Documentation/Nightly/Developers/Tutorials/MigrationGuide/ObsoleteCodeRemoval
Contents
Obsolete Code Removal
This section documents suggested code changes after removing support for a particular features. Each category has a short description, code snippets, a suggested upgrade path, and references to relevant commits.
Qt>=5.0.0: Remove obsolete code supporting Qt4 plugin infrastructure (C++)
These changes apply to Qt loadable modules and designer plugins
qSlicerNAMEModuleWidgetsPlugin.h
Before:
#include "vtkSlicerConfigure.h" // For Slicer_HAVE_QT5 // Qt includes #ifdef Slicer_HAVE_QT5 #include <QtUiPlugin/QDesignerCustomWidgetCollectionInterface> #else #include <QDesignerCustomWidgetCollectionInterface> #endif [...] class Q_SLICER_MODULE_SUBJECTHIERARCHY_WIDGETS_PLUGINS_EXPORT qSlicerSubjectHierarchyModuleWidgetsPlugin : public QObject , public QDesignerCustomWidgetCollectionInterface { Q_OBJECT #ifdef Slicer_HAVE_QT5 Q_PLUGIN_METADATA(IID "org.qt-project.Qt.QDesignerCustomWidgetCollectionInterface") #endif Q_INTERFACES(QDesignerCustomWidgetCollectionInterface);
After:
// Qt includes #include <QtUiPlugin/QDesignerCustomWidgetCollectionInterface> [...] class Q_SLICER_MODULE_SUBJECTHIERARCHY_WIDGETS_PLUGINS_EXPORT qSlicerSubjectHierarchyModuleWidgetsPlugin : public QObject , public QDesignerCustomWidgetCollectionInterface { Q_OBJECT Q_PLUGIN_METADATA(IID "org.qt-project.Qt.QDesignerCustomWidgetCollectionInterface") Q_INTERFACES(QDesignerCustomWidgetCollectionInterface);
qSlicerNAMEModule.h
Before:
class Q_SLICER_QTMODULES_SUBJECTHIERARCHY_EXPORT qSlicerSubjectHierarchyModule : public qSlicerLoadableModule { Q_OBJECT #ifdef Slicer_HAVE_QT5 Q_PLUGIN_METADATA(IID "org.slicer.modules.loadable.qSlicerLoadableModule/1.0"); #endif
After:
class Q_SLICER_QTMODULES_SUBJECTHIERARCHY_EXPORT qSlicerSubjectHierarchyModule : public qSlicerLoadableModule { Q_OBJECT Q_PLUGIN_METADATA(IID "org.slicer.modules.loadable.qSlicerLoadableModule/1.0");
qSlicerNAMEModuleWidgetsAbstractPlugin.h
Before:
#include <QtGlobal> #if(QT_VERSION < QT_VERSION_CHECKS(5, 0, 0)) #include <QDesignerCustomWidgetInterface> #else #include <QtUiPlugin/QDesignerCustomWidgetInterface> #endif [...] class Q_SLICER_MODULE_SEGMENTATIONS_WIDGETS_PLUGINS_EXPORT qSlicerSegmentationsModuleWidgetsAbstractPlugin : public QDesignerCustomWidgetInterface { #if (QT_VERSION >= QT_VERSION_CHECK(5, 0, 0)) Q_PLUGIN_METADATA(IID "org.qt-project.Qt.QDesignerCustomWidgetInterface") #endif Q_INTERFACES(QDesignerCustomWidgetInterface); }
After:
#include <QtUiPlugin/QDesignerCustomWidgetInterface> [...] class Q_SLICER_MODULE_SEGMENTATIONS_WIDGETS_PLUGINS_EXPORT qSlicerSegmentationsModuleWidgetsAbstractPlugin : public QDesignerCustomWidgetInterface { Q_PLUGIN_METADATA(IID "org.qt-project.Qt.QDesignerCustomWidgetInterface") Q_INTERFACES(QDesignerCustomWidgetInterface); }
qSlicerNAMEModule.cxx and qSlicerNAMEModuleWidgetsAbstractPlugin.cxx
Remove:
#if (QT_VERSION < QT_VERSION_CHECK(5, 0, 0)) #include <QtPlugin> Q_EXPORT_PLUGIN2(customwidgetplugin, qSlicerSegmentationsModuleWidgetsPlugin); #endif
Qt>=5.0.0: Simpler use of QHeaderView::setSectionResizeMode
This migration guide entry is obsolete: Documentation/Nightly/Developers/Tutorials/MigrationGuide#Qt5:_Fix_error:_.E2.80.98class_QHeaderView.E2.80.99_has_no_member_named_.E2.80.98setResizeMode.E2.80.99
Solution for Cpp
Before:
#if (QT_VERSION < QT_VERSION_CHECK(5, 0, 0)) this->SceneViewTableWidget->horizontalHeader()->setResizeMode(QHeaderView::Stretch); this->SceneViewTableWidget->horizontalHeader()->setResizeMode(QHeaderView::ResizeToContents); this->SceneViewTableWidget->horizontalHeader()->setResizeMode(SCENE_VIEW_DESCRIPTION_COLUMN, QHeaderView::Stretch); #else this->SceneViewTableWidget->horizontalHeader()->setSectionResizeMode(QHeaderView::Stretch); this->SceneViewTableWidget->horizontalHeader()->setSectionResizeMode(QHeaderView::ResizeToContents); this->SceneViewTableWidget->horizontalHeader()->setSectionResizeMode(SCENE_VIEW_DESCRIPTION_COLUMN, QHeaderView::Stretch); #endif
