Refactor Overlay Handling

Now all overlays icons in kitemviews are added in
KStandardItemListWidget::updatePixmapCache.

data[iconOverlays] now contains icon names.

DolphinFileItemListWidget::refreshCache is the sole responsible of
setting the overlays either coming from KFileItemModelRolesUpdater or
KVersionControlPlugin.

This garantees consistency in rendering.

BUG: 497372

7 files changed, 102 insertions, 68 deletions

diff --git a/src/kitemviews/kfileitemmodelrolesupdater.cpp b/src/kitemviews/kfileitemmodelrolesupdater.cpp
index 92bf2bf8d..97b51ae84 100644
--- a/src/kitemviews/kfileitemmodelrolesupdater.cpp
+++ b/src/kitemviews/kfileitemmodelrolesupdater.cpp
@@ -552,7 +552,7 @@ void KFileItemModelRolesUpdater::slotGotPreview(const KFileItem &item, const QPi
     }
 
     QHash<QByteArray, QVariant> data = rolesData(item, index);
-    data.insert("iconPixmap", transformPreviewPixmap(pixmap, data["iconOverlays"].toStringList()));
+    data.insert("iconPixmap", transformPreviewPixmap(pixmap));
 
     disconnect(m_model, &KFileItemModel::itemsChanged, this, &KFileItemModelRolesUpdater::slotItemsChanged);
     m_model->setData(index, data);
@@ -630,7 +630,7 @@ void KFileItemModelRolesUpdater::slotHoverSequenceGotPreview(const KFileItem &it
     if (wap < 0.0f || loadedIndex < static_cast<int>(wap)) {
         // Add the preview to the model data
 
-        const QPixmap scaledPixmap = transformPreviewPixmap(pixmap, data["iconOverlays"].toStringList());
+        const QPixmap scaledPixmap = transformPreviewPixmap(pixmap);
 
         pixmaps.append(scaledPixmap);
         data["hoverSequencePixmaps"] = QVariant::fromValue(pixmaps);
@@ -1001,7 +1001,7 @@ void KFileItemModelRolesUpdater::startPreviewJob()
     m_previewJob = job;
 }
 
-QPixmap KFileItemModelRolesUpdater::transformPreviewPixmap(const QPixmap &pixmap, const QStringList &overlays)
+QPixmap KFileItemModelRolesUpdater::transformPreviewPixmap(const QPixmap &pixmap)
 {
     QPixmap scaledPixmap = pixmap;
 
@@ -1042,10 +1042,6 @@ QPixmap KFileItemModelRolesUpdater::transformPreviewPixmap(const QPixmap &pixmap
         scaledPixmap.setDevicePixelRatio(m_devicePixelRatio);
     }
 
-    if (!overlays.isEmpty()) {
-        scaledPixmap = KIconUtils::addOverlays(scaledPixmap, overlays).pixmap(cacheSize(), m_devicePixelRatio);
-    }
-
     return scaledPixmap;
 }
 
diff --git a/src/kitemviews/kfileitemmodelrolesupdater.h b/src/kitemviews/kfileitemmodelrolesupdater.h
index 28a70cda3..3480713ee 100644
--- a/src/kitemviews/kfileitemmodelrolesupdater.h
+++ b/src/kitemviews/kfileitemmodelrolesupdater.h
@@ -299,7 +299,7 @@ private:
      * @param overlays the overlays to add to the pixmap
      * @return The scaled and decorated preview image.
      */
-    QPixmap transformPreviewPixmap(const QPixmap &pixmap, const QStringList &overlays);
+    QPixmap transformPreviewPixmap(const QPixmap &pixmap);
 
