Adjust the layout if a QGraphicsWidget is explicitly hidden

Since layout items can now be hidden, this also makes sure we respect
the QSizePolicy::retainSizeWhenHidden

Task-number: QTBUG-20132
Change-Id: Iab59fc9b61d4ca1bb2208c479a027da6eb0283a9
Reviewed-by: Paul Olav Tvete <paul.tvete@digia.com>

3 files changed, 150 insertions, 0 deletions

diff --git a/tests/auto/widgets/graphicsview/qgraphicsgridlayout/tst_qgraphicsgridlayout.cpp b/tests/auto/widgets/graphicsview/qgraphicsgridlayout/tst_qgraphicsgridlayout.cpp
index c90c431d8b..3b55fcd5fc 100644
--- a/tests/auto/widgets/graphicsview/qgraphicsgridlayout/tst_qgraphicsgridlayout.cpp
+++ b/tests/auto/widgets/graphicsview/qgraphicsgridlayout/tst_qgraphicsgridlayout.cpp
@@ -124,6 +124,7 @@ private slots:
     void heightForWidthWithSpanning();
     void stretchAndHeightForWidth();
     void testDefaultAlignment();
+    void hiddenItems();
 };
 
 class RectWidget : public QGraphicsWidget
@@ -3485,6 +3486,94 @@ void tst_QGraphicsGridLayout::testDefaultAlignment()
     QCOMPARE(w->geometry(), QRectF(0,0,50,50));
     QCOMPARE(w2->geometry(), QRectF(0,50,100,100));
 }
+
+static RectWidget *addWidget(QGraphicsGridLayout *grid, int row, int column)
+{
+    RectWidget *w = new RectWidget;
+    w->setPreferredSize(20, 20);
+    grid->addItem(w, row, column);
+    return w;
+}
+
+static void setVisible(bool visible, QGraphicsWidget **widgets)
+{
+    for (int i = 0; i < 3; ++i)
+        if (widgets[i]) widgets[i]->setVisible(visible);
+}
+
+static void setRetainSizeWhenHidden(bool retainSize, QGraphicsWidget **widgets)
+{
+    QSizePolicy sp = widgets[0]->sizePolicy();
+    sp.setRetainSizeWhenHidden(retainSize);
+    for (int i = 0; i < 3; ++i)
+        if (widgets[i]) widgets[i]->setSizePolicy(sp);
+}
+
+void tst_QGraphicsGridLayout::hiddenItems()
+{
+    QGraphicsWidget *widget = new QGraphicsWidget;
+    QGraphicsGridLayout *layout = new QGraphicsGridLayout(widget);
+    layout->setContentsMargins(0, 0, 0, 0);
+    layout->setSpacing(2);
+
+    // Create a 3x3 layout
+    addWidget(layout, 0, 0);
+    RectWidget *w01 = addWidget(layout, 0, 1);
+    addWidget(layout, 0, 2);
+    RectWidget *w10 = addWidget(layout, 1, 0);
+    RectWidget *w11 = addWidget(layout, 1, 1);
+    RectWidget *w12 = addWidget(layout, 1, 2);
+    addWidget(layout, 2, 0);
+    RectWidget *w21 = addWidget(layout, 2, 1);
+    addWidget(layout, 2, 2);
+
+    QGraphicsWidget *middleColumn[] = {w01, w11, w21 };
+    QGraphicsWidget *topTwoOfMiddleColumn[] = {w01, w11, 0 };
+
+    // hide and show middle column
+    QCOMPARE(layout->preferredWidth(), qreal(64));
+    setVisible(false, middleColumn);   // hide middle column
+    QCOMPARE(layout->preferredWidth(), qreal(42));
+    setVisible(true, middleColumn);    // show middle column
+    QCOMPARE(layout->preferredWidth(), qreal(64));
+    setRetainSizeWhenHidden(true, middleColumn);
+    QCOMPARE(layout->preferredWidth(), qreal(64));
+    setVisible(false, middleColumn);   // hide middle column
+    QCOMPARE(layout->preferredWidth(), qreal(64));
+    setRetainSizeWhenHidden(false, middleColumn);
+    QCOMPARE(layout->preferredWidth(), qreal(42));
+    setVisible(true, middleColumn);
+    QCOMPARE(layout->preferredWidth(), qreal(64));
+
+    // Hide only two items, => column should not collapse
+    setVisible(false, topTwoOfMiddleColumn);
+    QCOMPARE(layout->preferredWidth(), qreal(64));
+
+
+    QGraphicsWidget *middleRow[] = {w10, w11, w12 };
+    QGraphicsWidget *leftMostTwoOfMiddleRow[] = {w10, w11, 0 };
+
+    // hide and show middle row
+    QCOMPARE(layout->preferredHeight(), qreal(64));
+    setVisible(false, middleRow);
+    QCOMPARE(layout->preferredHeight(), qreal(42));
+    setVisible(true, middleRow);
+    QCOMPARE(layout->preferredHeight(), qreal(64));
+    setRetainSizeWhenHidden(true, middleColumn);
+    QCOMPARE(layout->preferredHeight(), qreal(64));
+    setVisible(false, middleRow);
+    QCOMPARE(layout->preferredHeight(), qreal(64));
+    setRetainSizeWhenHidden(false, middleRow);
+    QCOMPARE(layout->preferredHeight(), qreal(42));
+    setVisible(true, middleRow);
+    QCOMPARE(layout->preferredHeight(), qreal(64));
+
+    // Hide only two items => row should not collapse
+    setVisible(false, leftMostTwoOfMiddleRow);
+    QCOMPARE(layout->preferredHeight(), qreal(64));
+
+}
+
 QTEST_MAIN(tst_QGraphicsGridLayout)
 #include "tst_qgraphicsgridlayout.moc"
 
