item delegates: fix clicking on tristate checkboxes.

QCheckBox cycles through the 3 states, but item delegates didn't
do that.

Change-Id: Iad1e464341033ca357925fe8064f53bb584459f4
Reviewed-by: Thorbjørn Lund Martsum <tmartsum@gmail.com>
Reviewed-by: Stephen Kelly <stephen.kelly@kdab.com>

3 files changed, 61 insertions, 4 deletions

diff --git a/src/widgets/itemviews/qitemdelegate.cpp b/src/widgets/itemviews/qitemdelegate.cpp
index c040322ba1..3e34568a12 100644
--- a/src/widgets/itemviews/qitemdelegate.cpp
+++ b/src/widgets/itemviews/qitemdelegate.cpp
@@ -1295,8 +1295,11 @@ bool QItemDelegate::editorEvent(QEvent *event,
         return false;
     }
 
-    Qt::CheckState state = (static_cast<Qt::CheckState>(value.toInt()) == Qt::Checked
-                            ? Qt::Unchecked : Qt::Checked);
+    Qt::CheckState state = static_cast<Qt::CheckState>(value.toInt());
+    if (flags & Qt::ItemIsTristate)
+        state = ((Qt::CheckState)((state + 1) % 3));
+    else
+        state = (state == Qt::Checked) ? Qt::Unchecked : Qt::Checked;
     return model->setData(index, state, Qt::CheckStateRole);
 }
 
diff --git a/src/widgets/itemviews/qstyleditemdelegate.cpp b/src/widgets/itemviews/qstyleditemdelegate.cpp
index 7e1933ad1e..c1fa9fe28e 100644
--- a/src/widgets/itemviews/qstyleditemdelegate.cpp
+++ b/src/widgets/itemviews/qstyleditemdelegate.cpp
@@ -764,8 +764,11 @@ bool QStyledItemDelegate::editorEvent(QEvent *event,
         return false;
     }
 
-    Qt::CheckState state = (static_cast<Qt::CheckState>(value.toInt()) == Qt::Checked
-                            ? Qt::Unchecked : Qt::Checked);
+    Qt::CheckState state = static_cast<Qt::CheckState>(value.toInt());
+    if (flags & Qt::ItemIsTristate)
+        state = ((Qt::CheckState)((state + 1) % 3));
+    else
+        state = (state == Qt::Checked) ? Qt::Unchecked : Qt::Checked;
     return model->setData(index, state, Qt::CheckStateRole);
 }
 
diff --git a/tests/auto/widgets/itemviews/qitemdelegate/tst_qitemdelegate.cpp b/tests/auto/widgets/itemviews/qitemdelegate/tst_qitemdelegate.cpp
index 538cc7bb4c..439725b257 100644
--- a/tests/auto/widgets/itemviews/qitemdelegate/tst_qitemdelegate.cpp
+++ b/tests/auto/widgets/itemviews/qitemdelegate/tst_qitemdelegate.cpp
@@ -1198,6 +1198,57 @@ void tst_QItemDelegate::editorEvent_data()
         << (int)(Qt::LeftButton)
         << true
         << (int)(Qt::Unchecked);
+
+    QTest::newRow("unchecked, tristate, release")
+        << QRect(0, 0, 20, 20)
+        << QString("foo")
+        << (int)(Qt::Unchecked)
+        << (int)(Qt::ItemIsEditable
+            |Qt::ItemIsSelectable
+            |Qt::ItemIsUserCheckable
+            |Qt::ItemIsTristate
+            |Qt::ItemIsEnabled
+            |Qt::ItemIsDragEnabled
+            |Qt::ItemIsDropEnabled)
+        << true
+        << (int)(QEvent::MouseButtonRelease)
+        << (int)(Qt::LeftButton)
+        << true
+        << (int)(Qt::PartiallyChecked);
+
+    QTest::newRow("partially checked, tristate, release")
+        << QRect(0, 0, 20, 20)
+        << QString("foo")
+        << (int)(Qt::PartiallyChecked)
+        << (int)(Qt::ItemIsEditable
+            |Qt::ItemIsSelectable
+            |Qt::ItemIsUserCheckable
+            |Qt::ItemIsTristate
+            |Qt::ItemIsEnabled
+            |Qt::ItemIsDragEnabled
+            |Qt::ItemIsDropEnabled)
+        << true
+        << (int)(QEvent::MouseButtonRelease)
+        << (int)(Qt::LeftButton)
+        << true
+        << (int)(Qt::Checked);
+
+    QTest::newRow("checked, tristate, release")
+        << QRect(0, 0, 20, 20)
+        << QString("foo")
+        << (int)(Qt::Checked)
+        << (int)(Qt::ItemIsEditable
+            |Qt::ItemIsSelectable
+            |Qt::ItemIsUserCheckable
+            |Qt::ItemIsTristate
+            |Qt::ItemIsEnabled
+            |Qt::ItemIsDragEnabled
+            |Qt::ItemIsDropEnabled)
+        << true
+        << (int)(QEvent::MouseButtonRelease)
+        << (int)(Qt::LeftButton)
+        << true
+        << (int)(Qt::Unchecked);
 }
 
 void tst_QItemDelegate::editorEvent()