[aurorae] Improve reading the border elements from C++ side

The KWin::Borders element is provided by an extension plugin. The reason
for that is to be able to use it from e.g. the kcm or Plasmate without
needing to compile the code in.

But this results in Aurorae itself not being able to access the element.
The solution is to first load our decoration plugin and afterwards
register the borders element again with the version compiled in from
Aurorae.

With that we can now read all borders and paddings without using
properties. Also we could connect to change signals and have the borders
and padding handling completely stateful. Might be an idea for extending
the decoration library...

clients/aurorae/src/CMakeLists.txt

@@ -7,6 +7,7 @@ include_directories(
 
 set(kwin3_aurorae_PART_SRCS
     aurorae.cpp
+    decorationoptions.cpp
     lib/auroraetheme.cpp
     lib/themeconfig.cpp
 )

clients/aurorae/src/aurorae.cpp

@@ -18,9 +18,13 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include "aurorae.h"
 #include "auroraetheme.h"
 #include "config-kwin.h"
+// qml imports
+#include "decorationoptions.h"
 
 #include <QApplication>
 #include <QDebug>
+#include <QDirIterator>
+#include <QFileInfo>
 #include <QMutex>
 #include <QOpenGLFramebufferObject>
 #include <QPainter>
@@ -64,6 +68,33 @@ void AuroraeFactory::init()
 {
     qRegisterMetaType<uint>("Qt::MouseButtons");
 
+    // we need to first load our decoration plugin
+    // once it's loaded we can provide the Borders and access them from C++ side
+    // so let's try to locate our plugin:
+    QString pluginPath;
+    for (const QString &path : m_engine->importPathList()) {
+        QDirIterator it(path, QDirIterator::Subdirectories);
+        while (it.hasNext()) {
+            it.next();
+            QFileInfo fileInfo = it.fileInfo();
+            if (!fileInfo.isFile()) {
+                continue;
+            }
+            if (!fileInfo.path().endsWith(QLatin1String("/org/kde/kwin/decoration"))) {
+                continue;
+            }
+            if (fileInfo.fileName() == QLatin1String("libdecorationplugin.so")) {
+                pluginPath = fileInfo.absoluteFilePath();
+                break;
+            }
+        }
+        if (!pluginPath.isEmpty()) {
+            break;
+        }
+    }
+    m_engine->importPlugin(pluginPath, "org.kde.kwin.decoration", nullptr);
+    qmlRegisterType<KWin::Borders>("org.kde.kwin.decoration", 0, 1, "Borders");
+
     KConfig conf(QStringLiteral("auroraerc"));
     KConfigGroup group(&conf, "Engine");
     if (!group.hasKey("EngineType") && !group.hasKey("ThemeName")) {
@@ -250,6 +281,10 @@ AuroraeClient::AuroraeClient(KDecorationBridge *bridge, KDecorationFactory *fact
     : KDecoration(bridge, factory)
     , m_view(nullptr)
     , m_item(AuroraeFactory::instance()->createQmlDecoration(this))
+    , m_borders(nullptr)
+    , m_maximizedBorders(nullptr)
+    , m_extendedBorders(nullptr)
+    , m_padding(nullptr)
 {
     connect(AuroraeFactory::instance(), SIGNAL(buttonsChanged()), SIGNAL(buttonsChanged()));
     connect(AuroraeFactory::instance(), SIGNAL(configChanged()), SIGNAL(configChanged()));
@@ -295,6 +330,7 @@ void AuroraeClient::init()
     if (m_item) {
         m_item->setParentItem(m_view->contentItem());
         m_item->setParent(m_view);
+        setupBorders();
     }
     slotAlphaChanged();
 
@@ -333,18 +369,18 @@ void AuroraeClient::borders(int &left, int &right, int &top, int &bottom) const
         left = right = top = bottom = 0;
         return;
     }
-    QObject *borders = nullptr;
+    KWin::Borders *borders = nullptr;
     if (maximizeMode() == MaximizeFull) {
-        borders = m_item->findChild<QObject*>(QStringLiteral("maximizedBorders"));
+        borders = m_maximizedBorders;
     } else {
-        borders = m_item->findChild<QObject*>(QStringLiteral("borders"));
+        borders = m_borders;
     }
     sizesFromBorders(borders, left, right, top, bottom);
 }
 
 void AuroraeClient::padding(int &left, int &right, int &top, int &bottom) const
 {
-    if (!m_item) {
+    if (!m_padding) {
         left = right = top = bottom = 0;
         return;
     }
@@ -352,18 +388,19 @@ void AuroraeClient::padding(int &left, int &right, int &top, int &bottom) const
         left = right = top = bottom = 0;
         return;
     }
-    sizesFromBorders(m_item->findChild<QObject*>(QStringLiteral("padding")), left, right, top, bottom);
+    sizesFromBorders(m_padding, left, right, top, bottom);
 }
 
