b+strlen(ftelif)+elifsize+nextendif);
+
+ }
+
+ // Parse out the if else blocks themselves
while ((b = ReverseFind(output.Lower(), ft)) != -1) {
- // Loop until every #echo directive is found
+ // Loop until every #if directive is found
// We search from the end of the string so that #if statements will properly recurse
// and we avoid the hassle of matching statements with the correct <!--#endif-->
- int end, c, n;
+ bool notval = false;
+ int off = 0;
+ int end;
wxString usecode, code;
wxString cname;
wxString tag;
}
end += 3;
- tag = output.Mid(b, end);
+ // remove the <!--#if and --> sections from the tag before passing it on to be parsed
+ tag = output.Mid(b+strlen(ft), end-strlen(ft)-3);
output.Remove(b, end);
- c = tag.Find("-->");
- n = c;
-
- // find the classname
- c = (tag.Mid(8, n-8)).Find(" ");
- if (c == -1) n -= 8;
- else n = c;
- cname = tag.Mid(8, n);
-
- cname.Trim(false);
- c = cname.Find("\"");
- if (c != -1) cname = cname.Mid(c+1);
- c = cname.Find("\"");
- if (c != -1) cname = cname.Mid(0, c);
-
- // Grab the value from the variable class identified by cname
- value = wxIfElseVariable::GetValue(cname);
+ value = ParseIfStatementValue(tag);
// Find the end of the tag (<!--#endif-->) and copy it all into the variable code
- end = ((output.Mid(b)).Lower()).Find("<!--#endif-->");
+ end = ((output.Mid(b)).Lower()).Find(ftend);
if (end == -1) {
#ifdef CHECKED
wxMessageBox("wxHTML #if error: Premature end of file while searching for matching #endif.","Error",wxICON_ERROR);
}
code = output.Mid(b, end);
- output.Remove(b, end+13); // remove the entire #if block from original document
+ output.Remove(b, end+strlen(ftend)); // remove the entire #if block from original document
// Find out if there is an else statement
- end = (code.Lower()).Find("<!--#else-->");
+ end = (code.Lower()).Find(ftelse);
if (end != -1) {
if (!value) {
// Use the else statement
- usecode = code.Mid(end+12);
+ usecode = code.Mid(end+strlen(ftelse));
}
else {
// Use statement before #else
projects / wxWidgets.git / blobdiff