Merge pull request #2501 from hugobuddel/spacesyntaxautorebase

Make blank space less apparent.

spyderlib/widgets/sourcecode/codeeditor.py

@@ -1356,6 +1356,8 @@ def set_blanks_enabled(self, state):
         else:
             option.setFlags(option.flags() & ~QTextOption.ShowTabsAndSpaces)
         self.document().setDefaultTextOption(option)
+        # Rehighlight to make the spaces less apparent.
+        self.rehighlight()
 
     #-----scrollflagarea
     def set_scrollflagarea_enabled(self, state):

spyderlib/widgets/sourcecode/syntaxhighlighters.py

@@ -16,7 +16,8 @@
 import keyword
 
 from spyderlib.qt.QtGui import (QColor, QApplication, QFont,
-                                QSyntaxHighlighter, QCursor, QTextCharFormat)
+                                QSyntaxHighlighter, QCursor, QTextCharFormat,
+                                QTextOption)
 from spyderlib.qt.QtCore import Qt
 
 # Local imports
@@ -84,8 +85,12 @@ class BaseSH(QSyntaxHighlighter):
     """Base Syntax Highlighter Class"""
     # Syntax highlighting rules:
     PROG = None
+    BLANKPROG = re.compile("\s+")
     # Syntax highlighting states (from one text block to another):
     NORMAL = 0
+    # Syntax highlighting parameters.
+    BLANK_ALPHA_FACTOR = 0.31
+
     def __init__(self, parent, font=None, color_scheme='Spyder'):
         QSyntaxHighlighter.__init__(self, parent)
 
@@ -190,7 +195,37 @@ def set_color_scheme(self, color_scheme):
 
     def highlightBlock(self, text):
         raise NotImplementedError
-
+
+    def highlight_spaces(self, text, offset=0):
+        """
+        Make blank space less apparent by setting the foreground alpha.
+        This only has an effect when 'Show blank space' is turned on.
+        Derived classes could call this function at the end of
+        highlightBlock().
+        """
+        flags_text = self.document().defaultTextOption().flags()
+        show_blanks =  flags_text & QTextOption.ShowTabsAndSpaces
+        if show_blanks:
+            format_leading = self.formats.get("leading", None)
+            format_trailing = self.formats.get("trailing", None)
+            match = self.BLANKPROG.search(text, offset)
+            while match:
+                start, end = match.span()
+                start = max([0, start+offset])
+                end = max([0, end+offset])
+                # Format trailing spaces at the end of the line. 
+                if end == len(text) and format_trailing is not None:
+                    self.setFormat(start, end, format_trailing)
+                # Format leading spaces, e.g. indentation.
+                if start == 0 and format_leading is not None:
+                    self.setFormat(start, end, format_leading)
+                format = self.format(start)
+                color_foreground = format.foreground().color()
+                alpha_new = self.BLANK_ALPHA_FACTOR * color_foreground.alphaF()
+                color_foreground.setAlphaF(alpha_new)
+                self.setFormat(start, end-start, color_foreground)
+                match = self.BLANKPROG.search(text, match.end())
+
     def get_outlineexplorer_data(self):
         return self.outlineexplorer_data
 
@@ -202,9 +237,9 @@ def rehighlight(self):
 
 
 class TextSH(BaseSH):
-    """Simple Text Syntax Highlighter Class (do nothing)"""
+    """Simple Text Syntax Highlighter Class (only highlight spaces)"""
     def highlightBlock(self, text):
-        pass
+        self.highlight_spaces(text)
 
 
 class GenericSH(BaseSH):
@@ -225,6 +260,8 @@ def highlightBlock(self, text):
                     self.setFormat(start, end-start, self.formats[key])
 
             match = self.PROG.search(text, match.end())
+
+        self.highlight_spaces(text)
 
 
 #==============================================================================
@@ -413,9 +450,14 @@ def highlightBlock(self, text):
                                                    self.formats["keyword"])
 
             match = self.PROG.search(text, match.end())
-
+        
         self.setCurrentBlockState(state)
 
+        # Use normal format for indentation and trailing spaces.
+        self.formats['leading'] = self.formats['normal']
+        self.formats['trailing'] = self.formats['normal']
+        self.highlight_spaces(text, offset)
+
         if oedata is not None:
             block_nb = self.currentBlock().blockNumber()
             self.outlineexplorer_data[block_nb] = oedata
@@ -536,7 +578,9 @@ def highlightBlock(self, text):
                         self.setFormat(start, end-start, self.formats[key])
 
             match = self.PROG.search(text, match.end())
-
+
+        self.highlight_spaces(text)
+
         last_state = self.INSIDE_COMMENT if inside_comment else self.NORMAL
         self.setCurrentBlockState(last_state)
 
@@ -611,13 +655,16 @@ def highlightBlock(self, text):
                                            self.formats["definition"])
 
             match = self.PROG.search(text, match.end())
+
+        self.highlight_spaces(text)
 
 class Fortran77SH(FortranSH):
     """Fortran 77 Syntax Highlighter"""
     def highlightBlock(self, text):
         text = to_text_string(text)
         if text.startswith(("c", "C")):
             self.setFormat(0, len(text), self.formats["comment"])
+            self.highlight_spaces(text)
         else:
             FortranSH.highlightBlock(self, text)
             self.setFormat(0, 5, self.formats["comment"])
@@ -673,7 +720,8 @@ def highlightBlock(self, text):
             self.setFormat(0, len(text), self.formats["number"])
         elif text.startswith("@"):
             self.setFormat(0, len(text), self.formats["builtin"])
-
+
+        self.highlight_spaces(text)
 
 #==============================================================================
 # NSIS highlighter
@@ -803,6 +851,8 @@ def highlightBlock(self, text):
 
             match = self.PROG.search(text, match.end())
             match_count += 1
+
+        self.highlight_spaces(text)
 
 def make_html_patterns():
     """Strongly inspired from idlelib.ColorDelegator.make_pat """
@@ -885,7 +935,8 @@ def highlightBlock(self, text):
             start = ct
             ct += len(val)        
             self.setFormat(start, ct-start, self.formats[key])
-
+
+        self.highlight_spaces(text)
 
 def guess_pygments_highlighter(filename):
     """Factory to generate syntax highlighter for the given filename.