Color ramp dialogs no longer edit ramps in place

Now the dialogs use a copy of the ramp, and the edited
ramp is retrieved by calling ramp() on the dialog after
it is executed.

Avoids pointer lifetime issues by storing and working
on a ramp pointer which the dialog does not have ownership
on.

Also fix a bunch of leaks relating to cloning color ramps.

Author: nyalldawson

doc/api_break.dox

@@ -295,6 +295,13 @@ variant instead.</li>
 <li>GenericDataSourceURI has been renamed to GenericDataSourceUri</li>
 </ul>
 
+\subsection qgis_api_break_3_0_QgsColorBrewerColorRampDialog QgsColorBrewerColorRampDialog
+
+<ul>
+<li>The dialog no longer edits a color ramp in place. Instead, a copy of the ramp is edited
+and the new ramp can be retrieved after executing the dialog by calling ramp().</li>
+</ul>
+
 \subsection qgis_api_break_3_0_QgsComposerLabel QgsComposerLabel
 
 <ul>
@@ -389,6 +396,13 @@ plugins calling these methods will need to be updated.</li>
 be returned in place of a null pointer.</li>
 </ul>
 
+\subsection qgis_api_break_3_0_QgsCptCityColorRampDialog QgsCptCityColorRampDialog
+
+<ul>
+<li>The dialog no longer edits a color ramp in place. Instead, a copy of the ramp is edited
+and the new ramp can be retrieved after executing the dialog by calling ramp().</li>
+</ul>
+
 \subsection qgis_api_break_3_0_QgsCptCitySelectionItem QgsCptCitySelectionItem
 
 <ul>
@@ -559,6 +573,13 @@ method to determine if a geometry is valid.</li>
 a QgsGeometry value rather than a pointer.</li>
 </ul>
 
+\subsection qgis_api_break_3_0_QgsGradientColorRampDialog QgsGradientColorRampDialog
+
+<ul>
+<li>The dialog no longer edits a color ramp in place. Instead, a copy of the ramp is edited
+and the new ramp can be retrieved after executing the dialog by calling ramp().</li>
+</ul>
+
 \subsection qgis_api_break_3_0_QgsGraphBuilderInterface QgsGraphBuilderInterface
 
 <ul>
@@ -604,6 +625,13 @@ plugins calling this method will need to be updated.</li>
 <li>writeCommonXML() has been renamed to writeCommonXml()</li>
 </ul>
 
+\subsection qgis_api_break_3_0_QgsLimitedRandomRampDialog QgsLimitedRandomColorRampDialog
+
+<ul>
+<li>The dialog no longer edits a color ramp in place. Instead, a copy of the ramp is edited
+and the new ramp can be retrieved after executing the dialog by calling ramp().</li>
+</ul>
+
 \subsection qgis_api_break_3_0_QgsMapCanvas QgsMapCanvas
 
 <ul>

python/core/symbology-ng/qgsstyle.sip

@@ -16,11 +16,10 @@ class QgsStyle : QObject
      */
     enum StyleEntity { SymbolEntity, GroupEntity, TagEntity, ColorrampEntity, SmartgroupEntity };
 
-    //! add color ramp to style. takes ramp's ownership
-    /*!
+    /** Adds a color ramp to the style. Calling this method takes the ramp's ownership.
      *  \note Adding a color ramp with the name of existing one replaces it.
      *  \param name is the name of the color ramp being added or updated
-     *  \param colorRamp is the color ramp
+     *  \param colorRamp is the color ramp. Ownership is transferred.
      *  \param update set to true when the style DB has to be updated, by default it is false
      *  \return success status of the operation
      */
@@ -71,8 +70,10 @@ class QgsStyle : QObject
     //! remove all contents of the style
     void clear();
 
-    //! return a NEW copy of color ramp
-    QgsColorRamp* colorRamp( const QString& name ) /Factory/;
+    /** Returns a new copy of the specified color ramp. The caller
+     * takes responsibility for deleting the returned object.
+     */
+    QgsColorRamp* colorRamp( const QString& name ) const /Factory/;
 
     //! return count of color ramps
     int colorRampCount();

python/gui/qgscolorbrewercolorrampdialog.sip

@@ -5,7 +5,9 @@ class QgsColorBrewerColorRampDialog : QDialog
 %End
 
   public:
-    QgsColorBrewerColorRampDialog( QgsColorBrewerColorRamp* ramp, QWidget* parent /TransferThis/ = NULL );
+    QgsColorBrewerColorRampDialog( const QgsColorBrewerColorRamp& ramp, QWidget* parent /TransferThis/ = nullptr );
+
+    QgsColorBrewerColorRamp ramp() const;
 
   public slots:
     void setSchemeName();

