QgsProject: cleanup of read/write method + removal of unused bad layer handler class

doc/api_break.dox

@@ -262,6 +262,7 @@ should now call QgsCoordinateReferenceSystem::invalidateCache() and QgsCoordinat
 - QgsMapLayerRegistry. Its functionality has been moved to QgsProject.
 - QgsMapRenderer. It has been replaced by QgsMapRendererJob with subclasses and QgsMapSettings.
 - QgsPseudoColorShader. This shader has been broken for some time and was replaced by QgsSingleBandPseudoColorRenderer.
+- QgsProjectBadLayerGuiHandler was removed. It was unused in QGIS code and barely useful. Implement your own QgsProjectBadLayerHandler subclass if needed.
 - QgsRendererV2DataDefinedMenus was removed. Use QgsDataDefinedButton instead.
 - QgsLegacyHelpers.
 - QgsProviderCountCalcEvent and QgsProviderExtentCalcEvent. These classes were unused in QGIS core and unmaintained.
@@ -1381,6 +1382,10 @@ QgsProject        {#qgis_api_break_3_0_QgsProject}
 - title( const QString & title ) was removed. Use setTitle() instead.
 - dirty( bool b ) was removed. Use setDirty() instead.
 - clearProperties() was removed. Use clear() instead.
+- read( QDomNode& layerNode ) was renamed to readLayer( const QDomNode& layerNode ).
+- read( const QFileInfo& file ) was replaced by read( const QString& filename ).
+- write( const QFileInfo& file ) was replaced by write( const QString& filename ).
+
 
 QgsProjectPropertyValue        {#qgis_api_break_3_0_QgsProjectPropertyValue}
 -----------------------

python/core/qgsproject.sip

@@ -106,53 +106,37 @@ class QgsProject : QObject, QgsExpressionContextGenerator
      */
     void clear();
 
-    /** Reads a project file.
+    /** Reads given project file from the given file.
      * @param file name of project file to read
-     * @note Any current plug-in state is erased
-     * @note Calling read() performs the following operations:
-     *
-     * - Gets the extents
-     * - Creates maplayers
-     * - Registers maplayers
-     *
-     * @note it's presumed that the caller has already reset the map canvas, map registry, and legend
+     * @returns true if project file has been read successfully
      */
-    bool read( const QFileInfo& file );
+    bool read( const QString& filename );
 
-    /** Reads the current project file.
-     * @note Any current plug-in state is erased
-     * @note Calling read() performs the following operations:
-     *
-     * - Gets the extents
-     * - Creates maplayers
-     * - Registers maplayers
-     *
-     * @note it's presumed that the caller has already reset the map canvas, map registry, and legend
+    /** Reads the project from its currently associated file (see fileName() ).
+     * @returns true if project file has been read successfully
      */
     bool read();
 
     /** Reads the layer described in the associated DOM node.
+     *
+     * @note This method is mainly for use by QgsProjectBadLayerHandler subclasses
+     * that may fix definition of bad layers with the user's help in GUI. Calling
+     * this method with corrected DOM node adds the layer back to the project.
      *
      * @param layerNode represents a QgsProject DOM node that encodes a specific layer.
-     *
-     * QgsProject raises an exception when one of the QgsProject::read()
-     * implementations fails.  Since the read()s are invoked from qgisapp,
-     * then qgisapp handles the exception.  It prompts the user for the new
-     * location of the data, if any.  If there is a new location, the DOM
-     * node associated with the layer has its datasource tag corrected.
-     * Then that node is passed to this member function to be re-opened.
-     *
      */
-    bool read( QDomNode& layerNode );
-    bool write(const QString& filename);
+    bool readLayer( const QDomNode& layerNode );
 
-    /** Writes the project to a file.
-     * @param file destination file
+    /**
+     * Writes the project to a file.
+     * @param filename destination file
      * @note calling this implicitly sets the project's filename (see setFileName() )
      * @note isDirty() will be set to false if project is successfully written
      * @returns true if project was written successfully
+     *
+     * \note Added in QGIS 3.0
      */
-    bool write( const QFileInfo& file );
+    bool write( const QString& filename );
 
