QHeaderView - add parameter to control sizeHint precision

Currently Qt looks at 1000 rows when scaling a column.
That can be slow in some situations and too inaccurate in others.

With this patch we leave it up to the user to decide how precise
e.g resizeToContents should be.

Change-Id: I6ef60f9a3bb40fc331ce1a1544fdc77488d20ca3
Reviewed-by: Stephen Kelly <stephen.kelly@kdab.com>

6 files changed, 378 insertions, 0 deletions

diff --git a/tests/manual/widgets/itemviews/autoResizePrecision/tablehorz/testtable1.cpp b/tests/manual/widgets/itemviews/autoResizePrecision/tablehorz/testtable1.cpp
new file mode 100644
index 0000000000..463366433c
--- /dev/null
+++ b/tests/manual/widgets/itemviews/autoResizePrecision/tablehorz/testtable1.cpp
@@ -0,0 +1,115 @@
+/****************************************************************************
+**
+** Copyright (C) 2012 Thorbjørn Lund Martsum - tmartsum[at]gmail.com
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** 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 Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtWidgets/QtWidgets>
+
+const int rowCount = 2000;
+
+class TableDialog : public QDialog
+{
+    Q_OBJECT
+public:
+    TableDialog() : model(rowCount, 3) { create(); }
+    void create()
+    {
+        resize(1000, 233);
+        gridLayout = new QGridLayout(this);
+        tableView = new QTableView(this);
+
+        gridLayout->addWidget(tableView, 0, 0, 2, 1);
+        spinPrecision = new QSpinBox(this);
+        gridLayout->addWidget(spinPrecision, 0, 1, 1, 1);
+        verticalSpacer = new QSpacerItem(20, 20, QSizePolicy::Minimum, QSizePolicy::Expanding);
+        gridLayout->addItem(verticalSpacer, 1, 1, 1, 1);
+
+        QString ii = QString::fromLatin1("ii");
+        QStringList is;
+        spinPrecision->setMinimum(-1);
+        spinPrecision->setMaximum(rowCount + 2);
+        for (int u = 0; u < rowCount; ++u) {
+            if (u % 25 == 0)
+                ii += QString::fromLatin1("i");
+            else
+                ii[ii.length() - 1] = QChar::fromLatin1('a' + (u  % 25));
+            ii[ii.length() - 2] = QChar::fromLatin1('i');
+            is.append(ii);
+        }
+
+        for (int u = 0; u < rowCount; ++u) {
+            QString col1;
+            col1 = QString::fromLatin1("Row: %1").arg(u);
+            model.setData(model.index(u, 0), col1);
+            model.setData(model.index(u, 1), is[u]);
+            model.setData(model.index(u, 2), is[rowCount - u -1]);
+        }
+        tableView->setModel(&model);
+
+        tableView->horizontalHeader()->setSectionResizeMode(0, QHeaderView::ResizeToContents);
+        tableView->horizontalHeader()->setSectionResizeMode(1, QHeaderView::ResizeToContents);
+        tableView->horizontalHeader()->setSectionResizeMode(2, QHeaderView::ResizeToContents);
+        spinPrecision->setValue(tableView->horizontalHeader()->resizeContentsPrecision());
+        connect(spinPrecision, SIGNAL(valueChanged(int)), this, SLOT(slotValueChanged(int)));
+    } // setupUi
+protected slots:
+    void slotValueChanged(int newval);
+protected:
+    QGridLayout *gridLayout;
+    QTableView *tableView;
+    QSpinBox *spinPrecision;
+    QSpacerItem *verticalSpacer;
+    QStandardItemModel model;
+};
+
+void TableDialog::slotValueChanged(int newval)
+{
+    tableView->horizontalHeader()->setResizeContentsPrecision(newval, true);
+}
+
+
+int main(int argc, char *argv[])
+{
+    QApplication app(argc, argv);
+    TableDialog d1;
+    d1.show();
+    app.exec();
+}
+
+#include "testtable1.moc"
diff --git a/tests/manual/widgets/itemviews/autoResizePrecision/tablehorz/testtable1.pro b/tests/manual/widgets/itemviews/autoResizePrecision/tablehorz/testtable1.pro
new file mode 100644
index 0000000000..e07f40bc2f
--- /dev/null
+++ b/tests/manual/widgets/itemviews/autoResizePrecision/tablehorz/testtable1.pro
@@ -0,0 +1,2 @@
+SOURCES = testtable1.cpp
+QT += widgets
