QgsLayoutItemLabel::QgsLayoutItemLabel( QgsLayout *layout )
: QgsLayoutItem( layout )
{
mDistanceArea.reset( new QgsDistanceArea() );
mHtmlUnitsToLayoutUnits = htmlUnitsToLayoutUnits();
//get default layout font from settings
QgsSettings settings;
QString defaultFontString = settings.value( QStringLiteral( "LayoutDesigner/defaultFont" ), QVariant(), QgsSettings::Gui ).toString();
if ( !defaultFontString.isEmpty() )
{
mFont.setFamily( defaultFontString );
}
//default to a 10 point font size
mFont.setPointSizeF( 10 );
//default to no background
setBackgroundEnabled( false );
//a label added while atlas preview is enabled needs to have the expression context set,
//otherwise fields in the label aren't correctly evaluated until atlas preview feature changes (#9457)
refreshExpressionContext();
mWebPage.reset( new QgsWebPage( this ) );
mWebPage->setIdentifier( tr( "Layout label item" ) );
mWebPage->setNetworkAccessManager( QgsNetworkAccessManager::instance() );
//This makes the background transparent. Found on http://blog.qt.digia.com/blog/2009/06/30/transparent-qwebview-or-qwebpage/
QPalette palette = mWebPage->palette();
palette.setBrush( QPalette::Base, Qt::transparent );
mWebPage->setPalette( palette );
mWebPage->mainFrame()->setZoomFactor( 10.0 );
mWebPage->mainFrame()->setScrollBarPolicy( Qt::Horizontal, Qt::ScrollBarAlwaysOff );
mWebPage->mainFrame()->setScrollBarPolicy( Qt::Vertical, Qt::ScrollBarAlwaysOff );
connect( mWebPage.get(), &QWebPage::loadFinished, this, &QgsLayoutItemLabel::loadingHtmlFinished );
}
QgsLayoutItemHtml::QgsLayoutItemHtml( QgsLayout *layout )
: QgsLayoutMultiFrame( layout )
{
mHtmlUnitsToLayoutUnits = htmlUnitsToLayoutUnits();
mWebPage = qgis::make_unique< QgsWebPage >();
mWebPage->setIdentifier( tr( "Layout HTML item" ) );
mWebPage->mainFrame()->setScrollBarPolicy( Qt::Horizontal, Qt::ScrollBarAlwaysOff );
mWebPage->mainFrame()->setScrollBarPolicy( Qt::Vertical, Qt::ScrollBarAlwaysOff );
//This makes the background transparent. Found on http://blog.qt.digia.com/blog/2009/06/30/transparent-qwebview-or-qwebpage/
QPalette palette = mWebPage->palette();
palette.setBrush( QPalette::Base, Qt::transparent );
mWebPage->setPalette( palette );
mWebPage->setNetworkAccessManager( QgsNetworkAccessManager::instance() );
#if 0 //TODO
if ( mLayout )
{
connect( mLayout, &QgsComposition::itemRemoved, this, &QgsComposerMultiFrame::handleFrameRemoval );
}
if ( mComposition && mComposition->atlasMode() == QgsComposition::PreviewAtlas )
{
//a html item added while atlas preview is enabled needs to have the expression context set,
//otherwise fields in the html aren't correctly evaluated until atlas preview feature changes (#9457)
setExpressionContext( mComposition->atlasComposition().feature(), mComposition->atlasComposition().coverageLayer() );
}
//connect to atlas feature changes
//to update the expression context
connect( &mComposition->atlasComposition(), &QgsAtlasComposition::featureChanged, this, &QgsLayoutItemHtml::refreshExpressionContext );
#endif
mFetcher = new QgsNetworkContentFetcher();
}
double QgsLayoutItemHtml::findNearbyPageBreak( double yPos )
{
if ( !mWebPage || mRenderedPage.isNull() || !mUseSmartBreaks )
{
return yPos;
}
//convert yPos to pixels
int idealPos = yPos * htmlUnitsToLayoutUnits();
//if ideal break pos is past end of page, there's nothing we need to do
if ( idealPos >= mRenderedPage.height() )
{
return yPos;
}
int maxSearchDistance = mMaxBreakDistance * htmlUnitsToLayoutUnits();
//loop through all lines just before ideal break location, up to max distance
//of maxSearchDistance
int changes = 0;
QRgb currentColor;
bool currentPixelTransparent = false;
bool previousPixelTransparent = false;
QRgb pixelColor;
QList< QPair<int, int> > candidates;
int minRow = std::max( idealPos - maxSearchDistance, 0 );
for ( int candidateRow = idealPos; candidateRow >= minRow; --candidateRow )
{
changes = 0;
currentColor = qRgba( 0, 0, 0, 0 );
//check all pixels in this line
for ( int col = 0; col < mRenderedPage.width(); ++col )
{
//count how many times the pixels change color in this row
//eventually, we select a row to break at with the minimum number of color changes
//since this is likely a line break, or gap between table cells, etc
//but very unlikely to be midway through a text line or picture
pixelColor = mRenderedPage.pixel( col, candidateRow );
currentPixelTransparent = qAlpha( pixelColor ) == 0;
if ( pixelColor != currentColor && !( currentPixelTransparent && previousPixelTransparent ) )
{
//color has changed
currentColor = pixelColor;
changes++;
}
previousPixelTransparent = currentPixelTransparent;
}
candidates.append( qMakePair( candidateRow, changes ) );
}
//sort candidate rows by number of changes ascending, row number descending
std::sort( candidates.begin(), candidates.end(), candidateSort );
//first candidate is now the largest row with smallest number of changes
//OK, now take the mid point of the best candidate position
//we do this so that the spacing between text lines is likely to be split in half
//otherwise the html will be broken immediately above a line of text, which
//looks a little messy
int maxCandidateRow = candidates[0].first;
int minCandidateRow = maxCandidateRow + 1;
int minCandidateChanges = candidates[0].second;
QList< QPair<int, int> >::iterator it;
for ( it = candidates.begin(); it != candidates.end(); ++it )
{
if ( ( *it ).second != minCandidateChanges || ( *it ).first != minCandidateRow - 1 )
{
//no longer in a consecutive block of rows of minimum pixel color changes
//so return the row mid-way through the block
//first converting back to mm
return ( minCandidateRow + ( maxCandidateRow - minCandidateRow ) / 2 ) / htmlUnitsToLayoutUnits();
}
minCandidateRow = ( *it ).first;
}
//above loop didn't work for some reason
//return first candidate converted to mm
return candidates[0].first / htmlUnitsToLayoutUnits();
}
