Port item blend mode support to layouts

qgis · Nov 7, 2017 · 4e8878d · 4e8878d
1 parent 0143d0b
commit 4e8878d
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Showing 9 changed files with 255 additions and 9 deletions.
diff --git a/python/core/core_auto.sip b/python/core/core_auto.sip
@@ -158,7 +158,6 @@
 %Include composer/qgscomposertexttable.sip
 %Include composer/qgspaperitem.sip
 %Include layout/qgslayoutaligner.sip
-%Include layout/qgslayoutcontext.sip
 %Include layout/qgslayoutgridsettings.sip
 %Include layout/qgslayoutmeasurement.sip
 %Include layout/qgslayoutmeasurementconverter.sip
@@ -403,6 +402,8 @@
 %Include gps/qgsnmeaconnection.sip
 %Include gps/qgsgpsdconnection.sip
 %Include layout/qgslayout.sip
+%Include layout/qgslayoutcontext.sip
+%Include layout/qgslayouteffect.sip
 %Include layout/qgslayoutguidecollection.sip
 %Include layout/qgslayoutitem.sip
 %Include layout/qgslayoutitemgroup.sip

diff --git a/python/core/layout/qgslayoutitem.sip b/python/core/layout/qgslayoutitem.sip
@@ -412,6 +412,19 @@ class QgsLayoutItem : QgsLayoutObject, QGraphicsRectItem, QgsLayoutUndoObjectInt
  Sets the background ``color`` for this item.
 .. seealso:: backgroundColor()
 .. seealso:: setBackgroundEnabled()
+%End
+
+    QPainter::CompositionMode blendMode() const;
+%Docstring
+ Returns the item's composition blending mode.
+.. seealso:: setBlendMode()
+ :rtype: QPainter.CompositionMode
+%End
+
+    void setBlendMode( const QPainter::CompositionMode mode );
+%Docstring
+ Sets the item's composition blending ``mode``.
+.. seealso:: blendMode()
 %End
 
     virtual double estimatedFrameBleed() const;
@@ -579,6 +592,11 @@ class QgsLayoutItem : QgsLayoutObject, QGraphicsRectItem, QgsLayoutUndoObjectInt
  after the frame color is set and a later call to update() must be made.
 %End
 
+    void refreshBlendMode();
+%Docstring
+ Refresh item's blend mode, considering data defined blend mode.
+%End
+
     QPointF adjustPointForReferencePosition( const QPointF &point, const QSizeF &size, const ReferencePoint &reference ) const;
 %Docstring
  Adjusts the specified ``point`` at which a ``reference`` position of the item

diff --git a/src/core/CMakeLists.txt b/src/core/CMakeLists.txt
@@ -362,6 +362,7 @@ SET(QGIS_CORE_SRCS
   layout/qgslayout.cpp
   layout/qgslayoutaligner.cpp
   layout/qgslayoutcontext.cpp
+  layout/qgslayouteffect.cpp
   layout/qgslayoutgridsettings.cpp
   layout/qgslayoutguidecollection.cpp
   layout/qgslayoutitem.cpp
@@ -713,6 +714,8 @@ SET(QGIS_CORE_MOC_HDRS
   gps/qgsgpsdconnection.h
 
   layout/qgslayout.h
+  layout/qgslayoutcontext.h
+  layout/qgslayouteffect.h
   layout/qgslayoutguidecollection.h
   layout/qgslayoutitem.h
   layout/qgslayoutitemgroup.h

