[expression] rework the wordwrap to allow for maximum / minimum line …

…length to wrap, fix test and add two more
qgis · Feb 21, 2014 · d1c61a0 · d1c61a0
1 parent 3cfee81
commit d1c61a0
Show file tree

Hide file tree

Showing 3 changed files with 24 additions and 7 deletions.
diff --git a/resources/function_help/wordwrap b/resources/function_help/wordwrap
@@ -2,14 +2,15 @@
 Returns a string wrapped to a minimum number of characters.
 
 <p><h4>Syntax</h4>
-     replace(<i>string,delimiter_string,minimum_characters</i>)</p>
+     replace(<i>string,delimiter_string,wrap_characters</i>)</p>
 
 <p><h4>Arguments</h4>
 <!-- List args for functions here-->
 <i>  string</i> &rarr; is string.  The string to be wrapped.<br>
 <i>  delimiter_string</i> &rarr; is string.  The delimiter character(s) to break to a new line.<br>
-<i>  minimum_characters</i> &rarr; is number.  The minimum number of characters required to allow for break to a new line<br></p>
+<i>  wrap_characters</i> &rarr; is number.  IF positive, the number represents the ideal maximum number of characters to wrap; if negative, the number represents the minimum number of characters to wrap.<br></p>
 
 <p><h4>Example</h4>
 <!-- Show example of function.-->
-     wordwrap('UNIVERSITY OF QGIS',' ',3) &rarr; 'UNIVERSITY\nOF QGIS'</p>
+     wordwrap('UNIVERSITY OF QGIS',' ',13) &rarr; 'UNIVERSITY OF\nQGIS'<br>
+     wordwrap('UNIVERSITY OF QGIS',' ',-3) &rarr; 'UNIVERSITY\nOF QGIS'</p>
diff --git a/src/core/qgsexpression.cpp b/src/core/qgsexpression.cpp
@@ -639,20 +639,34 @@ static QVariant fcnWordwrap( const QVariantList& values, const QgsFeature* , Qgs
   QString delimiterstr = getStringValue ( values.at(1), parent );
   int delimiterlength = delimiterstr.length();
 
-  int wrapmin = getIntValue( values.at(2), parent );
+  //if wrap value is positive, wrap is (mostly) the maximum width before wrap on delimiter
+  //if wrap value is negative, wrap is the minimum width before permitting wrap delimiter
+  int wrap = getIntValue( values.at(2), parent );
 
   QStringList lines = str.split( "\n" );
-  int strlength, strcurrent, strhit;
+  int strlength, strcurrent, strhit, lasthit;
 
   for ( int i = 0; i < lines.size(); i++ )
   {
     strlength = lines[i].length();
     strcurrent = 0;
     strhit = 0;
+    lasthit = 0;
 
     while (strcurrent < strlength)
     {
-      strhit = lines[i].indexOf( delimiterstr, strcurrent + wrapmin );
+      if (wrap > 0)
+      {
+        //first try to locate delimiter backwards
+        strhit = lines[i].lastIndexOf( delimiterstr, strcurrent + wrap);
+        if (strhit == lasthit || strhit == -1) {
+          //if no new backward delimiter found, try to locate forward
+          strhit = lines[i].indexOf( delimiterstr, strcurrent + qAbs(wrap) );
+        }
+        lasthit = strhit;
+      } else {
+        strhit = lines[i].indexOf( delimiterstr, strcurrent + qAbs(wrap) );
+      }
       if (strhit > -1) {
         newstr.append( lines[i].midRef( strcurrent , strhit - strcurrent ) );
         newstr.append( "\n" );

diff --git a/tests/src/core/testqgsexpression.cpp b/tests/src/core/testqgsexpression.cpp
@@ -315,7 +315,9 @@ class TestQgsExpression: public QObject
       QTest::newRow( "title" ) << "title(' HeLlO   WORLD ')" << false << QVariant( " Hello   World " );
       QTest::newRow( "trim" ) << "trim('   Test String ')" << false << QVariant( "Test String" );
       QTest::newRow( "trim empty string" ) << "trim('')" << false << QVariant( "" );
-      QTest::newRow( "wordwrap" ) << "wordwrap('university of qgis')" << false << QVariant( "university\nof qgis" );
+      QTest::newRow( "wordwrap" ) << "wordwrap('university of qgis',' ',13)" << false << QVariant( "university of\nqgis" );
+      QTest::newRow( "wordwrap" ) << "wordwrap('university of qgis',' ',-3)" << false << QVariant( "university\nof qgis" );
+      QTest::newRow( "wordwrap" ) << "wordwrap('university of qgis\nsupports many multiline',' ',-5)" << false << QVariant( "university\nof qgis\nsupports\nmany multiline" );
       QTest::newRow( "format" ) << "format('%1 %2 %3 %1', 'One', 'Two', 'Three')" << false << QVariant( "One Two Three One" );
 
       // implicit conversions