Implement label editing feature in the QDateTimeAxis

Implement the labelsEditable property handling in the QDateTimeAxis.
If this property set to true the user will be able to manipulate
the axis labels by double clicking on it and entering a new date
in the same format as it is displayed. After finishing the edit
the axis range will be adjusted according to the entered date.

Change-Id: Ide45982875924c8bb4e937b47511dfa3c9237750
Reviewed-by: Miikka Heikkinen <miikka.heikkinen@qt.io>

1 files changed, 98 insertions, 0 deletions

diff --git a/src/charts/axis/datetimeaxis/datetimeaxislabel.cpp b/src/charts/axis/datetimeaxis/datetimeaxislabel.cpp
new file mode 100644
index 00000000..90646ae5
--- /dev/null
+++ b/src/charts/axis/datetimeaxis/datetimeaxislabel.cpp
@@ -0,0 +1,98 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the Qt Charts module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:GPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 or (at your option) any later version
+** approved by the KDE Free Qt Foundation. The licenses are as published by
+** the Free Software Foundation and appearing in the file LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+#include "datetimeaxislabel_p.h"
+
+#include <QtCore/qdatetime.h>
+
+QT_CHARTS_BEGIN_NAMESPACE
+
+DateTimeAxisLabel::DateTimeAxisLabel(QGraphicsItem *parent) :
+    EditableAxisLabel(parent)
+{
+
+}
+
+void DateTimeAxisLabel::finishEditing()
+{
+    QDateTime oldDateTime = m_dateTime;
+    QDateTime newDateTime = QDateTime::fromString(document()->toPlainText(), m_format);
+    if (newDateTime.isValid() && newDateTime != m_dateTime) {
+        m_dateTime = newDateTime;
+        emit dateTimeChanged(oldDateTime, newDateTime);
+    } else {
+        document()->setHtml(m_htmlBeforeEdit);
+    }
+}
+
+QDateTime DateTimeAxisLabel::value() const
+{
+    return m_dateTime;
+}
+
+void DateTimeAxisLabel::setValue(const QDateTime &value)
+{
+    setTextInteractionFlags(Qt::NoTextInteraction);
+    clearFocus();
+    m_dateTime = value;
+}
+
+void DateTimeAxisLabel::resetBeforeEditValue()
+{
+    m_dateTime = m_dateTimeBeforeEdit;
+}
+
+void DateTimeAxisLabel::setFormat(const QString &format)
+{
+    m_format = format;
+    // Labels should be edited as a single line regardless to their
+    // format because enter triggers applying the current text.
+    m_format.replace(QChar::fromLatin1('\n'), QChar::fromLatin1(' '));
+}
+
+void DateTimeAxisLabel::setInitialEditValue()
+{
+    m_dateTimeBeforeEdit = m_dateTime;
+    setHtml(m_dateTime.toString(m_format));
+}
+
+void DateTimeAxisLabel::keyPressEvent(QKeyEvent *event)
+{
+    if (isEditEndingKeyPress(event)) {
+        // prevent further event processing with a return
+        // because the focusOutEvent could have triggered
+        // a range change which might have invalidated the current label
+        return;
+    }
+
+    QGraphicsTextItem::keyPressEvent(event);
+}
+
+QT_CHARTS_END_NAMESPACE
+
+#include "moc_datetimeaxislabel_p.cpp"