mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "common.h"

#include <QFileDialog>
#include <QDirIterator>
#include <QImageReader>
#include <QDebug>
#include <QFutureWatcher>
#include <qtconcurrentmap.h>
#include <QtConcurrent>
#include <QImageWriter>

MainWindow* MainWindow::inst;

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    inst = this;
    ui->setupUi(this);
    on_qualitySlider_valueChanged(ui->qualitySlider->value());
    connect(this, SIGNAL(filesAdded(int)), this, SLOT(filesAddedSlot(int)), Qt::QueuedConnection);
}

MainWindow::~MainWindow()
{
    delete ui;
}

void MainWindow::on_selectFolderBtn_clicked()
{
    QString dirName = QFileDialog::getExistingDirectory(this, "Select Root Folder");
    if (dirName.isEmpty())
        return;    
    ui->rootDirLabel->setText(dirName);
    populateFilesInvoke();
}

void shrink(ImageData& id);
void MainWindow::on_startStopBtn_clicked()
{
    QFutureWatcher<void>* futureWatcher = new QFutureWatcher<void>();
    connect(futureWatcher, SIGNAL(finished()), this, SLOT(processFinished()));
    connect(futureWatcher, SIGNAL(progressRangeChanged(int,int)), ui->progressBar, SLOT(setRange(int,int)));
    connect(futureWatcher, SIGNAL(progressValueChanged(int)), ui->progressBar, SLOT(setValue(int)));
    connect(futureWatcher, SIGNAL(finished()), futureWatcher, SLOT(deleteLater()));

    futureWatcher->setFuture(QtConcurrent::map(files, ::shrink));
}

void MainWindow::on_overwriteCheckBox_clicked()
{
    ui->outputDirLineEdit->setEnabled(ui->overwriteCheckBox->isChecked());
    if (ui->overwriteCheckBox->isChecked()) {
        ui->outputDirLineEdit->setText(ui->rootDirLabel->text());
    }
}

void MainWindow::populateFilesInvoke()
{
    files.clear();
    QString rootDir = ui->rootDirLabel->text();
    QFutureWatcher<void>* futureWatcher = new QFutureWatcher<void>();
    QFuture<void> getImagesFuture = QtConcurrent::run(this, populateFilesAsync, rootDir);

    connect(futureWatcher, SIGNAL(finished()), futureWatcher, SLOT(deleteLater()));
    connect(futureWatcher, SIGNAL(finished()), this, SLOT(populatingFilesFinished()));
    futureWatcher->setFuture(getImagesFuture);
}

void MainWindow::populateFilesAsync(QString rootDir)
{
    QList<ImageData> newFiles;
    QDir dir(rootDir);
    QFileInfoList subdirs = dir.entryInfoList(QDir::Dirs | QDir::NoDotAndDotDot);
    QList<QFuture<void> > futures;
    for (int i = 0; i < subdirs.size(); i++) {
        futures.append(QtConcurrent::run(this, populateFilesAsync, subdirs[i].absoluteFilePath()));
    }
    QFileInfoList filesIL = dir.entryInfoList(QDir::Files);
    for (int i = 0; i < filesIL.size(); i++) {
        QImageReader ir(filesIL[i].absoluteFilePath());
        if (!ir.canRead())
            continue;
        newFiles.append(ImageData(filesIL[i].absoluteFilePath()));
    }
    addFiles(newFiles);
    for (int i = 0; i < futures.size(); i++) {
        futures[i].waitForFinished();
    }
}

void MainWindow::addFiles(const QList<ImageData> &newFiles)
{
    static QMutex mutex;
    {
        QMutexLocker ml(&mutex);
        files.append(newFiles);
    }
    emit filesAdded(newFiles.size());
}

void MainWindow::filesAddedSlot(int howMuch)
{
    qDebug() << "found so far" << files.size() << "files";
}

void MainWindow::updateProgressBarRange()
{
    ui->progressBar->setMaximum(files.size());
}

void MainWindow::Shrink(ImageData &id)
{
    qDebug() << id.path;
    QImage img(id.path);
    QImageWriter iw;
    iw.setQuality(ui->qualitySlider->value());
    QString newName = id.path;
    newName.replace(ui->rootDirLabel->text(), ui->outputDirLineEdit->text());
    iw.setFileName(newName);
    iw.write(img);
}

void shrink(ImageData &id)
{
    MainWindow::Inst()->Shrink(id);
}

ImageData::ImageData(QString _path):
    path(_path)
{
    QFileInfo fi(path);
    origFileSize = fi.size();
}

ImageData::ImageData(const ImageData &other)
{
    path = other.path;
    origFileSize = other.origFileSize;
}

void MainWindow::processFinished()
{
    long origSize = 0, newSize = 0;
    for (int i = 0; i < files.size(); i++) {
        origSize += files[i].origFileSize;
        newSize += QFileInfo(files[i].path).size();
    }
    qDebug()  << __FUNCTION__ << origSize << newSize << 100.0*newSize/origSize;
}

void MainWindow::populatingFilesFinished()
{
    DBGF;
    long totalSize = 0;
    for (int i = 0; i < files.size(); i++) {
        totalSize += files[i].origFileSize;
    }
    DBGF << "found" << files.size() << "files with total size" << totalSize;
    updateProgressBarRange();

    on_overwriteCheckBox_clicked();
    if (ui->outputDirLineEdit->text().isEmpty()) {
        ui->outputDirLineEdit->setFocus();
    }
    ui->startStopBtn->setEnabled(files.size() > 0);
    ui->progressBar->setEnabled(files.size() > 0);
    if (files.size() == 0) {
        this->statusBar()->setToolTip("input directory has no image files");
    }

}

void MainWindow::on_qualitySlider_valueChanged(int value)
{
    QString str = QString("%1%").arg(value);
    ui->qualityLabel->setText(str);
}