[needs-docs][composer] Remove Rectangle mode from composer maps

No longer required - the Cache mode is now performant enough
that we don't have to rely on the old rectangle preview
when desiring responsive composers

doc/api_break.dox

@@ -641,6 +641,7 @@ and setAtlasScalingMode() instead.
 associated project's annotationManager()
 - setDrawCanvasItems() and drawCanvasItems() were renamed to setDrawAnnotations() and drawAnnotations()
 - setCacheUpdated(), updateCachedImage() and cache() were removed. Use invalidateCache() instead.
+- The Rectangle mode enum was removed. Use the reworked Cache mode instead.
 
 
 QgsComposerMapGrid        {#qgis_api_break_3_0_QgsComposerMapGrid}

python/core/composer/qgscomposermap.sip

@@ -40,7 +40,6 @@ Return correct graphics item type.
     {
       Cache,
       Render,
-      Rectangle
     };
 
     enum AtlasScalingMode

src/app/composer/qgscomposermapwidget.cpp

@@ -62,7 +62,6 @@ QgsComposerMapWidget::QgsComposerMapWidget( QgsComposerMap *composerMap )
   blockAllSignals( true );
   mPreviewModeComboBox->insertItem( 0, tr( "Cache" ) );
   mPreviewModeComboBox->insertItem( 1, tr( "Render" ) );
-  mPreviewModeComboBox->insertItem( 2, tr( "Rectangle" ) );
 
   mCrsSelector->setOptionVisible( QgsProjectionSelectionWidget::CrsNotSet, true );
   mCrsSelector->setNotSetText( tr( "Use project CRS" ) );
@@ -446,20 +445,15 @@ void QgsComposerMapWidget::on_mPreviewModeComboBox_activated( int i )
   }
 
   QString comboText = mPreviewModeComboBox->currentText();
-  if ( comboText == tr( "Cache" ) )
-  {
-    mComposerMap->setPreviewMode( QgsComposerMap::Cache );
-    mUpdatePreviewButton->setEnabled( true );
-  }
-  else if ( comboText == tr( "Render" ) )
+  if ( comboText == tr( "Render" ) )
   {
     mComposerMap->setPreviewMode( QgsComposerMap::Render );
     mUpdatePreviewButton->setEnabled( true );
   }
-  else if ( comboText == tr( "Rectangle" ) )
+  else
   {
-    mComposerMap->setPreviewMode( QgsComposerMap::Rectangle );
-    mUpdatePreviewButton->setEnabled( false );
+    mComposerMap->setPreviewMode( QgsComposerMap::Cache );
+    mUpdatePreviewButton->setEnabled( true );
   }
 
   mComposerMap->invalidateCache();
@@ -630,20 +624,15 @@ void QgsComposerMapWidget::updateGuiElements()
   //preview mode
   QgsComposerMap::PreviewMode previewMode = mComposerMap->previewMode();
   int index = -1;
-  if ( previewMode == QgsComposerMap::Cache )
-  {
-    index = mPreviewModeComboBox->findText( tr( "Cache" ) );
-    mUpdatePreviewButton->setEnabled( true );
-  }
-  else if ( previewMode == QgsComposerMap::Render )
+  if ( previewMode == QgsComposerMap::Render )
   {
     index = mPreviewModeComboBox->findText( tr( "Render" ) );
     mUpdatePreviewButton->setEnabled( true );
   }
-  else if ( previewMode == QgsComposerMap::Rectangle )
+  else
   {
-    index = mPreviewModeComboBox->findText( tr( "Rectangle" ) );
-    mUpdatePreviewButton->setEnabled( false );
+    index = mPreviewModeComboBox->findText( tr( "Cache" ) );
+    mUpdatePreviewButton->setEnabled( true );
   }
   if ( index != -1 )
   {

src/core/composer/qgscomposermap.cpp

@@ -208,11 +208,6 @@ QgsMapSettings QgsComposerMap::mapSettings( const QgsRectangle &extent, QSizeF s
 
 void QgsComposerMap::recreateCachedImageInBackground()
 {
-  if ( mPreviewMode == Rectangle )
-  {
-    return;
-  }
-
   if ( mPainterJob )
   {
     disconnect( mPainterJob.get(), &QgsMapRendererCustomPainterJob::finished, this, &QgsComposerMap::painterJobFinished );
@@ -325,16 +320,7 @@ void QgsComposerMap::paint( QPainter *painter, const QStyleOptionGraphicsItem *,
   painter->save();
   painter->setClipRect( thisPaintRect );
 
