Horizontally center shadows and make them bigger

Summary:
FEATURE: 388256

#VDG has decided that shadows should be horizontally centered and bigger. This patch implements those changes in the following way:
- Window and menu shadows are now horizontally centered
- Shadow size increased to the maximum value
- Shadow color changed from pure black to a slightly lighter Breeze standard color: Shade Black

Test Plan:
Tested in KDE Neon. Before:
{F5587393}

After:
{F5587390}

Reviewers: abetts, hpereiradacosta, #vdg, #breeze, alake

Reviewed By: abetts, hpereiradacosta, #vdg

Subscribers: rkflx, zzag, cfeck, januz, rpelorosso, apol, mvourlakos, plasma-devel

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D9549

kdecoration/breezedecoration.cpp

@@ -668,8 +668,8 @@ namespace Breeze
 
             // contrast pixel
             QRectF innerRect = QRectF(
-                g_shadowSize - shadowOffset - Metrics::Shadow_Overlap, g_shadowSize - shadowOffset - Metrics::Shadow_Overlap,
-                shadowOffset + 2*Metrics::Shadow_Overlap, shadowOffset + 2*Metrics::Shadow_Overlap );
+                g_shadowSize - Metrics::Shadow_Overlap, g_shadowSize - shadowOffset - Metrics::Shadow_Overlap,
+                2*Metrics::Shadow_Overlap, shadowOffset + 2*Metrics::Shadow_Overlap );
 
             painter.setPen( gradientStopColor( g_shadowColor, g_shadowStrength*0.5 ) );
             painter.setBrush( Qt::NoBrush );
@@ -685,7 +685,7 @@ namespace Breeze
 
             g_sShadow = QSharedPointer<KDecoration2::DecorationShadow>::create();
             g_sShadow->setPadding( QMargins(
-                g_shadowSize - shadowOffset - Metrics::Shadow_Overlap,
+                g_shadowSize - Metrics::Shadow_Overlap,
                 g_shadowSize - shadowOffset - Metrics::Shadow_Overlap,
                 g_shadowSize - Metrics::Shadow_Overlap,
                 g_shadowSize - Metrics::Shadow_Overlap ) );

kdecoration/breezesettingsdata.kcfg

@@ -14,13 +14,13 @@
     </entry>
 
     <entry name="ShadowSize" type = "Int">
-       <default>16</default>
+       <default>64</default>
        <min>6</min>
-       <max>64</max>
+       <max>100</max>
     </entry>
 
     <entry name="ShadowColor" type = "Color">
-       <default>0, 0, 0</default>
+       <default>35, 38, 41</default>
     </entry>
 
     <!-- close button -->

kstyle/breezemdiwindowshadow.cpp

@@ -51,7 +51,7 @@ namespace Breeze
         const int size( shadowSize - Metrics::Shadow_Overlap );
         const int topSize( size - shadowOffset );
         const int bottomSize( size );
-        const int leftSize( size - shadowOffset );
+        const int leftSize( size );
         const int rightSize( size );
 
         // get tileSet rect

kstyle/breezeshadowhelper.cpp

@@ -261,8 +261,8 @@ namespace Breeze
             p.setBrush( Qt::black );
 
             QRectF innerRect(
-                shadowSize - shadowOffset - Metrics::Shadow_Overlap, shadowSize - shadowOffset - Metrics::Shadow_Overlap,
-                shadowOffset + 2*Metrics::Shadow_Overlap,shadowOffset + 2*Metrics::Shadow_Overlap );
+                shadowSize - Metrics::Shadow_Overlap, shadowSize - shadowOffset - Metrics::Shadow_Overlap,
+                2*Metrics::Shadow_Overlap,shadowOffset + 2*Metrics::Shadow_Overlap );
 
             p.setCompositionMode(QPainter::CompositionMode_DestinationOut );
 
@@ -516,7 +516,7 @@ namespace Breeze
         int size( shadowSize - Metrics::Shadow_Overlap );
         int topSize = ( size - shadowOffset ) * devicePixelRatio;
         int bottomSize = size * devicePixelRatio;
-        const int leftSize( (size - shadowOffset) * devicePixelRatio );
+        const int leftSize( size * devicePixelRatio );
         const int rightSize( size * devicePixelRatio );
 
         if( widget->inherits( "QBalloonTip" ) )