Add overlay support to Plasma IconItem.

By default Plasma IconItem renders the icon without an overlay even when an overlay is required.
This fixes this.

REVIEW:128573

src/declarativeimports/core/iconitem.cpp

@@ -19,7 +19,6 @@
  */
 
 #include "iconitem.h"
-
 #include <QDebug>
 #include <QPaintEngine>
 #include <QPainter>
@@ -74,6 +73,9 @@ IconItem::IconItem(QQuickItem *parent)
     connect(this, &QQuickItem::windowChanged,
             this, &IconItem::schedulePixmapUpdate);
 
+    connect(this, SIGNAL(overlaysChanged()),
+            this, SLOT(schedulePixmapUpdate()));
+
     //initialize implicit size to the Dialog size
     setImplicitWidth(KIconLoader::global()->currentSize(KIconLoader::Dialog));
     setImplicitHeight(KIconLoader::global()->currentSize(KIconLoader::Dialog));
@@ -212,6 +214,22 @@ Plasma::Theme::ColorGroup IconItem::colorGroup() const
     return m_colorGroup;
 }
 
+
+void IconItem::setOverlays(const QStringList &overlays)
+{
+    if (overlays == m_overlays) {
+        return;
+    }
+    m_overlays = overlays;
+    emit overlaysChanged();
+}
+
+QStringList IconItem::overlays() const
+{
+    return m_overlays;
+}
+
+
 bool IconItem::isActive() const
 {
     return m_active;
@@ -451,6 +469,20 @@ void IconItem::loadPixmap()
         return;
     }
 
+    // Strangely KFileItem::overlays() returns empty string-values, so
+    // we need to check first whether an overlay must be drawn at all.
+    // It is more efficient to do it here, as KIconLoader::drawOverlays()
+    // assumes that an overlay will be drawn and has some additional
+    // setup time.
+    foreach (const QString& overlay, m_overlays) {
+        if (!overlay.isEmpty()) {
+            // There is at least one overlay, draw all overlays above m_pixmap
+            // and cancel the check
+            KIconLoader::global()->drawOverlays(m_overlays, result, KIconLoader::Desktop);
+            break;
+        }
+    }
+
     if (!isEnabled()) {
         result = KIconLoader::global()->iconEffect()->apply(result, KIconLoader::Desktop, KIconLoader::DisabledState);
     } else if (m_active) {

src/declarativeimports/core/iconitem.h

@@ -60,6 +60,11 @@ class IconItem : public QQuickItem
      */
     Q_PROPERTY(Plasma::Theme::ColorGroup colorGroup READ colorGroup WRITE setColorGroup NOTIFY colorGroupChanged)
 
+    /**
+      * Specifies the overlay(s) for this icon
+      */
+    Q_PROPERTY(QStringList overlays READ overlays WRITE setOverlays NOTIFY overlaysChanged)
+
     /**
      * See QQuickItem::smooth
      */
@@ -119,6 +124,9 @@ public:
     void setColorGroup(Plasma::Theme::ColorGroup group);
     Plasma::Theme::ColorGroup colorGroup() const;
 
+    void setOverlays(const QStringList &overlays);
+    QStringList overlays() const;
+
     bool isActive() const;
     void setActive(bool active);
 
@@ -149,6 +157,7 @@ public:
     void componentComplete() Q_DECL_OVERRIDE;
 
 Q_SIGNALS:
+    void overlaysChanged();
     void activeChanged();
     void sourceChanged();
     void smoothChanged();
@@ -193,6 +202,8 @@ private:
     QPixmap m_iconPixmap;
     QPixmap m_oldIconPixmap;
 
+    QStringList m_overlays;
+
     Plasma::Theme::ColorGroup m_colorGroup;
 
     //animation on pixmap change