: QWidget(parent) {

// Add sample dialog will be instansiated upon Add Sample request.

addSampleDialog_ = 0;

setupModel();

setupMainLayout();

setupMainConnections();

setWindowTitle("Sample Manager 1.0 - David Leacock");

// Pop-up add sample dialog when add sample button clicked.

connect(addSampleButton_, SIGNAL(clicked()), this, SLOT(addNewSampleDialog()));

// Remove selected sample. Slot function will determine which sample is selected.

connect(removeSampleButton_, SIGNAL(clicked()), this, SLOT(removeSample()));

// When the user selects a different sample from the list (and thus the model), the QDataWidgetMapper will need to know the new index.

connect(sampleListView_->selectionModel(), SIGNAL(currentRowChanged(QModelIndex,QModelIndex)), modelToWidgetMapper_, SLOT(setCurrentModelIndex(QModelIndex)));

// Updates the sample name within the model as the user changes the name within the widget.

connect(nameEdit_, SIGNAL(textEdited(QString)), this, SLOT(updateSampleName(QString)));

// Updates the sample chemical symbol within the model as the user changes the symbol within the widget.

connect(chemEdit_, SIGNAL(textEdited(QString)), this, SLOT(updateSampleChemSymbol(QString)));

// Create QListView object and associate it with the sample model.

sampleListView_ = new QListView();

sampleListView_->setModel(sampleModel_);

// Prevent user from editing the text within the view.

sampleListView_->setEditTriggers(0);

// Set view to display column 4 (index 3) of the model, the sample title.

sampleListView_->setModelColumn(3);

// Sample list and it's groupbox layout setup.

sampleListGroupBox_ = new QGroupBox("Samples");

sampleListLayout_ = new QVBoxLayout;

sampleListLayout_->addWidget(sampleListView_);

sampleListGroupBox_->setLayout(sampleListLayout_);

nameLabel_ = new QLabel("Sample Name: ");

nameEdit_ = new QLineEdit();

chemLabel_ = new QLabel("Chemical Symbol: ");

chemEdit_ = new QLineEdit();

notesLabel_ = new QLabel("Notes: ");

notesEdit_ = new QTextEdit();

addSampleButton_ = new QPushButton("Add Sample");

removeSampleButton_ = new QPushButton("Remove Sample");

// Setup QDataWidgetMapper. Set approrpite UI elements to their respective rows in sample model.

// Set the widgets to display the first sample.

modelToWidgetMapper_ = new QDataWidgetMapper(this);

modelToWidgetMapper_->setModel(sampleModel_);

modelToWidgetMapper_->addMapping(nameEdit_, 0);

modelToWidgetMapper_->addMapping(chemEdit_, 1);

modelToWidgetMapper_->addMapping(notesEdit_, 2);

modelToWidgetMapper_->toFirst();

//Master layout

sampleWidgetLayout_ = new QHBoxLayout();

//Sample sub-layout

sampleNameLayout_ = new QHBoxLayout();

sampleChemLayout_ = new QHBoxLayout();

sampleNotesLayout_ = new QHBoxLayout();

sampleInfoLayout_ = new QVBoxLayout();

addRemoveButtonLayout_ = new QHBoxLayout();

//Add widgets to appropriate layouts

sampleNameLayout_->addWidget(nameLabel_);

sampleNameLayout_->addWidget(nameEdit_);

sampleChemLayout_->addWidget(chemLabel_);

sampleChemLayout_->addWidget(chemEdit_);

sampleNotesLayout_->addWidget(notesLabel_);

sampleNotesLayout_->addWidget(notesEdit_);

addRemoveButtonLayout_->addWidget(addSampleButton_);

addRemoveButtonLayout_->addWidget(removeSampleButton_);

sampleInfoLayout_->addLayout(sampleNameLayout_);

sampleInfoLayout_->addLayout(sampleChemLayout_);

sampleInfoLayout_->addLayout(sampleNotesLayout_);

sampleInfoLayout_->addLayout(addRemoveButtonLayout_);

//Setup master layout

sampleWidgetLayout_->addLayout(sampleInfoLayout_);

sampleWidgetLayout_->addSpacing(10);

sampleWidgetLayout_->addWidget(sampleListGroupBox_);

setLayout(sampleWidgetLayout_);

// Instantiate dialog if not done already.

if(!addSampleDialog_){

addSampleDialog_ = new QDialog(this, Qt::FramelessWindowHint);

addSampleDialog_->setFixedSize(300, 300);

setupAddSampleDialog();

connect(confirmAddSampleButton_, SIGNAL(clicked()), this, SLOT(validateNewSampleInfo()));

connect(cancelSampleAdd_, SIGNAL(clicked()), addSampleDialog_, SLOT(close()));

addSampleDialog_->setLayout(addSampleInfoLayout_);

}

addSampleDialog_->exec();

// Check to see if user has inputed a sample name.

if(newNameEdit_->text().isEmpty()){

QMessageBox msgBox;

msgBox.setText("Please add sample name.");

msgBox.exec();

} else {

// Send data from edit fields to the model to be added.

addSampleToModel(newNameEdit_->text(), newChemEdit_->text(), newNotesEdit_->toPlainText());

//Clear the fields once the sample has been added to the model. This is so when the user

//opens the addSampleDialog the previously added sample is gone from the fields.

newNameEdit_->clear();

newChemEdit_->clear();

newNotesEdit_->clear();

// Close dialog window.

addSampleDialog_->close();

}

// Models are 0-index so by getting the current row count, that number will be the value

// of the new row index.

int newSampleIndexRow = sampleModel_->rowCount();

// Sample display title is a concatenation of the name and chemical symbol and stored in the 4 column (index 3) of the model.

