NOISSUE move everything.

application/groupview/GroupView.h

@@ -0,0 +1,125 @@
+#pragma once
+
+#include <QListView>
+#include <QLineEdit>
+#include <QScrollBar>
+#include <QCache>
+
+struct GroupViewRoles
+{
+	enum
+	{
+		GroupRole = Qt::UserRole,
+		ProgressValueRole,
+		ProgressMaximumRole
+	};
+};
+
+struct VisualGroup;
+
+class GroupView : public QAbstractItemView
+{
+	Q_OBJECT
+
+public:
+	GroupView(QWidget *parent = 0);
+	~GroupView();
+
+	void setModel(QAbstractItemModel *model) override;
+
+	/// return geometry rectangle occupied by the specified model item
+	QRect geometryRect(const QModelIndex &index) const;
+	/// return visual rectangle occupied by the specified model item
+	virtual QRect visualRect(const QModelIndex &index) const override;
+	/// get the model index at the specified visual point
+	virtual QModelIndex indexAt(const QPoint &point) const override;
+	void setSelection(const QRect &rect,
+					  const QItemSelectionModel::SelectionFlags commands) override;
+
+	virtual int horizontalOffset() const override;
+	virtual int verticalOffset() const override;
+	virtual void scrollContentsBy(int dx, int dy) override;
+	virtual void scrollTo(const QModelIndex &index, ScrollHint hint = EnsureVisible) override;
+
+	virtual QModelIndex moveCursor(CursorAction cursorAction,
+								   Qt::KeyboardModifiers modifiers) override;
+
+	virtual QRegion visualRegionForSelection(const QItemSelection &selection) const override;
+
+	int spacing() const
+	{
+		return m_spacing;
+	};
+protected
+slots:
+	virtual void dataChanged(const QModelIndex &topLeft, const QModelIndex &bottomRight,
+							 const QVector<int> &roles) override;
+	virtual void rowsInserted(const QModelIndex &parent, int start, int end) override;
+	virtual void rowsAboutToBeRemoved(const QModelIndex &parent, int start, int end) override;
+	virtual void updateGeometries() override;
+	void modelReset();
+
+protected:
+	virtual bool isIndexHidden(const QModelIndex &index) const override;
+	void mousePressEvent(QMouseEvent *event) override;
+	void mouseMoveEvent(QMouseEvent *event) override;
+	void mouseReleaseEvent(QMouseEvent *event) override;
+	void mouseDoubleClickEvent(QMouseEvent *event) override;
+	void paintEvent(QPaintEvent *event) override;
+	void resizeEvent(QResizeEvent *event) override;
+
+	void dragEnterEvent(QDragEnterEvent *event) override;
+	void dragMoveEvent(QDragMoveEvent *event) override;
+	void dragLeaveEvent(QDragLeaveEvent *event) override;
+	void dropEvent(QDropEvent *event) override;
+
+	void startDrag(Qt::DropActions supportedActions) override;
+
+private:
+	friend struct VisualGroup;
+	QList<VisualGroup *> m_groups;
+
+	// geometry
+	int m_leftMargin = 5;
+	int m_rightMargin = 5;
+	int m_bottomMargin = 5;
+	int m_categoryMargin = 5;
+	int m_spacing = 5;
+	int m_itemWidth = 100;
+	int m_currentItemsPerRow = -1;
+	int m_currentCursorColumn= -1;
+	mutable QCache<int, QRect> geometryCache;
+
+	// point where the currently active mouse action started in geometry coordinates
+	QPoint m_pressedPosition;
+	QPersistentModelIndex m_pressedIndex;
+	bool m_pressedAlreadySelected;
+	VisualGroup *m_pressedCategory;
+	QItemSelectionModel::SelectionFlag m_ctrlDragSelectionFlag;
+	QPoint m_lastDragPosition;
+
+	VisualGroup *category(const QModelIndex &index) const;