python/gui/qgsgradientcolorrampdialog.sip

@@ -5,7 +5,10 @@ class QgsGradientColorRampDialog : QDialog
 %End
 
   public:
-    QgsGradientColorRampDialog( QgsGradientColorRamp* ramp, QWidget* parent /TransferThis/ = NULL );
+    QgsGradientColorRampDialog( const QgsGradientColorRamp& ramp, QWidget* parent /TransferThis/ = nullptr );
+    ~QgsGradientColorRampDialog();
+
+    QgsGradientColorRamp ramp() const;
 
   public slots:
     void setColor1( const QColor& color );

python/gui/qgslimitedrandomcolorrampdialog.sip

@@ -5,7 +5,9 @@ class QgsLimitedRandomColorRampDialog : QDialog
 %End
 
   public:
-    QgsLimitedRandomColorRampDialog( QgsLimitedRandomColorRamp* ramp, QWidget* parent /TransferThis/ = NULL );
+    QgsLimitedRandomColorRampDialog( const QgsLimitedRandomColorRamp& ramp, QWidget* parent /TransferThis/ = nullptr );
+
+    QgsLimitedRandomColorRamp ramp() const;
 
   public slots:
     void setCount( int val );

python/gui/symbology-ng/qgscolorrampcombobox.sip

@@ -11,11 +11,18 @@ class QgsColorRampComboBox : QComboBox
     //! initialize the combo box with color ramps from the style
     void populate( QgsStyle* style );
 
-    //! add/select color ramp which was used previously by the renderer
-    void setSourceColorRamp( QgsColorRamp* sourceRamp );
+    /** Adds or selects the current color ramp to show in the combo box. The ramp appears
+     * in the combo box as the "source" ramp.
+     * @param sourceRamp color ramp, ownership is transferred.
+     * @see currentColorRamp()
+     */
+    void setSourceColorRamp( QgsColorRamp* sourceRamp /Transfer/ );
 
-    //! return new instance of the current color ramp or NULL if there is no active color ramp
-    QgsColorRamp* currentColorRamp();
+    /** Returns a new instance of the current color ramp or NULL if there is no active color ramp.
+     * The caller takes responsibility for deleting the returned value.
+     * @see setSourceColorRamp()
+     */
+    QgsColorRamp* currentColorRamp() const /Factory/;
 
     /** Returns true if the current selection in the combo box is the option for creating
      * a new color ramp

python/gui/symbology-ng/qgscptcitycolorrampdialog.sip

@@ -5,9 +5,13 @@ class QgsCptCityColorRampDialog : QDialog
 %End
 
   public:
-    QgsCptCityColorRampDialog( QgsCptCityColorRamp* ramp, QWidget* parent /TransferThis/ = NULL );
+
+    QgsCptCityColorRampDialog( const QgsCptCityColorRamp& ramp, QWidget* parent /TransferThis/ = nullptr );
     ~QgsCptCityColorRampDialog();
 
+    QgsCptCityColorRamp ramp() const;
+
+
     QString selectedName() const;
 
     bool saveAsGradientRamp() const;

src/app/qgsprojectproperties.cpp

@@ -1713,10 +1713,9 @@ void QgsProjectProperties::populateStyles()
   for ( int i = 0; i < colorRamps.count(); ++i )
   {
     QString name = colorRamps[i];
-    QgsColorRamp* ramp = mStyle->colorRamp( name );
-    QIcon icon = QgsSymbolLayerUtils::colorRampPreviewIcon( ramp, cboStyleColorRamp->iconSize() );
+    QScopedPointer< QgsColorRamp > ramp( mStyle->colorRamp( name ) );
+    QIcon icon = QgsSymbolLayerUtils::colorRampPreviewIcon( ramp.data(), cboStyleColorRamp->iconSize() );
     cboStyleColorRamp->addItem( icon, name );
-    delete ramp;
   }
 
   // set current index if found

src/core/symbology-ng/qgsstyle.cpp

@@ -254,7 +254,7 @@ bool QgsStyle::removeColorRamp( const QString& name )
   return true;
 }
 
-QgsColorRamp* QgsStyle::colorRamp( const QString& name )
+QgsColorRamp* QgsStyle::colorRamp( const QString& name ) const
 {
   const QgsColorRamp *ramp = colorRampRef( name );
   return ramp ? ramp->clone() : nullptr;
@@ -1536,7 +1536,8 @@ bool QgsStyle::updateSymbol( StyleEntity type, const QString& name )
       return false;
     }
 
-    symEl = QgsSymbolLayerUtils::saveColorRamp( name, colorRamp( name ), doc );
+    QScopedPointer< QgsColorRamp > ramp( colorRamp( name ) );
+    symEl = QgsSymbolLayerUtils::saveColorRamp( name, ramp.data(), doc );
     if ( symEl.isNull() )
     {
       QgsDebugMsg( "Couldn't convert color ramp to valid XML!" );

src/core/symbology-ng/qgsstyle.h

@@ -82,11 +82,10 @@ class CORE_EXPORT QgsStyle : public QObject
      */
     enum StyleEntity { SymbolEntity, GroupEntity, TagEntity, ColorrampEntity, SmartgroupEntity };
 
