desktop: offer different colors for info tab titles

Add a preference option to set the color of the text on the information tab to
either MediumBlue, LightBlue or Black. The last two of these colors are meant
to enable areadable font contrast on displays with dark mode.
The choice is saved with the other preferences.

[Dirk Hohndel: this isn't really about dark mode, so changed many of the types
	       and variable names, changed the user visible texts, and
               addressed some whitespace issues]

Signed-off-by: willemferguson <willemferguson@zoology.up.ac.za>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

1 files changed, 73 insertions, 0 deletions

diff --git a/desktop-widgets/preferences/preferences_defaults.ui b/desktop-widgets/preferences/preferences_defaults.ui
index 030bb77d6..b6104b256 100644
--- a/desktop-widgets/preferences/preferences_defaults.ui
+++ b/desktop-widgets/preferences/preferences_defaults.ui
@@ -120,6 +120,77 @@
    </item>
 
    <item>
+    <widget class="QGroupBox" name="groupBox_headerstyle">
+     <property name="title">
+      <string>Header text colors</string>
+     </property>
+     <layout class="QVBoxLayout" name="headerModeLayout_4">
+      <property name="margin">
+       <number>5</number>
+      </property>
+
+      <item>
+       <widget class="QLabel" name="label_help_header">
+        <property name="toolTip">
+         <string extracomment="Help info header"/>
+        </property>
+        <property name="wordWrap">
+         <bool>true</bool>
+        </property>
+        <property name="text">
+         <string>Depending on the display mode, sometimes the blue text used in headers in the various information panes is not clearly visible. Select a color that fits the current theme of your computer. For dark mode, select either Light Blue or Black (rendered white using a dark theme). The default is Medium Blue.</string>
+        </property>
+       </widget>
+      </item>
+
+      <item>  
+       <layout class="QHBoxLayout" name="darkmodeLayout_5">
+
+         <item>
+          <widget class="QRadioButton" name="mediumblue_text">
+           <property name="text">
+            <string>Medium Blue</string>
+           </property>
+          </widget>
+         </item>
+
+         <item>
+          <widget class="QRadioButton" name="lightblue_text">
+           <property name="text">
+            <string>Light Blue</string>
+           </property>
+          </widget>
+         </item>
+
+         <item>
+          <widget class="QRadioButton" name="black_text">
+           <property name="text">
+            <string>Black</string>
+           </property>
+          </widget>
+         </item>
+
+        </layout>
+      </item>
+
+      </layout>
+    </widget>
+   </item>
+
+   <item>
+    <spacer name="verticalSpacer_3">
+     <property name="orientation">
+      <enum>Qt::Vertical</enum>
+     </property>
+     <property name="sizeHint" stdset="0">
+      <size>
+       <width>0</width>
+       <height>195</height>
+      </size>
+     </property>
+    </spacer>
+   </item>
+      <item>
     <spacer name="verticalSpacer_2">
      <property name="orientation">
       <enum>Qt::Vertical</enum>
@@ -132,8 +203,10 @@
      </property>
     </spacer>
    </item>
+
   </layout>
  </widget>
+
  <resources/>
  <connections>
   <connection>