Terminate user color calculation, when no solution can be found

fixes #172

CHANGELOG.md

@@ -12,6 +12,7 @@
 - Fix crash when trying to maximize image, that wasn't downloaded yet.
 - Fix Binding restorMode flooding logs on Qt 5.14.2+
 - Fix with some qml styles hidden menu items leave empty space
+- Fix hangs when generating colors with some system theme color schemes (#172)
 
 ## [0.7.0] -- 2020-04-19
 

src/Utils.cpp

@@ -540,6 +540,7 @@ utils::generateContrastingHexColor(const QString &input, const QString &backgrou
         // If the contrast doesn't meet our criteria,
         // try again and again until they do by modifying first
         // the lightness and then the saturation of the color.
+        int iterationCount = 9;
         while (contrast < 5) {
                 // if our lightness is at it's bounds, try changing
                 // saturation instead.
@@ -586,6 +587,11 @@ utils::generateContrastingHexColor(const QString &input, const QString &backgrou
                                 }
                         }
                 }
+
+                // don't loop forever, just give up at some point!
+                // Someone smart may find a better solution
+                if (--iterationCount < 0)
+                        break;
         }
 
         // get the hex value of the generated color.