3D Slicer Qt Port

Julien FinetKitware Inc.Dec. 16th 2009

Background

• 3D Slicer version 3.x use KWWidgets– VTK-style interface to Tk– 3D Slicer 1.x, 2.x used Tk directly

• Qt 4.6– Embedded Linux, Mac OS X, Windows, Linux/X11,

Windows CE/Mobile, Symbian, Maemo– LGPL– 600+ classes– Tens of thousands of applications– 15+ millions of users

• NIH Supplement to help with port– 9/17/2009 - 9/16/2011

Qt – How to get Qt

• Required version: Qt 4.6• Building Slicer with Qt

– http://wiki.slicer.org/slicerWiki/index.php/Slicer3:Developers:Projects:QtSlicer/Tutorials/CompileWithQt

• Links: – Doc: http://qt.nokia.com/doc/4.6/index.html– Tutorials:

http://qt.nokia.com/doc/4.6/tutorials.html

Qt – First steps

• Hello World

• Signals / Slots

• Events vs Signals/Slots

• Layouts

• What QObject does for you ?– Parent / child relationship

• Designer

• Not only GUI widgets in Qt

Qt in Slicer

• Events with KWWidgets1. Fire event

2. Connect

3. Process

void vtkSlicerCamerasGUI::AddGUIObservers(){ … this->ViewSelectorWidget->AddObserver( vtkSlicerNodeSelectorWidget::NodeSelectedEvent, (vtkCommand *)this->GUICallbackCommand ); …}

void vtkSlicerCamerasGUI::ProcessGUIEvents( vtkObject *caller, unsigned long event, void *callData ){ if (vtkSlicerNodeSelectorWidget::SafeDownCast(caller)) { if (event == vtkSlicerNodeSelectorWidget::NodeSelectedEvent) { …}

void vtkSlicerNodeSelectorWidget::ProcessCommand(char *selectedID){ … this->InvokeEvent(vtkSlicerNodeSelectorWidget::NodeSelectedEvent, NULL); …} vtkSlicerNodeSelectorWidget.cxx

vtkSlicerCamerasGUI.cxx

vtkSlicerCamerasGUI.cxx

Qt in Slicer

• Events with Qt1. Fire event

2. Connect

3. Process

void qSlicerCamerasModuleWidget::setup(){ … connect(d->ViewNodeSelector, SIGNAL(currentNodeChanged(vtkMRMLNode*)), this, SLOT(onCurrentViewNodeChanged(vtkMRMLNode*))); …}

void qSlicerCamerasModuleWidget::onCurrentViewNodeChanged(vtkMRMLNode* mrmlNode){ vtkMRMLViewNode* currentViewNode = vtkMRMLViewNode::SafeDownCast(mrmlNode); …}

void qMRMLNodeSelector::nodeIdSelected(int index){ … emit currentNodeChanged(d->MRMLCurrentNode);}

qSlicerCamerasModuleWidget.cxx

qSlicerCamerasModuleWidget.cxx

qMRMLNodeSelector.cxx

Qt and VTK

• qVTKConnect() – Based on

VTK/GUISupport/Qt/vtkEventQtSlotConnect

void qMRMLNodeSelector::addNode(vtkMRMLNode* mrmlNode){ … this->qvtkConnect(mrmlNode, vtkCommand::ModifiedEvent, this, SLOT(onMRMLNodeModified(vtkObject*, void*))); …}

// qVTK includes#include <qVTKObject.h>…class QMRML_WIDGETS_EXPORT qMRMLNodeSelector : public qCTKAddRemoveComboBox{ Q_OBJECT QVTK_OBJECTpublic: … qMRMLNodeSelector.h

qMRMLNodeSelector.cxx

QVTK_OBJECT adds the function qvtkConnect()

Porting Slicer to Qt

• Create Qt/KWW co-existence layer (done!)• Prototype a few modules (done!)• Create an architecture for Qt based modules

(in process)• Train developers (first session at January

2010 Project Week)• Port modules (ongoing through 2010…)• Turn off KWW (by end of 2010?)• Continual Improvement (through end of

supplement and beyond…)

Porting Slicer to Qt

• Slicer: Qt only

• Slicer: KWWidgets + Qt

Executable: Slicer3

Executable: SlicerQT

Modules

• Core Modules: Slicer3/Base/QTCoreModules– qSlicerTransformsModule

• Loadable Modules: Slicer3/QTModules– Measurements– Volumes

• CLI Modules

Plugin Mechanism

• Previously: itksys::DynamicLoader(dlopen)

• Now: Use the QT Plugins framework…class Q_SLICER_QTMODULES_VOLUMES_EXPORT qSlicerVolumesModule : public qSlicerAbstractLoadableModule{ Q_INTERFACES(qSlicerAbstractLoadableModule);public: …};

