src/Gui/FlowLayout.cpp

   1 /* Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
   2    All rights reserved.
   3    Contact: Nokia Corporation (qt-info@nokia.com)
   4
   5    This file is part of the Trojita Qt IMAP e-mail client,
   6    http://trojita.flaska.net/
   7
   8    It was taken from the examples of the Qt Toolkit.
   9
  10    $QT_BEGIN_LICENSE:LGPL$
  11    Commercial Usage
  12    Licensees holding valid Qt Commercial licenses may use this file in
  13    accordance with the Qt Commercial License Agreement provided with the
  14    Software or, alternatively, in accordance with the terms contained in
  15    a written agreement between you and Nokia.
  16
  17    GNU Lesser General Public License Usage
  18    Alternatively, this file may be used under the terms of the GNU Lesser
  19    General Public License version 2.1 as published by the Free Software
  20    Foundation and appearing in the file LICENSE.LGPL included in the
  21    packaging of this file.  Please review the following information to
  22    ensure the GNU Lesser General Public License version 2.1 requirements
  23    will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
  24
  25    In addition, as a special exception, Nokia gives you certain additional
  26    rights.  These rights are described in the Nokia Qt LGPL Exception
  27    version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
  28
  29    GNU General Public License Usage
  30    Alternatively, this file may be used under the terms of the GNU
  31    General Public License version 3.0 as published by the Free Software
  32    Foundation and appearing in the file LICENSE.GPL included in the
  33    packaging of this file.  Please review the following information to
  34    ensure the GNU General Public License version 3.0 requirements will be
  35    met: http://www.gnu.org/copyleft/gpl.html.
  36
  37    If you have questions regarding the use of this file, please contact
  38    Nokia at qt-info@nokia.com.
  39    $QT_END_LICENSE$
  40 */
  41
  42 #include <QWidget>
  43
  44 #include "FlowLayout.h"
  45
  46 namespace Gui
  47 {
  48
  49 FlowLayout::FlowLayout(QWidget *parent, int margin, int hSpacing, int vSpacing)
  50     : QLayout(parent), m_hSpace(hSpacing), m_vSpace(vSpacing)
  51 {
  52     setContentsMargins(margin, margin, margin, margin);
  53 }
  54
  55 FlowLayout::FlowLayout(int margin, int hSpacing, int vSpacing)
  56     : m_hSpace(hSpacing), m_vSpace(vSpacing)
  57 {
  58     setContentsMargins(margin, margin, margin, margin);
  59 }
  60
  61 FlowLayout::~FlowLayout()
  62 {
  63     QLayoutItem *item;
  64     while ((item = takeAt(0)))
  65         delete item;
  66 }
  67
  68 void FlowLayout::addItem(QLayoutItem *item)
  69 {
  70     itemList.append(item);
  71 }
  72
  73 int FlowLayout::horizontalSpacing() const
  74 {
  75     if (m_hSpace >= 0) {
  76         return m_hSpace;
  77     } else {
  78         return smartSpacing(QStyle::PM_LayoutHorizontalSpacing);
  79     }
  80 }
  81
  82 int FlowLayout::verticalSpacing() const
  83 {
  84     if (m_vSpace >= 0) {
  85         return m_vSpace;
  86     } else {
  87         return smartSpacing(QStyle::PM_LayoutVerticalSpacing);
  88     }
  89 }
  90
  91 int FlowLayout::count() const
  92 {
  93     return itemList.size();
  94 }
  95
  96 QLayoutItem *FlowLayout::itemAt(int index) const
  97 {
  98     return itemList.value(index);
  99 }
 100
 101 QLayoutItem *FlowLayout::takeAt(int index)
 102 {
 103     if (index >= 0 && index < itemList.size())
 104         return itemList.takeAt(index);
 105     else
 106         return 0;
 107 }
 108
 109 Qt::Orientations FlowLayout::expandingDirections() const
 110 {
 111     return 0;
 112 }
 113
 114 bool FlowLayout::hasHeightForWidth() const
 115 {
 116     return true;
 117 }
 118
 119 int FlowLayout::heightForWidth(int width) const
 120 {
 121     int height = doLayout(QRect(0, 0, width, 0), true);
 122     return height;
 123 }
 124
 125 void FlowLayout::setGeometry(const QRect &rect)
 126 {
 127     QLayout::setGeometry(rect);
 128     doLayout(rect, false);
 129 }
 130
 131 QSize FlowLayout::sizeHint() const
 132 {
 133     return minimumSize();
 134 }
 135
 136 QSize FlowLayout::minimumSize() const
 137 {
 138     QSize size;
 139     QLayoutItem *item;
 140     foreach(item, itemList)
 141     size = size.expandedTo(item->minimumSize());
 142
 143     size += QSize(2*margin(), 2*margin());
 144     return size;
 145 }
 146
 147 int FlowLayout::doLayout(const QRect &rect, bool testOnly) const
 148 {
 149     int left, top, right, bottom;
 150     getContentsMargins(&left, &top, &right, &bottom);
 151     QRect effectiveRect = rect.adjusted(+left, +top, -right, -bottom);
 152     int x = effectiveRect.x();
 153     int y = effectiveRect.y();
 154     int lineHeight = 0;
 155
 156     QLayoutItem *item;
 157     foreach(item, itemList) {
 158         QWidget *wid = item->widget();
 159         int spaceX = horizontalSpacing();
 160         if (spaceX == -1)
 161             spaceX = wid->style()->layoutSpacing(
 162                          QSizePolicy::PushButton, QSizePolicy::PushButton, Qt::Horizontal);
 163         int spaceY = verticalSpacing();
 164         if (spaceY == -1)
 165             spaceY = wid->style()->layoutSpacing(
 166                          QSizePolicy::PushButton, QSizePolicy::PushButton, Qt::Vertical);
 167         int nextX = x + item->sizeHint().width() + spaceX;
 168         if (nextX - spaceX > effectiveRect.right() && lineHeight > 0) {
 169             x = effectiveRect.x();
 170             y = y + lineHeight + spaceY;
 171             nextX = x + item->sizeHint().width() + spaceX;
 172             lineHeight = 0;
 173         }
 174
 175         if (!testOnly)
 176             item->setGeometry(QRect(QPoint(x, y), item->sizeHint()));
 177
 178         x = nextX;
 179         lineHeight = qMax(lineHeight, item->sizeHint().height());
 180     }
 181     return y + lineHeight - rect.y() + bottom;
 182 }
 183 int FlowLayout::smartSpacing(QStyle::PixelMetric pm) const
 184 {
 185     QObject *parent = this->parent();
 186     if (!parent) {
 187         return -1;
 188     } else if (parent->isWidgetType()) {
 189         QWidget *pw = static_cast<QWidget *>(parent);
 190         return pw->style()->pixelMetric(pm, 0, pw);
 191     } else {
 192         return static_cast<QLayout *>(parent)->spacing();
 193     }
 194 }
 195
 196 } // namespace Gui