examples/layouts/flowlayout/flowlayout.cpp
changeset 0 1918ee327afb
child 4 3b1da2848fc7
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/examples/layouts/flowlayout/flowlayout.cpp	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,214 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** 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, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtGui>
+
+#include "flowlayout.h"
+//! [1]
+FlowLayout::FlowLayout(QWidget *parent, int margin, int hSpacing, int vSpacing)
+    : QLayout(parent), m_hSpace(hSpacing), m_vSpace(vSpacing)
+{
+    setContentsMargins(margin, margin, margin, margin);
+}
+
+FlowLayout::FlowLayout(int margin, int hSpacing, int vSpacing)
+    : m_hSpace(hSpacing), m_vSpace(vSpacing)
+{
+    setContentsMargins(margin, margin, margin, margin);
+}
+//! [1]
+
+//! [2]
+FlowLayout::~FlowLayout()
+{
+    QLayoutItem *item;
+    while ((item = takeAt(0)))
+        delete item;
+}
+//! [2]
+
+//! [3]
+void FlowLayout::addItem(QLayoutItem *item)
+{
+    itemList.append(item);
+}
+//! [3]
+
+//! [4]
+int FlowLayout::horizontalSpacing() const
+{
+    if (m_hSpace >= 0) {
+        return m_hSpace;
+    } else {
+        return smartSpacing(QStyle::PM_LayoutHorizontalSpacing);
+    }
+}
+
+int FlowLayout::verticalSpacing() const
+{
+    if (m_vSpace >= 0) {
+        return m_vSpace;
+    } else {
+        return smartSpacing(QStyle::PM_LayoutVerticalSpacing);
+    }
+}
+//! [4]
+
+//! [5]
+int FlowLayout::count() const
+{
+    return itemList.size();
+}
+
+QLayoutItem *FlowLayout::itemAt(int index) const
+{
+    return itemList.value(index);
+}
+
+QLayoutItem *FlowLayout::takeAt(int index)
+{
+    if (index >= 0 && index < itemList.size())
+        return itemList.takeAt(index);
+    else
+        return 0;
+}
+//! [5]
+
+//! [6]
+Qt::Orientations FlowLayout::expandingDirections() const
+{
+    return 0;
+}
+//! [6]
+
+//! [7]
+bool FlowLayout::hasHeightForWidth() const
+{
+    return true;
+}
+
+int FlowLayout::heightForWidth(int width) const
+{
+    int height = doLayout(QRect(0, 0, width, 0), true);
+    return height;
+}
+//! [7]
+
+//! [8]
+void FlowLayout::setGeometry(const QRect &rect)
+{
+    QLayout::setGeometry(rect);
+    doLayout(rect, false);
+}
+
+QSize FlowLayout::sizeHint() const
+{
+    return minimumSize();
+}
+
+QSize FlowLayout::minimumSize() const
+{
+    QSize size;
+    QLayoutItem *item;
+    foreach (item, itemList)
+        size = size.expandedTo(item->minimumSize());
+
+    size += QSize(2*margin(), 2*margin());
+    return size;
+}
+//! [8]
+
+//! [9]
+int FlowLayout::doLayout(const QRect &rect, bool testOnly) const
+{
+    int left, top, right, bottom;
+    getContentsMargins(&left, &top, &right, &bottom);
+    QRect effectiveRect = rect.adjusted(+left, +top, -right, -bottom);
+    int x = effectiveRect.x();
+    int y = effectiveRect.y();
+    int lineHeight = 0;
+//! [9]
+
+//! [10]
+    QLayoutItem *item;
+    foreach (item, itemList) {
+        QWidget *wid = item->widget();
+        int spaceX = horizontalSpacing();
+        if (spaceX == -1)
+            spaceX = wid->style()->layoutSpacing(
+                QSizePolicy::PushButton, QSizePolicy::PushButton, Qt::Horizontal);
+        int spaceY = verticalSpacing();
+        if (spaceY == -1)
+            spaceY = wid->style()->layoutSpacing(
+                QSizePolicy::PushButton, QSizePolicy::PushButton, Qt::Vertical);
+//! [10]
+//! [11]
+        int nextX = x + item->sizeHint().width() + spaceX;
+        if (nextX - spaceX > effectiveRect.right() && lineHeight > 0) {
+            x = effectiveRect.x();
+            y = y + lineHeight + spaceY;
+            nextX = x + item->sizeHint().width() + spaceX;
+            lineHeight = 0;
+        }
+
+        if (!testOnly)
+            item->setGeometry(QRect(QPoint(x, y), item->sizeHint()));
+
+        x = nextX;
+        lineHeight = qMax(lineHeight, item->sizeHint().height());
+    }
+    return y + lineHeight - rect.y() + bottom;
+}
+//! [11]
+//! [12]
+int FlowLayout::smartSpacing(QStyle::PixelMetric pm) const
+{
+    QObject *parent = this->parent();
+    if (!parent) {
+        return -1;
+    } else if (parent->isWidgetType()) {
+        QWidget *pw = static_cast<QWidget *>(parent);
+        return pw->style()->pixelMetric(pm, 0, pw);
+    } else {
+        return static_cast<QLayout *>(parent)->spacing();
+    }
+}
+//! [12]