[composer] Set base stylesheet of composer labels to match the

label font and margins when rendering as HTML.

This allows interactive choice of font, margins and colors and
avoids the need to manually set these with CSS within the
label HTML code.

Author: nyalldawson

ci/travis/linux/qt5/blacklist.txt

@@ -74,6 +74,7 @@ PyQgsZonalStatistics
 qgis_alignrastertest
 qgis_atlascompositiontest
 qgis_composereffectstest
+qgis_composerlabeltest
 qgis_composermapgridtest
 qgis_composermapoverviewtest
 qgis_composermaptest

src/app/composer/qgscomposerlabelwidget.cpp

@@ -50,18 +50,10 @@ void QgsComposerLabelWidget::on_mHtmlCheckBox_stateChanged( int state )
 {
   if ( mComposerLabel )
   {
-    if ( state )
-    {
-      mFontButton->setEnabled( false );
-      mFontColorButton->setEnabled( false );
-      mAppearanceGroup->setEnabled( false );
-    }
-    else
-    {
-      mFontButton->setEnabled( true );
-      mFontColorButton->setEnabled( true );
-      mAppearanceGroup->setEnabled( true );
-    }
+    mVerticalAlignementLabel->setDisabled( state );
+    mTopRadioButton->setDisabled( state );
+    mMiddleRadioButton->setDisabled( state );
+    mBottomRadioButton->setDisabled( state );
 
     mComposerLabel->beginCommand( tr( "Label text HTML state changed" ), QgsComposerMergeCommand::ComposerLabelSetText );
     mComposerLabel->blockSignals( true );
@@ -249,6 +241,13 @@ void QgsComposerLabelWidget::setGuiElementValues()
   mCenterRadioButton->setChecked( mComposerLabel->hAlign() == Qt::AlignHCenter );
   mRightRadioButton->setChecked( mComposerLabel->hAlign() == Qt::AlignRight );
   mFontColorButton->setColor( mComposerLabel->fontColor() );
+
+
+  mVerticalAlignementLabel->setDisabled( mComposerLabel->htmlState() );
+  mTopRadioButton->setDisabled( mComposerLabel->htmlState() );
+  mMiddleRadioButton->setDisabled( mComposerLabel->htmlState() );
+  mBottomRadioButton->setDisabled( mComposerLabel->htmlState() );
+
   blockAllSignals( false );
 }
 

src/core/composer/qgscomposerlabel.cpp

@@ -133,6 +133,7 @@ void QgsComposerLabel::paint( QPainter* painter, const QStyleOptionGraphicsItem*
     webPage->mainFrame()->setZoomFactor( 10.0 );
     webPage->mainFrame()->setScrollBarPolicy( Qt::Horizontal, Qt::ScrollBarAlwaysOff );
     webPage->mainFrame()->setScrollBarPolicy( Qt::Vertical, Qt::ScrollBarAlwaysOff );
+    webPage->settings()->setUserStyleSheetUrl( createStylesheetUrl() );
 
     // QGIS segfaults when rendering web page while in composer if html
     // contains images. So if we are not printing the composition, then
@@ -633,3 +634,18 @@ void QgsComposerLabel::itemShiftAdjustSize( double newWidth, double newHeight, d
     }
   }
 }
+
+QUrl QgsComposerLabel::createStylesheetUrl() const
+{
+  QString stylesheet;
+  stylesheet += QString( "body { margin: %1 %2;" ).arg( qMax( mMarginX * mHtmlUnitsToMM, 0.0 ) ).arg( qMax( mMarginY * mHtmlUnitsToMM, 0.0 ) );
+  stylesheet += QgsFontUtils::asCSS( mFont, 0.352778 * mHtmlUnitsToMM );
+  stylesheet += QString( "color: %1;" ).arg( mFontColor.name() );
+  stylesheet += QString( "text-align: %1; }" ).arg( mHAlignment == Qt::AlignLeft ? "left" : mHAlignment == Qt::AlignRight ? "right" : "center" );
+
+  QByteArray ba;
+  ba.append( stylesheet.toUtf8() );
+  QUrl cssFileURL = QUrl( "data:text/css;charset=utf-8;base64," + ba.toBase64() );
+
+  return cssFileURL;
+}

src/core/composer/qgscomposerlabel.h

@@ -204,10 +204,14 @@ class CORE_EXPORT QgsComposerLabel: public QgsComposerItem
     /** Replaces replace '$CURRENT_DATE<(FORMAT)>' with the current date (e.g. $CURRENT_DATE(d 'June' yyyy)*/
     void replaceDateText( QString& text ) const;
 