     /**
      * Starts a PreviewJob for loading the next hover sequence image.
diff --git a/src/kitemviews/kstandarditemlistwidget.cpp b/src/kitemviews/kstandarditemlistwidget.cpp
index aebcfa7d4..dd0ad8dc4 100644
--- a/src/kitemviews/kstandarditemlistwidget.cpp
+++ b/src/kitemviews/kstandarditemlistwidget.cpp
@@ -276,7 +276,7 @@ KStandardItemListWidget::KStandardItemListWidget(KItemListWidgetInformant *infor
     , m_expansionArea()
     , m_customTextColor()
     , m_additionalInfoTextColor()
-    , m_overlay()
+    , m_overlays()
     , m_rating()
     , m_roleEditor(nullptr)
     , m_oldRoleEditor(nullptr)
@@ -737,16 +737,21 @@ QColor KStandardItemListWidget::textColor(const QWidget &widget) const
     return styleOption().palette.color(group, role);
 }
 
-void KStandardItemListWidget::setOverlay(const QPixmap &overlay)
+void KStandardItemListWidget::setOverlays(QHash<Qt::Corner, QString> &overlays)
 {
-    m_overlay = overlay;
+    if (overlays == m_overlays) {
+        return;
+    }
+
+    m_overlays = overlays;
     m_dirtyContent = true;
+    m_dirtyContentRoles.insert("iconOverlays");
     update();
 }
 
-QPixmap KStandardItemListWidget::overlay() const
+QHash<Qt::Corner, QString> KStandardItemListWidget::overlays() const
 {
-    return m_overlay;
+    return m_overlays;
 }
 
 QString KStandardItemListWidget::roleText(const QByteArray &role, const QHash<QByteArray, QVariant> &values) const
@@ -1105,14 +1110,18 @@ void KStandardItemListWidget::updatePixmapCache()
             const QStringList overlays = values["iconOverlays"].toStringList();
             const bool hasFocus = scene()->views()[0]->parentWidget()->hasFocus();
             m_pixmap = pixmapForIcon(iconName,
-                                     overlays,
-                                     maxIconHeight,
+                                     m_overlays,
+                                     QSize(maxIconWidth, maxIconHeight),
                                      m_layout != IconsLayout && isActiveWindow() && isSelected() && hasFocus ? QIcon::Selected : QIcon::Normal);
 
-        } else if (m_pixmap.width() / m_pixmap.devicePixelRatio() != maxIconWidth || m_pixmap.height() / m_pixmap.devicePixelRatio() != maxIconHeight) {
-            // A custom pixmap has been applied. Assure that the pixmap
-            // is scaled to the maximum available size.
-            KPixmapModifier::scale(m_pixmap, QSize(maxIconWidth, maxIconHeight) * dpr);
+        } else {
+            if (!m_overlays.isEmpty()) {
+                m_pixmap = addOverlays(m_pixmap, m_overlays, QSize(maxIconWidth, maxIconHeight), dpr);
+            } else if (m_pixmap.width() / m_pixmap.devicePixelRatio() != maxIconWidth || m_pixmap.height() / m_pixmap.devicePixelRatio() != maxIconHeight) {
+                // A custom pixmap has been applied. Assure that the pixmap
+                // is scaled to the maximum available size.
+                KPixmapModifier::scale(m_pixmap, QSize(maxIconWidth, maxIconHeight) * dpr);
+            }
         }
 
         if (m_pixmap.isNull()) {
@@ -1140,11 +1149,6 @@ void KStandardItemListWidget::updatePixmapCache()
         }
     }
 
-    if (!m_overlay.isNull()) {
-        QPainter painter(&m_pixmap);
-        painter.drawPixmap(0, (m_pixmap.height() - m_overlay.height()) / m_pixmap.devicePixelRatio(), m_overlay);
-    }
-
     int scaledIconSize = 0;
     if (iconOnTop) {
         const TextInfo *textInfo = m_textInfo.value("text");
@@ -1538,6 +1542,25 @@ void KStandardItemListWidget::updateAdditionalInfoTextColor()
         QColor((c1.red() * p1 + c2.red() * p2) / 100, (c1.green() * p1 + c2.green() * p2) / 100, (c1.blue() * p1 + c2.blue() * p2) / 100);
 }
 
