Qt example: Updated to follow advice from @alexallmont

Author: paulbendixen

CMakeLists.txt

@@ -33,10 +33,9 @@ else()
  -Wpedantic # warn if non-standard C++ is used
  -Wconversion # warn on type conversions that may lose data
  -Wsign-conversion # warn on sign conversions
- #-Wmisleading-indentation # warn if identation implies blocks where blocks
- # do not exist
- #-Wduplicated-cond # warn if if / else chain has duplicated conditions
- #-Wduplicated-branches # warn if if / else branches have duplicated code
+ #-Wmisleading-indentation # warn if identation implies blocks where blocks do not exist
+ #-Wduplicated-cond # warn if if / else chain has duplicated conditions
+ #-Wduplicated-branches # warn if if / else branches have duplicated code
  -Wlogical-op # warn about logical operations being used where bitwise were
  # probably wanted
  #-Wnull-dereference # warn if a null dereference is detected
@@ -61,12 +60,7 @@ add_test(Tester tester)
 #qt
 if( DEFINED CPP_STARTER_USE_QT )
 message( "Using Qt" )
-find_package( Qt5Widgets REQUIRED )
-set( CMAKE_AUTOMOC ON )
-add_executable( helloQt qt/qtMain.cpp qt/HelloQt.cpp )
-#set_target_properties( helloQt PROPERTIES CMAKE_AUTOMOC ON )
-target_link_libraries( helloQt Qt5::Widgets )
-target_compile_features( helloQt PUBLIC cxx_nullptr cxx_lambdas )
+add_subdirectory(qt)
 endif()
 
 #fltk test

qt/CMakeLists.txt

@@ -0,0 +1,6 @@
+find_package( Qt5Widgets REQUIRED )
+set( CMAKE_AUTOMOC ON )
+add_executable( helloQt qtMain.cpp HelloQt.cpp )
+#set_target_properties( helloQt PROPERTIES CMAKE_AUTOMOC ON )
+target_link_libraries( helloQt Qt5::Widgets )
+target_compile_features( helloQt PUBLIC cxx_nullptr cxx_lambdas )

qt/HelloQt.cpp

@@ -5,41 +5,43 @@
 #include <QLabel>
 #include <QDebug>
 
-HelloQt::HelloQt( QWidget* parent )
-:QWidget( parent )
-{
-// The memory management is not done explicitly but by using the parent relationship built into Qt
-// The tr calls are not strictly neccesary, but it is all that is needed for future i18n.
-auto mainLayout = new QVBoxLayout;
-auto descriptiveLabel = new QLabel( tr("Descriptive") );
-auto pushButton = new QPushButton( tr("Push me!") );
-auto grouping = new QHBoxLayout;
-auto directButton = new QPushButton( tr( "Directly!" ) );
-auto fatal = new QPushButton( tr( "Don't push this button" ) );
-// By adding the widgets to the main widget, they get parented and the parenting takes care of freeing the memory
-grouping->addWidget( descriptiveLabel );
-grouping->addWidget( pushButton );
-mainLayout->addLayout( grouping );
-mainLayout->addWidget( directButton );
-mainLayout->addWidget( fatal );
-setLayout( mainLayout );
-// Signals and slots are use to simply define relationships between actions and effects
-// By using this "new style" connect the types are checked at compile time to match
-connect( pushButton, &QPushButton::clicked, this, &HelloQt::writeToDebug );
-// Lambdas can also be used as can ordinary freestanding functions
-connect( directButton, &QPushButton::clicked, [](){ qDebug() << tr( "I am in line" ); } );
-// Most usefull signals and slots are already built into the framework.
-connect( fatal, &QPushButton::clicked, this, &HelloQt::close );
+HelloQt::HelloQt(QWidget *parent) : QWidget(parent) {
+ // The memory management is not done explicitly but by using the parent
+ // relationship built into Qt
+ // The tr calls are not strictly neccesary, but it is all that is needed for
+ // future i18n.
+ auto mainLayout = new QVBoxLayout;
+ auto descriptiveLabel = new QLabel(tr("Descriptive"));
+ auto pushButton = new QPushButton(tr("Push me!"));
+ auto grouping = new QHBoxLayout;
+ auto directButton = new QPushButton(tr("Directly!"));
+ auto fatal = new QPushButton(tr("Don't push this button"));
+ // By adding the widgets to the main widget, they get parented and the
+ // parenting takes care of freeing the memory.
+ // Laying out in layouts makes the GUI automatically resize.
+ grouping->addWidget(descriptiveLabel);
+ grouping->addWidget(pushButton);
+ mainLayout->addLayout(grouping);
+ mainLayout->addWidget(directButton);
+ mainLayout->addWidget(fatal);
+ setLayout(mainLayout);
+ // Signals and slots are use to simply define relationships between actions
+ // and effects
+ // By using this "new style" connect the types are checked at compile time to
+ // match
+ connect(pushButton, &QPushButton::clicked, this, &HelloQt::writeToDebug);
+ // Lambdas can also be used as can ordinary freestanding functions
+ connect(directButton, &QPushButton::clicked,
+ []() { qDebug() << tr("I am in line"); });
+ // Most usefull signals and slots are already built into the framework.
+ connect(fatal, &QPushButton::clicked, this, &HelloQt::close); // could just use close
 };
 
-HelloQt::~HelloQt()
-{
-// Nothing to do here, the parent system makes sure that all the elements that are 
-// parented to this is cleaned up
+HelloQt::~HelloQt() {
+ // Nothing to do here, the parent system makes sure that all the elements that
+ // are parented to this is cleaned up
 }
 
-void HelloQt::writeToDebug( void )
-{
-qDebug() << tr( "I don't know what I was supposed to debug here..." );
+void HelloQt::writeToDebug(void) {
+ qDebug() << tr("I don't know what I was supposed to debug here...");
 }
-

qt/HelloQt.hpp

@@ -2,11 +2,11 @@
 
 class HelloQt : public QWidget
 {
-Q_OBJECT // Very Important, this is all the magic that is needed
-public:
-explicit HelloQt( QWidget* parent = nullptr );
-~HelloQt();
-private slots:
-void writeToDebug( void );
+ Q_OBJECT // Very Important, this is all the magic that is needed
+ public:
+ explicit HelloQt(QWidget* parent = nullptr);
+ ~HelloQt();
+ private slots:
+ void writeToDebug();
 
 };

qt/qtMain.cpp

@@ -1,12 +1,12 @@
 #include "HelloQt.hpp"
 #include <QApplication>
 
-int main( int argc, char* argv[] )
+int main(int argc, char* argv[])
 {
-QApplication app( argc, argv );
-HelloQt dialog;
-dialog.show();
+ QApplication app(argc, argv);
+ HelloQt dialog;
+ dialog.show();
 
-return app.exec(); // this runs the main event loop and sees to it that cleanup is done
+ return app.exec(); // this runs the main event loop and sees to it that cleanup is done
 }