-    //! add color ramp to style. takes ramp's ownership
-    /*!
+    /** Adds a color ramp to the style. Calling this method takes the ramp's ownership.
      *  \note Adding a color ramp with the name of existing one replaces it.
      *  \param name is the name of the color ramp being added or updated
-     *  \param colorRamp is the Vector color ramp
+     *  \param colorRamp is the color ramp. Ownership is transferred.
      *  \param update set to true when the style DB has to be updated, by default it is false
      *  \return success status of the operation
      */
@@ -137,8 +136,10 @@ class CORE_EXPORT QgsStyle : public QObject
     //! remove all contents of the style
     void clear();
 
-    //! return a NEW copy of color ramp
-    QgsColorRamp* colorRamp( const QString& name );
+    /** Returns a new copy of the specified color ramp. The caller
+     * takes responsibility for deleting the returned object.
+     */
+    QgsColorRamp* colorRamp( const QString& name ) const;
 
     //! return count of color ramps
     int colorRampCount();

src/gui/qgscolorbrewercolorrampdialog.cpp

@@ -31,7 +31,7 @@ static void updateColorButton( QAbstractButton* button, QColor color )
 /////////
 
 
-QgsColorBrewerColorRampDialog::QgsColorBrewerColorRampDialog( QgsColorBrewerColorRamp* ramp, QWidget* parent )
+QgsColorBrewerColorRampDialog::QgsColorBrewerColorRampDialog( const QgsColorBrewerColorRamp& ramp, QWidget* parent )
     : QDialog( parent )
     , mRamp( ramp )
 {
@@ -51,9 +51,9 @@ QgsColorBrewerColorRampDialog::QgsColorBrewerColorRampDialog( QgsColorBrewerColo
     cboSchemeName->addItem( icon, schemeName );
   }
 
-  cboSchemeName->setCurrentIndex( cboSchemeName->findText( ramp->schemeName() ) );
+  cboSchemeName->setCurrentIndex( cboSchemeName->findText( mRamp.schemeName() ) );
   populateVariants();
-  cboColors->setCurrentIndex( cboColors->findText( QString::number( ramp->colors() ) ) );
+  cboColors->setCurrentIndex( cboColors->findText( QString::number( mRamp.colors() ) ) );
 
   connect( cboSchemeName, SIGNAL( currentIndexChanged( int ) ), this, SLOT( setSchemeName() ) );
   connect( cboColors, SIGNAL( currentIndexChanged( int ) ), this, SLOT( setColors() ) );
@@ -86,21 +86,21 @@ void QgsColorBrewerColorRampDialog::populateVariants()
 void QgsColorBrewerColorRampDialog::updatePreview()
 {
   QSize size( 300, 40 );
-  lblPreview->setPixmap( QgsSymbolLayerUtils::colorRampPreviewPixmap( mRamp, size ) );
+  lblPreview->setPixmap( QgsSymbolLayerUtils::colorRampPreviewPixmap( &mRamp, size ) );
 }
 
 void QgsColorBrewerColorRampDialog::setSchemeName()
 {
   // populate list of variants
   populateVariants();
 
-  mRamp->setSchemeName( cboSchemeName->currentText() );
+  mRamp.setSchemeName( cboSchemeName->currentText() );
   updatePreview();
 }
 
 void QgsColorBrewerColorRampDialog::setColors()
 {
   int num = cboColors->currentText().toInt();
-  mRamp->setColors( num );
+  mRamp.setColors( num );
   updatePreview();
 }

src/gui/qgscolorbrewercolorrampdialog.h

@@ -18,6 +18,7 @@
 
 #include <QDialog>
 
+#include "qgscolorramp.h"
 #include "ui_qgscolorbrewercolorrampdialogbase.h"
 
 class QgsColorBrewerColorRamp;
@@ -30,7 +31,9 @@ class GUI_EXPORT QgsColorBrewerColorRampDialog : public QDialog, private Ui::Qgs
     Q_OBJECT
 
   public:
-    QgsColorBrewerColorRampDialog( QgsColorBrewerColorRamp* ramp, QWidget* parent = nullptr );
+    QgsColorBrewerColorRampDialog( const QgsColorBrewerColorRamp& ramp, QWidget* parent = nullptr );
+
+    QgsColorBrewerColorRamp ramp() const { return mRamp; }
 
   public slots:
     void setSchemeName();
@@ -42,7 +45,7 @@ class GUI_EXPORT QgsColorBrewerColorRampDialog : public QDialog, private Ui::Qgs
 
     void updatePreview();
 
-    QgsColorBrewerColorRamp* mRamp;
+    QgsColorBrewerColorRamp mRamp;
 };
 
 #endif