+QPixmap KStandardItemListWidget::addOverlays(const QPixmap &pixmap,
+                                             const QHash<Qt::Corner, QString> &overlays,
+                                             const QSize &size,
+                                             qreal devicePixelRatioF,
+                                             QIcon::Mode mode) const
+{
+    if (overlays.isEmpty()) {
+        return pixmap;
+    }
+
+    QHash<Qt::Corner, QIcon> overlayIcons;
+
+    for (const auto &[corner, overlay] : overlays.asKeyValueRange()) {
+        overlayIcons.insert(corner, QIcon::fromTheme(overlay));
+    }
+
+    return KIconUtils::addOverlays(pixmap, overlayIcons).pixmap(size, devicePixelRatioF, mode);
+}
+
 void KStandardItemListWidget::drawPixmap(QPainter *painter, const QPixmap &pixmap)
 {
     if (m_scaledPixmapSize != pixmap.size() / pixmap.devicePixelRatio()) {
@@ -1625,15 +1648,16 @@ void KStandardItemListWidget::closeRoleEditor()
     m_roleEditor = nullptr;
 }
 
-QPixmap KStandardItemListWidget::pixmapForIcon(const QString &name, const QStringList &overlays, int size, QIcon::Mode mode) const
+QPixmap KStandardItemListWidget::pixmapForIcon(const QString &name, const QHash<Qt::Corner, QString> &overlays, const QSize &size, QIcon::Mode mode) const
 {
     static const QIcon fallbackIcon = QIcon::fromTheme(QStringLiteral("unknown"));
     const qreal dpr = KItemViewsUtils::devicePixelRatio(this);
 
-    size *= dpr;
+    int iconHeight = size.height();
+    QSize iconSize = QSize(iconHeight, iconHeight);
 
-    const QString key = "KStandardItemListWidget:" % name % ":" % overlays.join(QLatin1Char(':')) % ":" % QString::number(size) % "@" % QString::number(dpr)
-        % ":" % QString::number(mode);
+    const QString key = "KStandardItemListWidget:" % name % ":" % overlays.values().join(QLatin1Char(':')) % ":" % QString::number(iconHeight) % "@"
+        % QString::number(dpr) % ":" % QString::number(mode);
     QPixmap pixmap;
 
     if (!QPixmapCache::find(key, &pixmap)) {
@@ -1641,26 +1665,18 @@ QPixmap KStandardItemListWidget::pixmapForIcon(const QString &name, const QStrin
         if (icon.isNull()) {
             icon = QIcon(name);
         }
-        if (icon.isNull() || icon.pixmap(size / dpr, size / dpr, mode).isNull()) {
+        if (!icon.isNull()) {
+            pixmap = icon.pixmap(iconSize, dpr, mode);
+        }
+        if (pixmap.isNull()) {
             icon = fallbackIcon;
+            pixmap = icon.pixmap(iconSize, dpr, mode);
         }
-
-        pixmap = icon.pixmap(QSize(size / dpr, size / dpr), dpr, mode);
-        if (pixmap.width() != size || pixmap.height() != size) {
-            KPixmapModifier::scale(pixmap, QSize(size, size));
+        if (pixmap.width() != iconHeight * dpr || pixmap.height() != iconHeight * dpr) {
+            KPixmapModifier::scale(pixmap, iconSize * dpr);
         }
 
-        // Strangely KFileItem::overlays() returns empty string-values, so
-        // we need to check first whether an overlay must be drawn at all.
-        for (const QString &overlay : overlays) {
-            if (!overlay.isEmpty()) {
-                // There is at least one overlay, draw all overlays above m_pixmap
-                // and cancel the check
-                const QSize size = pixmap.size();
-                pixmap = KIconUtils::addOverlays(pixmap, overlays).pixmap(size, dpr, mode);
-                break;
-            }
-        }
+        pixmap = addOverlays(pixmap, overlays, size, dpr, mode);
 