-  if ( mComposition->plotStyle() == QgsComposition::Preview && mPreviewMode == Rectangle )
-  {
-    // Fill with background color
-    drawBackground( painter );
-    QFont messageFont( QLatin1String( "" ), 12 );
-    painter->setFont( messageFont );
-    painter->setPen( QColor( 0, 0, 0, 125 ) );
-    painter->drawText( thisPaintRect, tr( "Map will be printed here" ) );
-  }
-  else if ( mComposition->plotStyle() == QgsComposition::Preview )
+  if ( mComposition->plotStyle() == QgsComposition::Preview )
   {
     if ( !mCacheFinalImage || mCacheFinalImage->isNull() )
     {
@@ -416,13 +402,11 @@ void QgsComposerMap::paint( QPainter *painter, const QStyleOptionGraphicsItem *,
   }
 
   painter->setClipRect( thisPaintRect, Qt::NoClip );
-  if ( shouldDrawPart( OverviewMapExtent ) &&
-       ( mComposition->plotStyle() != QgsComposition::Preview || mPreviewMode != Rectangle ) )
+  if ( shouldDrawPart( OverviewMapExtent ) )
   {
     mOverviewStack->drawItems( painter );
   }
-  if ( shouldDrawPart( Grid ) &&
-       ( mComposition->plotStyle() != QgsComposition::Preview || mPreviewMode != Rectangle ) )
+  if ( shouldDrawPart( Grid ) )
   {
     mGridStack->drawItems( painter );
   }
@@ -1304,21 +1288,16 @@ bool QgsComposerMap::readXml( const QDomElement &itemElem, const QDomDocument &d
     mId = idRead.toInt();
     updateToolTip();
   }
-  mPreviewMode = Rectangle;
 
   //previewMode
   QString previewMode = itemElem.attribute( QStringLiteral( "previewMode" ) );
-  if ( previewMode == QLatin1String( "Cache" ) )
-  {
-    mPreviewMode = Cache;
-  }
-  else if ( previewMode == QLatin1String( "Render" ) )
+  if ( previewMode == QLatin1String( "Render" ) )
   {
     mPreviewMode = Render;
   }
   else
   {
-    mPreviewMode = Rectangle;
+    mPreviewMode = Cache;
   }
 
   //extent

src/core/composer/qgscomposermap.h

@@ -69,7 +69,6 @@ class CORE_EXPORT QgsComposerMap : public QgsComposerItem
     {
       Cache = 0,   // Use raster cache
       Render,      // Render the map
-      Rectangle    // Display only rectangle
     };
 
     /** Scaling modes used for the serial rendering (atlas)

tests/src/core/testqgsatlascomposition.cpp

@@ -151,8 +151,6 @@ void TestQgsAtlasComposition::init()
   // the atlas map
   mAtlasMap = new QgsComposerMap( mComposition, 20, 20, 130, 130 );
   mAtlasMap->setFrameEnabled( true );
-  // Make sure it doesn't try to render a map for caching onto a still 0-sized image
-  mAtlasMap->setPreviewMode( QgsComposerMap::Rectangle );
   mComposition->addComposerMap( mAtlasMap );
   mAtlasMap->setLayers( QList<QgsMapLayer *>() << mVectorLayer );
 
@@ -165,7 +163,6 @@ void TestQgsAtlasComposition::init()
   mOverview = new QgsComposerMap( mComposition, 180, 20, 50, 50 );
   mOverview->setFrameEnabled( true );
   mOverview->overview()->setFrameMap( mAtlasMap->id() );
-  mOverview->setPreviewMode( QgsComposerMap::Rectangle );
   mOverview->setLayers( QList<QgsMapLayer *>() << mVectorLayer );
   mComposition->addComposerMap( mOverview );
   mOverview->setNewExtent( QgsRectangle( 49670.718, 6415139.086, 699672.519, 7065140.887 ) );