Qt实现扇形图（2）

#include "pieview.h"
#include "mainwindow.h"

#include <QtWidgets>

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
{
QMenu *fileMenu = new QMenu(tr("&File"), this);
QAction *openAction = fileMenu->addAction(tr("&Open..."));
openAction->setShortcuts(QKeySequence::Open);
QAction *saveAction = fileMenu->addAction(tr("&Save As..."));
saveAction->setShortcuts(QKeySequence::SaveAs);
QAction *quitAction = fileMenu->addAction(tr("E&xit"));
quitAction->setShortcuts(QKeySequence::Quit);

setupModel();
setupViews();

connect(openAction, &QAction::triggered, this, &MainWindow::openFile);
connect(saveAction, &QAction::triggered, this, &MainWindow::saveFile);
connect(quitAction, &QAction::triggered, qApp, &QCoreApplication::quit);

menuBar()->addMenu(fileMenu);
statusBar();

loadFile(":/Charts/qtdata.cht");

setWindowTitle(tr("Chart"));
resize(870, 550);
}

void MainWindow::setupModel()
{
model = new QStandardItemModel(8, 2, this);
model->setHeaderData(0, Qt::Horizontal, tr("Label"));
model->setHeaderData(1, Qt::Horizontal, tr("Quantity"));
}

void MainWindow::setupViews()
{
QSplitter *splitter = new QSplitter;
QTableView *table = new QTableView;
pieChart = new PieView;
splitter->addWidget(table);
splitter->addWidget(pieChart);
splitter->setStretchFactor(0, 0);
splitter->setStretchFactor(1, 1);

table->setModel(model);
pieChart->setModel(model);

QItemSelectionModel *selectionModel = new QItemSelectionModel(model);
table->setSelectionModel(selectionModel);
pieChart->setSelectionModel(selectionModel);

QHeaderView *headerView = table->horizontalHeader();
headerView->setStretchLastSection(true);

setCentralWidget(splitter);
}

void MainWindow::openFile()
{
const QString fileName =
QFileDialog::getOpenFileName(this, tr("Choose a data file"), "", "*.cht");
if (!fileName.isEmpty())
loadFile(fileName);
}

void MainWindow::loadFile(const QString &fileName)
{
QFile file(fileName);
if (!file.open(QFile::ReadOnly | QFile::Text))
return;

QTextStream stream(&file);

model->removeRows(0, model->rowCount(QModelIndex()), QModelIndex());

int row = 0;
while (!stream.atEnd()) {
const QString line = stream.readLine();
if (!line.isEmpty()) {
model->insertRows(row, 1, QModelIndex());

const QStringList pieces = line.split(',', QString::SkipEmptyParts);
if (pieces.size() < 3)
continue;
model->setData(model->index(row, 0, QModelIndex()),
pieces.value(0));
model->setData(model->index(row, 1, QModelIndex()),
pieces.value(1));
model->setData(model->index(row, 0, QModelIndex()),
QColor(pieces.value(2)), Qt::DecorationRole);
row++;
        }
    };

file.close();
statusBar()->showMessage(tr("Loaded %1").arg(fileName), 2000);
}

void MainWindow::saveFile()
{
QString fileName = QFileDialog::getSaveFileName(this,
tr("Save file as"), "", "*.cht");

if (fileName.isEmpty())
return;

QFile file(fileName);
if (!file.open(QFile::WriteOnly | QFile::Text))
return;

QTextStream stream(&file);
for (int row = 0; row < model->rowCount(QModelIndex()); ++row) {

QStringList pieces;

pieces.append(model->data(model->index(row, 0, QModelIndex()),
Qt::DisplayRole).toString());
pieces.append(model->data(model->index(row, 1, QModelIndex()),
Qt::DisplayRole).toString());
pieces.append(model->data(model->index(row, 0, QModelIndex()),
Qt::DecorationRole).toString());

stream << pieces.join(',') << "\n";
    }

file.close();
statusBar()->showMessage(tr("Saved %1").arg(fileName), 2000);
}