         QPixmapCache::insert(key, pixmap);
     }
diff --git a/src/kitemviews/kstandarditemlistwidget.h b/src/kitemviews/kstandarditemlistwidget.h
index d4a4f1231..3e542b4c5 100644
--- a/src/kitemviews/kstandarditemlistwidget.h
+++ b/src/kitemviews/kstandarditemlistwidget.h
@@ -158,8 +158,8 @@ protected:
     void setTextColor(const QColor &color);
     QColor textColor(const QWidget &widget) const;
 
-    void setOverlay(const QPixmap &overlay);
-    QPixmap overlay() const;
+    void setOverlays(QHash<Qt::Corner, QString> &overlay);
+    QHash<Qt::Corner, QString> overlays() const;
 
     /**
      * @see KStandardItemListWidgetInformant::roleText().
@@ -212,6 +212,12 @@ private:
     void updateCompactLayoutTextCache();
     void updateDetailsLayoutTextCache();
 
+    QPixmap addOverlays(const QPixmap &pixmap,
+                        const QHash<Qt::Corner, QString> &overlays,
+                        const QSize &size,
+                        qreal devicePixelRatioF,
+                        QIcon::Mode mode = QIcon::Normal) const;
+
     void drawPixmap(QPainter *painter, const QPixmap &pixmap);
     /** Draw the lines and arrows that visualize the expanded state and level of this row. */
     void drawSiblingsInformation(QPainter *painter);
@@ -231,7 +237,7 @@ private:
      */
     void closeRoleEditor();
 
-    QPixmap pixmapForIcon(const QString &name, const QStringList &overlays, int size, QIcon::Mode mode) const;
+    QPixmap pixmapForIcon(const QString &name, const QHash<Qt::Corner, QString> &overlays, const QSize &size, QIcon::Mode mode) const;
 
     /**
      * @return Preferred size of the rating-image based on the given
@@ -283,7 +289,7 @@ private:
     QColor m_customTextColor;
     QColor m_additionalInfoTextColor;
 
-    QPixmap m_overlay;
+    QHash<Qt::Corner, QString> m_overlays;
     QPixmap m_rating;
 
     KItemListRoleEditor *m_roleEditor;
diff --git a/src/panels/information/informationpanelcontent.cpp b/src/panels/information/informationpanelcontent.cpp
index b112b2caf..14a470b11 100644
--- a/src/panels/information/informationpanelcontent.cpp
+++ b/src/panels/information/informationpanelcontent.cpp
@@ -362,8 +362,23 @@ void InformationPanelContent::showPreview(const KFileItem &item, const QPixmap &
 {
     m_outdatedPreviewTimer->stop();
 
-    QPixmap p = KIconUtils::addOverlays(pixmap, item.overlays()).pixmap(m_preview->size(), devicePixelRatioF());
-    p.setDevicePixelRatio(devicePixelRatioF());
+    QPixmap p = pixmap;
+    if (!item.overlays().isEmpty()) {
+        // Avoid scaling the images that are smaller than the preview size, to be consistent when there is no overlays
+        if (pixmap.height() < m_preview->height() && pixmap.width() < m_preview->width()) {
+            p = QPixmap(m_preview->size() * devicePixelRatioF());
+            p.fill(Qt::transparent);
+            p.setDevicePixelRatio(devicePixelRatioF());
+
+            QPainter painter(&p);
+            painter.drawPixmap(QPointF{m_preview->width() / 2.0 - pixmap.width() / pixmap.devicePixelRatioF() / 2,
+                                       m_preview->height() / 2.0 - pixmap.height() / pixmap.devicePixelRatioF() / 2}
+                                   .toPoint(),
+                               pixmap);
+        }
+        p = KIconUtils::addOverlays(p, item.overlays()).pixmap(m_preview->size(), devicePixelRatioF());
+        p.setDevicePixelRatio(devicePixelRatioF());
+    }
 
