Add a syntax theme colour entry for text highlighting

docs/source/int_customise.rst

@@ -179,15 +179,20 @@ A syntax theme ``.conf`` file consists of the following settings:
    errorline      =   0,   0,   0
    replacetag     =   0,   0,   0
    modifier       =   0,   0,   0
+   texthighlight  = 255, 255, 255, 128
 
 In the Main section, you must define at least the ``name`` setting. The Syntax colour values are
-RGB numbers of the format ``r, g, b`` where each is an integer from  to 255. Omitted values default
+RGB(A) numbers of the format ``r, g, b, a`` where each is an integer from to 255. The fourth value
-to black, except ``background`` which defaults to white,
+is the alpha channel, which can be omitted.
+
+Omitted syntax colours default to black, except ``background`` which defaults to white, and
+``texthighlight`` which defaults to grey.
 
 .. versionadded:: 2.2
-   The `shortcode` syntax colour entry was added, so you need to update your custom themes if you
+   The `shortcode` syntax colour entry was added.
-   made any before version 2.2.
 
 .. versionadded:: 2.3
-   The `optional` syntax colour entry was added, so you need to update your custom themes if you
+   The `optional` syntax colour entry was added.
-   made any before version 2.3.
+
+.. versionadded:: 2.4
+   The `texthighlight` syntax colour entry was added.

novelwriter/assets/syntax/default_dark.conf

@@ -25,3 +25,4 @@ spellcheckline = 200,  46,   0
 errorline      =  46, 200,   0
 replacetag     =   0, 184,  46
 modifier       = 200, 120,   0
+texthighlight  = 136, 200,   0, 96

novelwriter/assets/syntax/default_light.conf

@@ -25,3 +25,4 @@ spellcheckline = 200,   0,   0
 errorline      =   0, 150,   0
 replacetag     =   0, 150,   0
 modifier       = 150, 110,  30
+texthighlight  = 150, 150,   0, 96

novelwriter/assets/syntax/grey_dark.conf

@@ -25,3 +25,4 @@ spellcheckline = 200,  46,   0
 errorline      =  46, 200,   0
 replacetag     = 225, 225, 225
 modifier       = 225, 225, 225
+texthighlight  = 255, 255, 255, 64

novelwriter/assets/syntax/grey_light.conf

@@ -25,3 +25,4 @@ spellcheckline = 200,   0,   0
 errorline      =   0, 150,   0
 replacetag     =   0,   0,   0
 modifier       =   0,   0,   0
+texthighlight  =   0,   0,   0, 64

novelwriter/assets/syntax/light_owl.conf

@@ -45,3 +45,4 @@ spellcheckline = 222,  61,  58
 errorline      =   8, 145, 106
 replacetag     =  42, 162, 152
 modifier       = 224, 175,   5
+texthighlight  = 218, 170,   1, 96

novelwriter/assets/syntax/night_owl.conf

@@ -45,3 +45,4 @@ spellcheckline = 247, 140, 108
 errorline      = 173, 219, 103
 replacetag     = 127, 219, 202
 modifier       = 236, 196, 141
+texthighlight  = 255, 235, 149, 96

novelwriter/assets/syntax/solarized_dark.conf

@@ -25,3 +25,4 @@ spellcheckline = 203,  75,  22
 errorline      = 220,  50,  47
 replacetag     = 133, 153,   0
 modifier       = 181, 137,   0
+texthighlight  = 181, 137,   0, 96

novelwriter/assets/syntax/solarized_light.conf

@@ -25,3 +25,4 @@ spellcheckline = 203,  75,  22
 errorline      = 220,  50,  47
 replacetag     = 133, 153,   0
 modifier       = 181, 137,   0
+texthighlight  = 181, 137,   0, 96

novelwriter/assets/syntax/tomorrow.conf

@@ -45,3 +45,4 @@ spellcheckline = 240,  40,  41
 errorline      = 113, 140,   0
 replacetag     =  62, 153, 159
 modifier       = 245, 135,  31
+texthighlight  = 234, 183,   0, 96

novelwriter/assets/syntax/tomorrow_night.conf

@@ -45,3 +45,4 @@ spellcheckline = 204, 102, 102
 errorline      = 181, 189, 104
 replacetag     = 138, 190, 183
 modifier       = 222, 147,  95
+texthighlight  = 240, 198, 116, 96

novelwriter/assets/syntax/tomorrow_night_blue.conf

@@ -45,3 +45,4 @@ spellcheckline = 255, 157, 164
 errorline      = 209, 241, 169
 replacetag     = 153, 255, 255
 modifier       = 255, 197, 143
+texthighlight  = 255, 238, 173, 96

novelwriter/assets/syntax/tomorrow_night_bright.conf

@@ -45,3 +45,4 @@ spellcheckline = 213,  78,  83
 errorline      = 185, 202,  74
 replacetag     = 112, 192, 177
 modifier       = 231, 140,  69
+texthighlight  = 231, 197,  71, 128

novelwriter/assets/syntax/tomorrow_night_eighties.conf

@@ -45,3 +45,4 @@ spellcheckline = 242, 119, 122
 errorline      = 153, 204, 153
 replacetag     = 102, 204, 204
 modifier       = 249, 145,  57
+texthighlight  = 255, 204, 102, 96

novelwriter/core/tohtml.py

@@ -29,7 +29,9 @@ import logging
 from time import time
 from pathlib import Path
 
-from novelwriter import CONFIG
+from PyQt5.QtGui import QColor
+
+from novelwriter import CONFIG, SHARED
 from novelwriter.common import formatTimeStamp
 from novelwriter.constants import nwHeadFmt, nwKeyWords, nwLabels, nwHtmlUnicode
 from novelwriter.core.project import NWProject
@@ -124,6 +126,7 @@ class ToHtml(Tokenizer):
     def doConvert(self) -> None:
         """Convert the list of text tokens into an HTML document."""
         if self._genMode == self.M_PREVIEW:
+            colMark = SHARED.theme.colMark.name(QColor.NameFormat.HexArgb)
             htmlTags = {  # HTML4 + CSS2 (for Qt)
                 self.FMT_B_B: "<b>",
                 self.FMT_B_E: "</b>",
@@ -133,7 +136,7 @@ class ToHtml(Tokenizer):
                 self.FMT_D_E: "</span>",
                 self.FMT_U_B: "<u>",
                 self.FMT_U_E: "</u>",
-                self.FMT_M_B: "<span style='background-color: yellow;'>",
+                self.FMT_M_B: f"<span style='background-color: {colMark};'>",
                 self.FMT_M_E: "</span>",
             }
         else:

novelwriter/gui/theme.py

@@ -106,6 +106,7 @@ class GuiTheme:
         self.colError  = QColor(0, 0, 0)
         self.colRepTag = QColor(0, 0, 0)
         self.colMod    = QColor(0, 0, 0)
+        self.colMark   = QColor(255, 255, 255, 128)
 
         # Class Setup
         # ===========
@@ -329,6 +330,7 @@ class GuiTheme:
             self.colError  = self._parseColour(confParser, cnfSec, "errorline")
             self.colRepTag = self._parseColour(confParser, cnfSec, "replacetag")
             self.colMod    = self._parseColour(confParser, cnfSec, "modifier")
+            self.colMark   = self._parseColour(confParser, cnfSec, "texthighlight")
 
         return True