diff --git a/src/core/layout/qgslayouteffect.cpp b/src/core/layout/qgslayouteffect.cpp
@@ -0,0 +1,62 @@
+/***************************************************************************
+                             qgslayouteffect.cpp
+                             -------------------
+    begin                : October 2017
+    copyright            : (C) 2017 by Nyall Dawson
+    email                : nyall.dawson@gmail.com
+ ***************************************************************************/
+
+/***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+#include <QPainter>
+
+#include "qgslayouteffect.h"
+
+void QgsLayoutEffect::draw( QPainter *painter )
+{
+  QPoint offset;
+  QPixmap pixmap;
+
+  // Set desired composition mode then draw source
+  painter->setCompositionMode( mCompositionMode );
+
+  if ( mCompositionMode == QPainter::CompositionMode_SourceOver )
+  {
+    // Normal (sourceover) blending, do faster drawSource operation
+    drawSource( painter );
+    return;
+  }
+
+  // Otherwise, draw using pixmap so QPrinter output works as expected
+  if ( sourceIsPixmap() )
+  {
+    // No point in drawing in device coordinates (pixmap will be scaled anyways).
+    pixmap = sourcePixmap( Qt::LogicalCoordinates, &offset );
+  }
+  else
+  {
+    // Draw pixmap in device coordinates to avoid pixmap scaling;
+    pixmap = sourcePixmap( Qt::DeviceCoordinates, &offset );
+    painter->setWorldTransform( QTransform() );
+  }
+
+  painter->drawPixmap( offset, pixmap );
+}
+
+void QgsLayoutEffect::setCompositionMode( QPainter::CompositionMode compositionMode )
+{
+  mCompositionMode = compositionMode;
+
+  // force redraw with new composition mode
+  update();
+}
+
+
+
diff --git a/src/core/layout/qgslayouteffect.h b/src/core/layout/qgslayouteffect.h
@@ -0,0 +1,70 @@
+/***************************************************************************
+                              qgslayouteffect.h
+                             -------------------
+    begin                : October 2017
+    copyright            : (C) 2017 by Nyall Dawson
+    email                : nyall.dawson@gmail.com
+ ***************************************************************************/
+
+/***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+#ifndef QGSLAYOUTEFFECT_H
+#define QGSLAYOUTEFFECT_H
+
+#include <QGraphicsEffect>
+#include <QPainter>
+
+#include "qgis_core.h"
+
+/**
+ * \ingroup core
+ * \class QgsLayoutEffect
+ *
+ * A QGraphicsEffect subclass used for rendering layout items
+ * onto a scene with custom composition modes.
+ *
+ * \since QGIS 3.0
+ */
+class CORE_EXPORT QgsLayoutEffect : public QGraphicsEffect
+{
+    Q_OBJECT
+
+  public:
+
+    /**
+     * Constructor for QgsLayoutEffect.
+     */
+    QgsLayoutEffect() = default;
+
+    /**
+     * Sets the composition (blending) \a mode used for rendering
+     * the item.
+     * \see compositionMode()
+     */
+    void setCompositionMode( QPainter::CompositionMode mode );
+
+    /**
+     * Returns the composition (blending) mode used for rendering
+     * the item.
+     * \see setCompositionMode()
+     */
+    QPainter::CompositionMode compositionMode() const { return mCompositionMode; }
+
+  protected:
+
+    virtual void draw( QPainter *painter ) override;
+
+  private:
+
+    QPainter::CompositionMode mCompositionMode = QPainter::CompositionMode_SourceOver;
+};
+
+#endif // QGSLAYOUTEFFECT_H
+
diff --git a/src/core/layout/qgslayoutitem.cpp b/src/core/layout/qgslayoutitem.cpp
@@ -22,6 +22,8 @@
 #include "qgslayoutmodel.h"
 #include "qgssymbollayerutils.h"
 #include "qgslayoutitemgroup.h"
+#include "qgspainting.h"
+#include "qgslayouteffect.h"
 #include <QPainter>
 #include <QStyleOptionGraphicsItem>
 #include <QUuid>
@@ -61,6 +63,18 @@ QgsLayoutItem::QgsLayoutItem( QgsLayout *layout, bool manageZValue )
   {
     mLayoutManagesZValue = false;
   }
+
+  // Setup layout effect
+  mEffect.reset( new QgsLayoutEffect() );
+  if ( mLayout )
+  {
+    mEffect->setEnabled( mLayout->context().flags() & QgsLayoutContext::FlagUseAdvancedEffects );
+    connect( &mLayout->context(), &QgsLayoutContext::flagsChanged, this, [ = ]( QgsLayoutContext::Flags flags )
+    {
+      mEffect->setEnabled( flags & QgsLayoutContext::FlagUseAdvancedEffects );
+    } );
+  }
+  setGraphicsEffect( mEffect.get() );
 }
 
 QgsLayoutItem::~QgsLayoutItem()
@@ -497,6 +511,13 @@ void QgsLayoutItem::setBackgroundColor( const QColor &color )
   refreshBackgroundColor( true );
 }
 
+void QgsLayoutItem::setBlendMode( const QPainter::CompositionMode mode )
+{
+  mBlendMode = mode;
+  // Update the item effect to use the new blend mode
+  refreshBlendMode();
+}
+
 double QgsLayoutItem::estimatedFrameBleed() const
 {
   if ( !hasFrame() )
@@ -592,6 +613,10 @@ void QgsLayoutItem::refreshDataDefinedProperty( const QgsLayoutObject::DataDefin
   {
     refreshBackgroundColor( false );
   }
+  if ( property == QgsLayoutObject::BlendMode || property == QgsLayoutObject::AllProperties )
+  {
+    refreshBlendMode();
+  }
 }
 
 void QgsLayoutItem::setItemRotation( const double angle )
@@ -810,11 +835,11 @@ bool QgsLayoutItem::writePropertiesToElement( QDomElement &element, QDomDocument
   bgColorElem.setAttribute( QStringLiteral( "alpha" ), QString::number( mBackgroundColor.alpha() ) );
   element.appendChild( bgColorElem );
 
-  //TODO
-#if 0
   //blend mode
-  //  composerItemElem.setAttribute( "blendMode", QgsMapRenderer::getBlendModeEnum( mBlendMode ) );
+  element.setAttribute( "blendMode", QgsPainting::getBlendModeEnum( mBlendMode ) );
 
+  //TODO
+#if 0
   //transparency
   //  composerItemElem.setAttribute( "transparency", QString::number( mTransparency ) );
 
@@ -937,9 +962,10 @@ bool QgsLayoutItem::readPropertiesFromElement( const QDomElement &element, const
     refreshBackgroundColor( false );
   }
 