     /** Writes the project to its current associated file (see fileName() ).
      * @note isDirty() will be set to false if project is successfully written

python/core/qgsprojectbadlayerhandler.sip

@@ -32,7 +32,6 @@ class QgsProjectBadLayerHandler
      * log.
      *
      * @note Added in QGIS 3.0
-     * @see QgsProjectBadLayerGuiHandler
      */
     virtual void handleBadLayers( const QList<QDomNode>& layers );
     virtual ~QgsProjectBadLayerHandler();

python/gui/gui.sip

@@ -140,7 +140,6 @@
 %Include qgspluginmanagerinterface.sip
 %Include qgspresetcolorrampdialog.sip
 %Include qgsprevieweffect.sip
-%Include qgsprojectbadlayerguihandler.sip
 %Include qgsprojectionselectionwidget.sip
 %Include qgsprojectionselector.sip
 %Include qgsquerybuilder.sip

python/gui/qgsprojectbadlayerguihandler.sip

@@ -1,47 +0,0 @@
-
-/** \ingroup gui
-  Handler for missing layers within project.
-
-  Gives user a chance to select path to the missing layers.
- */
-class QgsProjectBadLayerGuiHandler : QObject, QgsProjectBadLayerHandler
-{
-%TypeHeaderCode
-#include <qgsprojectbadlayerguihandler.h>
-%End
-
-  public:
-    QgsProjectBadLayerGuiHandler();
-
-    /** Implementation of the handler */
-    virtual void handleBadLayers( const QList<QDomNode>& layers );
-
-    /** Flag to store the Ignore button press of MessageBox used by QgsLegend */
-    static bool mIgnore;
-
-  protected:
-    /** This is used to locate files that have moved or otherwise are missing */
-    bool findMissingFile( const QString& fileFilters, QDomNode& layerNode );
-
-    /**
-     * Find relocated data source for the given layer
-     *
-     * This QDom object represents a QgsProject node that maps to a specific layer.
-     *
-     * @param fileFilters file filters to use
-     * @param constLayerNode QDom node containing layer project information
-     *
-     * @todo
-     *
-     * XXX Only implemented for file based layers.  It will need to be extended for
-     * XXX other data source types such as databases.
-     */
-    bool findLayer( const QString& fileFilters, const QDomNode& constLayerNode );
-
-    /**
-     * Find relocated data sources for given layers
-     * These QDom objects represent QgsProject nodes that map to specific layers.
-     */
-    void findLayers( const QString& fileFilters, const QList<QDomNode>& layerNodes );
-
-};

src/app/qgshandlebadlayers.cpp

@@ -369,7 +369,7 @@ void QgsHandleBadLayers::apply()
     QString datasource = item->text();
 
     node.namedItem( QStringLiteral( "datasource" ) ).toElement().firstChild().toText().setData( datasource );
-    if ( QgsProject::instance()->read( node ) )
+    if ( QgsProject::instance()->readLayer( node ) )
     {
       mLayerList->removeRow( i-- );
     }

src/app/qgsoptions.cpp

@@ -973,7 +973,7 @@ void QgsOptions::on_cbxProjectDefaultNew_toggled( bool checked )
 void QgsOptions::on_pbnProjectDefaultSetCurrent_clicked()
 {
   QString fileName = QgsApplication::qgisSettingsDirPath() + QStringLiteral( "project_default.qgs" );
-  if ( QgsProject::instance()->write( QFileInfo( fileName ) ) )
+  if ( QgsProject::instance()->write( fileName ) )
   {
     QMessageBox::information( nullptr, tr( "Save default project" ), tr( "Current project saved as default" ) );
   }

src/core/qgsproject.cpp

@@ -757,9 +757,9 @@ bool QgsProject::addLayer( const QDomElement &layerElem, QList<QDomNode> &broken
   }
 }
 
-bool QgsProject::read( const QFileInfo& file )
+bool QgsProject::read( const QString& filename )
 {
-  mFile.setFileName( file.filePath() );
+  mFile.setFileName( filename );
 
   return read();
 }
@@ -1123,7 +1123,7 @@ void QgsProject::cleanTransactionGroups( bool force )
     emit transactionGroupsChanged();
 }
 
-bool QgsProject::read( QDomNode &layerNode )
+bool QgsProject::readLayer( const QDomNode& layerNode )
 {
   QList<QDomNode> brokenNodes;
   QList< QPair< QgsVectorLayer*, QDomElement > > vectorLayerList;
@@ -1154,13 +1154,6 @@ bool QgsProject::write( const QString& filename )
   return write();
 }
 