…Q_EXPORT_PLUGIN2(qSlicerVolumesModule, qSlicerVolumesModule);…

QPluginLoader loader;loader.setFileName(pluginPath);loader.load();QObject * object = this->Loader.instance();qSlicerAbstractLoadableModule* module = qobject_cast<qSlicerAbstractLoadableModule*>(object); Plugin Loader

Plugin implementation

Plugin header

Modules: Logic + UI

Logic(qSlicerAbstractModuleLogic)

create()create() create()create()

UI (qSlicerAbstractModuleWidget)

Module(qSlicerAbstractModule)

vtkMRMLScene

QWidget

QObject

How to write a loadable module

• Create directories in Slicer3/QTModules– MyModule– MyModule/Resources– MyModule/Resources/UI– MyModule/Resources/Icons (optional)

• Create the files– MyModule/CMakeLists.txt– MyModule/qSlicerMyModule.[h/cxx]– MyModule/qSlicerMyModuleWidget.[h/cxx]– MyModule/qSlicerMyModuleLogic.[h/cxx] (optional)– MyModule/Resources/qSlicerMyModule.qrc (optional)– MyModule/Resources/UI/qSlicerMyModule.ui

MyModule UI – 1 / 4

• Open Qt Designer with QT_PLUGIN_PATH set to “Slicer3-build/bin” – Designing a module UI requires the plugins:

qCTKWidgets, qVTKWidgets, qMRMLWidgets and qSlicerBaseQTGUI

– Warning: plugins must be compiled under the same mode than Qt (Release vs. Debug)

– On Linux: cd Slicer3-build; python Designer.py– More info on

http://wiki.slicer.org/slicerWiki/index.php/Slicer3:Developers:Projects:QtSlicer/Tutorials/QtDesigner

My Module UI – 2 / 4

• Create a UI form:– MyModule/Resources/UI/qSlicerMyModule.ui

• qSlicerWidget has the signal mrmlSceneChanged()

Qt Designer

MyModule UI – 3 / 4

Drag widgets on the form

Names are important Qt Designer

My Module UI – 4 / 4

Connect widgets together with the signals/slots

Here the MRMLScene of the module is propagated to the NodeSelector

Qt Designer

MyModule Resources

• If icons are used, they should be in – MyModule/Resources/Icons/

• Update the resource .qrc file– MyModule/Resources/qSlicerMyModule.qrc

<!DOCTYPE RCC><RCC version="1.0"> <qresource> <file>Icons/MyIcon.png</file> …</qresource></RCC> qSlicerMyModule.qrc

qSlicerMyModule.h#ifndef __qSlicerMyModule_h#define __qSlicerMyModule_h

// SlicerQT includes#include "qSlicerAbstractLoadableModule.h“

#include "qSlicerMyModuleWin32Header.h“ // generated by CMakeclass qSlicerMyModulePrivate;

class Q_SLICER_QTMODULES_MYMODULE_EXPORT qSlicerMyModule : public qSlicerAbstractLoadableModule{ Q_OBJECTpublic: qSlicerTransformsModule(QObject *parent=0);

virtual QString title()const { return “Transforms”; }

virtual QString helpText()const; virtual QString acknowledgementText()const;

protected: // Create and return a widget representation of the object virtual qSlicerAbstractModuleWidget * createWidgetRepresentation(); virtual qSlicerAbstractModuleLogic* createLogic();};#endif qSlicerMyModule.h

qSlicerMyModule.cxx#include "qSlicerMyModule.h"

// SlicerQT includes#include "qSlicerMyModuleWidget.h"

// QT includes#include <QtPlugin>//-----------------------------------------------------------------------------Q_EXPORT_PLUGIN2(qSlicerMyModule, qSlicerMyModule);//-----------------------------------------------------------------------------qSlicerWelcomeModule(QObject* parent) :public qSlicerAbstractLoadableModule(parent){}//-----------------------------------------------------------------------------qSlicerAbstractModuleWidget * qSlicerWelcomeModule::createWidgetRepresentation(){ return new qSlicerWelcomeModuleWidget;}//-----------------------------------------------------------------------------qSlicerAbstractModuleWidget * qSlicerTransformsModule::createWidgetRepresentation(){ return new qSlicerMyModuleWidget;}//-----------------------------------------------------------------------------qSlicerAbstractModuleLogic* qSlicerTransformsModule::createLogic(){ return 0;}

Instantiate the UI widget

qSlicerMyModule.cxx

qSlicerMyModuleWidget.h

#ifndef __qSlicerMyModuleWidget_h#define __qSlicerMyModuleWidget_h

// SlicerQT includes#include "qSlicerAbstractModuleWidget.h"