+	VisualGroup *category(const QString &cat) const;
+	VisualGroup *categoryAt(const QPoint &pos) const;
+
+	int itemsPerRow() const
+	{
+		return m_currentItemsPerRow;
+	};
+	int contentWidth() const;
+
+private: /* methods */
+	int itemWidth() const;
+	int calculateItemsPerRow() const;
+	int verticalScrollToValue(const QModelIndex &index, const QRect &rect,
+							  QListView::ScrollHint hint) const;
+	QPixmap renderToPixmap(const QModelIndexList &indices, QRect *r) const;
+	QList<QPair<QRect, QModelIndex>> draggablePaintPairs(const QModelIndexList &indices,
+														 QRect *r) const;
+
+	bool isDragEventAccepted(QDropEvent *event);
+
+	QPair<VisualGroup *, int> rowDropPos(const QPoint &pos);
+
+	QPoint offset() const;
+};

application/groupview/GroupedProxyModel.cpp

@@ -0,0 +1,42 @@
+#include "GroupedProxyModel.h"
+
+#include "GroupView.h"
+#include <QDebug>
+
+GroupedProxyModel::GroupedProxyModel(QObject *parent) : QSortFilterProxyModel(parent)
+{
+}
+
+bool GroupedProxyModel::lessThan(const QModelIndex &left, const QModelIndex &right) const
+{
+	const QString leftCategory = left.data(GroupViewRoles::GroupRole).toString();
+	const QString rightCategory = right.data(GroupViewRoles::GroupRole).toString();
+	if (leftCategory == rightCategory)
+	{
+		return subSortLessThan(left, right);
+	}
+	else
+	{
+		// FIXME: real group sorting happens in GroupView::updateGeometries(), see LocaleString
+		auto result = leftCategory.localeAwareCompare(rightCategory);
+		if(result < 0)
+		{
+			qDebug() << leftCategory << "<" << rightCategory;
+		}
+		if(result == 0)
+		{
+			qDebug() << leftCategory << "=" << rightCategory;
+			return subSortLessThan(left, right);
+		}
+		if(result > 0)
+		{
+			qDebug() << leftCategory << ">" << rightCategory;
+		}
+		return result < 0;
+	}
+}
+
+bool GroupedProxyModel::subSortLessThan(const QModelIndex &left, const QModelIndex &right) const
+{
+	return left.row() < right.row();
+}

application/groupview/GroupedProxyModel.h

@@ -0,0 +1,15 @@
+#pragma once
+
+#include <QSortFilterProxyModel>
+
+class GroupedProxyModel : public QSortFilterProxyModel
+{
+	Q_OBJECT
+
+public:
+	GroupedProxyModel(QObject *parent = 0);
+
+protected:
+	virtual bool lessThan(const QModelIndex &left, const QModelIndex &right) const override;
+	virtual bool subSortLessThan(const QModelIndex &left, const QModelIndex &right) const;
+};

application/groupview/InstanceDelegate.cpp

@@ -0,0 +1,362 @@
+/* Copyright 2013-2015 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "InstanceDelegate.h"
+#include <QPainter>
+#include <QTextOption>
+#include <QTextLayout>
+#include <QApplication>
+#include <QtMath>
+
+#include "GroupView.h"
+#include "BaseInstance.h"
+#include "InstanceList.h"
+
+QCache<QString, QPixmap> ListViewDelegate::m_pixmapCache;
+
+// Origin: Qt
+static void viewItemTextLayout(QTextLayout &textLayout, int lineWidth, qreal &height,
+							   qreal &widthUsed)
+{
+	height = 0;
+	widthUsed = 0;
+	textLayout.beginLayout();
+	QString str = textLayout.text();
+	while (true)
+	{
+		QTextLine line = textLayout.createLine();
+		if (!line.isValid())
+			break;
+		if (line.textLength() == 0)
+			break;
+		line.setLineWidth(lineWidth);
+		line.setPosition(QPointF(0, height));
+		height += line.height();
