Clip button backgrounds with rounded corners

paulmcauley · Mar 30, 2021 · 1b42947 · 1b42947
1 parent a5b65e9
commit 1b42947
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Showing 4 changed files with 40 additions and 21 deletions.
diff --git a/kdecoration/breezebutton.cpp b/kdecoration/breezebutton.cpp
@@ -139,8 +139,8 @@ namespace Breeze
             if( d->internalSettings()->buttonHighlightStyle() == InternalSettings::EnumButtonHighlightStyle::HighlightSquare ) 
                 paintSquareBackground(painter);
 
-            // translate from offset -- this is the main offset that applies to all button geometries to space each button correctly
-            if( m_flag == FlagFirstInList ) painter->translate( m_offset );
+            // translate from offset
+            if( m_flag == FlagLeftmostAndAtEdge ) painter->translate( m_offset );
             else painter->translate( 0, m_offset.y() );
 
             const QRectF iconRect( geometry().topLeft(), m_iconSize );
@@ -181,7 +181,7 @@ namespace Breeze
             paintSquareBackground(painter);
 
         // translate from offset
-        if( m_flag == FlagFirstInList ) painter->translate( m_offset );
+        if( m_flag == FlagLeftmostAndAtEdge ) painter->translate( m_offset );
         else painter->translate( 0, m_offset.y() );
 
         /*
@@ -459,13 +459,19 @@ namespace Breeze
     void Button::paintSquareBackground(QPainter* painter) const
     {
         auto d = qobject_cast<Decoration*>( decoration() );
+        auto s = d->settings();
+        QPainterPath* titlebarPath = d->titleBarPath();
 
         if( m_backgroundColor.isValid() )
         {            
             painter->save();
             painter->setRenderHints( QPainter::Antialiasing );
             painter->setBrush( m_backgroundColor );
 
+            //clip the rounded corners using the titlebar path
+            if( !d->isMaximized() && s->isAlphaChannelSupported() && (m_flag == FlagLeftmostNotAtEdge || m_flag == FlagRightmostNotAtEdge) )
+                painter->setClipPath(*titlebarPath, Qt::IntersectClip);
+
             if( shouldDrawBackgroundStroke() )
             {   
                 QColor strokeColor = d->fontColor();

diff --git a/kdecoration/breezebutton.h b/kdecoration/breezebutton.h
@@ -42,16 +42,18 @@ namespace Breeze
         {
             FlagNone,
             FlagStandalone,
-            FlagFirstInList,
-            FlagLastInList,
+            FlagLeftmostNotAtEdge,
+            FlagLeftmostAndAtEdge,
+            FlagRightmostNotAtEdge,
+            FlagRightmostAndAtEdge,
         };
 
         //* flag
         void setFlag( Flag value )
         { m_flag = value; }
 
         //* standalone buttons
-        bool isStandAlone() const { return m_flag == FlagStandalone; }
+        bool isStandAlone() const { return ( m_flag == FlagStandalone || m_flag == FlagLeftmostNotAtEdge || m_flag == FlagRightmostNotAtEdge); }
 
         //* offset
         void setOffset( const QPointF& value )

diff --git a/kdecoration/breezedecoration.cpp b/kdecoration/breezedecoration.cpp
@@ -590,13 +590,15 @@ namespace Breeze
             if( m_internalSettings->buttonHighlightStyle() == InternalSettings::EnumButtonHighlightStyle::HighlightSquare ) vPadding = 0;
             else vPadding = isTopEdge() ? 0 : s->smallSpacing()*titleBarTopMargin;
             const int hPadding = s->smallSpacing()*m_internalSettings->titlebarSideMargins();
+
+            auto firstButton = static_cast<Button*>( m_leftButtons->buttons().front().data() );
+            firstButton->setFlag( Button::FlagLeftmostNotAtEdge);
             if( isLeftEdge() )
             {
                 // add offsets on the side buttons, to preserve padding, but satisfy Fitts law
-                auto button = static_cast<Button*>( m_leftButtons->buttons().front().data() );
-                button->setGeometry( QRectF( QPoint( 0, 0 ), QSizeF( button->geometry().width() + hPadding, button->geometry().height() ) ) );
-                button->setHorizontalOffset( hPadding );
-                button->setFlag( Button::FlagFirstInList );
+                firstButton->setGeometry( QRectF( QPoint( 0, 0 ), QSizeF( firstButton->geometry().width() + hPadding, firstButton->geometry().height() ) ) );
+                firstButton->setHorizontalOffset( hPadding );
+                firstButton->setFlag( Button::FlagLeftmostAndAtEdge );
 
                 m_leftButtons->setPos(QPointF(0, vPadding));
 
@@ -619,12 +621,13 @@ namespace Breeze
             if( m_internalSettings->buttonHighlightStyle() == InternalSettings::EnumButtonHighlightStyle::HighlightSquare ) vPadding = 0;
             else vPadding = isTopEdge() ? 0 : s->smallSpacing()*titleBarTopMargin;
             const int hPadding = s->smallSpacing()*m_internalSettings->titlebarSideMargins();
+
+            auto lastButton = static_cast<Button*>( m_rightButtons->buttons().back().data() );
+            lastButton->setFlag( Button::FlagRightmostNotAtEdge );
             if( isRightEdge() )
             {
-
-                auto button = static_cast<Button*>( m_rightButtons->buttons().back().data() );
-                button->setGeometry( QRectF( QPoint( 0, 0 ), QSizeF( button->geometry().width() + hPadding, button->geometry().height() ) ) );
-                button->setFlag( Button::FlagLastInList );
+                lastButton->setGeometry( QRectF( QPoint( 0, 0 ), QSizeF( lastButton->geometry().width() + hPadding, lastButton->geometry().height() ) ) );
+                lastButton->setFlag( Button::FlagRightmostAndAtEdge );
 
                 m_rightButtons->setPos(QPointF(size().width() - m_rightButtons->geometry().width(), vPadding));
 
@@ -718,26 +721,29 @@ namespace Breeze
 
         auto s = settings();
         double cornerRadiusScaled = m_internalSettings->cornerRadius()*s->smallSpacing();
+
+        m_titleBarPath.clear(); //clear the path for subsequent calls to this function
         if( isMaximized() || !s->isAlphaChannelSupported() )
         {
-
-            painter->drawRect(titleRect);
+            m_titleBarPath.addRect(titleRect);
+            painter->drawPath(m_titleBarPath);
 
         } else if( c->isShaded() ) {
-
-            painter->drawRoundedRect(titleRect, cornerRadiusScaled, cornerRadiusScaled);
+            m_titleBarPath.addRoundedRect(titleRect, cornerRadiusScaled, cornerRadiusScaled);
+            painter->drawPath(m_titleBarPath);
 
         } else {
-
+            
             painter->setClipRect(titleRect, Qt::IntersectClip);
-
             // the rect is made a little bit larger to be able to clip away the rounded corners at the bottom and sides
-            painter->drawRoundedRect(titleRect.adjusted(
+            m_titleBarPath.addRoundedRect(titleRect.adjusted(
                 isLeftEdge() ? -cornerRadiusScaled:0,
                 isTopEdge() ? -cornerRadiusScaled:0,
                 isRightEdge() ? cornerRadiusScaled:0,
                 cornerRadiusScaled),
                 cornerRadiusScaled, cornerRadiusScaled);
+
+            painter->drawPath(m_titleBarPath);
 
         }
 

diff --git a/kdecoration/breezedecoration.h b/kdecoration/breezedecoration.h
@@ -18,6 +18,7 @@
 #include <QPalette>
 #include <QVariant>
 #include <QVariantAnimation>
+#include <QPainterPath>
 
 class QVariantAnimation;
 
@@ -87,6 +88,8 @@ namespace Breeze
 
         inline bool hideTitleBar() const;
         //@}
+
+        QPainterPath* titleBarPath(){return &m_titleBarPath;}
 
         public Q_SLOTS:
         void init() override;
@@ -147,6 +150,8 @@ namespace Breeze
         //*tilebar main state opacity
         int m_titleBarOpacityActive = 255;
         int m_titleBarOpacityInactive = 255;
+
+        QPainterPath m_titleBarPath;
 
     };