Add Theme::blurBehindEnabled()

Summary:
Allows themes to disable the blurring of what is behind panels,
if they either do not need it (being fully opaque) or by design want
non-blurry transparency.

Reviewers: #plasma, davidedmundson

Reviewed By: #plasma, davidedmundson

Subscribers: kde-frameworks-devel

Tags: #frameworks

Differential Revision: https://phabricator.kde.org/D19907

src/plasma/private/theme_p.cpp

@@ -75,6 +75,7 @@ ThemePrivate::ThemePrivate(QObject *parent)
       backgroundIntensity(qQNaN()),
       backgroundSaturation(qQNaN()),
       backgroundContrastEnabled(true),
+      blurBehindEnabled(true),
       apiMajor(1),
       apiMinor(0),
       apiRevision(0)
@@ -736,6 +737,17 @@ void ThemePrivate::processContrastSettings(KConfigBase *metadata)
     }
 }
 
+void ThemePrivate::processBlurBehindSettings(KConfigBase *metadata)
+{
+    KConfigGroup cg;
+    if (metadata->hasGroup("BlurBehindEffect")) {
+        cg = KConfigGroup(metadata, "BlurBehindEffect");
+        blurBehindEnabled = cg.readEntry("enabled", true);
+    } else {
+        blurBehindEnabled = true;
+    }
+}
+
 void ThemePrivate::setThemeName(const QString &tempThemeName, bool writeSettings, bool emitChanged)
 {
     QString theme = tempThemeName;
@@ -800,6 +812,7 @@ void ThemePrivate::setThemeName(const QString &tempThemeName, bool writeSettings
         pluginInfo = KPluginInfo(metadataPath);
 
         processContrastSettings(&metadata);
+        processBlurBehindSettings(&metadata);
 
         processWallpaperSettings(&metadata);
 

src/plasma/private/theme_p.h

@@ -76,6 +76,7 @@ public:
     void setThemeName(const QString &themeName, bool writeSettings, bool emitChanged);
     void processWallpaperSettings(KConfigBase *metadata);
     void processContrastSettings(KConfigBase *metadata);
+    void processBlurBehindSettings(KConfigBase *metadata);
 
     const QString processStyleSheet(const QString &css, Plasma::Svg::Status status);
     const QString svgStyleSheet(Plasma::Theme::ColorGroup group, Plasma::Svg::Status status);
@@ -156,6 +157,7 @@ public:
     qreal backgroundIntensity;
     qreal backgroundSaturation;
     bool backgroundContrastEnabled;
+    bool blurBehindEnabled;
 
     //Version number of Plasma the Theme has been designed for
     int apiMajor;

src/plasma/theme.cpp

@@ -510,6 +510,11 @@ qreal Theme::backgroundSaturation() const
     return d->backgroundSaturation;
 }
 
+bool Theme::blurBehindEnabled() const
+{
+    return d->blurBehindEnabled;
+}
+
 }
 
 #include "moc_theme.cpp"

src/plasma/theme.h

@@ -380,6 +380,22 @@ public:
      */
     qreal backgroundSaturation() const;
 
+    /** This method allows Plasma to enable and disable the blurring
+     * of what is behind the background for a given theme. The
+     * value is read from the "enabled" key in the "BlurBehindEffect"
+     * group in the Theme's metadata file. Default is @c true.
+     *
+     * The configuration in the metadata.desktop file of the theme
+     * could look like this:
+     * \code
+     * [BlurBehindEffect]
+     * enabled=false
+     * \endcode
+     * @return Whether or not to enable blurring of what is behind
+     * @since 5.57
+     */
+    bool blurBehindEnabled() const;
+
     /**
      * Returns the size of the letter "M" as rendered on the screen with the given font.
      * This values gives you a base size that:

src/plasmaquick/dialog.cpp

@@ -241,7 +241,7 @@ void DialogPrivate::updateTheme()
             frameSvgItem->setImagePath(QStringLiteral("dialogs/background"));
         }
 
-        KWindowEffects::enableBlurBehind(q->winId(), true, frameSvgItem->frameSvg()->mask());
+        KWindowEffects::enableBlurBehind(q->winId(), theme.blurBehindEnabled(), frameSvgItem->frameSvg()->mask());
 
         KWindowEffects::enableBackgroundContrast(q->winId(), theme.backgroundContrastEnabled(),
                 theme.backgroundContrast(),