support overlap dock cases by using free space

--this commit uses free region from corona instead
of free rectangle in order to calculate size and
positioning for the docks. This way is possible to
be positioned more intelligently.

app/dockcorona.cpp

@@ -205,10 +205,102 @@ QRect DockCorona::screenGeometry(int id) const
 
 QRegion DockCorona::availableScreenRegion(int id) const
 {
-    return availableScreenRect(id);
-    //FIXME::: availableGeometry is probably broken
-    // in Qt, so this have to be updated as plasma is doing it
-    // for example the availableScreenRect
+    const auto screens = qGuiApp->screens();
+    const QScreen *screen{qGuiApp->primaryScreen()};
+    QString scrName = m_screenPool->connector(id);
+
+    foreach (auto scr, screens) {
+        if (scr->name() == scrName) {
+            screen = scr;
+            break;
+        }
+    }
+
+    if (!screen)
+        return QRegion();
+
+    QRegion available(screen->geometry());
+
+    for (const auto *view : m_dockViews) {
+        if (view && view->containment() && view->screen() == screen) {
+            int realThickness = view->normalThickness() - view->shadow();
+
+            // Usually availableScreenRect is used by the desktop,
+            // but Latte dont have desktop, then here just
+            // need calculate available space for top and bottom location,
+            // because the left and right are those who dodge others docks
+            switch (view->location()) {
+                case Plasma::Types::TopEdge:
+                    if (view->drawShadows()) {
+                        available -= view->geometry();
+                    } else {
+                        QRect realGeometry;
+                        int realWidth = view->maxLength() * view->width();
+
+                        switch (view->alignment()) {
+                            case Latte::Dock::Left:
+                                realGeometry = QRect(view->x(), view->y(),
+                                                     realWidth, realThickness);
+                                break;
+
+                            case Latte::Dock::Center:
+                            case Latte::Dock::Justify:
+                                realGeometry = QRect(view->geometry().center().x() - realWidth / 2 , view->y(),
+                                                     realWidth , realThickness);
+                                break;
+
+                            case Latte::Dock::Right:
+                                realGeometry = QRect(view->geometry().right() - realWidth + 1, view->y(),
+                                                     realWidth, realThickness);
+                                break;
+                        }
+
+                        available -= realGeometry;
+                    }
+
+                    break;
+
+                case Plasma::Types::BottomEdge:
+                    if (view->drawShadows()) {
+                        available -= view->geometry();
+                    } else {
+                        QRect realGeometry;
+                        int realWidth = view->maxLength() * view->width();
+                        int realY = view->geometry().bottom() - realThickness + 1;
+
+                        switch (view->alignment()) {
+                            case Latte::Dock::Left:
+                                realGeometry = QRect(view->x(), realY,
+                                                     realWidth, realThickness);
+                                break;
+
+                            case Latte::Dock::Center:
+                            case Latte::Dock::Justify:
+                                realGeometry = QRect(qMax(view->geometry().x(), view->geometry().center().x() - realWidth / 2),
+                                                     realY, realWidth, realThickness);
+                                break;
+
+                            case Latte::Dock::Right:
+                                realGeometry = QRect(view->geometry().right() - realWidth + 1, realY,
+                                                     realWidth, realThickness);
+                                break;
+                        }
+
+                        available -= realGeometry;
+                    }
+
+                    break;
+            }
+        }
+    }
+
+    /*qDebug() << "::::: FREE AREAS :::::";
+    for (int i = 0; i < available.rectCount(); ++i) {
+        qDebug() << available.rects().at(i);
+    }
+    qDebug() << "::::: END OF FREE AREAS :::::";*/
+
+    return available;
 }
 
 QRect DockCorona::availableScreenRect(int id) const

app/dockview.cpp

@@ -378,15 +378,86 @@ void DockView::showConfigurationInterface(Plasma::Applet *applet)
     }
 }
 
