validate top/bottom borders for vertical panels

--make the top/bottom borders identification much
smarter in order to identify in they must be drawn.
There are many corner cases that these borders should
be drawn, for example when a vertical top aligned
panel is half shown its top border because of a
top panel

app/view/effects.cpp

@@ -135,18 +135,24 @@ void Effects::setDrawEffects(bool draw)
     emit drawEffectsChanged();
 }
 
-bool Effects::forceDrawCenteredBorders() const
+void Effects::setForceBottomBorder(bool draw)
 {
-    return m_forceDrawCenteredBorders;
+    if (m_forceBottomBorder == draw) {
+        return;
+    }
+
+    m_forceBottomBorder = draw;
+    updateEnabledBorders();
 }
 
-void Effects::setForceDrawCenteredBorders(bool draw)
+void Effects::setForceTopBorder(bool draw)
 {
-    if (m_forceDrawCenteredBorders == draw) {
+    if (m_forceTopBorder == draw) {
         return;
     }
 
-    m_forceDrawCenteredBorders = draw;
+    m_forceTopBorder = draw;
+    updateEnabledBorders();
 }
 
 int Effects::backgroundOpacity() const
@@ -519,16 +525,21 @@ void Effects::updateEnabledBorders()
     }
 
     if ((m_view->location() == Plasma::Types::LeftEdge || m_view->location() == Plasma::Types::RightEdge)) {
-        if (m_view->maxLength() == 1 && m_view->alignment() == Latte::Types::Justify && !m_forceDrawCenteredBorders) {
-            borders &= ~Plasma::FrameSvg::TopBorder;
-            borders &= ~Plasma::FrameSvg::BottomBorder;
+        if (m_view->maxLength() == 1 && m_view->alignment() == Latte::Types::Justify) {
+            if (!m_forceTopBorder) {
+                borders &= ~Plasma::FrameSvg::TopBorder;
+            }
+
+            if (!m_forceBottomBorder) {
+                borders &= ~Plasma::FrameSvg::BottomBorder;
+            }
         }
 
-        if (m_view->alignment() == Latte::Types::Top && !m_forceDrawCenteredBorders && m_view->offset() == 0) {
+        if (m_view->alignment() == Latte::Types::Top && !m_forceTopBorder && m_view->offset() == 0) {
             borders &= ~Plasma::FrameSvg::TopBorder;
         }
 
-        if (m_view->alignment() == Latte::Types::Bottom && !m_forceDrawCenteredBorders && m_view->offset() == 0) {
+        if (m_view->alignment() == Latte::Types::Bottom && !m_forceBottomBorder && m_view->offset() == 0) {
             borders &= ~Plasma::FrameSvg::BottomBorder;
         }
     }

app/view/effects.h

@@ -68,8 +68,8 @@ public:
     bool drawEffects() const;
     void setDrawEffects(bool draw);
 
-    bool forceDrawCenteredBorders() const;
-    void setForceDrawCenteredBorders(bool draw);
+    void setForceTopBorder(bool draw);
+    void setForceBottomBorder(bool draw);
 
     bool settingsMaskSubtracted() const;
     void setSettingsMaskSubtracted(bool enabled);
@@ -127,7 +127,8 @@ private:
     bool m_animationsBlocked{false};
     bool m_drawShadows{true};
     bool m_drawEffects{false};
-    bool m_forceDrawCenteredBorders{false};
+    bool m_forceTopBorder{false};
+    bool m_forceBottomBorder{false};
     bool m_settingsMaskSubtracted{false};
 
     int m_backgroundOpacity{100};

app/view/positioner.cpp

@@ -158,6 +158,12 @@ void Positioner::init()
         }
     });
 
+    connect(m_view, &Latte::View::screenEdgeMarginChanged, this, [&]() {
+        if (m_view->screenEdgeMarginEnabled() && m_view->inEditMode()) {
+            syncGeometry();
+        }
+    });
+
     connect(m_view->effects(), &Latte::ViewPart::Effects::drawShadowsChanged, this, [&]() {
         if (!m_view->behaveAsPlasmaPanel()) {
             syncGeometry();
@@ -452,6 +458,11 @@ void Positioner::syncGeometry()
                     area = tempArea;
                 }
             }
+
+            validateTopBottomBorders(availableScreenRect, freeRegion);
+        } else {
+            m_view->effects()->setForceTopBorder(false);
+            m_view->effects()->setForceBottomBorder(false);
         }
 
         m_view->effects()->updateEnabledBorders();
@@ -518,6 +529,44 @@ QRect Positioner::maximumNormalGeometry()
     return maxGeometry;
 }
 
+void Positioner::validateTopBottomBorders(QRect availableScreenRect, QRegion availableScreenRegion)
+{
+    //! Check if the the top/bottom borders must be drawn also
+    int edgeMargin = qMax(1, m_view->screenEdgeMargin());
+
+    if (availableScreenRect.top() != m_view->screenGeometry().top()) {
+        //! check top border
+        QRegion fitInRegion = QRect(m_view->screenGeometry().x(), availableScreenRect.y()-1, edgeMargin, 1);
+        QRegion subtracted = fitInRegion.subtracted(availableScreenRegion);
+
+        if (subtracted.isNull()) {
+            //!FitIn rectangle fits TOTALLY in the free screen region and as such
+            //!the top border should be drawn
+            m_view->effects()->setForceTopBorder(true);
+        } else {
+            m_view->effects()->setForceTopBorder(false);
+        }
+    } else {
+        m_view->effects()->setForceTopBorder(false);
+    }
+
+    if (availableScreenRect.bottom() != m_view->screenGeometry().bottom()) {
+        //! check top border
+        QRegion fitInRegion = QRect(m_view->screenGeometry().x(), availableScreenRect.bottom()+1, edgeMargin, 1);
+        QRegion subtracted = fitInRegion.subtracted(availableScreenRegion);
+
+        if (subtracted.isNull()) {
+            //!FitIn rectangle fits TOTALLY in the free screen region and as such
+            //!the BOTTOM border should be drawn
+            m_view->effects()->setForceBottomBorder(true);
+        } else {
+            m_view->effects()->setForceBottomBorder(false);
+        }
+    } else {
+        m_view->effects()->setForceBottomBorder(false);
+    }
+}
+
 void Positioner::updatePosition(QRect availableScreenRect)
 {
     QRect screenGeometry{availableScreenRect};
@@ -785,7 +834,7 @@ bool Positioner::isStickedOnTopEdge() const
 void Positioner::setIsStickedOnTopEdge(bool sticked)
 {
     if (m_isStickedOnTopEdge == sticked) {
-         return;
+        return;
     }
 
     m_isStickedOnTopEdge = sticked;

app/view/positioner.h

@@ -134,6 +134,8 @@ private:
     void updateFormFactor();
     void updatePosition(QRect availableScreenRect = QRect());
 
+    void validateTopBottomBorders(QRect availableScreenRect, QRegion availableScreenRegion);
+
     QRect maximumNormalGeometry();
 
 private: