Allow to optionally limit the maximum number of text lines

Showing the whole filename unclipped seems to be a good default,
however for users with a lot of files that have extremely long names
this might get a problem especially in the icons-view.

- Allow to limit the maximum number of lines in the icons-view
- Allow to specify a maximum width in the compact-view

(No limit is required for the details-view, as the name is shortened
automatically to show other columns)

BUG: 288596
FIXED-IN: 4.9.0

4 files changed, 60 insertions, 21 deletions

diff --git a/src/kitemviews/kfileitemlistwidget.cpp b/src/kitemviews/kfileitemlistwidget.cpp
index f3b4da892..5c5690c40 100644
--- a/src/kitemviews/kfileitemlistwidget.cpp
+++ b/src/kitemviews/kfileitemlistwidget.cpp
@@ -279,7 +279,8 @@ QSizeF KFileItemListWidget::itemSizeHint(int index, const KItemListView* view)
     case IconsLayout: {
         const QString text = KStringHandler::preProcessWrap(values["name"].toString());
 
-        const qreal maxWidth = view->itemSize().width() - 2 * option.padding;
+        const qreal itemWidth = view->itemSize().width();
+        const qreal maxWidth = itemWidth - 2 * option.padding;
         QTextLine line;
 
         // Calculate the number of lines required for wrapping the name
@@ -298,11 +299,14 @@ QSizeF KFileItemListWidget::itemSizeHint(int index, const KItemListView* view)
         layout.endLayout();
 
         // Add one line for each additional information
-        const qreal height = textHeight +
-                             additionalRolesCount * option.fontMetrics.lineSpacing() +
-                             option.iconSize +
-                             option.padding * 3;
-        return QSizeF(view->itemSize().width(), height);
+        textHeight += additionalRolesCount * option.fontMetrics.lineSpacing();
+
+        const qreal maxTextHeight = option.maxTextSize.height();
+        if (maxTextHeight > 0 && textHeight > maxTextHeight) {
+            textHeight = maxTextHeight;
+        }
+
+        return QSizeF(itemWidth, textHeight + option.iconSize + option.padding * 3);
     }
 
     case CompactLayout: {
@@ -316,7 +320,11 @@ QSizeF KFileItemListWidget::itemSizeHint(int index, const KItemListView* view)
             maximumRequiredWidth = qMax(maximumRequiredWidth, requiredWidth);
         }
 
-        const qreal width = option.padding * 4 + option.iconSize + maximumRequiredWidth;
+        qreal width = option.padding * 4 + option.iconSize + maximumRequiredWidth;
+        const qreal maxWidth = option.maxTextSize.width();
+        if (maxWidth > 0 && width > maxWidth) {
+            width = maxWidth;
+        }
         const qreal height = option.padding * 2 + qMax(option.iconSize, (1 + additionalRolesCount) * option.fontMetrics.lineSpacing());
         return QSizeF(width, height);
     }
@@ -756,25 +764,46 @@ void KFileItemListWidget::updateIconsLayoutTextCache()
     // Initialize properties for the "name" role. It will be used as anchor
     // for initializing the position of the other roles.
     TextInfo* nameTextInfo = m_textInfo.value("name");
-    nameTextInfo->staticText.setText(KStringHandler::preProcessWrap(values["name"].toString()));
+    const QString nameText = KStringHandler::preProcessWrap(values["name"].toString());
+    nameTextInfo->staticText.setText(nameText);
 
     // Calculate the number of lines required for the name and the required width
     qreal nameWidth = 0;
     qreal nameHeight = 0;
     QTextLine line;
 
+    const int additionalRolesCount = qMax(visibleRoles().count() - 1, 0);
+    const int maxNameLines = (option.maxTextSize.height() / int(lineSpacing)) - additionalRolesCount;
+
     QTextLayout layout(nameTextInfo->staticText.text(), option.font);
     layout.setTextOption(nameTextInfo->staticText.textOption());
     layout.beginLayout();
+    int nameLineIndex = 0;
     while ((line = layout.createLine()).isValid()) {
         line.setLineWidth(maxWidth);
         nameWidth = qMax(nameWidth, line.naturalTextWidth());
         nameHeight += line.height();
+
+        ++nameLineIndex;
+        if (nameLineIndex == maxNameLines) {
+            // The maximum number of textlines has been reached. If this is
+            // the case provide an elided text if necessary.
+            const int textLength = line.textStart() + line.textLength();
+            if (textLength < nameText.length()) {
+                // Elide the last line of the text
+                QString lastTextLine = nameText.mid(line.textStart(), line.textLength());
+                lastTextLine = option.fontMetrics.elidedText(lastTextLine,
+                                                             Qt::ElideRight,
+                                                             line.naturalTextWidth() - 1);
+                const QString elidedText = nameText.left(line.textStart()) + lastTextLine;
+                nameTextInfo->staticText.setText(elidedText);
+            }
+            break;
+        }
     }
     layout.endLayout();
 
