when selecting text in wxHTML, selecting half a character is enough to select it (patch #1719530; this is standard behaviour when selecting text)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_8_BRANCH@46507 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/changes.txt

@@ -95,6 +95,8 @@ All (GUI):
 
 - Added colour normalization to PNM image handler (Ray Johnston)
 - Fixed selecting part of word from right to left in wxHTML (Michael Hieke)
+- Selecting text in wxHTML with character precision was made easier, it's
+  enough to select half of a character (Michael Hieke)
 
 wxMSW:
 

src/html/htmlcell.cpp

@@ -403,19 +403,26 @@ void wxHtmlWordCell::Split(const wxDC& dc,
         pt2.x = m_Width;
 
     // before selection:
+    // (include character under caret only if in first half of width)
 #ifdef __WXMAC__
     // implementation using PartialExtents to support fractional widths
     wxArrayInt widths ;
     dc.GetPartialTextExtents(m_Word,widths) ;
     while( i < len && pt1.x >= widths[i] )
         i++ ;
-#else // __WXMAC__
+    if ( i < len )
+    {
+        int charW = (i > 0) ? widths[i] - widths[i-1] : widths[i];
+        if ( widths[i] - pt1.x < charW/2 )
+            i++;
+    }
+#else // !__WXMAC__
     wxCoord charW, charH;
     while ( pt1.x > 0 && i < len )
     {
         dc.GetTextExtent(m_Word[i], &charW, &charH);
         pt1.x -= charW;
-        if ( pt1.x >= 0 )
+        if ( pt1.x >= -charW/2 )
         {
             pos1 += charW;
             i++;
@@ -424,18 +431,25 @@ void wxHtmlWordCell::Split(const wxDC& dc,
 #endif // __WXMAC__/!__WXMAC__
 
     // in selection:
+    // (include character under caret only if in first half of width)
     unsigned j = i;
 #ifdef __WXMAC__
     while( j < len && pt2.x >= widths[j] )
         j++ ;
-#else // __WXMAC__
+    if ( j < len )
+    {
+        int charW = (j > 0) ? widths[j] - widths[j-1] : widths[j];
+        if ( widths[j] - pt2.x < charW/2 )
+            j++;
+    }
+#else // !__WXMAC__
     pos2 = pos1;
     pt2.x -= pos2;
     while ( pt2.x > 0 && j < len )
     {
         dc.GetTextExtent(m_Word[j], &charW, &charH);
         pt2.x -= charW;
-        if ( pt2.x >= 0 )
+        if ( pt2.x >= -charW/2 )
         {
             pos2 += charW;
             j++;