+		widthUsed = qMax(widthUsed, line.naturalTextWidth());
+	}
+	textLayout.endLayout();
+}
+
+ListViewDelegate::ListViewDelegate(QObject *parent) : QStyledItemDelegate(parent)
+{
+}
+
+void drawSelectionRect(QPainter *painter, const QStyleOptionViewItemV4 &option,
+					   const QRect &rect)
+{
+	if ((option.state & QStyle::State_Selected))
+		painter->fillRect(rect, option.palette.brush(QPalette::Highlight));
+	else
+	{
+		QColor backgroundColor = option.palette.color(QPalette::Background);
+		backgroundColor.setAlpha(160);
+		painter->fillRect(rect, QBrush(backgroundColor));
+	}
+}
+
+void drawFocusRect(QPainter *painter, const QStyleOptionViewItemV4 &option, const QRect &rect)
+{
+	if (!(option.state & QStyle::State_HasFocus))
+		return;
+	QStyleOptionFocusRect opt;
+	opt.direction = option.direction;
+	opt.fontMetrics = option.fontMetrics;
+	opt.palette = option.palette;
+	opt.rect = rect;
+	// opt.state           = option.state | QStyle::State_KeyboardFocusChange |
+	// QStyle::State_Item;
+	auto col = option.state & QStyle::State_Selected ? QPalette::Highlight : QPalette::Base;
+	opt.backgroundColor = option.palette.color(col);
+	// Apparently some widget styles expect this hint to not be set
+	painter->setRenderHint(QPainter::Antialiasing, false);
+
+	QStyle *style = option.widget ? option.widget->style() : QApplication::style();
+
+	style->drawPrimitive(QStyle::PE_FrameFocusRect, &opt, painter, option.widget);
+
+	painter->setRenderHint(QPainter::Antialiasing);
+}
+
+// TODO this can be made a lot prettier
+void drawProgressOverlay(QPainter *painter, const QStyleOptionViewItemV4 &option,
+						 const int value, const int maximum)
+{
+	if (maximum == 0 || value == maximum)
+	{
+		return;
+	}
+
+	painter->save();
+
+	qreal percent = (qreal)value / (qreal)maximum;
+	QColor color = option.palette.color(QPalette::Dark);
+	color.setAlphaF(0.70f);
+	painter->setBrush(color);
+	painter->setPen(QPen(QBrush(), 0));
+	painter->drawPie(option.rect, 90 * 16, -percent * 360 * 16);
+
+	painter->restore();
+}
+
+void drawBadges(QPainter *painter, const QStyleOptionViewItemV4 &option, BaseInstance *instance)
+{
+	QList<QString> pixmaps;
+	const BaseInstance::InstanceFlags flags = instance->flags();
+	if (flags & BaseInstance::VersionBrokenFlag)
+	{
+		pixmaps.append("broken");
+	}
+	if (flags & BaseInstance::UpdateAvailable)
+	{
+		pixmaps.append("updateavailable");
+	}
+
+	// begin easter eggs
+	if (instance->name().contains("btw", Qt::CaseInsensitive) ||
+		instance->name().contains("better then wolves", Qt::CaseInsensitive) ||
+		instance->name().contains("better than wolves", Qt::CaseInsensitive))
+	{
+		pixmaps.append("herobrine");
+	}
+	if (instance->name().contains("direwolf", Qt::CaseInsensitive))
+	{
+		pixmaps.append("enderman");
+	}
+	if (instance->name().contains("kitten", Qt::CaseInsensitive))
+	{
+		pixmaps.append("kitten");
+	}
+	if (instance->name().contains("derp", Qt::CaseInsensitive))
+	{
+		pixmaps.append("derp");
+	}
+	// end easter eggs
+
+	static const int itemSide = 24;
+	static const int spacing = 1;
+	const int itemsPerRow = qMax(1, qFloor(double(option.rect.width() + spacing) / double(itemSide + spacing)));
+	const int rows = qCeil((double)pixmaps.size() / (double)itemsPerRow);
+	QListIterator<QString> it(pixmaps);
+	painter->translate(option.rect.topLeft());