-bool QgsProject::write( QFileInfo const &file )
-{
-  mFile.setFileName( file.filePath() );
-
-  return write();
-}
-
 bool QgsProject::write()
 {
   clearError();

src/core/qgsproject.h

@@ -166,44 +166,26 @@ class CORE_EXPORT QgsProject : public QObject, public QgsExpressionContextGenera
      */
     void clear();
 
-    /** Reads a project file.
+    /** Reads given project file from the given file.
      * @param file name of project file to read
-     * @note Any current plug-in state is erased
-     * @note Calling read() performs the following operations:
-     *
-     * - Gets the extents
-     * - Creates maplayers
-     * - Registers maplayers
-     *
-     * @note it's presumed that the caller has already reset the map canvas, map registry, and legend
+     * @returns true if project file has been read successfully
      */
-    bool read( const QFileInfo& file );
+    bool read( const QString& filename );
 
-    /** Reads the current project file.
-     * @note Any current plug-in state is erased
-     * @note Calling read() performs the following operations:
-     *
-     * - Gets the extents
-     * - Creates maplayers
-     * - Registers maplayers
-     *
-     * @note it's presumed that the caller has already reset the map canvas, map registry, and legend
+    /** Reads the project from its currently associated file (see fileName() ).
+     * @returns true if project file has been read successfully
      */
     bool read();
 
     /** Reads the layer described in the associated DOM node.
+     *
+     * @note This method is mainly for use by QgsProjectBadLayerHandler subclasses
+     * that may fix definition of bad layers with the user's help in GUI. Calling
+     * this method with corrected DOM node adds the layer back to the project.
      *
      * @param layerNode represents a QgsProject DOM node that encodes a specific layer.
-     *
-     * QgsProject raises an exception when one of the QgsProject::read()
-     * implementations fails.  Since the read()s are invoked from qgisapp,
-     * then qgisapp handles the exception.  It prompts the user for the new
-     * location of the data, if any.  If there is a new location, the DOM
-     * node associated with the layer has its datasource tag corrected.
-     * Then that node is passed to this member function to be re-opened.
-     *
      */
-    bool read( QDomNode& layerNode );
+    bool readLayer( const QDomNode& layerNode );
 
     /**
      * Writes the project to a file.
@@ -216,14 +198,6 @@ class CORE_EXPORT QgsProject : public QObject, public QgsExpressionContextGenera
      */
     bool write( const QString& filename );
 
-    /** Writes the project to a file.
-     * @param file destination file
-     * @note calling this implicitly sets the project's filename (see setFileName() )
-     * @note isDirty() will be set to false if project is successfully written
-     * @returns true if project was written successfully
-     */
-    bool write( const QFileInfo& file );
-
     /** Writes the project to its current associated file (see fileName() ).
      * @note isDirty() will be set to false if project is successfully written
      * @returns true if project was written successfully

src/core/qgsprojectbadlayerhandler.h

@@ -35,7 +35,6 @@ class CORE_EXPORT QgsProjectBadLayerHandler
      * log.
      *
      * @note Added in QGIS 3.0
-     * @see QgsProjectBadLayerGuiHandler
      */
     virtual void handleBadLayers( const QList<QDomNode>& layers );
     virtual ~QgsProjectBadLayerHandler() = default;

src/gui/CMakeLists.txt

@@ -287,7 +287,6 @@ SET(QGIS_GUI_SRCS
   qgspluginmanagerinterface.cpp
   qgspresetcolorrampdialog.cpp
   qgsprevieweffect.cpp
-  qgsprojectbadlayerguihandler.cpp
   qgsprojectionselectionwidget.cpp
   qgsprojectionselector.cpp
   qgsquerybuilder.cpp
@@ -450,7 +449,6 @@ SET(QGIS_GUI_MOC_HDRS
   qgspluginmanagerinterface.h
   qgspresetcolorrampdialog.h
   qgsprevieweffect.h
-  qgsprojectbadlayerguihandler.h
   qgsprojectionselectionwidget.h
   qgsprojectionselector.h
   qgsquerybuilder.h

