Profile: add white outline to all text

To draw the white outline around profile text we trace a text path
using QPainterPath::addText() and then create a couple of
QGraphicsPathItem objects. One of the objects is outlined using
QPainterPathStroker and is placed at the bottom of a QGraphicsItemGroup
with a white brush. The other object holds the standard colored text
and is placed on top.

Notes:
- possibly quite expensive on older machines
- ProfileGraphicsView::plot_text() now returns a QGraphicsItemGroup
- QGraphicsSimpleTextItem uses a top-left baseline anchor
while QPainterPath::addText() uses a bottom-left baseline
which is a bit mysterious, requires the -3 offset for a match
and is possibly non-portable across fonts and sizes.

Signed-off-by: Lubomir I. Ivanov <neolit123@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
This commit is contained in:
Lubomir I. Ivanov 2013-07-01 15:21:01 +03:00 committed by Dirk Hohndel
parent 9d9d516c26
commit b68e86a141
2 changed files with 23 additions and 10 deletions

View file

@ -1061,23 +1061,36 @@ void ProfileGraphicsView::plot_depth_profile()
}
}
QGraphicsSimpleTextItem *ProfileGraphicsView::plot_text(text_render_options_t *tro,const QPointF& pos, const QString& text, QGraphicsItem *parent)
QGraphicsItemGroup *ProfileGraphicsView::plot_text(text_render_options_t *tro,const QPointF& pos, const QString& text, QGraphicsItem *parent)
{
QFontMetrics fm(font());
QFont fnt(font());
QFontMetrics fm(fnt);
QPointF point(SCALEGC(pos.x(), pos.y())); // This is neded because of the SCALE macro.
double dx = tro->hpos * (fm.width(text));
double dy = tro->vpos * (fm.height());
QGraphicsSimpleTextItem *item = new QGraphicsSimpleTextItem(text, parent);
QPointF point(SCALEGC(pos.x(), pos.y())); // This is neded because of the SCALE macro.
QGraphicsItemGroup *group = new QGraphicsItemGroup(parent);
QPainterPath textPath;
/* addText() uses bottom-left text baseline and the -3 offset is probably slightly off
* for different font sizes. */
textPath.addText(0, fm.height() - 3, fnt, text);
QPainterPathStroker stroker;
stroker.setWidth(3);
QGraphicsPathItem *strokedItem = new QGraphicsPathItem(stroker.createStroke(textPath), group);
strokedItem->setBrush(QBrush(profile_color[TEXT_BACKGROUND].first()));
strokedItem->setPen(Qt::NoPen);
item->setPos(point.x() + dx, point.y() + dy);
item->setBrush(QBrush(profile_color[tro->color].first()));
item->setFlag(QGraphicsItem::ItemIgnoresTransformations);
QGraphicsPathItem *textItem = new QGraphicsPathItem(textPath, group);
textItem->setBrush(QBrush(profile_color[tro->color].first()));
textItem->setPen(Qt::NoPen);
group->setPos(point.x() + dx, point.y() + dy);
group->setFlag(QGraphicsItem::ItemIgnoresTransformations);
if (!parent)
scene()->addItem(item);
return item;
scene()->addItem(group);
return group;
}
void ProfileGraphicsView::resizeEvent(QResizeEvent *event)

View file

@ -104,7 +104,7 @@ public slots:
private:
void plot_depth_profile();
QGraphicsSimpleTextItem* plot_text(text_render_options_t *tro, const QPointF& pos, const QString &text, QGraphicsItem *parent = 0);
QGraphicsItemGroup *plot_text(text_render_options_t *tro, const QPointF& pos, const QString &text, QGraphicsItem *parent = 0);
void plot_events(struct divecomputer *dc);
void plot_one_event(struct event *event);
void plot_temperature_profile();