// qCTK includes#include <qCTKPimpl.h>

#include "qSlicerMyModuleWin32Header.h"

class qSlicerMyModuleWidgetPrivate;

class Q_SLICER_QTMODULES_MYMODULE_EXPORT qSlicerMyModuleWidget : public qSlicerAbstractModuleWidget{ Q_OBJECTpublic: typedef qSlicerAbstractModuleWidget Superclass; qSlicerMyModuleWidget(QWidget *parent=0);

protected: virtual void setup();

private: QCTK_DECLARE_PRIVATE(qSlicerMyModuleWidget);};

#endif

Generated by CMake

Setup the UI

qSlicerMyModuleWidget.h

qSlicerMyModuleWidget.cxx

#include "qSlicerMyModuleWidget.h"#include "ui_qSlicerMyModule.h"

//-----------------------------------------------------------------------------struct qSlicerMyModuleWidgetPrivate: public qCTKPrivate<qSlicerMyModuleWidget>, public Ui_qSlicerMyModule{};

//-----------------------------------------------------------------------------qSlicerMyModuleWidget ::qSlicerMyModuleWidget( QWidget* parent) :qSlicerAbstractModuleWidget(parent){ QCTK_INIT_PRIVATE(qSlicerMyModuleWidget);}

//-----------------------------------------------------------------------------void qSlicerWelcomeModuleWidget::setup(){ QCTK_D(qSlicerWelcomeModuleWidget); d->setupUi(this);}

Generated by CMake (via uic) from qSlicerMyModule.ui

Creates the QWidgets

…void setupUi(qSlicerWidget *qSlicerMyModule){ … verticalLayout = new QVBoxLayout(qSlicerMyModule); CTKCollapsibleButton = new qCTKCollapsibleButton(qSlicerMyModule); CTKCollapsibleButton->setCollapsed(true);

horizontalLayout = new QHBoxLayout(CTKCollapsibleButton); label = new QLabel(CTKCollapsibleButton); horizontalLayout->addWidget(label);

horizontalSlider = new QSlider(CTKCollapsibleButton); …} Ui_qSlicerMyModule.h

qSlicerMyModuleWidget.cxx

MyModule project

• Create a CMakeLists.txt in MyModule

• Add your module name in QTModules/CMakeLists.txt

SET(qt_module_SRCS qSlicerMyModule.cxx qSlicerMyModule.h qSlicerMyModuleWidget.cxx qSlicerMyModuleWidget.h )Slicer3_build_qtmodule( NAME “MyModule” TITLE “My Module” EXPORT_DIRECTIVE "Q_SLICER_QTMODULES_MYMODULE_EXPORT“ SRCS ${qt_module_SRCS} MOC_SRCS qSlicerMyModuleWidget.h UI_SRCS Resources/UI/qSlicerMyModule.ui TARGET_LIBRARIES ${qt_module_target_libraries} RESOURCES Resources/qSlicerMyModule.qrc ) QTModules/MyModule/CMakeLists.txt

Tadam !

MyModule Panelhere

MyModule

Slicer3

Module: with a logic and slots:qSlicerTransformsModuleWidget

class … qSlicerTransformsModuleWidget : public qSlicerAbstractModuleWidget{ Q_OBJECT …public slots: void loadTransform();…};

struct qSlicerTransformsModuleWidgetPrivate: public qCTKPrivate<qSlicerTransformsModuleWidget>, public Ui_qSlicerTransformsModule{ qSlicerTransformsModuleLogic* logic() const;};

void qSlicerTransformsModuleWidget::loadTransform(){ QCTK_D(qSlicerTransformsModuleWidget); QString fileName = QFileDialog::getOpenFileName(this); d->logic()->AddTransform(fileName);}

void qSlicerTransformsModuleWidget::setup(){ QCTK_D(qSlicerTransformsModuleWidget); d->setupUi(this); …this->connect(d->LoadTransformPushButton, SIGNAL(clicked()), SLOT(loadTransform()));}

Called by the “Load Transform” pushbutton

Widgets

Library QT VTK MRML

qCTKWidgets Yes

qVTKWidgets Yes Yes

qMRMLWidgets Yes Yes Yes

qSlicerBaseQTGUI Yes Yes Yes

qCTKWidgets

• Common Toolkit (CTK)

• Currently hosted on the Slicer repository

qCTKCollapsibleButton

qCTKCollapsibleGroupBox

qCTKColorPickerButton qCTKTreeComboBox

qCTKFixedTitleComboBox

qMRMLWidgets• Depends on QT and MRML• Usually contains the slot

setMRMLScene(vtkMRMLScene*)

qMRMLNodeSelector

qMRMLMatrixWidget

qMRMLTreeWidget

qMRMLListWidget

qCTKPimpl

• Hide the implementation details of an interface

• http://en.wikipedia.org/wiki/Opaque_pointer

// qCTK includes#include "qCTKPimpl.h"