-#if 0 //TODO
   //blend mode
-  setBlendMode( QgsMapRenderer::getCompositionMode( ( QgsMapRenderer::BlendMode ) itemElem.attribute( "blendMode", "0" ).toUInt() ) );
+  setBlendMode( QgsPainting::getCompositionMode( static_cast< QgsPainting::BlendMode >( element.attribute( QStringLiteral( "blendMode" ), QStringLiteral( "0" ) ).toUInt() ) ) );
+
+#if 0 //TODO
   //transparency
   setTransparency( itemElem.attribute( "transparency", "0" ).toInt() );
   mExcludeFromExports = itemElem.attribute( "excludeFromExports", "0" ).toInt();
@@ -1059,3 +1085,21 @@ void QgsLayoutItem::refreshBackgroundColor( bool updateItem )
     update();
   }
 }
+
+void QgsLayoutItem::refreshBlendMode()
+{
+  QPainter::CompositionMode blendMode = mBlendMode;
+
+  //data defined blend mode set?
+  bool ok = false;
+  QString blendStr = mDataDefinedProperties.valueAsString( QgsLayoutObject::BlendMode, createExpressionContext(), QString(), &ok );
+  if ( ok && !blendStr.isEmpty() )
+  {
+    QString blendstr = blendStr.trimmed();
+    QPainter::CompositionMode blendModeD = QgsSymbolLayerUtils::decodeBlendMode( blendstr );
+    blendMode = blendModeD;
+  }
+
+  // Update the item effect to use the new blend mode
+  mEffect->setCompositionMode( blendMode );
+}
diff --git a/src/core/layout/qgslayoutitem.h b/src/core/layout/qgslayoutitem.h
@@ -25,10 +25,12 @@
 #include "qgslayoutundocommand.h"
 #include "qgslayoutmeasurement.h"
 #include <QGraphicsRectItem>
+#include <QPainter>
 
 class QgsLayout;
 class QPainter;
 class QgsLayoutItemGroup;
+class QgsLayoutEffect;
 
 /**
  * \ingroup core
@@ -415,6 +417,18 @@ class CORE_EXPORT QgsLayoutItem : public QgsLayoutObject, public QGraphicsRectIt
      */
     void setBackgroundColor( const QColor &color );
 
+    /**
+     * Returns the item's composition blending mode.
+     * \see setBlendMode()
+     */
+    QPainter::CompositionMode blendMode() const { return mBlendMode; }
+
+    /**
+     * Sets the item's composition blending \a mode.
+     * \see blendMode()
+     */
+    void setBlendMode( const QPainter::CompositionMode mode );
+
     /**
      * Returns the estimated amount the item's frame bleeds outside the item's
      * actual rectangle. For instance, if the item has a 2mm frame stroke, then
@@ -577,6 +591,11 @@ class CORE_EXPORT QgsLayoutItem : public QgsLayoutObject, public QGraphicsRectIt
      */
     void refreshBackgroundColor( bool updateItem = true );
 
+    /**
+     * Refresh item's blend mode, considering data defined blend mode.
+     */
+    void refreshBlendMode();
+
     /**
      * Adjusts the specified \a point at which a \a reference position of the item
      * sits and returns the top left corner of the item, if reference point were placed at the specified position.
@@ -638,6 +657,10 @@ class CORE_EXPORT QgsLayoutItem : public QgsLayoutObject, public QGraphicsRectIt
     QgsLayoutPoint mItemPosition;
     double mItemRotation = 0.0;
 
+    //! Composition blend mode for item
+    QPainter::CompositionMode mBlendMode = QPainter::CompositionMode_SourceOver;
+    std::unique_ptr< QgsLayoutEffect > mEffect;
+
     QImage mItemCachedImage;
     double mItemCacheDpi = -1;
 

diff --git a/src/gui/layout/qgslayoutitemwidget.cpp b/src/gui/layout/qgslayoutitemwidget.cpp
@@ -640,8 +640,8 @@ void QgsLayoutItemPropertiesWidget::setValuesForGuiNonPositionElements()
   mItemIdLineEdit->setText( mItem->id() );
   mFrameGroupBox->setChecked( mItem->hasFrame() );
   mBackgroundGroupBox->setChecked( mItem->hasBackground() );
-#if 0//TODO
   mBlendModeCombo->setBlendMode( mItem->blendMode() );
+#if 0//TODO
   mOpacityWidget->setOpacity( mItem->itemOpacity() );
   mItemRotationSpinBox->setValue( mItem->itemRotation( QgsComposerObject::OriginalValue ) );
   mExcludeFromPrintsCheckBox->setChecked( mItem->excludeFromExports( QgsComposerObject::OriginalValue ) );
@@ -698,9 +698,7 @@ void QgsLayoutItemPropertiesWidget::mBlendModeCombo_currentIndexChanged( int ind
   if ( mItem )
   {
     mItem->layout()->undoStack()->beginCommand( mItem, tr( "Change Blend Mode" ) );
-#if 0 //TODO
     mItem->setBlendMode( mBlendModeCombo->blendMode() );
-#endif
     mItem->layout()->undoStack()->endCommand();
   }
 }