Allow relative links in composer labels

Now labels and HTML boxes can contain relative URLs. If we don't have
a base URL, the project file will be used as a base URL (closes #7236).

Remove the exception for the labels where the images where not
loaded (unless in in PDF or image mode). It was because of a crash. Qt didn't
like having the HTML loading to be done synchronously during painting.

Fix a leak when rendering labels.

Author: Patrick Valsecchi

src/core/composer/qgscomposerhtml.cpp

@@ -184,8 +184,11 @@ void QgsComposerHtml::loadHtml( const bool useCache, const QgsExpressionContext
   //reset page size. otherwise viewport size increases but never decreases again
   mWebPage->setViewportSize( QSize( maxFrameWidth() * mHtmlUnitsToMM, 0 ) );
 
-  //set html, using the specified url as base if in Url mode
-  mWebPage->mainFrame()->setHtml( loadedHtml, mContentMode == QgsComposerHtml::Url ? QUrl( mActualFetchedUrl ) : QUrl() );
+  //set html, using the specified url as base if in Url mode or the project file if in manual mode
+  const QUrl baseUrl = mContentMode == QgsComposerHtml::Url ?
+                       QUrl( mActualFetchedUrl ) :
+                       QUrl::fromLocalFile( QgsProject::instance()->fileInfo().absoluteFilePath() );
+  mWebPage->mainFrame()->setHtml( loadedHtml, baseUrl );
 
   //set user stylesheet
   QWebSettings* settings = mWebPage->settings();

src/core/composer/qgscomposerlabel.cpp

@@ -79,11 +79,27 @@ QgsComposerLabel::QgsComposerLabel( QgsComposition *composition )
     //to update the expression context
     connect( &mComposition->atlasComposition(), SIGNAL( featureChanged( QgsFeature* ) ), this, SLOT( refreshExpressionContext() ) );
   }
+
+  mWebPage = new QWebPage( this );
+  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 );
+  //webPage->setAttribute(Qt::WA_OpaquePaintEvent, false); //this does not compile, why ?
+
+  mWebPage->mainFrame()->setZoomFactor( 10.0 );
+  mWebPage->mainFrame()->setScrollBarPolicy( Qt::Horizontal, Qt::ScrollBarAlwaysOff );
+  mWebPage->mainFrame()->setScrollBarPolicy( Qt::Vertical, Qt::ScrollBarAlwaysOff );
+
+  connect( mWebPage, SIGNAL( loadFinished( bool ) ), SLOT( loadingHtmlFinished( bool ) ) );
 }
 
 QgsComposerLabel::~QgsComposerLabel()
 {
   delete mDistanceArea;
+  delete mWebPage;
 }
 
 void QgsComposerLabel::paint( QPainter* painter, const QStyleOptionGraphicsItem* itemStyle, QWidget* pWidget )
@@ -110,79 +126,66 @@ void QgsComposerLabel::paint( QPainter* painter, const QStyleOptionGraphicsItem*
   double yPenAdjust = mMarginY < 0 ? -penWidth : penWidth;
   QRectF painterRect( xPenAdjust + mMarginX, yPenAdjust + mMarginY, rect().width() - 2 * xPenAdjust - 2 * mMarginX, rect().height() - 2 * yPenAdjust - 2 * mMarginY );
 