+	for (int y = 0; y < rows; ++y)
+	{
+		for (int x = 0; x < itemsPerRow; ++x)
+		{
+			if (!it.hasNext())
+			{
+				return;
+			}
+			const QPixmap pixmap = ListViewDelegate::requestBadgePixmap(it.next()).scaled(
+				itemSide, itemSide, Qt::KeepAspectRatio, Qt::FastTransformation);
+			painter->drawPixmap(option.rect.width() - x * itemSide + qMax(x - 1, 0) * spacing - itemSide,
+								y * itemSide + qMax(y - 1, 0) * spacing, itemSide, itemSide,
+								pixmap);
+		}
+	}
+	painter->translate(-option.rect.topLeft());
+}
+
+static QSize viewItemTextSize(const QStyleOptionViewItemV4 *option)
+{
+	QStyle *style = option->widget ? option->widget->style() : QApplication::style();
+	QTextOption textOption;
+	textOption.setWrapMode(QTextOption::WrapAtWordBoundaryOrAnywhere);
+	QTextLayout textLayout;
+	textLayout.setTextOption(textOption);
+	textLayout.setFont(option->font);
+	textLayout.setText(option->text);
+	const int textMargin =
+		style->pixelMetric(QStyle::PM_FocusFrameHMargin, option, option->widget) + 1;
+	QRect bounds(0, 0, 100 - 2 * textMargin, 600);
+	qreal height = 0, widthUsed = 0;
+	viewItemTextLayout(textLayout, bounds.width(), height, widthUsed);
+	const QSize size(qCeil(widthUsed), qCeil(height));
+	return QSize(size.width() + 2 * textMargin, size.height());
+}
+
+void ListViewDelegate::paint(QPainter *painter, const QStyleOptionViewItem &option,
+							 const QModelIndex &index) const
+{
+	QStyleOptionViewItemV4 opt = option;
+	initStyleOption(&opt, index);
+	painter->save();
+	painter->setClipRect(opt.rect);
+
+	opt.features |= QStyleOptionViewItem::WrapText;
+	opt.text = index.data().toString();
+	opt.textElideMode = Qt::ElideRight;
+	opt.displayAlignment = Qt::AlignTop | Qt::AlignHCenter;
+
+	QStyle *style = opt.widget ? opt.widget->style() : QApplication::style();
+
+	// const int iconSize =  style->pixelMetric(QStyle::PM_IconViewIconSize);
+	const int iconSize = 48;
+	QRect iconbox = opt.rect;
+	const int textMargin = style->pixelMetric(QStyle::PM_FocusFrameHMargin, 0, opt.widget) + 1;
+	QRect textRect = opt.rect;
+	QRect textHighlightRect = textRect;
+	// clip the decoration on top, remove width padding
+	textRect.adjust(textMargin, iconSize + textMargin + 5, -textMargin, 0);
+
+	textHighlightRect.adjust(0, iconSize + 5, 0, 0);
+
+	// draw background
+	{
+		// FIXME: unused
+		// QSize textSize = viewItemTextSize ( &opt );
+		QPalette::ColorGroup cg;
+		QStyleOptionViewItemV4 opt2(opt);
+
+		if ((opt.widget && opt.widget->isEnabled()) || (opt.state & QStyle::State_Enabled))
+		{
+			if (!(opt.state & QStyle::State_Active))
+				cg = QPalette::Inactive;
+			else
+				cg = QPalette::Normal;
+		}
+		else
+		{
+			cg = QPalette::Disabled;
+		}
+		opt2.palette.setCurrentColorGroup(cg);
+
+		// fill in background, if any
+
+		if (opt.backgroundBrush.style() != Qt::NoBrush)
+		{
+			QPointF oldBO = painter->brushOrigin();
+			painter->setBrushOrigin(opt.rect.topLeft());
+			painter->fillRect(opt.rect, opt.backgroundBrush);
+			painter->setBrushOrigin(oldBO);
+		}
+
+		drawSelectionRect(painter, opt2, textHighlightRect);
+
+		/*
+		if (opt.showDecorationSelected)
+		{
+			drawSelectionRect(painter, opt2, opt.rect);
+			drawFocusRect(painter, opt2, opt.rect);
