/* * Copyright 2007 by Matias Valdenegro T. * Copyright 2007 by Robert Knight * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU Library General Public License as * published by the Free Software Foundation; either version 2, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details * * You should have received a copy of the GNU Library General Public * License along with this program; if not, write to the * Free Software Foundation, Inc., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ #include "boxlayout.h" #include #include #include #include "layoutanimator.h" namespace Plasma { class BoxLayout::Private { public: BoxLayout *const q; Direction direction; QRectF geometry; QList children; Private(BoxLayout *parent) : q(parent) , direction(LeftToRight) { } // returns the component of 'size' in the expanding direction // of this layout qreal size(const QSizeF& size) const { switch (direction) { case LeftToRight: case RightToLeft: return size.width(); case TopToBottom: case BottomToTop: return size.height(); default: Q_ASSERT(false); return 0; } } // returns the direction in which this layout expands // or shrinks Qt::Orientation expandingDirection() const { switch ( direction ) { case LeftToRight: case RightToLeft: return Qt::Horizontal; case TopToBottom: case BottomToTop: return Qt::Vertical; default: Q_ASSERT(false); return Qt::Horizontal; } } // returns the position from which layouting should // begin depending on the direction of this layout qreal startPos(const QRectF& geometry) const { switch ( direction ) { case LeftToRight: case TopToBottom: return q->margin(); case RightToLeft: return geometry.width() - q->margin(); case BottomToTop: return geometry.height() - q->margin(); default: Q_ASSERT(false); return 0; } } // lays out an item // // 'geometry' the geometry of the layout // 'item' the item whoose geometry should be altered // 'pos' the position of the item (in the expanding direction of the layout) // 'size' the size of the item (in the expanding direction of the layout) // // returns the position for the next item in the layout // qreal layoutItem(const QRectF& geometry , LayoutItem *item , const qreal pos , qreal size) { //qDebug() << "layoutItem: " << direction << "item size" << size; QRectF newGeometry; qreal newPos = 0; qreal top = 0; qreal height = 0; QSizeF minSize = item->minimumSize(); QSizeF maxSize = item->maximumSize(); switch ( direction ) { case LeftToRight: case RightToLeft: height = qBound(minSize.height(),geometry.height(),maxSize.height()); top = geometry.top(); break; case TopToBottom: case BottomToTop: height = qBound(minSize.width(),geometry.width(),maxSize.width()); top = geometry.left(); break; } switch ( direction ) { case LeftToRight: newGeometry = QRectF(pos,top,size,height); newPos = pos+size+q->spacing(); break; case RightToLeft: newGeometry = QRectF(geometry.width()-pos-size,top, size,height); newPos = pos-size-q->spacing(); break; case TopToBottom: newGeometry = QRectF(top,pos,height,size); newPos = pos+size+q->spacing(); break; case BottomToTop: newGeometry = QRectF(top,geometry.height()-pos-size, height,size); newPos = pos-size-q->spacing(); break; } // qDebug() << "Item geometry: " << newGeometry; if ( q->animator() ) q->animator()->setGeometry(item,newGeometry); else item->setGeometry(newGeometry); return newPos; } enum SizeType { MinSize, MaxSize, HintSize }; // this provides a + function which can be passed as the 'op' // argument to calculateSize static qreal sum(const qreal a , const qreal b) { return a+b; } // calcualtes a size hint or value for this layout // 'sizeType' - The item size ( minimum , maximum , hint ) to use // 'dir' - The direction component of the item size to use // 'op' - A function to apply to the size of each item in the layout // , usually qMax,qMin or sum template qreal calculateSize(SizeType sizeType , Qt::Orientation dir , T (*op)(T,T)) const { qreal value = 0; for ( int i = 0 ; i < children.count() ; i++ ) { QSizeF itemSize; switch ( sizeType ) { case MinSize: itemSize = children[i]->minimumSize(); break; case MaxSize: itemSize = children[i]->maximumSize(); break; case HintSize: itemSize = children[i]->sizeHint(); break; } if ( dir == Qt::Horizontal ) { value = op(value,itemSize.width()); } else { value = op(value,itemSize.height()); } } return value; } // calculates a size hint or value for this layout // 'calculateSizeType' specifies the value to be calculated QSizeF calculateSize(SizeType calculateSizeType) const { QSizeF result; const qreal totalMargin = q->margin() * 2; const qreal totalSpacing = q->spacing() * (children.count()-1); switch ( direction ) { case LeftToRight: case RightToLeft: result = QSizeF(calculateSize(calculateSizeType,Qt::Horizontal,sum), calculateSize(calculateSizeType,Qt::Vertical,qMax)); result.rwidth() += totalMargin + totalSpacing; result.rheight() += totalMargin; break; case TopToBottom: case BottomToTop: result = QSizeF(calculateSize(calculateSizeType,Qt::Horizontal,qMax), calculateSize(calculateSizeType,Qt::Vertical,sum)); result.rheight() += totalMargin + totalSpacing; result.rwidth() += totalMargin; break; } return result; } }; BoxLayout::BoxLayout(Direction direction , LayoutItem *parent) : Layout(parent), d(new Private(this)) { if (parent) { parent->setLayout(this); } d->direction = direction; } void BoxLayout::setDirection(Direction direction) { d->direction = direction; update(); } BoxLayout::Direction BoxLayout::direction() const { return d->direction; } BoxLayout::~BoxLayout() { foreach (LayoutItem* item, d->children) { item->unsetManagingLayout(this); } delete d; } Qt::Orientations BoxLayout::expandingDirections() const { switch ( d->direction ) { case LeftToRight: case RightToLeft: return Qt::Horizontal; case TopToBottom: case BottomToTop: return Qt::Vertical; default: Q_ASSERT(false); return 0; } } QRectF BoxLayout::geometry() const { return d->geometry; } int BoxLayout::count() const { return d->children.count(); } void BoxLayout::insertItem(int index, LayoutItem *item) { if (!item) { return; } item->setManagingLayout(this); if ( index == -1 ) index = d->children.size(); d->children.insert(index, item); if ( animator() ) animator()->setCurrentState(item,LayoutAnimator::InsertedState); update(); } void BoxLayout::addItem(LayoutItem *item) { insertItem(-1,item); } void BoxLayout::removeItem(LayoutItem *item) { if (!item) { return; } item->unsetManagingLayout(this); d->children.removeAll(item); if ( animator() ) animator()->setCurrentState(item,LayoutAnimator::RemovedState); update(); } int BoxLayout::indexOf(LayoutItem *l) const { return d->children.indexOf(l); } LayoutItem *BoxLayout::itemAt(int i) const { return d->children[i]; } LayoutItem *BoxLayout::takeAt(int i) { return d->children.takeAt(i); update(); } void BoxLayout::setGeometry(const QRectF& geo) { QRectF geometry = geo.adjusted(margin(),margin(),-margin(),-margin()); //qDebug() << "geo before " << geo << "after" << geometry << "margin" << margin(); //qDebug() << "Box layout beginning with geo" << geometry; //qDebug() << "This box max size" << maximumSize(); QVector sizes(count()); QVector expansionSpace(count()); qreal available = d->size(geometry.size()) - spacing()*(d->children.count()-1); qreal perItemSize = available / count(); // initial distribution of space to items for ( int i = 0 ; i < sizes.count() ; i++ ) { const LayoutItem *item = d->children[i]; const bool isExpanding = item->expandingDirections() & d->expandingDirection(); if ( isExpanding ) sizes[i] = perItemSize; else sizes[i] = d->size(item->sizeHint()); const qreal minItemSize = d->size(item->minimumSize()); const qreal maxItemSize = d->size(item->maximumSize()); // qDebug() << "Layout max item " << i << "size: " << maxItemSize; sizes[i] = qMin( sizes[i] , maxItemSize ); sizes[i] = qMax( sizes[i] , minItemSize ); // qDebug() << "Available: " << available << "per item:" << perItemSize << // "Initial size: " << sizes[i]; if ( isExpanding ) expansionSpace[i] = maxItemSize-sizes[i]; else expansionSpace[i] = 0; available -= sizes[i]; // adjust the per-item size if the space was over or under used if ( sizes[i] != perItemSize && i != sizes.count()-1 ) { perItemSize = available / (sizes.count()-i-1); } } // distribute out any remaining space to items which can still expand // // space is distributed equally amongst remaining items until we run // out of space or items to expand int expandable = sizes.count(); const qreal threshold = 1.0; while ( available > threshold && expandable > 0 ) { qreal extraSpace = available / expandable; for ( int i = 0 ; i < sizes.count() ; i++ ) { if ( expansionSpace[i] > threshold ) { qreal oldSize = sizes[i]; sizes[i] += qMin(extraSpace,expansionSpace[i]); expansionSpace[i] -= sizes[i]-oldSize; available -= sizes[i]-oldSize; } else { expandable--; } } } // set items' geometry according to new sizes qreal pos = d->startPos(geometry); for ( int i = 0 ; i < sizes.count() ; i++ ) { //QObject *obj = dynamic_cast(d->children[i]); //if ( obj ) //qDebug() << "Item " << i << obj->metaObject()->className() << "size:" << sizes[i]; pos = d->layoutItem( geometry , d->children[i] , pos , sizes[i] ); } d->geometry = geometry; startAnimation(); } QSizeF BoxLayout::maximumSize() const { return Layout::maximumSize(); } QSizeF BoxLayout::minimumSize() const { return d->calculateSize(Private::MinSize); } QSizeF BoxLayout::sizeHint() const { return d->calculateSize(Private::HintSize); } HBoxLayout::HBoxLayout(LayoutItem *parent) : BoxLayout(LeftToRight,parent) { } VBoxLayout::VBoxLayout(LayoutItem *parent) : BoxLayout(TopToBottom,parent) { } } // Plasma namespace