Add a positioning 'mode' to positionViewAtIndex()

Provides more control over where and how the view is positioned.

1 files changed, 54 insertions, 17 deletions

diff --git a/src/declarative/graphicsitems/qdeclarativegridview.cpp b/src/declarative/graphicsitems/qdeclarativegridview.cpp
index e66bcf6..b1391f9 100644
--- a/src/declarative/graphicsitems/qdeclarativegridview.cpp
+++ b/src/declarative/graphicsitems/qdeclarativegridview.cpp
@@ -1666,47 +1666,84 @@ void QDeclarativeGridView::moveCurrentIndexRight()
 }
 
 /*!
-    \qmlmethod GridView::positionViewAtIndex(int index)
+    \qmlmethod GridView::positionViewAtIndex(int index, PositionMode mode)
+
+    Positions the view such that the \a index is at the position specified by
+    \a mode:
+
+    \list
+    \o Beginning - position item at the top (or left for TopToBottom flow) of the view.
+    \o Center- position item in the center of the view.
+    \o End - position item at bottom (or right for horizontal orientation) of the view.
+    \o Visible - if any part of the item is visible then take no action, otherwise
+    bring the item into view.
+    \o Contain - ensure the entire item is visible.  If the item is larger than
+    the view the item is positioned at the top (or left for TopToBottom flow) of the view.
+    \endlist
 
-    Positions the view such that the \a index is at the top (or left for horizontal orientation) of the view.
     If positioning the view at the index would cause empty space to be displayed at
-    the end of the view, the view will be positioned at the end.
+    the beginning or end of the view, the view will be positioned at the boundary.
 
     It is not recommended to use contentX or contentY to position the view
     at a particular index.  This is unreliable since removing items from the start
-    of the list does not cause all other items to be repositioned.
+    of the view does not cause all other items to be repositioned.
     The correct way to bring an item into view is with positionViewAtIndex.
 */
-void QDeclarativeGridView::positionViewAtIndex(int index)
+void QDeclarativeGridView::positionViewAtIndex(int index, int mode)
 {
     Q_D(QDeclarativeGridView);
     if (!d->isValid() || index < 0 || index >= d->model->count())
         return;
+    if (mode < Beginning || mode > Contain)
+        return;
 
-    qreal maxExtent = d->flow == QDeclarativeGridView::LeftToRight ? -maxYExtent() : -maxXExtent();
+    qreal pos = d->position();
     FxGridItem *item = d->visibleItem(index);
-    if (item) {
-        // Already created - just move to top of view
-        int pos = qMin(item->rowPos(), maxExtent);
-        d->setPosition(pos);
-    } else {
-        int pos = d->rowPosAt(index);
+    if (!item) {
+        int itemPos = d->rowPosAt(index);
         // save the currently visible items in case any of them end up visible again
         QList<FxGridItem*> oldVisible = d->visibleItems;
         d->visibleItems.clear();
         d->visibleIndex = index - index % d->columns;
-        d->setPosition(pos);
-        // setPosition() will cause refill.  Adjust if we have moved beyond range
-        if (d->position() > maxExtent)
-            d->setPosition(maxExtent);
+        d->setPosition(itemPos);
         // now release the reference to all the old visible items.
         for (int i = 0; i < oldVisible.count(); ++i)
             d->releaseItem(oldVisible.at(i));
+        item = d->visibleItem(index);
+    }
+    if (item) {
+        qreal itemPos = item->rowPos();
+        switch (mode) {
+        case Beginning:
+            pos = itemPos;
+            break;
+        case Center:
+            pos = itemPos - (d->size() - d->rowSize())/2;
+            break;
+        case End:
+            pos = itemPos - d->size() + d->rowSize();
+            break;
+        case Visible:
+            if (itemPos > pos + d->size())
+                pos = itemPos - d->size() + d->rowSize();
+            else if (item->endRowPos() < pos)
+                pos = itemPos;
+            break;
+        case Contain:
+            if (item->endRowPos() > pos + d->size())
+                pos = itemPos - d->size() + d->rowSize();
+            if (itemPos < pos)
+                pos = itemPos;
+        }
+        qreal maxExtent = d->flow == QDeclarativeGridView::LeftToRight ? -maxYExtent() : -maxXExtent();
+        pos = qMin(pos, maxExtent);
+        qreal minExtent = d->flow == QDeclarativeGridView::LeftToRight ? -minYExtent() : -minXExtent();
+        pos = qMax(pos, minExtent);
+        d->setPosition(pos);
     }
     d->fixupPosition();
 }
 
-
 void QDeclarativeGridView::componentComplete()
 {
     Q_D(QDeclarativeGridView);