+			// painter->fillRect ( opt.rect, opt.palette.brush ( cg, QPalette::Highlight ) );
+		}
+		else
+		{
+
+			// if ( opt.state & QStyle::State_Selected )
+			{
+				// QRect textRect = subElementRect ( QStyle::SE_ItemViewItemText,  opt,
+				// opt.widget );
+				// painter->fillRect ( textHighlightRect, opt.palette.brush ( cg,
+				// QPalette::Highlight ) );
+				drawSelectionRect(painter, opt2, textHighlightRect);
+				drawFocusRect(painter, opt2, textHighlightRect);
+			}
+		}
+		*/
+	}
+
+	// draw the icon
+	{
+		QIcon::Mode mode = QIcon::Normal;
+		if (!(opt.state & QStyle::State_Enabled))
+			mode = QIcon::Disabled;
+		else if (opt.state & QStyle::State_Selected)
+			mode = QIcon::Selected;
+		QIcon::State state = opt.state & QStyle::State_Open ? QIcon::On : QIcon::Off;
+
+		iconbox.setHeight(iconSize);
+		opt.icon.paint(painter, iconbox, Qt::AlignCenter, mode, state);
+	}
+	// set the text colors
+	QPalette::ColorGroup cg =
+		opt.state & QStyle::State_Enabled ? QPalette::Normal : QPalette::Disabled;
+	if (cg == QPalette::Normal && !(opt.state & QStyle::State_Active))
+		cg = QPalette::Inactive;
+	if (opt.state & QStyle::State_Selected)
+	{
+		painter->setPen(opt.palette.color(cg, QPalette::HighlightedText));
+	}
+	else
+	{
+		painter->setPen(opt.palette.color(cg, QPalette::Text));
+	}
+
+	// draw the text
+	QTextOption textOption;
+	textOption.setWrapMode(QTextOption::WrapAtWordBoundaryOrAnywhere);
+	textOption.setTextDirection(opt.direction);
+	textOption.setAlignment(QStyle::visualAlignment(opt.direction, opt.displayAlignment));
+	QTextLayout textLayout;
+	textLayout.setTextOption(textOption);
+	textLayout.setFont(opt.font);
+	textLayout.setText(opt.text);
+
+	qreal width, height;
+	viewItemTextLayout(textLayout, textRect.width(), height, width);
+
+	const int lineCount = textLayout.lineCount();
+
+	const QRect layoutRect = QStyle::alignedRect(
+		opt.direction, opt.displayAlignment, QSize(textRect.width(), int(height)), textRect);
+	const QPointF position = layoutRect.topLeft();
+	for (int i = 0; i < lineCount; ++i)
+	{
+		const QTextLine line = textLayout.lineAt(i);
+		line.draw(painter, position);
+	}
+
+	// FIXME: this really has no business of being here. Make generic.
+	auto instance = (BaseInstance*)index.data(InstanceList::InstancePointerRole)
+			.value<void *>();
+	if (instance)
+	{
+		drawBadges(painter, opt, instance);
+	}
+
+	drawProgressOverlay(painter, opt, index.data(GroupViewRoles::ProgressValueRole).toInt(),
+						index.data(GroupViewRoles::ProgressMaximumRole).toInt());
+
+	painter->restore();
+}
+
+QSize ListViewDelegate::sizeHint(const QStyleOptionViewItem &option,
+								 const QModelIndex &index) const
+{
+	QStyleOptionViewItemV4 opt = option;
+	initStyleOption(&opt, index);
+	opt.features |= QStyleOptionViewItem::WrapText;
+	opt.text = index.data().toString();
+	opt.textElideMode = Qt::ElideRight;
+	opt.displayAlignment = Qt::AlignTop | Qt::AlignHCenter;
+
+	QStyle *style = opt.widget ? opt.widget->style() : QApplication::style();
+	const int textMargin =
+		style->pixelMetric(QStyle::PM_FocusFrameHMargin, &option, opt.widget) + 1;
+	int height = 48 + textMargin * 2 + 5; // TODO: turn constants into variables
+	QSize szz = viewItemTextSize(&opt);
+	height += szz.height();
+	// FIXME: maybe the icon items could scale and keep proportions?
