Add baseline support for Qt Quick Layouts

Change-Id: Ieb5f1a2c9fa81bdb6ff587ef84e97b2233f2e289
Reviewed-by: J-P Nurmi <jpnurmi@digia.com>

4 files changed, 21 insertions, 14 deletions

diff --git a/src/layouts/qgridlayoutengine.cpp b/src/layouts/qgridlayoutengine.cpp
index bba1efbd0..e6b21e51b 100644
--- a/src/layouts/qgridlayoutengine.cpp
+++ b/src/layouts/qgridlayoutengine.cpp
@@ -610,8 +610,11 @@ QGridLayoutBox QGridLayoutItem::box(Qt::Orientation orientation, qreal constrain
         }
 
         result.q_minimumDescent = sizeHint(Qt::MinimumDescent, constraintSize).height();
-        if (result.q_minimumDescent >= 0.0)
+        if (result.q_minimumDescent != -1.0) {
+            const qreal minSizeHint = sizeHint(Qt::MinimumSize, constraintSize).height();
+            result.q_minimumDescent -= (minSizeHint - result.q_minimumSize);
             result.q_minimumAscent = result.q_minimumSize - result.q_minimumDescent;
+        }
     }
     if (policy & QLayoutPolicy::IgnoreFlag)
         result.q_preferredSize = result.q_minimumSize;
@@ -622,10 +625,8 @@ QGridLayoutBox QGridLayoutItem::box(Qt::Orientation orientation, qreal constrain
 QRectF QGridLayoutItem::geometryWithin(qreal x, qreal y, qreal width, qreal height,
                                        qreal rowDescent, Qt::Alignment align) const
 {
-    rowDescent = -1.0; // ### This disables the descent
-
     QGridLayoutBox vBox = box(Qt::Vertical);
-    if (vBox.q_minimumDescent < 0.0 || rowDescent < 0.0) {
+    if (!(align & Qt::AlignBaseline) || vBox.q_minimumDescent < 0.0 || rowDescent < 0.0) {
         qreal cellWidth = width;
         qreal cellHeight = height;
 
diff --git a/src/layouts/qquickgridlayoutengine.cpp b/src/layouts/qquickgridlayoutengine.cpp
index 7f65d0d5b..b6c0a2448 100644
--- a/src/layouts/qquickgridlayoutengine.cpp
+++ b/src/layouts/qquickgridlayoutengine.cpp
@@ -250,14 +250,18 @@ void QQuickGridLayoutItem::effectiveSizeHints_helper(QQuickItem *item, QSizeF *c
         }
     }
 
-    //--- GATHER DESCENT
-    // ### Not implemented
 
 
     // Normalize again after the implicit hints have been gathered
     expandSize(prefS, minS);
     boundSize(prefS, maxS);
 
+    //--- GATHER DESCENT
+    // Minimum descent is only applicable for the effective minimum height,
+    // so we gather the descent last.
+    const qreal minimumDescent = minS.height() - item->baselineOffset();
+    descentS.setHeight(minimumDescent);
+
     if (attachedInfo)
         *attachedInfo = info;
 }
diff --git a/src/layouts/qquicklinearlayout.cpp b/src/layouts/qquicklinearlayout.cpp
index 7639d337d..530241d42 100644
--- a/src/layouts/qquicklinearlayout.cpp
+++ b/src/layouts/qquicklinearlayout.cpp
@@ -265,8 +265,8 @@ QQuickGridLayoutBase::~QQuickGridLayoutBase()
         QQuickItem *item = itemAt(i);
         QObject::disconnect(item, SIGNAL(destroyed()), this, SLOT(onItemDestroyed()));
         QObject::disconnect(item, SIGNAL(visibleChanged()), this, SLOT(onItemVisibleChanged()));
-        QObject::disconnect(item, SIGNAL(implicitWidthChanged()), this, SLOT(onItemImplicitSizeChanged()));
-        QObject::disconnect(item, SIGNAL(implicitHeightChanged()), this, SLOT(onItemImplicitSizeChanged()));
+        QObject::disconnect(item, SIGNAL(implicitWidthChanged()), this, SLOT(invalidateSenderItem()));
+        QObject::disconnect(item, SIGNAL(implicitHeightChanged()), this, SLOT(invalidateSenderItem()));
     }
 }
 
@@ -390,8 +390,9 @@ void QQuickGridLayoutBase::itemChange(ItemChange change, const ItemChangeData &v
         QQuickItem *item = value.item;
         QObject::connect(item, SIGNAL(destroyed()), this, SLOT(onItemDestroyed()));
         QObject::connect(item, SIGNAL(visibleChanged()), this, SLOT(onItemVisibleChanged()));
-        QObject::connect(item, SIGNAL(implicitWidthChanged()), this, SLOT(onItemImplicitSizeChanged()));
-        QObject::connect(item, SIGNAL(implicitHeightChanged()), this, SLOT(onItemImplicitSizeChanged()));
+        QObject::connect(item, SIGNAL(implicitWidthChanged()), this, SLOT(invalidateSenderItem()));
+        QObject::connect(item, SIGNAL(implicitHeightChanged()), this, SLOT(invalidateSenderItem()));
+        QObject::connect(item, SIGNAL(baselineOffsetChanged(qreal)), this, SLOT(invalidateSenderItem()));
 
         if (isReady() && isVisible())
             updateLayoutItems();
@@ -400,8 +401,9 @@ void QQuickGridLayoutBase::itemChange(ItemChange change, const ItemChangeData &v
         QQuickItem *item = value.item;
         QObject::disconnect(item, SIGNAL(destroyed()), this, SLOT(onItemDestroyed()));
         QObject::disconnect(item, SIGNAL(visibleChanged()), this, SLOT(onItemVisibleChanged()));
-        QObject::disconnect(item, SIGNAL(implicitWidthChanged()), this, SLOT(onItemImplicitSizeChanged()));
-        QObject::disconnect(item, SIGNAL(implicitHeightChanged()), this, SLOT(onItemImplicitSizeChanged()));
+        QObject::disconnect(item, SIGNAL(implicitWidthChanged()), this, SLOT(invalidateSenderItem()));
+        QObject::disconnect(item, SIGNAL(implicitHeightChanged()), this, SLOT(invalidateSenderItem()));
+        QObject::disconnect(item, SIGNAL(baselineOffsetChanged(qreal)), this, SLOT(invalidateSenderItem()));
         if (isReady() && isVisible())
             updateLayoutItems();
     }
@@ -465,7 +467,7 @@ void QQuickGridLayoutBase::onItemDestroyed()
     }
 }
 
-void QQuickGridLayoutBase::onItemImplicitSizeChanged()
+void QQuickGridLayoutBase::invalidateSenderItem()
 {
     if (!isReady())
         return;
diff --git a/src/layouts/qquicklinearlayout_p.h b/src/layouts/qquicklinearlayout_p.h
index ed8bf8f96..1b5a3a182 100644
--- a/src/layouts/qquicklinearlayout_p.h
+++ b/src/layouts/qquicklinearlayout_p.h
@@ -94,7 +94,7 @@ signals:
 protected slots:
     void onItemVisibleChanged();
     void onItemDestroyed();
-    void onItemImplicitSizeChanged();
+    void invalidateSenderItem();
 
 private:
     void removeGridItem(QGridLayoutItem *gridItem);