Themes: Fix UI recoloring for flat themes

Reduce the usage of half-transparent colors to just the Fancy* widgets.
Otherwise, we have side effects like QTCREATORBUG-15770 in other
widgets (e.g. search results pane).

Change-Id: I0e2b0155441c4f1a071bd3c1029577accb73d56b
Reviewed-by: Tobias Hunger <tobias.hunger@theqtcompany.com>

share/qtcreator/themes/dark.creatortheme

@@ -7,8 +7,8 @@ DefaultTextEditorColorScheme=dark.xml
 shadowBackground=ff232323
 text=ffe7e7e7
 textDisabled=7fffffff
-hoverBackground=35ffffff
-selectedBackground=66000000
+hoverBackground=ff515151
+selectedBackground=ff151515
 normalBackground=ff333333
 alternateBackground=ff515151
 error=ffff0000
@@ -19,7 +19,7 @@ BackgroundColorDark=shadowBackground
 BackgroundColorHover=hoverBackground
 BackgroundColorNormal=normalBackground
 BackgroundColorDisabled=ff444444
-BackgroundColorSelected=7effffff
+BackgroundColorSelected=ff909090
 BadgeLabelBackgroundColorChecked=normalBackground
 BadgeLabelBackgroundColorUnchecked=selectedBackground
 BadgeLabelTextColorChecked=text
@@ -46,8 +46,8 @@ FancyTabWidgetDisabledSelectedTextColor=textDisabled
 FancyTabWidgetDisabledUnselectedTextColor=textDisabled
 FancyTabWidgetEnabledSelectedTextColor=text
 FancyTabWidgetEnabledUnselectedTextColor=text
-FancyToolButtonHoverColor=hoverBackground
-FancyToolButtonSelectedColor=selectedBackground
+FancyToolButtonHoverColor=35ffffff
+FancyToolButtonSelectedColor=66000000
 FutureProgressBackgroundColor=shadowBackground
 IconsBaseColor=ffdcdcdc
 IconsDisabledColor=textDisabled

src/plugins/coreplugin/fancytabwidget.cpp

@@ -300,8 +300,7 @@ void FancyTabBar::paintTab(QPainter *painter, int tabIndex) const
     if (selected) {
         if (creatorTheme()->widgetStyle() == Theme::StyleFlat) {
           // background color of a fancy tab that is active
-          painter->fillRect(rect.adjusted(0, 0, 0, -1),
-                            creatorTheme()->color(Theme::BackgroundColorSelected));
+          painter->fillRect(rect, creatorTheme()->color(Theme::FancyToolButtonSelectedColor));
         } else {
             paintSelectedTabBackground(painter, rect);
         }
@@ -324,7 +323,7 @@ void FancyTabBar::paintTab(QPainter *painter, int tabIndex) const
         painter->save();
         painter->setOpacity(fader);
         if (creatorTheme()->widgetStyle() == Theme::StyleFlat)
-            painter->fillRect(rect, creatorTheme()->color(Theme::BackgroundColorHover));
+            painter->fillRect(rect, creatorTheme()->color(Theme::FancyToolButtonHoverColor));
         else
             FancyToolButton::hoverOverlay(painter, rect);
         painter->restore();