// QT includes#include <QAbstractButton>

class qCTKCollapsibleButtonPrivate;

class QCTK_WIDGETS_EXPORT qCTKCollapsibleButton : public QAbstractButton{ Q_OBJECT public: qCTKCollapsibleButton(QWidget *parent = 0);…private: QCTK_DECLARE_PRIVATE(qCTKCollapsibleButton);};

#endif

friend class qCTKCollapsibleButtonPrivate; qCTKPrivateInterface<qCTKCollapsibleButton, qCTKCollapsibleButtonPrivate> qctk_d;

Don’t forget to declare the private class

qCTKPimpl//-----------------------------------------------------------------------------class qCTKCollapsibleButtonPrivate : public qCTKPrivate<qCTKCollapsibleButton>{public: QCTK_DECLARE_PUBLIC(qCTKCollapsibleButton); void init();

bool Collapsed; …};

//-----------------------------------------------------------------------------void qCTKCollapsibleButtonPrivate::init(){ QCTK_P(qCTKCollapsibleButton); p->setCheckable(true); // checked and Collapsed are synchronized: checked != Collapsed p->setChecked(true);

this->Collapsed = false;}

//-----------------------------------------------------------------------------qCTKCollapsibleButton::qCTKCollapsibleButton(QWidget* parent) :QAbstractButton(parent){ QCTK_INIT_PRIVATE(qCTKCollapsibleButton); qctk_d()->init();}

//-----------------------------------------------------------------------------void qCTKCollapsibleButton::collapse(bool c){ QCTK_D(qCTKCollapsibleButton); if (c == d->Collapsed) { return; } …}

friend class qCTKCollapsibleButton

qctk_d.setPublic(this)

qCTKCollapsibleButtonPrivate* d = qctk_d()

qCTKCollapsibleButton* p = qctk_p()

Widgets in Qt Designer

• A plugin must be created– Slicer3/Libs/qCTKWidgets/Plugins/

qMRMLNodeSelectorPlugin.[h|cxx]– Slicer3/Libs/qMRMLWidgets/Plugins/

qMRMLNodeSelectorPlugin.[h|cxx]

• More info on– http://wiki.slicer.org/slicerWiki/index.php/

Slicer3:Developers:Projects:QtSlicer/Tutorials/WidgetWriting

Widget ExampleQt Designer

class QCTK_WIDGETS_EXPORT qCTKCollapsibleButton : public QAbstractButton{ Q_OBJECT Q_PROPERTY(bool collapsed READ collapsed WRITE setCollapsed) Q_PROPERTY(int collapsedHeight READ collapsedHeight WRITE setCollapsedHeight) …

public: void setCollapsed(bool); bool collapsed()const;

void setCollapsedHeight(int); int collapsedHeight()const;

qCTKCollapsibleButton.h

void qCTKCollapsibleButtonPrivate::init(){ QCTK_P(qCTKCollapsibleButton); … this->Collapsed = false; … this->CollapsedHeight = 10; …} qCTKCollapsibleButton.cxx

10 = default value

QTCLI

• Same idea than KWWidgets– Parse XML to build UI

• Support– Shared Libraries– Executables– Python

UI panel in Slicer

QTCLI: Example…<parameters> <label>Registration Parameters</label> <description>Parameters used for registration</description> <integer> <name>HistogramBins</name> <flag>b</flag> <longflag>histogrambins</longflag> <description>Number of histogram bins to use for Mattes Mutual Information. </description> <label>Histogram Bins</label> <default>30</default> <constraints> <minimum>1</minimum> <maximum>500</maximum> <step>5</step> </constraints> </integer>…

…qCTKCollapsibleButton* registrationParameters = new qCTKCollapsibleButton(“Registration Parameters”, this);QLabel* histogramBinLabel = new QLabel(“Histogram Bins”, registrationParameters);QSlider* histogramBin = new QSlider(registrationParameters);histogramBin->setMinimum(1);histogramBin->setMaximum(500);histogramBin->setStep(5);histogramBin->setValue(30);QObject::connect(histogramBin, SIGNAL(valueChanged(int)), this, SIGNAL(onHistogramValueChanged(int)));…

UI panel in SlicerXml description

Generated code

Slicer Architecture

QTBaseqSlicerAbstractModule, qSlicerIOManager

QTCLIqSlicerCLIModule

QTCoreModulesqSlicerCamerasModules, qSlicerTransformsModule

QTCoreqSlicerModuleFactory

QTGUIqSlicerModulePanel, qSlicerApplication, qSlicerIOManager

What’s coming soon ?

• CLI modules

• Node tree widgets

• 3D view widget

• Lookup table editor

• Slice view widget

• …

What’s in the Pipeline ?

• Wizards

• Python

• More widgets – help from the CTK community– http://www.commontk.org/cgi-bin/trac.cgi/

wiki/WidgetPlans

Questions ?