diff --git a/tests/manual/widgets/itemviews/autoResizePrecision/tablevert/testtable2.cpp b/tests/manual/widgets/itemviews/autoResizePrecision/tablevert/testtable2.cpp
new file mode 100644
index 0000000000..027801d528
--- /dev/null
+++ b/tests/manual/widgets/itemviews/autoResizePrecision/tablevert/testtable2.cpp
@@ -0,0 +1,125 @@
+/****************************************************************************
+**
+** Copyright (C) 2012 Thorbjørn Lund Martsum - tmartsum[at]gmail.com
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** 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 Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtWidgets/QtWidgets>
+
+const int columnCount = 1500;
+
+class TableDialog : public QDialog
+{
+    Q_OBJECT
+public:
+    TableDialog() : model(2, columnCount) { create(); }
+    void create()
+    {
+        resize(1200, 400);
+        gridLayout = new QGridLayout(this);
+        tableView = new QTableView(this);
+
+        gridLayout->addWidget(tableView, 0, 0, 2, 1);
+        spinPrecision = new QSpinBox(this);
+        gridLayout->addWidget(spinPrecision, 0, 1, 1, 1);
+        verticalSpacer = new QSpacerItem(20, 20, QSizePolicy::Minimum, QSizePolicy::Expanding);
+        gridLayout->addItem(verticalSpacer, 1, 1, 1, 1);
+
+        QString ii = QString::fromLatin1("ii");
+        QStringList is;
+        spinPrecision->setMinimum(-1);
+        spinPrecision->setMaximum(columnCount + 2);
+
+        QFont f = QApplication::font();
+        for (int u = 0; u < columnCount; ++u) {
+            int size = 10 + (u % 63);
+            f.setPixelSize(size);
+            QString col;
+            if (u % 50 < 25)
+                col = QChar::fromLatin1('a' + (u % 25));
+            else
+                col = QChar::fromLatin1('A' + (u % 25));
+
+            int v = columnCount - u - 1;
+            model.setData(model.index(0, u), col);
+            model.setData(model.index(1, v), col);
+
+            model.setData(model.index(0, u), f,  Qt::FontRole);
+            model.setData(model.index(1, v), f,  Qt::FontRole);
+        }
+        tableView->setModel(&model);
+
+        for (int u = 0; u < columnCount; ++ u)
+            tableView->horizontalHeader()->resizeSection(u, 60);
+
+        // Make last index in first row a bit special
+        f.setPixelSize(96);
+        model.setData(model.index(0, columnCount - 1), f,  Qt::FontRole);
+        model.setData(model.index(0, columnCount - 1), QString::fromLatin1("qI"));
+        tableView->horizontalHeader()->resizeSection(columnCount - 1, 140);
+
+        tableView->verticalHeader()->setSectionResizeMode(0, QHeaderView::ResizeToContents);
+        tableView->verticalHeader()->setSectionResizeMode(1, QHeaderView::ResizeToContents);
+        spinPrecision->setValue(tableView->verticalHeader()->resizeContentsPrecision());
+        connect(spinPrecision, SIGNAL(valueChanged(int)), this, SLOT(slotValueChanged(int)));
+    } // setupUi
+protected slots:
+    void slotValueChanged(int newval);
+protected:
+    QGridLayout *gridLayout;
+    QTableView *tableView;
+    QSpinBox *spinPrecision;
+    QSpacerItem *verticalSpacer;
+    QStandardItemModel model;
+};
+
+void TableDialog::slotValueChanged(int newval)
+{
+    tableView->verticalHeader()->setResizeContentsPrecision(newval, true);
+}
+
+
+int main(int argc, char *argv[])
+{
+    QApplication app(argc, argv);
+    TableDialog d1;
+    d1.show();
+    app.exec();
+}
+
+#include "testtable2.moc"
diff --git a/tests/manual/widgets/itemviews/autoResizePrecision/tablevert/testtable2.pro b/tests/manual/widgets/itemviews/autoResizePrecision/tablevert/testtable2.pro
new file mode 100644
index 0000000000..b887fcb14b
--- /dev/null
+++ b/tests/manual/widgets/itemviews/autoResizePrecision/tablevert/testtable2.pro
@@ -0,0 +1,2 @@
+SOURCES = testtable2.cpp
+QT += widgets
diff --git a/tests/manual/widgets/itemviews/autoResizePrecision/treeview/testtree.cpp b/tests/manual/widgets/itemviews/autoResizePrecision/treeview/testtree.cpp