+	QSize sz(100, height);
+	return sz;
+}
+
+QPixmap ListViewDelegate::requestBadgePixmap(const QString &key)
+{
+	if (!m_pixmapCache.contains(key))
+	{
+		m_pixmapCache.insert(key, new QPixmap(":/icons/badges/" + key + ".png"));
+	}
+	return *m_pixmapCache.object(key);
+}

application/groupview/InstanceDelegate.h

@@ -0,0 +1,35 @@
+/* Copyright 2013-2015 MultiMC Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <QStyledItemDelegate>
+#include <QCache>
+
+class ListViewDelegate : public QStyledItemDelegate
+{
+public:
+	explicit ListViewDelegate(QObject *parent = 0);
+
+	static QPixmap requestBadgePixmap(const QString &key);
+
+protected:
+	void paint(QPainter *painter, const QStyleOptionViewItem &option,
+			   const QModelIndex &index) const;
+	QSize sizeHint(const QStyleOptionViewItem &option, const QModelIndex &index) const;
+
+private:
+	static QCache<QString, QPixmap> m_pixmapCache;
+};

application/groupview/VisualGroup.cpp

@@ -0,0 +1,301 @@
+#include "VisualGroup.h"
+
+#include <QModelIndex>
+#include <QPainter>
+#include <QtMath>
+#include <QApplication>
+
+#include "GroupView.h"
+
+VisualGroup::VisualGroup(const QString &text, GroupView *view) : view(view), text(text), collapsed(false)
+{
+}
+
+VisualGroup::VisualGroup(const VisualGroup *other)
+	: view(other->view), text(other->text), collapsed(other->collapsed)
+{
+}
+
+void VisualGroup::update()
+{
+	auto temp_items = items();
+	auto itemsPerRow = view->itemsPerRow();
+
+	int numRows = qMax(1, qCeil((qreal)temp_items.size() / (qreal)itemsPerRow));
+	rows = QVector<VisualRow>(numRows);
+
+	int maxRowHeight = 0;
+	int positionInRow = 0;
+	int currentRow = 0;
+	int offsetFromTop = 0;
+	for (auto item: temp_items)
+	{
+		if(positionInRow == itemsPerRow)
+		{
+			rows[currentRow].height = maxRowHeight;
+			rows[currentRow].top = offsetFromTop;
+			currentRow ++;
+			offsetFromTop += maxRowHeight + 5;
+			positionInRow = 0;
+			maxRowHeight = 0;
+		}
+		auto itemHeight = view->itemDelegate()->sizeHint(view->viewOptions(), item).height();
+		if(itemHeight > maxRowHeight)
+		{
+			maxRowHeight = itemHeight;
+		}
+		rows[currentRow].items.append(item);
+		positionInRow++;
+	}
+	rows[currentRow].height = maxRowHeight;
+	rows[currentRow].top = offsetFromTop;
+}
+
+QPair<int, int> VisualGroup::positionOf(const QModelIndex &index) const
+{
+	int x = 0;
+	int y = 0;
+	for (auto & row: rows)
+	{
+		for(auto x = 0; x < row.items.size(); x++)
+		{
+			if(row.items[x] == index)
+			{
+				return qMakePair(x,y);
+			}
+		}
+		y++;
+	}
+	return qMakePair(x, y);
+}
+
+int VisualGroup::rowTopOf(const QModelIndex &index) const
+{
+	auto position = positionOf(index);
+	return rows[position.second].top;
+}
+
+int VisualGroup::rowHeightOf(const QModelIndex &index) const
+{
+	auto position = positionOf(index);
+	return rows[position.second].height;
+}
+
+VisualGroup::HitResults VisualGroup::hitScan(const QPoint &pos) const
+{
+	VisualGroup::HitResults results = VisualGroup::NoHit;
+	int y_start = verticalPosition();
+	int body_start = y_start + headerHeight();
+	int body_end = body_start + contentHeight() + 5; // FIXME: wtf is this 5?