     // Use one line for each additional information
-    const int additionalRolesCount = qMax(visibleRoles().count() - 1, 0);
     nameTextInfo->staticText.setTextWidth(maxWidth);
     nameTextInfo->pos = QPointF(padding, widgetHeight -
                                          nameHeight -
diff --git a/src/kitemviews/kitemliststyleoption.cpp b/src/kitemviews/kitemliststyleoption.cpp
index c512fa43e..36cfeb088 100644
--- a/src/kitemviews/kitemliststyleoption.cpp
+++ b/src/kitemviews/kitemliststyleoption.cpp
@@ -30,7 +30,8 @@ KItemListStyleOption::KItemListStyleOption() :
     horizontalMargin(0),
     verticalMargin(0),
     iconSize(KIconLoader::SizeMedium),
-    extendedSelectionRegion(false)
+    extendedSelectionRegion(false),
+    maxTextSize()
 {
 }
 
@@ -43,7 +44,8 @@ KItemListStyleOption::KItemListStyleOption(const KItemListStyleOption& other) :
     horizontalMargin(other.horizontalMargin),
     verticalMargin(other.verticalMargin),
     iconSize(other.iconSize),
-    extendedSelectionRegion(other.extendedSelectionRegion)
+    extendedSelectionRegion(other.extendedSelectionRegion),
+    maxTextSize(other.maxTextSize)
 {
 }
 
diff --git a/src/kitemviews/kitemliststyleoption.h b/src/kitemviews/kitemliststyleoption.h
index 62441ef4b..1a304fc28 100644
--- a/src/kitemviews/kitemliststyleoption.h
+++ b/src/kitemviews/kitemliststyleoption.h
@@ -43,6 +43,7 @@ public:
     int verticalMargin;
     int iconSize;
     bool extendedSelectionRegion;
+    QSize maxTextSize;
 };
 #endif
 
diff --git a/src/kitemviews/kitemlistview.cpp b/src/kitemviews/kitemlistview.cpp
index 732ed24e4..c62523410 100644
--- a/src/kitemviews/kitemlistview.cpp
+++ b/src/kitemviews/kitemlistview.cpp
@@ -148,10 +148,10 @@ Qt::Orientation KItemListView::scrollOrientation() const
     return m_layouter->scrollOrientation();
 }
 
-void KItemListView::setItemSize(const QSizeF& itemSize)
+void KItemListView::setItemSize(const QSizeF& size)
 {
     const QSizeF previousSize = m_itemSize;
-    if (itemSize == previousSize) {
+    if (size == previousSize) {
         return;
     }
 
@@ -159,14 +159,14 @@ void KItemListView::setItemSize(const QSizeF& itemSize)
     // are changed in the grid layout. Although the animation
     // engine can handle this usecase, it looks obtrusive.
     const bool animate = !changesItemGridLayout(m_layouter->size(),
-                                                itemSize,
+                                                size,
                                                 m_layouter->itemMargin());
 
     const bool alternateBackgroundsChanged = (m_visibleRoles.count() > 1) &&
-                                             (( m_itemSize.isEmpty() && !itemSize.isEmpty()) ||
-                                              (!m_itemSize.isEmpty() && itemSize.isEmpty()));
+                                             (( m_itemSize.isEmpty() && !size.isEmpty()) ||
+                                              (!m_itemSize.isEmpty() && size.isEmpty()));
 
-    m_itemSize = itemSize;
+    m_itemSize = size;
 
     if (alternateBackgroundsChanged) {
         // For an empty item size alternate backgrounds are drawn if more than
@@ -175,23 +175,23 @@ void KItemListView::setItemSize(const QSizeF& itemSize)
         updateAlternateBackgrounds();
     }
 
-    if (itemSize.isEmpty()) {
+    if (size.isEmpty()) {
         if (m_headerWidget->automaticColumnResizing()) {
             updatePreferredColumnWidths();
         } else {
             // Only apply the changed height and respect the header widths
             // set by the user
             const qreal currentWidth = m_layouter->itemSize().width();
-            const QSizeF newSize(currentWidth, itemSize.height());
+            const QSizeF newSize(currentWidth, size.height());
             m_layouter->setItemSize(newSize);
         }
     } else {
-        m_layouter->setItemSize(itemSize);
+        m_layouter->setItemSize(size);
     }
 
     m_sizeHintResolver->clearCache();
     doLayout(animate ? Animation : NoAnimation);
-    onItemSizeChanged(itemSize, previousSize);
+    onItemSizeChanged(size, previousSize);
 }
 
 QSizeF KItemListView::itemSize() const
@@ -392,6 +392,12 @@ void KItemListView::setStyleOption(const KItemListStyleOption& option)
         updateGroupHeaderHeight();
     }
 
+    if (animate && previousOption.maxTextSize != option.maxTextSize) {
+        // Animating a change of the maximum text size just results in expensive
+        // temporary eliding and clipping operations and does not look good visually.
+        animate = false;
+    }
+
     QHashIterator<int, KItemListWidget*> it(m_visibleItems);
     while (it.hasNext()) {
         it.next();
@@ -399,6 +405,7 @@ void KItemListView::setStyleOption(const KItemListStyleOption& option)
     }
 
     m_sizeHintResolver->clearCache();
+    m_layouter->markAsDirty();
     doLayout(animate ? Animation : NoAnimation);
 
     onStyleOptionChanged(option, previousOption);