-  QString textToDraw = displayText();
-
   if ( mHtmlState )
   {
     painter->scale( 1.0 / mHtmlUnitsToMM / 10.0, 1.0 / mHtmlUnitsToMM / 10.0 );
-    QWebPage *webPage = new QWebPage();
-    webPage->setNetworkAccessManager( QgsNetworkAccessManager::instance() );
-
-    //Setup event loop and timeout for rendering html
-    QEventLoop loop;
-    QTimer timeoutTimer;
-    timeoutTimer.setSingleShot( true );
-
-    //This makes the background transparent. Found on http://blog.qt.digia.com/blog/2009/06/30/transparent-qwebview-or-qwebpage/
-    QPalette palette = webPage->palette();
-    palette.setBrush( QPalette::Base, Qt::transparent );
-    webPage->setPalette( palette );
-    //webPage->setAttribute(Qt::WA_OpaquePaintEvent, false); //this does not compile, why ?
-
-    webPage->setViewportSize( QSize( painterRect.width() * mHtmlUnitsToMM * 10.0, painterRect.height() * mHtmlUnitsToMM * 10.0 ) );
-    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
-    // disable image loading
-    if ( mComposition->plotStyle() != QgsComposition::Print &&
-         mComposition->plotStyle() != QgsComposition::Postscript )
-    {
-      webPage->settings()->setAttribute( QWebSettings::AutoLoadImages, false );
-    }
+    mWebPage->setViewportSize( QSize( painterRect.width() * mHtmlUnitsToMM * 10.0, painterRect.height() * mHtmlUnitsToMM * 10.0 ) );
+    mWebPage->settings()->setUserStyleSheetUrl( createStylesheetUrl() );
+    mWebPage->mainFrame()->render( painter );
+  }
+  else
+  {
+    const QString textToDraw = displayText();
+    painter->setFont( mFont );
+    //debug
+    //painter->setPen( QColor( Qt::red ) );
+    //painter->drawRect( painterRect );
+    QgsComposerUtils::drawText( painter, painterRect, textToDraw, mFont, mFontColor, mHAlignment, mVAlignment, Qt::TextWordWrap );
+  }
+
+  painter->restore();
+
+  drawFrame( painter );
+  if ( isSelected() )
+  {
+    drawSelectionBoxes( painter );
+  }
+}
 
-    //Connect timeout and webpage loadFinished signals to loop
-    connect( &timeoutTimer, SIGNAL( timeout() ), &loop, SLOT( quit() ) );
-    connect( webPage, SIGNAL( loadFinished( bool ) ), &loop, SLOT( quit() ) );
+void QgsComposerLabel::contentChanged()
+{
+  if ( mHtmlState )
+  {
+    const QString textToDraw = displayText();
 
     //mHtmlLoaded tracks whether the QWebPage has completed loading
     //its html contents, set it initially to false. The loadingHtmlFinished slot will
     //set this to true after html is loaded.
     mHtmlLoaded = false;
-    connect( webPage, SIGNAL( loadFinished( bool ) ), SLOT( loadingHtmlFinished( bool ) ) );
 
-    webPage->mainFrame()->setHtml( textToDraw );
+    const QUrl baseUrl = QUrl::fromLocalFile( QgsProject::instance()->fileInfo().absoluteFilePath() );
+    mWebPage->mainFrame()->setHtml( textToDraw, baseUrl );
 
     //For very basic html labels with no external assets, the html load will already be
     //complete before we even get a chance to start the QEventLoop. Make sure we check
     //this before starting the loop
     if ( !mHtmlLoaded )
     {
+      //Setup event loop and timeout for rendering html
+      QEventLoop loop;
+
+      //Connect timeout and webpage loadFinished signals to loop
+      connect( mWebPage, SIGNAL( loadFinished( bool ) ), &loop, SLOT( quit() ) );
+
       // Start a 20 second timeout in case html loading will never complete
+      QTimer timeoutTimer;
+      timeoutTimer.setSingleShot( true );
+      connect( &timeoutTimer, SIGNAL( timeout() ), &loop, SLOT( quit() ) );
       timeoutTimer.start( 20000 );
+
       // Pause until html is loaded
       loop.exec();
     }
-    webPage->mainFrame()->render( painter );//DELETE WEBPAGE ?
-  }
-  else
-  {
-    painter->setFont( mFont );
-    //debug
-    //painter->setPen( QColor( Qt::red ) );
-    //painter->drawRect( painterRect );
-    QgsComposerUtils::drawText( painter, painterRect, textToDraw, mFont, mFontColor, mHAlignment, mVAlignment, Qt::TextWordWrap );
-  }
-
-  painter->restore();
-
-  drawFrame( painter );
-  if ( isSelected() )
-  {
-    drawSelectionBoxes( painter );
   }
 }
 
@@ -209,6 +212,8 @@ void QgsComposerLabel::setText( const QString& text )
   mText = text;
   emit itemChanged();
 
+  contentChanged();
+
   if ( mComposition && id().isEmpty() && !mHtmlState )
   {
     //notify the model that the display name has changed
@@ -224,6 +229,7 @@ void QgsComposerLabel::setHtmlState( int state )
   }
 
   mHtmlState = state;
+  contentChanged();
 
   if ( mComposition && id().isEmpty() )
   {
@@ -253,6 +259,7 @@ void QgsComposerLabel::setExpressionContext( QgsFeature *feature, QgsVectorLayer
     mDistanceArea->setEllipsoidalMode( mComposition->mapSettings().hasCrsTransformEnabled() );
   }
   mDistanceArea->setEllipsoid( QgsProject::instance()->readEntry( "Measure", "/Ellipsoid", GEO_NONE ) );
+  contentChanged();
 