src/gui/qgsprojectbadlayerguihandler.cpp

@@ -1,190 +0,0 @@
-/***************************************************************************
-    qgsprojectbadlayerguihandler.cpp - handle bad layers
-    ---------------------
-    begin                : December 2009
-    copyright            : (C) 2009 by Martin Dobias
-    email                : wonder dot sk at gmail dot 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 "qgsprojectbadlayerguihandler.h"
-
-#include <QApplication>
-#include <QDomDocument>
-#include <QFileInfo>
-#include <QMessageBox>
-#include <QPushButton>
-
-#include "qgslogger.h"
-#include "qgisgui.h"
-#include "qgsproviderregistry.h"
-#include "qgsproject.h"
-#include "qgsapplication.h"
-
-QgsProjectBadLayerGuiHandler::QgsProjectBadLayerGuiHandler()
-{
-}
-
-bool QgsProjectBadLayerGuiHandler::mIgnore = false;
-
-void QgsProjectBadLayerGuiHandler::handleBadLayers( const QList<QDomNode>& layers )
-{
-  QgsDebugMsg( QString( "%1 bad layers found" ).arg( layers.size() ) );
-
-  // make sure we have arrow cursor (and not a wait cursor)
-  QApplication::setOverrideCursor( Qt::ArrowCursor );
-
-  QMessageBox messageBox;
-
-  QAbstractButton *ignoreButton =
-    messageBox.addButton( tr( "Ignore" ), QMessageBox::ActionRole );
-
-  QAbstractButton *okButton = messageBox.addButton( QMessageBox :: Ok );
-
-  messageBox.addButton( QMessageBox :: Cancel );
-
-  messageBox.setWindowTitle( tr( "QGIS Project Read Error" ) );
-  messageBox.setText( tr( "Unable to open one or more project layers.\nChoose "
-                          "ignore to continue loading without the missing layers. Choose cancel to "
-                          "return to your pre-project load state. Choose OK to try to find the "
-                          "missing layers." ) );
-  messageBox.setIcon( QMessageBox::Critical );
-  messageBox.exec();
-
-  QgsProjectBadLayerGuiHandler::mIgnore = false;
-
-  if ( messageBox.clickedButton() == okButton )
-  {
-    QgsDebugMsg( "want to find missing layers is true" );
-
-    // attempt to find the new locations for missing layers
-    // XXX vector file hard-coded -- but what if it's raster?
-
-    QString filter = QgsProviderRegistry::instance()->fileVectorFilters();
-    findLayers( filter, layers );
-  }
-  else if ( messageBox.clickedButton() == ignoreButton )
-  {
-    QgsProjectBadLayerGuiHandler::mIgnore = true;
-  }
-  else
-  {
-    // Do nothing
-  }
-
-  QApplication::restoreOverrideCursor();
-}
-
-bool QgsProjectBadLayerGuiHandler::findLayer( const QString& fileFilters, const QDomNode& constLayerNode )
-{
-  // XXX actually we could possibly get away with a copy of the node
-  QDomNode& layerNode = const_cast<QDomNode&>( constLayerNode );
-
-  bool retVal = false;
-
-  switch ( providerType( layerNode ) )
-  {
-    case IS_FILE:
-      QgsDebugMsg( "layer is file based" );
-      retVal = findMissingFile( fileFilters, layerNode );
-      break;
-
-    case IS_DATABASE:
-      QgsDebugMsg( "layer is database based" );
-      break;
-
-    case IS_URL:
-      QgsDebugMsg( "layer is URL based" );
-      break;
-
-    case IS_Unknown:
-      QgsDebugMsg( "layer has an unknown type" );
-      break;
-  }
-  return retVal;
-}
-bool QgsProjectBadLayerGuiHandler::findMissingFile( const QString& fileFilters, QDomNode& layerNode )
-{
-  // Prepend that file name to the valid file format filter list since it
-  // makes it easier for the user to not only find the original file, but to
-  // perhaps find a similar file.
-
-  QFileInfo originalDataSource( dataSource( layerNode ) );
-
-  QString memoryQualifier;    // to differentiate between last raster and
-  // vector directories
-
-  switch ( dataType( layerNode ) )
-  {
-    case IS_VECTOR:
-    {
-      memoryQualifier = QStringLiteral( "lastVectorFileFilter" );
-
-      break;
-    }
-    case IS_RASTER:
-    {
-      memoryQualifier = QStringLiteral( "lastRasterFileFilter" );
-
-      break;
-    }
-    default:
-      QgsDebugMsg( "unable to determine data type" );
-      return false;
-  }
-
-  // Prepend the original data source base name to make it easier to pick it
-  // out from a list of other files; however the appropriate filter strings
-  // for the file type will also be added in case the file name itself has
-  // changed, too.
-
-  QString myFileFilters = originalDataSource.fileName() + ";;" + fileFilters;
-
-  QStringList selectedFiles;
-  QString enc;
-  QString title = QObject::tr( "Where is '%1' (original location: %2)?" )
-                  .arg( originalDataSource.fileName(),
-                        originalDataSource.absoluteFilePath() );
-
-  bool retVal = QgisGui::openFilesRememberingFilter( memoryQualifier,
-                myFileFilters,
-                selectedFiles,
-                enc,
-                title,
-                true );
-
-  if ( selectedFiles.isEmpty() )
-  {
-    return retVal;
-  }
-  else
-  {
-    setDataSource( layerNode, selectedFiles.first() );
-    if ( ! QgsProject::instance()->read( layerNode ) )
-    {
-      QgsDebugMsg( "unable to re-read layer" );
-    }
-  }
-  return retVal;
-}
-
-void QgsProjectBadLayerGuiHandler::findLayers( const QString& fileFilters, const QList<QDomNode>& layerNodes )
-{
-
-  for ( QList<QDomNode>::const_iterator i = layerNodes.begin();
-        i != layerNodes.end();
-        ++i )
-  {
-    if ( findLayer( fileFilters, *i ) )
-    {
-      // If findLayer returns true, the user hit Cancel All button
-      break;
-    }
-  }
-}