+	int y = pos.y();
+	// int x = pos.x();
+	if (y < y_start)
+	{
+		results = VisualGroup::NoHit;
+	}
+	else if (y < body_start)
+	{
+		results = VisualGroup::HeaderHit;
+		int collapseSize = headerHeight() - 4;
+
+		// the icon
+		QRect iconRect = QRect(view->m_leftMargin + 2, 2 + y_start, collapseSize, collapseSize);
+		if (iconRect.contains(pos))
+		{
+			results |= VisualGroup::CheckboxHit;
+		}
+	}
+	else if (y < body_end)
+	{
+		results |= VisualGroup::BodyHit;
+	}
+	return results;
+}
+
+void VisualGroup::drawHeader(QPainter *painter, const QStyleOptionViewItem &option)
+{
+	painter->setRenderHint(QPainter::Antialiasing);
+
+	const QRect optRect = option.rect;
+	QFont font(QApplication::font());
+	font.setBold(true);
+	const QFontMetrics fontMetrics = QFontMetrics(font);
+
+	QColor outlineColor = option.palette.text().color();
+	outlineColor.setAlphaF(0.35);
+
+	//BEGIN: top left corner
+	{
+		painter->save();
+		painter->setPen(outlineColor);
+		const QPointF topLeft(optRect.topLeft());
+		QRectF arc(topLeft, QSizeF(4, 4));
+		arc.translate(0.5, 0.5);
+		painter->drawArc(arc, 1440, 1440);
+		painter->restore();
+	}
+	//END: top left corner
+
+	//BEGIN: left vertical line
+	{
+		QPoint start(optRect.topLeft());
+		start.ry() += 3;
+		QPoint verticalGradBottom(optRect.topLeft());
+		verticalGradBottom.ry() += fontMetrics.height() + 5;
+		QLinearGradient gradient(start, verticalGradBottom);
+		gradient.setColorAt(0, outlineColor);
+		gradient.setColorAt(1, Qt::transparent);
+		painter->fillRect(QRect(start, QSize(1, fontMetrics.height() + 5)), gradient);
+	}
+	//END: left vertical line
+
+	//BEGIN: horizontal line
+	{
+		QPoint start(optRect.topLeft());
+		start.rx() += 3;
+		QPoint horizontalGradTop(optRect.topLeft());
+		horizontalGradTop.rx() += optRect.width() - 6;
+		painter->fillRect(QRect(start, QSize(optRect.width() - 6, 1)), outlineColor);
+	}
+	//END: horizontal line
+
+	//BEGIN: top right corner
+	{
+		painter->save();
+		painter->setPen(outlineColor);
+		QPointF topRight(optRect.topRight());
+		topRight.rx() -= 4;
+		QRectF arc(topRight, QSizeF(4, 4));
+		arc.translate(0.5, 0.5);
+		painter->drawArc(arc, 0, 1440);
+		painter->restore();
+	}
+	//END: top right corner
+
+	//BEGIN: right vertical line
+	{
+		QPoint start(optRect.topRight());
+		start.ry() += 3;
+		QPoint verticalGradBottom(optRect.topRight());
+		verticalGradBottom.ry() += fontMetrics.height() + 5;
+		QLinearGradient gradient(start, verticalGradBottom);
+		gradient.setColorAt(0, outlineColor);
+		gradient.setColorAt(1, Qt::transparent);
+		painter->fillRect(QRect(start, QSize(1, fontMetrics.height() + 5)), gradient);
+	}
+	//END: right vertical line
+
+	//BEGIN: checkboxy thing
+	{
+		painter->save();
+		painter->setRenderHint(QPainter::Antialiasing, false);
+		painter->setFont(font);
+		QColor penColor(option.palette.text().color());
+		penColor.setAlphaF(0.6);
+		painter->setPen(penColor);
+		QRect iconSubRect(option.rect);
+		iconSubRect.setTop(iconSubRect.top() + 7);
+		iconSubRect.setLeft(iconSubRect.left() + 7);
+
+		int sizing = fontMetrics.height();
+		int even = ( (sizing - 1) % 2 );
+
+		iconSubRect.setHeight(sizing - even);
+		iconSubRect.setWidth(sizing - even);
+		painter->drawRect(iconSubRect);
+
+
+		/*
+		if(collapsed)
+			painter->drawText(iconSubRect, Qt::AlignHCenter | Qt::AlignVCenter, "+");
+		else
+			painter->drawText(iconSubRect, Qt::AlignHCenter | Qt::AlignVCenter, "-");
+		*/
+		painter->setBrush(option.palette.text());
+		painter->fillRect(iconSubRect.x(), iconSubRect.y() + iconSubRect.height() / 2,
+						  iconSubRect.width(), 2, penColor);
+		if (collapsed)
+		{
+			painter->fillRect(iconSubRect.x() + iconSubRect.width() / 2, iconSubRect.y(), 2,
+							  iconSubRect.height(), penColor);
+		}
+
+		painter->restore();
+	}
+	//END: checkboxy thing
+
+	//BEGIN: text
+	{
+		QRect textRect(option.rect);
+		textRect.setTop(textRect.top() + 7);
+		textRect.setLeft(textRect.left() + 7 + fontMetrics.height() + 7);
+		textRect.setHeight(fontMetrics.height());
+		textRect.setRight(textRect.right() - 7);
+
+		painter->save();
+		painter->setFont(font);
+		QColor penColor(option.palette.text().color());
+		penColor.setAlphaF(0.6);
+		painter->setPen(penColor);
+		painter->drawText(textRect, Qt::AlignLeft | Qt::AlignVCenter, text);
+		painter->restore();
+	}
+	//END: text
+}
+
+int VisualGroup::totalHeight() const
+{
+	return headerHeight() + 5 + contentHeight(); // FIXME: wtf is that '5'?
