@PauloCarvalhoRJ Dear Paulo,
I am facing a very similar issue. I do not have that many charts to draw, yet too many labels on a Y axis. The QChart are so badly shaped, that it seems it is impossible to easily fix it. A first option, is to change the pixel size of the font used to draw the labels in the resize event.
void yourCharView::resizeEvent(QResizeEvent *event)
{
if(series.size() > 0) {
QFont font = this->axis_y_stack->labelsFont();
int pixel_size = event->size().height() / series.size() / 3;
font.setPixelSize(pixel_size);
this->axis_y->setLabelsFont(font);
}
QChartView::resizeEvent(event);
}
(this->y_axis beeing your y axis)
But it might prove insufficient, as in my case.
Labels are truncated in verticalaxis.cpp (for the vertical axes) :
QRectF boundingRect;
// don't truncate empty labels
if (text.isEmpty()) {
labelItem->setHtml(text);
} else {
qreal labelHeight = (axisRect.height() / layout.count()) - (2 * labelPadding());
QString truncatedText = ChartPresenter::truncatedText(axis()->labelsFont(), text,
axis()->labelsAngle(),
availableSpace,
labelHeight, boundingRect);
labelItem->setTextWidth(ChartPresenter::textBoundingRect(axis()->labelsFont(),
truncatedText).width());
labelItem->setHtml(truncatedText);
}
The truncation code lies here :
QString ChartPresenter::truncatedText(const QFont &font, const QString &text, qreal angle,
qreal maxWidth, qreal maxHeight, QRectF &boundingRect)
{
QString truncatedString(text);
boundingRect = textBoundingRect(font, truncatedString, angle);
if (boundingRect.width() > maxWidth || boundingRect.height() > maxHeight) {
// It can be assumed that almost any amount of string manipulation is faster
// than calculating one bounding rectangle, so first prepare a list of truncated strings
// to try.
static QRegularExpression truncateMatcher(QStringLiteral("&#?[0-9a-zA-Z]*;$"));
........
static QLatin1String ellipsis("...");
........
// Default to "..." if nothing fits
if (bestIndex == count) {
boundingRect = textBoundingRect(font, ellipsis, angle);
truncatedString = ellipsis;
} else {
truncatedString = testStrings.at(bestIndex);
}
}
return truncatedString;
}
I can't think of any way to interfere with this and avoid turning my nice labels into three dots...
Any input from anyone else ? We can't even change the labelPadding() !!!!
inline qreal labelPadding() const { return qreal(4.0); }
=> I will hide the presenter labels and draw the labels myself, overriding the paintEvent.
Cheers
Côme