+//! this is used mainly from vertical panels in order to
+//! to get the maximum geometry that can be used from the dock
+//! based on their alignment type and the location dock
+QRect DockView::maximumNormalGeometry()
+{
+    if (!this->screen()) {
+        return;
+    }
+
+    int xPos = 0;
+    int yPos = 0;
+    int maxHeight = maxLength() * screen()->geometry().height();
+    int maxWidth = normalThickness();
+
+    QRect maxGeometry;
+
+    maxGeometry.setRect(0, 0, maxWidth, maxHeight);
+
+    switch (location()) {
+        case Plasma::Types::LeftEdge:
+            xPos = screen()->geometry().x();
+
+            switch (alignment()) {
+                case Latte::Dock::Top:
+                    yPos = screen()->geometry().y();
+                    break;
+
+                case Latte::Dock::Center:
+                case Latte::Dock::Justify:
+                    yPos = qMax(screen()->geometry().center().y() - maxHeight / 2, screen()->geometry().y());
+                    break;
+
+                case Latte::Dock::Bottom:
+                    yPos = screen()->geometry().bottom() - maxHeight + 1;
+                    break;
+            }
+
+            maxGeometry.setRect(xPos, yPos, maxWidth, maxHeight);
+
+            break;
+
+        case Plasma::Types::RightEdge:
+            xPos = screen()->geometry().right() - maxWidth + 1;
+
+            switch (alignment()) {
+                case Latte::Dock::Top:
+                    yPos = screen()->geometry().y();
+                    break;
+
+                case Latte::Dock::Center:
+                case Latte::Dock::Justify:
+                    yPos = qMax(screen()->geometry().center().y() - maxHeight / 2, screen()->geometry().y());
+                    break;
+
+                case Latte::Dock::Bottom:
+                    yPos = screen()->geometry().bottom() - maxHeight + 1;
+                    break;
+            }
+
+            maxGeometry.setRect(xPos, yPos, maxWidth, maxHeight);
+
+            break;
+    }
+
+    return maxGeometry;
+}
+
 void DockView::resizeWindow()
 {
     if (formFactor() == Plasma::Types::Vertical) {
-        QSize screenSize = corona()->availableScreenRect(this->containment()->screen()).size();
-        QSize size{maxThickness(), screenSize.height()};
+        QRegion freeRegion = corona()->availableScreenRegion(this->containment()->screen());
+        QRect maximumRect = maximumNormalGeometry();
+        QRect availableRect = freeRegion.intersected(maximumRect).boundingRect();
+
+        //qDebug() << "MAXIMUM RECT :: " << maximumRect << " - AVAILABLE RECT :: " << availableRect;
+        QSize size{maxThickness(), availableRect.height()};
 
         if (m_drawShadows) {
             size.setWidth(normalThickness());
-            size.setHeight(static_cast<int>(maxLength() * screenSize.height()));
+            size.setHeight(static_cast<int>(maxLength() * availableRect.height()));
         }
 
         setMinimumSize(size);
@@ -432,6 +503,10 @@ void DockView::updatePosition()
 {
     QRect screenGeometry;
     QPoint position;
+    QRegion freeRegion;
+    QRect maximumRect;
+    QRect availableRect;
+
     position = {0, 0};
 
     const auto length = [&](int length) -> int {
@@ -466,25 +541,31 @@ void DockView::updatePosition()
             break;
 
         case Plasma::Types::RightEdge:
-            screenGeometry = corona()->availableScreenRect(this->containment()->screen());
+            //screenGeometry = corona()->availableScreenRect(this->containment()->screen());
+            freeRegion = corona()->availableScreenRegion(this->containment()->screen());
+            maximumRect = maximumNormalGeometry();
+            availableRect = freeRegion.intersected(maximumRect).boundingRect();
 
             if (m_drawShadows && !mask().isNull()) {
-                position = {screenGeometry.x() + screenGeometry.width() - cleanThickness,
-                            screenGeometry.y() + length(screenGeometry.height())
+                position = {availableRect.right() - cleanThickness + 1,
+                            availableRect.y() + length(availableRect.height())
                            };
             } else {
-                position = {screenGeometry.x() + screenGeometry.width() - width(), screenGeometry.y()};
+                position = {availableRect.right() - width() + 1, availableRect.y()};
             }
 
             break;
 
         case Plasma::Types::LeftEdge:
-            screenGeometry = corona()->availableScreenRect(this->containment()->screen());
+            //screenGeometry = corona()->availableScreenRect(this->containment()->screen());
+            freeRegion = corona()->availableScreenRegion(this->containment()->screen());
+            maximumRect = maximumNormalGeometry();
+            availableRect = freeRegion.intersected(maximumRect).boundingRect();
 
             if (m_drawShadows && !mask().isNull()) {
-                position = {screenGeometry.x(), screenGeometry.y() + length(screenGeometry.height())};
+                position = {availableRect.x(), availableRect.y() + length(availableRect.height())};
             } else {
-                position = {screenGeometry.x(), screenGeometry.y()};
+                position = {availableRect.x(), availableRect.y()};
             }
 
             break;

app/dockview.h

@@ -184,6 +184,8 @@ private:
     void updatePosition();
     void updateFormFactor();
 
+    QRect maximumNormalGeometry();
+
 private:
     Plasma::Containment *containmentById(uint id);