+}
+
+int VisualGroup::headerHeight() const
+{
+	QFont font(QApplication::font());
+    font.setBold(true);
+    QFontMetrics fontMetrics(font);
+
+    const int height = fontMetrics.height() + 1 /* 1 pixel-width gradient */
+                                            + 11 /* top and bottom separation */;
+    return height;
+	/*
+	int raw = view->viewport()->fontMetrics().height() + 4;
+	// add english. maybe. depends on font height.
+	if (raw % 2 == 0)
+		raw++;
+	return std::min(raw, 25);
+	*/
+}
+
+int VisualGroup::contentHeight() const
+{
+	if (collapsed)
+	{
+		return 0;
+	}
+	auto last = rows[numRows() - 1];
+	return last.top + last.height;
+}
+
+int VisualGroup::numRows() const
+{
+	return rows.size();
+}
+
+int VisualGroup::verticalPosition() const
+{
+	return m_verticalPosition;
+}
+
+QList<QModelIndex> VisualGroup::items() const
+{
+	QList<QModelIndex> indices;
+	for (int i = 0; i < view->model()->rowCount(); ++i)
+	{
+		const QModelIndex index = view->model()->index(i, 0);
+		if (index.data(GroupViewRoles::GroupRole).toString() == text)
+		{
+			indices.append(index);
+		}
+	}
+	return indices;
+}

application/groupview/VisualGroup.h

@@ -0,0 +1,91 @@
+#pragma once
+
+#include <QString>
+#include <QRect>
+#include <QVector>
+#include <QStyleOption>
+
+class GroupView;
+class QPainter;
+class QModelIndex;
+
+struct VisualRow
+{
+	QList<QModelIndex> items;
+	int height = 0;
+	int top = 0;
+	inline int size() const
+	{
+		return items.size();
+	}
+	inline QModelIndex &operator[](int i)
+	{
+		return items[i];
+	}
+};
+
+struct VisualGroup
+{
+/* constructors */
+	VisualGroup(const QString &text, GroupView *view);
+	VisualGroup(const VisualGroup *other);
+
+/* data */
+	GroupView *view = nullptr;
+	QString text;
+	bool collapsed = false;
+	QVector<VisualRow> rows;
+	int firstItemIndex = 0;
+	int m_verticalPosition = 0;
+
+/* logic */
+	/// update the internal list of items and flow them into the rows.
+	void update();
+
+	/// draw the header at y-position.
+	void drawHeader(QPainter *painter, const QStyleOptionViewItem &option);
+
+	/// height of the group, in total. includes a small bit of padding.
+	int totalHeight() const;
+
+	/// height of the group header, in pixels
+	int headerHeight() const;
+
+	/// height of the group content, in pixels
+	int contentHeight() const;
+
+	/// the number of visual rows this group has
+	int numRows() const;
+
+	/// actually calculate the above value
+	int calculateNumRows() const;
+
+	/// the height at which this group starts, in pixels
+	int verticalPosition() const;
+
+	/// relative geometry - top of the row of the given item
+	int rowTopOf(const QModelIndex &index) const;
+
+	/// height of the row of the given item
+	int rowHeightOf(const QModelIndex &index) const;
+
+	/// x/y position of the given item inside the group (in items!)
+	QPair<int, int> positionOf(const QModelIndex &index) const;
+
+	enum HitResult
+	{
+		NoHit = 0x0,
+		TextHit = 0x1,
+		CheckboxHit = 0x2,
+		HeaderHit = 0x4,
+		BodyHit = 0x8
+	};
+	Q_DECLARE_FLAGS(HitResults, HitResult)
+
+	/// shoot! BANG! what did we hit?
+	HitResults hitScan (const QPoint &pos) const;
+
+	QList<QModelIndex> items() const;
+};
+
+Q_DECLARE_OPERATORS_FOR_FLAGS(VisualGroup::HitResults)