     if (m_isVideo) {
         // adds a play arrow overlay
diff --git a/src/views/dolphinfileitemlistwidget.cpp b/src/views/dolphinfileitemlistwidget.cpp
index 11c88d402..7ad242f3f 100644
--- a/src/views/dolphinfileitemlistwidget.cpp
+++ b/src/views/dolphinfileitemlistwidget.cpp
@@ -24,6 +24,7 @@ void DolphinFileItemListWidget::refreshCache()
 {
     QColor color;
     const QHash<QByteArray, QVariant> values = data();
+    QHash<Qt::Corner, QString> overlays;
     if (values.contains("version")) {
         // The item is under version control. Apply the text color corresponding
         // to its version state.
@@ -70,27 +71,28 @@ void DolphinFileItemListWidget::refreshCache()
                        (tintColor.blue() + textColor.blue()) / 2,
                        (tintColor.alpha() + textColor.alpha()) / 2);
 
-        setOverlay(overlayForState(version, styleOption().iconSize));
-    } else if (!overlay().isNull()) {
-        setOverlay(QPixmap());
+        overlays.insert(Qt::Corner::BottomLeftCorner, overlayForState(version));
     }
 
+    if (values.contains("iconOverlays")) {
+        const auto corners = {Qt::Corner::BottomRightCorner, Qt::Corner::TopLeftCorner, Qt::Corner::TopRightCorner};
+        const auto iconOverlays = values.value("iconOverlays").toStringList();
+        auto overlaysIt = iconOverlays.constBegin();
+        for (const auto &corner : corners) {
+            if (overlaysIt == iconOverlays.constEnd()) {
+                break;
+            }
+            overlays.insert(corner, *overlaysIt);
+            overlaysIt = ++overlaysIt;
+        }
+    }
+
+    setOverlays(overlays);
     setTextColor(color);
 }
 
-QPixmap DolphinFileItemListWidget::overlayForState(KVersionControlPlugin::ItemVersion version, int size) const
+QString DolphinFileItemListWidget::overlayForState(KVersionControlPlugin::ItemVersion version) const
 {
-    int overlayHeight = KIconLoader::SizeSmall;
-    if (size >= KIconLoader::SizeEnormous) {
-        overlayHeight = KIconLoader::SizeMedium;
-    } else if (size >= KIconLoader::SizeLarge) {
-        overlayHeight = KIconLoader::SizeSmallMedium;
-    } else if (size >= KIconLoader::SizeMedium) {
-        overlayHeight = KIconLoader::SizeSmall;
-    } else {
-        overlayHeight = KIconLoader::SizeSmall / 2;
-    }
-
     QString iconName;
     switch (version) {
     case KVersionControlPlugin::NormalVersion:
@@ -123,8 +125,7 @@ QPixmap DolphinFileItemListWidget::overlayForState(KVersionControlPlugin::ItemVe
         break;
     }
 
-    const qreal dpr = KItemViewsUtils::devicePixelRatio(this);
-    return QIcon::fromTheme(iconName).pixmap(QSize(overlayHeight, overlayHeight), dpr);
+    return iconName;
 }
 
 #include "moc_dolphinfileitemlistwidget.cpp"
diff --git a/src/views/dolphinfileitemlistwidget.h b/src/views/dolphinfileitemlistwidget.h
index 92fc66fcc..af15074d5 100644
--- a/src/views/dolphinfileitemlistwidget.h
+++ b/src/views/dolphinfileitemlistwidget.h
@@ -29,7 +29,7 @@ protected:
     void refreshCache() override;
 
 private:
-    QPixmap overlayForState(KVersionControlPlugin::ItemVersion version, int size) const;
+    QString overlayForState(KVersionControlPlugin::ItemVersion version) const;
 };
 
 #endif