new file mode 100644
index 0000000000..c48d933fcd
--- /dev/null
+++ b/tests/manual/widgets/itemviews/autoResizePrecision/treeview/testtree.cpp
@@ -0,0 +1,132 @@
+/****************************************************************************
+**
+** Copyright (C) 2012 Thorbjørn Lund Martsum - tmartsum[at]gmail.com
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** 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 Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtWidgets/QtWidgets>
+
+class TreeDialog : public QDialog
+{
+    Q_OBJECT
+public:
+    TreeDialog() { create(); }
+protected:
+    void create()
+    {
+        resize(1000, 233);
+        gridLayout = new QGridLayout(this);
+        treeWidget = new QTreeWidget(this);
+
+        gridLayout->addWidget(treeWidget, 0, 0, 2, 1);
+        spinPrecision = new QSpinBox(this);
+        gridLayout->addWidget(spinPrecision, 0, 1, 1, 1);
+        verticalSpacer = new QSpacerItem(20, 20, QSizePolicy::Minimum, QSizePolicy::Expanding);
+        gridLayout->addItem(verticalSpacer, 1, 1, 1, 1);
+
+        QStringList itemInfo("Col1");
+        itemInfo.append("Col2");
+        itemInfo.append("Col3");
+        itemInfo.append("Dummy");
+        // Developer no. could also have been social security number og some other id.
+        treeWidget->setHeaderLabels(itemInfo);
+
+        QStringList sl1("This is Root Item");
+        sl1.append("i");
+        QTreeWidgetItem *rootitem = new QTreeWidgetItem(treeWidget, sl1);
+
+        QStringList sl2("This is Child1 Item");
+        sl2.append("WW");
+        QTreeWidgetItem *child1 = new QTreeWidgetItem(rootitem, sl2);
+
+        QString ii = QString::fromLatin1("ii");
+        QStringList is;
+        const int rowCount = 3000;
+        spinPrecision->setMinimum(-1);
+        spinPrecision->setMaximum(rowCount + 5);
+        for (int u = 0; u < rowCount; ++u) {
+            if (u % 25 == 0)
+                ii += QString::fromLatin1("i");
+            else
+                ii[ii.length() - 1] = QChar::fromLatin1('a' + (u  % 25));
+            ii[ii.length() - 2] = QChar::fromLatin1('i');
+            is.append(ii);
+        }
+
+        for (int u = 0; u < rowCount - 2; ++u) { // -2 since we have rootitem and child1
+            QString col1;
+            col1 = QString::fromLatin1("This is child item %1").arg(u + 2);
+
+            QStringList sl(col1);
+            sl.append(is[u]);
+            sl.append(is[rowCount - u - 1]);
+
+            if (u > 500)
+                new QTreeWidgetItem(rootitem, sl);
+            else
+                new QTreeWidgetItem(child1, sl);
+        }
+        treeWidget->header()->setSectionResizeMode(0, QHeaderView::ResizeToContents);
+        treeWidget->header()->setSectionResizeMode(1, QHeaderView::ResizeToContents);
+        treeWidget->header()->setSectionResizeMode(2, QHeaderView::ResizeToContents);
+        spinPrecision->setValue(treeWidget->header()->resizeContentsPrecision());
+        connect(spinPrecision, SIGNAL(valueChanged(int)), this, SLOT(slotValueChanged(int)));
+    } // setupUi
+protected slots:
+    void slotValueChanged(int newval);
+protected:
+    QGridLayout *gridLayout;
+    QTreeWidget *treeWidget;
+    QSpinBox *spinPrecision;
+    QSpacerItem *verticalSpacer;
+};
+
+void TreeDialog::slotValueChanged(int newval)
+{
+    treeWidget->header()->setResizeContentsPrecision(newval, true);
+}
+
+int main(int argc, char *argv[])
+{
+    QApplication app(argc, argv);
+    TreeDialog d1;
+    d1.show();
+    app.exec();
+}
+
+#include "testtree.moc"
diff --git a/tests/manual/widgets/itemviews/autoResizePrecision/treeview/testtree.pro b/tests/manual/widgets/itemviews/autoResizePrecision/treeview/testtree.pro
new file mode 100644
index 0000000000..c062586eac
--- /dev/null
+++ b/tests/manual/widgets/itemviews/autoResizePrecision/treeview/testtree.pro
@@ -0,0 +1,2 @@
+SOURCES = testtree.cpp
+QT += widgets