src/context/layouts/ContextLayout.cpp

   1 /*
   2 *   Copyright 2007 by Robert Knight <robertknight@gmail.com>
   3 *   Copyright 2007 by Leo Franchi <lfranchi@gmail.com>
   4 *
   5 *   This program is free software; you can redistribute it and/or modify
   6 *   it under the terms of the GNU Library General Public License
   7 *   as published by the Free Software Foundation; either
   8 *   version 2 of the License, or (at your option) any later version.
   9 *
  10 *   This program is distributed in the hope that it will be useful,
  11 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 *   GNU General Public License for more details
  14 *
  15 *   You should have received a copy of the GNU Library General Public
  16 *   License along with this program; if not, write to the
  17 *   Free Software Foundation, Inc.,
  18 *   51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  19 */
  20
  21 #include "ContextLayout.h"
  22
  23 #include <limits.h>
  24 #include <math.h>
  25
  26 #include "kdebug.h"
  27 #include <QtCore/QList>
  28 #include <QtCore/QRectF>
  29 #include <QtCore/QTimeLine>
  30
  31 #include <QtDebug>
  32
  33 #include "plasma/layouts/layoutanimator.h"
  34
  35 using namespace Context;
  36
  37 class ContextLayout::Private
  38 {
  39 public:
  40     Private() : columnWidth( -1 ) {}
  41     QList<LayoutItem*> items;
  42     qreal columnWidth;
  43 };
  44
  45 ContextLayout::ContextLayout(LayoutItem* parent)
  46     : Layout(parent)
  47     , d(new Private)
  48 {
  49 }
  50 ContextLayout::~ContextLayout()
  51 {
  52     delete d;
  53 }
  54
  55 int ContextLayout::count() const
  56 {
  57     return d->items.count();
  58 }
  59
  60 void ContextLayout::addItem(LayoutItem* item)
  61 {
  62     if (d->items.contains(item)) {
  63         return;
  64     }
  65
  66     d->items << item;
  67
  68     if (animator()) {
  69         animator()->setCurrentState(item,Plasma::LayoutAnimator::InsertedState);
  70     }
  71
  72     item->setManagingLayout(this);
  73 }
  74 void ContextLayout::removeItem(LayoutItem* item)
  75 {
  76     item->unsetManagingLayout(this);
  77     d->items.removeAll(item);
  78
  79     if (animator()) {
  80         animator()->setCurrentState(item,Plasma::LayoutAnimator::RemovedState);
  81     }
  82 }
  83 int ContextLayout::indexOf(LayoutItem* item) const
  84 {
  85     return d->items.indexOf(item);
  86 }
  87
  88 Plasma::LayoutItem* ContextLayout::itemAt(int i) const
  89 {
  90     return d->items[i];
  91 }
  92 QSizeF ContextLayout::sizeHint() const
  93 {
  94     // TODO A proper algorithm here
  95     //
  96     // Idea:  Return a size hint based on the golden ratio to
  97     //        make it aesthetically good
  98     //        eg. Longer side is 1.61x the length of the shorter side
  99     //
 100
 101     // testing
 102     return QSizeF(500,500);
 103 }
 104
 105 Plasma::LayoutItem* ContextLayout::takeAt(int i)
 106 {
 107     return d->items.takeAt(i);
 108 }
 109
 110 template <class T>
 111 T qSum(const QList<T>& container)
 112 {
 113     T total = 0;
 114     foreach( const T& item , container ) {
 115         total += item;
 116     }
 117     return total;
 118 }
 119
 120 void ContextLayout::relayout()
 121 {
 122     QRectF rect = geometry().adjusted(margin(LeftMargin), margin(TopMargin), -margin(RightMargin), -margin(BottomMargin));
 123
 124     qDebug() << "Context layout geometry set to " << geometry() << " using column width: " << d->columnWidth;
 125     const int columnCount = qMax( (int)(rect.width() / d->columnWidth), 1 );    //use at least one column
 126
 127     int insertColumn = 0;
 128     qreal rowPos = 0;
 129     qreal rowHeight = 0;
 130
 131     // lay the items out in left-to-right , top-to-bottom order
 132     foreach( LayoutItem *item , d->items ) {
 133
 134         const QSizeF& itemSize = item->sizeHint();
 135
 136         int columnSpan = (int)ceil(itemSize.width() / d->columnWidth);
 137
 138         if ( insertColumn + columnSpan > columnCount ) {
 139             // start a new row
 140             insertColumn = 0;
 141             rowPos += rowHeight + spacing();
 142         }
 143
 144        // qDebug() << "Inserting item at column" << insertColumn
 145        //          << "spanning" << columnSpan << "columns"
 146        //          << "with offset" << offset;
 147
 148
 149         // try to expand the item to fill its allocated number of columns
 150         qreal itemWidth = itemSize.width();
 151         const qreal idealWidth = columnSpan * d->columnWidth - spacing();
 152         if ( itemWidth < idealWidth &&
 153              idealWidth < item->maximumSize().width() ) {
 154              itemWidth = idealWidth;
 155         }
 156
 157         // calculate offset to horizontally center item
 158         //if there is space for only one column,
 159         //center the item relative to the whole available rectangle
 160         qreal offset;
 161         if( columnCount > 1 ) {
 162             offset = (columnSpan * d->columnWidth) - itemWidth;
 163         } else {
 164             offset = rect.width() - itemWidth;
 165         }
 166         if( columnCount > 1 ) { //no need for spacing if there is only one column
 167             offset -= spacing() / 4;
 168         }
 169         if( offset < 0 )
 170         {
 171             offset = 0;
 172         }
 173         offset /= 2;
 174
 175         // try to restrict the item width to the available geometry's
 176         // width
 177         if ( itemWidth > rect.width() ) {
 178             itemWidth = qMax(rect.width(),item->minimumSize().width());
 179             offset = 0;
 180         }
 181
 182         // position the item
 183         qreal itemHeight;
 184         if( item->hasHeightForWidth() )
 185             itemHeight = item->heightForWidth( itemWidth );
 186         else
 187             itemHeight = itemSize.height(); // this is not good, applets should provide heightForWidth
 188
 189         const QRectF newGeometry(rect.left() + insertColumn * d->columnWidth + offset,
 190                                  rect.top() + margin( TopMargin ) + rowPos,
 191                                  itemWidth,
 192                                  itemHeight );
 193
 194         rowHeight = qMax(rowHeight,itemHeight);
 195         insertColumn += columnSpan;
 196
 197         kDebug() << "Setting a child item geometry to:" << newGeometry;
 198         if ( animator() )
 199             animator()->setGeometry( item , newGeometry );
 200         else
 201             item->setGeometry( newGeometry );
 202     }
 203
 204     startAnimation();
 205 }
 206
 207 Qt::Orientations ContextLayout::expandingDirections() const
 208 {
 209     return Qt::Vertical | Qt::Horizontal;
 210 }
 211
 212 qreal ContextLayout::columnWidth() const
 213 {
 214     return d->columnWidth;
 215 }
 216
 217 void ContextLayout::setColumnWidth( const qreal width )
 218 {
 219     d->columnWidth = width;
 220 }