From a31e4ce4ec4c0a7083b9bdfa962dafec4ac8f784 Mon Sep 17 00:00:00 2001
From: Nate Graham <nate@kde.org>
Date: Thu, 17 Feb 2022 11:11:23 -0700
Subject: [PATCH] Lock/login themes: stop adjusting shadows based on color
 scheme

Right now we change the intensity of shadows based on the color scheme's
text color, but with a property called "lightBackground". This indicates
that we wanted to do it based on the background color itself, but did
not or could not, so settled on using the text color as a proxy. However
this is wrong; there is no relationship between the active color
scheme's text color and the color of the background image.

Even if we could or did fix that, it would probably still be wrong,
because using lighter shadows on a genuinely light background would
result in worse contrast and readability, especially if the light
background was very visually busy.

For these reasons, in most other places, we have since settled on the
mantra of "shadows should be black", and this commit makes the lock and
login screens follow that convention as well.

BUG: 449985
FIXED-IN: 5.24.2


(cherry picked from commit 146ef22fcbdaf8bc4648e1fb29a6415a524f83dd)
---
 lookandfeel/contents/lockscreen/LockScreenUi.qml |  8 +-------
 sddm-theme/Main.qml                              | 15 ++-------------
 2 files changed, 3 insertions(+), 20 deletions(-)

diff --git a/lookandfeel/contents/lockscreen/LockScreenUi.qml b/lookandfeel/contents/lockscreen/LockScreenUi.qml
index 25b7b2d92..3fa056038 100644
--- a/lookandfeel/contents/lockscreen/LockScreenUi.qml
+++ b/lookandfeel/contents/lockscreen/LockScreenUi.qml
@@ -22,7 +22,6 @@ PlasmaCore.ColorScope {
     // If we're using software rendering, draw outlines instead of shadows
     // See https://bugs.kde.org/show_bug.cgi?id=398317
     readonly property bool softwareRendering: GraphicsInfo.api === GraphicsInfo.Software
-    readonly property bool lightBackground: Math.max(PlasmaCore.ColorScope.backgroundColor.r, PlasmaCore.ColorScope.backgroundColor.g, PlasmaCore.ColorScope.backgroundColor.b) > 0.5
 
     colorGroup: PlasmaCore.Theme.ComplementaryColorGroup
 
@@ -179,12 +178,7 @@ PlasmaCore.ColorScope {
             radius: 6
             samples: 14
             spread: 0.3
-                                                  // Soften the color a bit so it doesn't look so stark against light backgrounds
-            color: lockScreenUi.lightBackground ? Qt.rgba(PlasmaCore.ColorScope.backgroundColor.r,
-                                                          PlasmaCore.ColorScope.backgroundColor.g,
-                                                          PlasmaCore.ColorScope.backgroundColor.b,
-                                                          0.6)
-                                                : "black" // black matches Breeze window decoration and desktopcontainment
+            color : "black" // shadows should always be black
             Behavior on opacity {
                 OpacityAnimator {
                     duration: PlasmaCore.Units.veryLongDuration * 2
diff --git a/sddm-theme/Main.qml b/sddm-theme/Main.qml
index 733108504..00e3cd904 100644
--- a/sddm-theme/Main.qml
+++ b/sddm-theme/Main.qml
@@ -30,7 +30,6 @@ PlasmaCore.ColorScope {
     readonly property bool softwareRendering: GraphicsInfo.api === GraphicsInfo.Software
 
     colorGroup: PlasmaCore.Theme.ComplementaryColorGroup
-    readonly property bool lightBackground: Math.max(PlasmaCore.ColorScope.backgroundColor.r, PlasmaCore.ColorScope.backgroundColor.g, PlasmaCore.ColorScope.backgroundColor.b) > 0.5
 
     width: 1600
     height: 900
@@ -124,12 +123,7 @@ PlasmaCore.ColorScope {
             radius: 6
             samples: 14
             spread: 0.3
-                                          // Soften the color a bit so it doesn't look so stark against light backgrounds
-            color: root.lightBackground ? Qt.rgba(PlasmaCore.ColorScope.backgroundColor.r,
-                                                  PlasmaCore.ColorScope.backgroundColor.g,
-                                                  PlasmaCore.ColorScope.backgroundColor.b,
-                                                  0.6)
-                                        : "black" // black matches Breeze window decoration and desktopcontainment
+            color : "black" // shadows should always be black
             Behavior on opacity {
                 OpacityAnimator {
                     duration: PlasmaCore.Units.veryLongDuration * 2
@@ -503,12 +497,7 @@ PlasmaCore.ColorScope {
             radius: 6
             samples: 14
             spread: 0.3
-                                          // Soften the color a bit so it doesn't look so stark against light backgrounds
-            color: root.lightBackground ? Qt.rgba(PlasmaCore.ColorScope.backgroundColor.r,
-                                                  PlasmaCore.ColorScope.backgroundColor.g,
-                                                  PlasmaCore.ColorScope.backgroundColor.b,
-                                                  0.6)
-                                        : "black" // black matches Breeze window decoration and desktopcontainment
+            color : "black" // shadows should always be black
             opacity: loginScreenRoot.uiVisible ? 0 : 1
             Behavior on opacity {
                 //OpacityAnimator when starting from 0 is buggy (it shows one frame with opacity 1)"