diff --git a/tests/auto/widgets/graphicsview/qgraphicslayout/tst_qgraphicslayout.cpp b/tests/auto/widgets/graphicsview/qgraphicslayout/tst_qgraphicslayout.cpp
index d35667f215..107e3eb48a 100644
--- a/tests/auto/widgets/graphicsview/qgraphicslayout/tst_qgraphicslayout.cpp
+++ b/tests/auto/widgets/graphicsview/qgraphicslayout/tst_qgraphicslayout.cpp
@@ -50,6 +50,7 @@ private slots:
     void compressLayoutRequest();
     void automaticReparenting();
     void verifyActivate();
+    void sizeHintOfHiddenLayout();
     void invalidate();
     void constructors();
     void alternativeLayoutItems();
@@ -279,6 +280,30 @@ void tst_QGraphicsLayout::verifyActivate()
 
 }
 
+
+void tst_QGraphicsLayout::sizeHintOfHiddenLayout()
+{
+    QGraphicsScene scene;
+    QGraphicsView view(&scene);
+
+    QGraphicsWidget *window = new QGraphicsWidget(0, Qt::Window);
+    scene.addItem(window);
+    TestLayout *lout = new TestLayout(window);
+    lout->setContentsMargins(1,2,2,1);
+    QGraphicsWidget *w = new QGraphicsWidget;
+    w->setPreferredSize(20, 20);
+    w->setMaximumSize(50, 50);
+    lout->addItem(w);
+    window->setLayout(lout);
+
+    for (int pass = 0; pass < 3; ++pass) {
+        QCOMPARE(lout->sizeHint(Qt::MinimumSize), QSizeF(3,3));
+        QCOMPARE(lout->sizeHint(Qt::PreferredSize), QSizeF(23,23));
+        QCOMPARE(lout->sizeHint(Qt::MaximumSize), QSizeF(53,53));
+        window->setVisible(pass % 2);
+    }
+}
+
 static void clearAllCounters(TestGraphicsWidget *widget)
 {
     if (!widget)
diff --git a/tests/auto/widgets/graphicsview/qgraphicslinearlayout/tst_qgraphicslinearlayout.cpp b/tests/auto/widgets/graphicsview/qgraphicslinearlayout/tst_qgraphicslinearlayout.cpp
index 7147bb8cce..1513abf0b1 100644
--- a/tests/auto/widgets/graphicsview/qgraphicslinearlayout/tst_qgraphicslinearlayout.cpp
+++ b/tests/auto/widgets/graphicsview/qgraphicslinearlayout/tst_qgraphicslinearlayout.cpp
@@ -103,6 +103,7 @@ private slots:
     void testOffByOneInLargerLayout();
     void testDefaultAlignment();
     void combineSizePolicies();
+    void hiddenItems();
 
     // Task specific tests
     void task218400_insertStretchCrash();
@@ -1721,6 +1722,41 @@ void tst_QGraphicsLinearLayout::combineSizePolicies()
     QCOMPARE(layout->maximumHeight(), qreal(200));
 }
 
+void tst_QGraphicsLinearLayout::hiddenItems()
+{
+    QGraphicsWidget *widget = new QGraphicsWidget;
+    QGraphicsLinearLayout *layout = new QGraphicsLinearLayout(Qt::Horizontal, widget);
+    layout->setContentsMargins(0, 0, 0, 0);
+    layout->setSpacing(2);
+
+    RectWidget *w1 = new RectWidget;
+    w1->setPreferredSize(QSizeF(20, 20));
+    layout->addItem(w1);
+
+    RectWidget *w2 = new RectWidget;
+    w2->setPreferredSize(QSizeF(20, 20));
+    layout->addItem(w2);
+
+    RectWidget *w3 = new RectWidget;
+    w3->setPreferredSize(QSizeF(20, 20));
+    layout->addItem(w3);
+
+    QCOMPARE(layout->preferredWidth(), qreal(64));
+    w2->hide();
+    QCOMPARE(layout->preferredWidth(), qreal(42));
+    w2->show();
+    QCOMPARE(layout->preferredWidth(), qreal(64));
+    QSizePolicy sp = w2->sizePolicy();
+    sp.setRetainSizeWhenHidden(true);
+    w2->setSizePolicy(sp);
+    QCOMPARE(layout->preferredWidth(), qreal(64));
+    w2->hide();
+    QCOMPARE(layout->preferredWidth(), qreal(64));
+    sp.setRetainSizeWhenHidden(false);
+    w2->setSizePolicy(sp);
+    QCOMPARE(layout->preferredWidth(), qreal(42));
+}
+
 QTEST_MAIN(tst_QGraphicsLinearLayout)
 #include "tst_qgraphicslinearlayout.moc"