Details view: Optionally remember user changed column-widths

If the user changed a column-width in the details-view, up to now
the width got reset when changing a directory or when restarting
Dolphin. Now the column-widths automatically get remembered for each
directory in case if the user has modified the width. The automatic
resizing is still turn on per default. The storing of the custom
column-width can easily be reset by right clicking on the header and
selecting "Automatic Column Widths" from the context-menu.

Some finetuning is still necessary (e.g. the "Adjust View Properties"
dialog currently is not aware about this setting) but this will
be fixed during the next weeks.

BUG: 264434
FIXED-IN: 4.9.0

1 files changed, 41 insertions, 36 deletions

diff --git a/src/kitemviews/kitemlistview.h b/src/kitemviews/kitemlistview.h
index bbdb4081c..70ba03061 100644
--- a/src/kitemviews/kitemlistview.h
+++ b/src/kitemviews/kitemlistview.h
@@ -36,6 +36,7 @@
 class KItemListController;
 class KItemListGroupHeaderCreatorBase;
 class KItemListHeader;
+class KItemListHeaderWidget;
 class KItemListSizeHintResolver;
 class KItemListRubberBand;
 class KItemListViewAnimation;
@@ -192,13 +193,13 @@ public:
     virtual QSizeF itemSizeHint(int index) const;
 
     /**
-     * @param itemRanges Items that must be checked for getting the visible roles sizes.
-     * @return           The size of each visible role in case if KItemListView::itemSize()
-     *                   is empty. This allows to have dynamic but equal role sizes between
-     *                   all items, like used in the classic "table-views". Per default an
-     *                   empty hash is returned.
+     * @param itemRanges Items that must be checked for getting the widths of columns.
+     * @return           The width of the column of each visible role. The width will
+     *                   be respected if the width of the item size is <= 0 (see
+     *                   KItemListView::setItemSize()). Per default an empty hash
+     *                   is returned.
      */
-    virtual QHash<QByteArray, QSizeF> visibleRolesSizes(const KItemRangeList& itemRanges) const;
+    virtual QHash<QByteArray, qreal> columnWidths(const KItemRangeList& itemRanges) const;
 
     /**
      * If set to true, items having child-items can be expanded to show the child-items as
@@ -253,12 +254,18 @@ public:
     bool isTransactionActive() const;
 
     /**
-     * Turns on the header if \p show is true. Per default the
-     * header is not shown. Usually the header is turned on when
+     * Turns on the header if \p visible is true. Per default the
+     * header is not visible. Usually the header is turned on when
      * showing a classic "table-view" to describe the shown columns.
      */
-    void setHeaderShown(bool show);
-    bool isHeaderShown() const;
+    void setHeaderVisible(bool visible);
+    bool isHeaderVisible() const;
+
+    /**
+     * @return Header of the list. The header is also available if it is not shown
+     *         (see KItemListView::setHeaderShown()).
+     */
+    KItemListHeader* header() const;
 
     /**
      * @return Pixmap that is used for a drag operation based on the
@@ -364,22 +371,22 @@ private slots:
     void slotRubberBandActivationChanged(bool active);
 
     /**
-     * Is invoked if the visible role-width of one role in the header has
+     * Is invoked if the column-width of one role in the header has
      * been changed by the user. It is remembered that the user has modified
      * the role-width, so that it won't be changed anymore automatically to
      * calculate an optimized width.
      */
-    void slotVisibleRoleWidthChanged(const QByteArray& role,
-                                     qreal currentWidth,
-                                     qreal previousWidth);
+    void slotHeaderColumnWidthChanged(const QByteArray& role,
+                                      qreal currentWidth,
+                                      qreal previousWidth);
 
     /**
-     * Is invoked if a visible role has been moved by the user. Applies
+     * Is invoked if a column has been moved by the user. Applies
      * the moved role to the view.
      */
-    void slotVisibleRoleMoved(const QByteArray& role,
-                              int currentIndex,
-                              int previousIndex);
+    void slotHeaderColumnMoved(const QByteArray& role,
+                               int currentIndex,
+                               int previousIndex);
 
     /**
      * Triggers the autoscrolling if autoScroll() is enabled by checking the
@@ -517,10 +524,13 @@ private:
      */
     bool useAlternateBackgrounds() const;
 
+    void applyColumnWidthsFromHeader();
+
     /**
-     * @return The widths of each visible role that is shown in the KItemListHeader.
+     * Applies the roles-sizes from m_stretchedVisibleRolesSizes
+     * to \a widget.
      */
-    QHash<QByteArray, qreal> headerRolesWidths() const;
+    void updateWidgetColumnWidths(KItemListWidget* widget);
 
     /**
      * Updates m_visibleRolesSizes by calling KItemListView::visibleRolesSizes().
@@ -528,29 +538,23 @@ private:
      * are used (see m_useHeaderWidths). Also m_strechedVisibleRolesSizes will be adjusted
      * to respect the available view-size.
      */
-    void updateVisibleRolesSizes(const KItemRangeList& itemRanges);
+    void updateColumnWidthsCache(const KItemRangeList& itemRanges);
 
     /**
      * Convenience method for updateVisibleRoleSizes(KItemRangeList() << KItemRange(0, m_model->count()).
      */
-    void updateVisibleRolesSizes();
+    void updateColumnWidthsCache();
 
     /**
-     * Updates m_stretchedVisibleRolesSizes based on m_visibleRolesSizes and the available
-     * view-size. Nothing will be done if m_itemRect is not empty or custom header-widths
-     * are used (see m_useHeaderWidths).
+     * Updates the column widhts of the header based on m_columnWidthsCache and the available
+     * view-size.
      */
-    void updateStretchedVisibleRolesSizes();
+    void updateColumnWidthsForHeader();
 
     /**
-     * @return Sum of the widths of all visible roles.
+     * @return Sum of the widths of all columns.
      */
-    qreal visibleRolesSizesWidthSum() const;
-
-    /**
-     * @return Sum of the heights of all visible roles.
-     */
-    qreal visibleRolesSizesHeightSum() const;
+    qreal columnWidthsSum() const;
 
     /**
      * @return Boundaries of the header. An empty rectangle is returned
@@ -634,8 +638,6 @@ private:
     KItemListController* m_controller;
     KItemModelBase* m_model;
     QList<QByteArray> m_visibleRoles;
-    QHash<QByteArray, QSizeF> m_visibleRolesSizes;
-    QHash<QByteArray, QSizeF> m_stretchedVisibleRolesSizes;
     KItemListWidgetCreatorBase* m_widgetCreator;
     KItemListGroupHeaderCreatorBase* m_groupHeaderCreator;
     KItemListStyleOption m_styleOption;
@@ -643,6 +645,8 @@ private:
     QHash<int, KItemListWidget*> m_visibleItems;
     QHash<KItemListWidget*, KItemListGroupHeader*> m_visibleGroups;
 
+    QHash<QByteArray, qreal> m_columnWidthsCache; // Cache for columnWidths() result
+
     struct Cell
     {
         Cell() : column(-1), row(-1) {}
@@ -671,9 +675,10 @@ private:
     QTimer* m_autoScrollTimer;
 
     KItemListHeader* m_header;
-    bool m_useHeaderWidths;
+    KItemListHeaderWidget* m_headerWidget;
 
     friend class KItemListContainer; // Accesses scrollBarRequired()
+    friend class KItemListHeader;    // Accesses m_headerWidget
     friend class KItemListController;
     friend class KItemListControllerTest;
 };