-void AuroraeClient::sizesFromBorders(const QObject *borders, int &left, int &right, int &top, int &bottom) const
+void AuroraeClient::sizesFromBorders(const KWin::Borders *borders, int &left, int &right, int &top, int &bottom) const
 {
     if (!borders) {
+        left = right = top = bottom = 0;
         return;
     }
-    left = borders->property("left").toInt();
-    right = borders->property("right").toInt();
-    top = borders->property("top").toInt();
-    bottom = borders->property("bottom").toInt();
+    left   = borders->left();
+    right  = borders->right();
+    top    = borders->top();
+    bottom = borders->bottom();
 }
 
 QSize AuroraeClient::minimumSize() const
@@ -461,11 +498,16 @@ void AuroraeClient::themeChanged()
     m_item->deleteLater();
     m_item = AuroraeFactory::instance()->createQmlDecoration(this);
     if (!m_item) {
+        m_borders = nullptr;
+        m_extendedBorders = nullptr;
+        m_maximizedBorders = nullptr;
+        m_padding = nullptr;
         return;
     }
 
     m_item->setParentItem(m_view->contentItem());
     m_item->setParent(m_view);
+    setupBorders();
     connect(m_item, SIGNAL(alphaChanged()), SLOT(slotAlphaChanged()));
     slotAlphaChanged();
 }
@@ -548,7 +590,7 @@ QRegion AuroraeClient::region(KDecorationDefines::Region r)
     }
     int left, right, top, bottom;
     left = right = top = bottom = 0;
-    sizesFromBorders(m_item->findChild<QObject*>(QStringLiteral("extendedBorders")), left, right, top, bottom);
+    sizesFromBorders(m_extendedBorders, left, right, top, bottom);
     if (top == 0 && right == 0 && bottom == 0 && left == 0) {
         // no extended borders
         return QRegion();
@@ -576,6 +618,17 @@ void AuroraeClient::render(QPaintDevice *device, const QRegion &sourceRegion)
     painter.drawImage(QPoint(0, 0), m_buffer);
 }
 
+void AuroraeClient::setupBorders()
+{
+    if (!m_item) {
+        return;
+    }
+    m_borders          = m_item->findChild<KWin::Borders*>(QStringLiteral("borders"));
+    m_maximizedBorders = m_item->findChild<KWin::Borders*>(QStringLiteral("maximizedBorders"));
+    m_extendedBorders  = m_item->findChild<KWin::Borders*>(QStringLiteral("extendedBorders"));
+    m_padding          = m_item->findChild<KWin::Borders*>(QStringLiteral("padding"));
+}
+
 } // namespace Aurorae
 
 #include "aurorae.moc"

clients/aurorae/src/aurorae.h

@@ -32,6 +32,11 @@ class QQuickWindow;
 class KConfig;
 class KConfigGroup;
 
+namespace KWin
+{
+class Borders;
+}
+
 namespace Aurorae
 {
 class AuroraeTheme;
@@ -162,11 +167,16 @@ private Q_SLOTS:
     void slotAlphaChanged();
 
 private:
-    void sizesFromBorders(const QObject *borders, int &left, int &right, int &top, int &bottom) const;
+    void sizesFromBorders(const KWin::Borders *borders, int &left, int &right, int &top, int &bottom) const;
+    void setupBorders();
     QQuickWindow *m_view;
     QQuickItem *m_item;
     QScopedPointer<QOpenGLFramebufferObject> m_fbo;
     QImage m_buffer;
+    KWin::Borders *m_borders;
+    KWin::Borders *m_maximizedBorders;
+    KWin::Borders *m_extendedBorders;
+    KWin::Borders *m_padding;
 };
 
 }