src/gui/qgsprojectbadlayerguihandler.h

@@ -1,65 +0,0 @@
-/***************************************************************************
-    qgsprojectbadlayerguihandler.h - handle bad layers
-    ---------------------
-    begin                : December 2009
-    copyright            : (C) 2009 by Martin Dobias
-    email                : wonder dot sk at gmail dot 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 QGSPROJECTBADLAYERGUIHANDLER_H
-#define QGSPROJECTBADLAYERGUIHANDLER_H
-
-#include "qgsprojectbadlayerhandler.h"
-#include <QObject>
-
-/** \ingroup gui
-  Handler for missing layers within project.
-
-  Gives user a chance to select path to the missing layers.
- */
-class GUI_EXPORT QgsProjectBadLayerGuiHandler : public QObject, public QgsProjectBadLayerHandler
-{
-    Q_OBJECT
-
-  public:
-    QgsProjectBadLayerGuiHandler();
-
-    virtual void handleBadLayers( const QList<QDomNode>& layers ) override;
-
-    //! Flag to store the Ignore button press of MessageBox used by QgsLegend
-    static bool mIgnore;
-
-  protected:
-    //! This is used to locate files that have moved or otherwise are missing
-    bool findMissingFile( const QString& fileFilters, QDomNode& layerNode );
-
-    /**
-     * Find relocated data source for the given layer
-     *
-     * This QDom object represents a QgsProject node that maps to a specific layer.
-     *
-     * @param fileFilters file filters to use
-     * @param constLayerNode QDom node containing layer project information
-     *
-     * @todo
-     *
-     * XXX Only implemented for file based layers.  It will need to be extended for
-     * XXX other data source types such as databases.
-     */
-    bool findLayer( const QString& fileFilters, const QDomNode& constLayerNode );
-
-    /**
-     * Find relocated data sources for given layers
-     * These QDom objects represent QgsProject nodes that map to specific layers.
-     */
-    void findLayers( const QString& fileFilters, const QList<QDomNode>& layerNodes );
-
-};
-
-#endif // QGSPROJECTBADLAYERGUIHANDLER_H

tests/bench/qgsbench.cpp

@@ -141,8 +141,7 @@ QgsBench::~QgsBench()
 
 bool QgsBench::openProject( const QString & theFileName )
 {
-  QFileInfo file( theFileName );
-  if ( ! QgsProject::instance()->read( file ) )
+  if ( ! QgsProject::instance()->read( theFileName ) )
   {
     return false;
   }