After:
this->SceneViewTableWidget->horizontalHeader()->setSectionResizeMode(QHeaderView::Stretch); this->SceneViewTableWidget->horizontalHeader()->setSectionResizeMode(QHeaderView::ResizeToContents); this->SceneViewTableWidget->horizontalHeader()->setSectionResizeMode(SCENE_VIEW_DESCRIPTION_COLUMN, QHeaderView::Stretch);
Solution for Python
Before:
def _setSectionResizeMode(header, *args, **kwargs): if version.parse(qt.Qt.qVersion()) < version.parse("5.0.0"): header.setResizeMode(*args, **kwargs) else: header.setSectionResizeMode(*args, **kwargs) [...] _setSectionResizeMode(self.horizontalHeader(), 0, qt.QHeaderView.Stretch)
After:
self.horizontalHeader().setSectionResizeMode(0, qt.QHeaderView.Stretch)
C++11: Update source code to use nullptr
C++11 introduced the keyword nullptr allowing to explicitly identify a pointer of type std::nullptr_t. It avoids ambiguous function overloads. See also https://stackoverflow.com/questions/20509734/null-vs-nullptr-why-was-it-replaced
Prior to supporting only C++11, 0 and NULL integral type were used to check for pointer value, and macro like Q_NULLPTR and ITK_NULLPTR macros were used to ensure usage of nullptr when C++11 support was enabled.
Updating the code base to use nullptr is a 2-step process:
- use clang-tidy for updating source code being explicitly compiled in the project.
- directly update source code not being compiled: conditionally compiled code, templated headers, comments, ...
Automatic update: Using clang-tidy
This will iteratively check files for updates. It takes a while. The sources are only modified at the end of the process, so you could cancel anytime before with no consequences.
- Compile Slicer with the CMake option -DCMAKE_EXPORT_COMPILE_COMMANDS:BOOL=ON to generate the file compile_commands.json at configuration time.
- Run clang-tidy on the generated compile_commands.json (in the build folder: Slicer-build)
run-clang-tidy.py -header-filter='.*' -checks='-*,modernize-use-nullptr' -fix
clang-tidy is a tool from clang. In Archlinux: sudo pacman -S clang, in other distros might be clang-extra-tools or similar.
clang-tidy will substitute NULL and 0 for nullptr when appropiate. It is an iterative process, so it may take time. Also, it replaces all the compiled code, including external dependencies. It is recommended to do a fresh build with the modified code, for testing it without modifications in any external repo.
Direct update: Using shell script
After clang-tidy has modified the compiled code with the help of compile_commands.json, there will still be ignored instances of NULL and 0 in some headers, and comments.
Manually replace with the following regex to change those.
1) Change NULL to nullptr except when there is a quote or an underscore in front of it. And there is not a quote after.
ack --cpp "NULL" -l --print0 | xargs -0 -n 1 sed -i 's/\([^\"\_]\)NULL\([^\"\_]\)/\1nullptr\2/g'
2) The same than before but match end of line NULL
ack --cpp "NULL" -l --print0 | xargs -0 -n 1 sed -i 's/\([^\"\_]\)NULL$/\1nullptr/g'
Replace ITK_NULLPTR
It was adapted from the ITK script in ReplaceITK_NULLPTRMacroNames.sh
git grep -l "ITK_NULLPTR" | fgrep -v CMakeLists.txt |fgrep -v .cmake | xargs sed -i -e "s/ITK_NULLPTR/nullptr/g"
C++11: Update source code to use override
Replace ITK_OVERRIDE
The regexp involving ITK were extracted from the ReplaceITK_OVERRIDEMacroNames.sh script in ITK.
git grep -l "ITK_OVERRIDE" | fgrep -v CMakeLists.txt |fgrep -v .cmake | xargs sed -i -e "s/ITK_OVERRIDE/override/g"
Replace VTK_OVERRIDE
git grep -l "VTK_OVERRIDE" | fgrep -v CMakeLists.txt |fgrep -v .cmake | xargs sed -i -e "s/VTK_OVERRIDE/override/g"