+    //! Creates an encoded stylesheet url using the current font and label appearance settings
+    QUrl createStylesheetUrl() const;
+
     QScopedPointer<QgsFeature> mExpressionFeature;
     QgsVectorLayer* mExpressionLayer;
     QMap<QString, QVariant> mSubstitutions;
     QgsDistanceArea* mDistanceArea;
+
 };
 
 #endif

tests/src/core/testqgscomposerlabel.cpp

@@ -22,6 +22,8 @@
 #include "qgsmaprenderer.h"
 #include "qgsvectorlayer.h"
 #include "qgsvectordataprovider.h"
+#include "qgsmultirenderchecker.h"
+#include "qgsfontutils.h"
 
 #include <QObject>
 #include <QtTest/QtTest>
@@ -50,14 +52,16 @@ class TestQgsComposerLabel : public QObject
     void feature_evaluation();
     // test page expressions
     void page_evaluation();
-
     void marginMethods(); //tests getting/setting margins
+    void render();
+    void renderAsHtml();
 
   private:
     QgsComposition* mComposition;
     QgsComposerLabel* mComposerLabel;
     QgsMapSettings *mMapSettings;
     QgsVectorLayer* mVectorLayer;
+    QString mReport;
 };
 
 void TestQgsComposerLabel::initTestCase()
@@ -89,6 +93,15 @@ void TestQgsComposerLabel::initTestCase()
 
 void TestQgsComposerLabel::cleanupTestCase()
 {
+  QString myReportFile = QDir::tempPath() + "/qgistest.html";
+  QFile myFile( myReportFile );
+  if ( myFile.open( QIODevice::WriteOnly | QIODevice::Append ) )
+  {
+    QTextStream myQTextStream( &myFile );
+    myQTextStream << mReport;
+    myFile.close();
+  }
+
   delete mComposition;
   delete mMapSettings;
 
@@ -225,5 +238,32 @@ void TestQgsComposerLabel::marginMethods()
   QCOMPARE( label3.marginY(), 12.0 );
 }
 
+void TestQgsComposerLabel::render()
+{
+  mComposerLabel->setText( "test label" );
+  mComposerLabel->setFont( QgsFontUtils::getStandardTestFont( "Bold", 48 ) );
+  mComposerLabel->setPos( 70, 70 );
+  mComposerLabel->adjustSizeToText();
+
+  QgsCompositionChecker checker( "composerlabel_render", mComposition );
+  checker.setControlPathPrefix( "composer_label" );
+  QVERIFY( checker.testComposition( mReport, 0, 0 ) );
+}
+
+void TestQgsComposerLabel::renderAsHtml()
+{
+  mComposerLabel->setFontColor( QColor( 200, 40, 60 ) );
+  mComposerLabel->setText( "test <i>html</i>" );
+  mComposerLabel->setFont( QgsFontUtils::getStandardTestFont( "Bold", 48 ) );
+  mComposerLabel->setPos( 70, 70 );
+  mComposerLabel->adjustSizeToText();
+  mComposerLabel->setHtmlState( 1 );
+  mComposerLabel->update();
+
+  QgsCompositionChecker checker( "composerlabel_renderhtml", mComposition );
+  checker.setControlPathPrefix( "composer_label" );
+  QVERIFY( checker.testComposition( mReport, 0, 0 ) );
+}
+
 QTEST_MAIN( TestQgsComposerLabel )
 #include "testqgscomposerlabel.moc"