QString displayTitle = name + " - " + chem;

QStandardItem *newItemDisplayTitle = new QStandardItem(displayTitle);

QStandardItem *newItemName = new QStandardItem(name);

QStandardItem *newItemChemSymbol = new QStandardItem(chem);

QStandardItem *newItemNotes = new QStandardItem(notes);

sampleModel_->setItem(newSampleIndexRow, 0, newItemName);

sampleModel_->setItem(newSampleIndexRow, 1, newItemChemSymbol);

sampleModel_->setItem(newSampleIndexRow, 2, newItemNotes);

sampleModel_->setItem(newSampleIndexRow, 3, newItemDisplayTitle);

newNameLabel_ = new QLabel("Name: ");

newNameEdit_ = new QLineEdit();

newChemLabel_ = new QLabel("Chem: ");

newChemEdit_ = new QLineEdit();

newNotesLabel_ = new QLabel("Notes: ");

newNotesEdit_ = new QTextEdit();

confirmAddSampleButton_ = new QPushButton("Confirm");

cancelSampleAdd_ = new QPushButton("Cancel");

addNameLayout_ = new QHBoxLayout;

addChemLayout_ = new QHBoxLayout;

addNotesLayout_ = new QHBoxLayout;

addSampleInfoLayout_ = new QVBoxLayout;

addButtonLayout_ = new QHBoxLayout;

addNameLayout_->addWidget(newNameLabel_);

addNameLayout_->addWidget(newNameEdit_);

addChemLayout_->addWidget(newChemLabel_);

addChemLayout_->addWidget(newChemEdit_);

addNotesLayout_->addWidget(newNotesLabel_);

addNotesLayout_->addWidget(newNotesEdit_);

addButtonLayout_->addWidget(confirmAddSampleButton_);

addButtonLayout_->addWidget(cancelSampleAdd_);

addSampleInfoLayout_ = new QVBoxLayout;

addSampleInfoLayout_->addLayout(addNameLayout_);

addSampleInfoLayout_->addLayout(addChemLayout_);

addSampleInfoLayout_->addLayout(addNotesLayout_);

addSampleInfoLayout_->addLayout(addButtonLayout_);

// Grab model index of currently selected sample.

QModelIndex currentIndex = sampleListView_->selectionModel()->currentIndex();

// In order to keep the sample chemical symbol constant as the user updates the name, grab the index of the chem symbol value

// of the currently selected sample and store it as a string. Sample chem symbol is index-1 of model.

QModelIndex indexOfChem(currentIndex.model()->index(currentIndex.row(), 1, currentIndex.parent()));

QString currentChemValue_ = (indexOfChem.data(Qt::DisplayRole).toString());

// The updated sample title.

QStandardItem *item = new QStandardItem(name + " - " + currentChemValue_);

// Set item in the model at the selected index row. Recall column 4 (index 3) is the sample title.

sampleModel_->setItem(currentIndex.row(), 3, item);

// Ensure proper mapping from edit widgets to model. Behaviour is buggy without it.

modelToWidgetMapper_->submit();

// Once a single character has changed the focus is lost on the sampleListView and any additional changes to the edit will not be

// noticed by the sampleListView and cause the program to crash. This returns focus, and more imporantly the index selection, back to the sampleListView.

sampleListView_->selectionModel()->setCurrentIndex(currentIndex, QItemSelectionModel::Select);

// Grab model index of currently selected sample.

QModelIndex currentIndex = sampleListView_->selectionModel()->currentIndex();

// In order to keep the sample name constant as the user updates the chemical symbol, grab the index of the name value

// of the currently selected sample and store it as a string. Sample name is index-0 of model.

QModelIndex indexOfName(currentIndex.model()->index(currentIndex.row(), 0, currentIndex.parent()));

QString currentNameValue_ = (indexOfName.data(Qt::DisplayRole).toString());

// The updated sample title.

QStandardItem *item = new QStandardItem(currentNameValue_ + " - " + chemSymbol);

// Set the model at the selected index row. Recall column 4 (index 3) is the sample title.

sampleModel_->setItem(currentIndex.row(), 3, item);

// Ensure proper mapping from edit widgets to model. Behaviour is buggy without it.

modelToWidgetMapper_->submit();

// Once a single character has changed the focus is lost on the sampleListView and any additional changes to the edit will not be

// noticed by the sampleListView and cause program to crash. This returns focus, and more imporantly the index selection, back to the sampleListView.

sampleListView_->selectionModel()->setCurrentIndex(currentIndex, QItemSelectionModel::Select);

QModelIndex currentIndex = sampleListView_->selectionModel()->currentIndex();

sampleModel_->removeRow(currentIndex.row());

sampleModel_ = new QStandardItemModel(0, 4, this);