   // Force label to redraw -- fixes label printing for labels with blend modes when used with atlas
   update();
@@ -289,6 +296,7 @@ void QgsComposerLabel::refreshExpressionContext()
   }
   mDistanceArea->setEllipsoidalMode( mComposition->mapSettings().hasCrsTransformEnabled() );
   mDistanceArea->setEllipsoid( QgsProject::instance()->readEntry( "Measure", "/Ellipsoid", GEO_NONE ) );
+  contentChanged();
 
   update();
 }
@@ -488,6 +496,7 @@ bool QgsComposerLabel::readXML( const QDomElement& itemElem, const QDomDocument&
     _readXML( composerItemElem, doc );
   }
   emit itemChanged();
+  contentChanged();
   return true;
 }
 

src/core/composer/qgscomposerlabel.h

@@ -23,6 +23,7 @@
 class QgsVectorLayer;
 class QgsFeature;
 class QgsDistanceArea;
+class QWebPage;
 
 /** \ingroup MapComposer
  * A label that can be placed onto a map composition.
@@ -184,6 +185,9 @@ class CORE_EXPORT QgsComposerLabel: public QgsComposerItem
     /** Helper function to calculate x/y shift for adjustSizeToText() depending on rotation, current size and alignment*/
     void itemShiftAdjustSize( double newWidth, double newHeight, double& xShift, double& yShift ) const;
 
+    /** Called when the content is changed to handle HTML loading */
+    void contentChanged();
+
     // Font
     QFont mFont;
 
@@ -212,6 +216,7 @@ class CORE_EXPORT QgsComposerLabel: public QgsComposerItem
     QMap<QString, QVariant> mSubstitutions;
     QgsDistanceArea* mDistanceArea;
 
+    QWebPage* mWebPage;
 };
 
 #endif

src/core/qgsmultirenderchecker.cpp

@@ -154,7 +154,7 @@ bool QgsCompositionChecker::testComposition( QString &theReport, int page, int p
   //QRectF targetArea( 0, 0, 3507, 2480 );
   mComposition->renderPage( &expectedPainter, page );
   expectedPainter.end();
-  newImage.save( mExpectedImageFile, "PNG" );
+  newImage.save( controlImagePath() + QDir::separator() + "expected_" + mTestName + ".png", "PNG" );
   return true;
 #endif //0
 

tests/src/core/testqgscomposerlabel.cpp

@@ -24,6 +24,7 @@
 #include "qgsvectordataprovider.h"
 #include "qgsmultirenderchecker.h"
 #include "qgsfontutils.h"
+#include "qgsproject.h"
 
 #include <QObject>
 #include <QtTest/QtTest>
@@ -55,6 +56,7 @@ class TestQgsComposerLabel : public QObject
     void marginMethods(); //tests getting/setting margins
     void render();
     void renderAsHtml();
+    void renderAsHtmlRelative();
 
   private:
     QgsComposition* mComposition;
@@ -265,5 +267,21 @@ void TestQgsComposerLabel::renderAsHtml()
   QVERIFY( checker.testComposition( mReport, 0, 0 ) );
 }
 
+void TestQgsComposerLabel::renderAsHtmlRelative()
+{
+  QgsProject::instance()->setFileName( QString( TEST_DATA_DIR ) +  QDir::separator() + "test.qgs" );
+  mComposerLabel->setFontColor( QColor( 200, 40, 60 ) );
+  mComposerLabel->setText( "test <img src=\"small_sample_image.png\" />" );
+  mComposerLabel->setFont( QgsFontUtils::getStandardTestFont( "Bold", 48 ) );
+  mComposerLabel->setPos( 70, 70 );
+  mComposerLabel->adjustSizeToText();
+  mComposerLabel->setHtmlState( 1 );
+  mComposerLabel->update();
+
+  QgsCompositionChecker checker( "composerlabel_renderhtmlrelative", mComposition );
+  checker.setControlPathPrefix( "composer_label" );
+  QVERIFY( checker.testComposition( mReport, 0, 0 ) );
+}
+
 QTEST_MAIN( TestQgsComposerLabel )
 #include "testqgscomposerlabel.moc"