How? I show a message, while the task is running

[lincoln]

Hi guys, I have the following code.

A method compress (), where I do the task of compressing an entire directory, I call this method from my button, with a QtConcurrent, as you can see. so far so good.

My question is, how can I display a message while compressing the folder is running.

I am using QuaZIP, for the compression process.

#ifndef WIDGET_H
#define WIDGET_H

#include <QWidget>

QT_BEGIN_NAMESPACE
namespace Ui { class Widget; }
QT_END_NAMESPACE

class Widget : public QWidget
{
  Q_OBJECT

public:
  Widget(QWidget *parent = nullptr);
  ~Widget();
 
private slots:
  void on_pushButton_5_clicked();

private:
  Ui::Widget *ui;
  void compress();
public:
 
};
#endif // WIDGET_H

#include "widget.h"
#include "ui_widget.h"
#include <QMessageBox>
#include <QDebug>
#include <JlCompress.h>
#include <QtConcurrent/QtConcurrent>
#include <QFuture>

Widget::Widget(QWidget *parent)
  : QWidget(parent), ui(new Ui::Widget)
{
  ui->setupUi(this); 
}
Widget::~Widget()
{
  delete ui;
}
void Widget::on_pushButton_5_clicked()
{
  QGuiApplication::setOverrideCursor(Qt::WaitCursor);
  QFuture<void> future=QtConcurrent::run(this,&Widget::compress);
  future.waitForFinished();
  QGuiApplication::restoreOverrideCursor();
  QMessageBox::information(this,qApp->applicationName(),"The folder was compressed successfully.");
}
void Widget::compress()
{
  if(!JlCompress::compressDir("C:/Users/Mypc/Desktop/iconos.zip", "D:/images/iconos")){
    QMessageBox::warning(this,qApp->applicationName(),"Error compressing folder.");
    return;
  }
}

[JonB]

@lincoln said in How? I show a message, while the task is running:

QFuture<void> future=QtConcurrent::run(this,&Widget::compress);
future.waitForFinished();

Display it after the run(), and don't do the waitForFinished() in the slot if you want the user to see it.

[lincoln]

@JonB
I did this, but now when the backup finishes, the entire application closes.

void Widget::on_pushButton_5_clicked()
{

  QMessageBox box;
  //  box->setWindowFlags(Qt::Dialog | Qt::SplashScreen);
  box.setStandardButtons(QMessageBox::NoButton);
  box.setText("Realizando una tarea!");
  box.setWindowTitle(qApp->applicationName());
  box.setIcon(QMessageBox::Information);
  box.setAttribute(Qt::WA_DeleteOnClose);

  QFutureWatcher<void> watcher;

  QFuture<void> future=QtConcurrent::run(this,&Widget::compress);
  watcher.setFuture(future);

  QGuiApplication::setOverrideCursor(Qt::WaitCursor);


  QObject::connect(&watcher,&QFutureWatcher<void>::finished,[&](){

    box.close();
    box.deleteLater();
    QGuiApplication::restoreOverrideCursor();
  });
  box.exec();
  QMessageBox::information(this,qApp->applicationName(),"Carpeta comprimirda.");

}

[lincoln]

Also try a ProgressDialog and QFutureWatcher as follows, but it doesn't compile, I get this error.

void Widget::on_pushButton_5_clicked()
{

  QStringList files;
  QDir dir("D:/images/iconos/uigenericicon");
  files=dir.entryList(QStringList() << "*.jpg" << "*.JPG"<<"*.PNG",QDir::Files);
  
  qInfo()<<files;

  QProgressDialog pDialog;
  pDialog.setLabelText("Porecessing!!");

  QFutureWatcher<void> watcher;

  QObject::connect(&pDialog,SIGNAL(canceled()),&watcher,SLOT(cancel()));
  QObject::connect(&watcher,SIGNAL(finished()),&pDialog,SLOT(reset()));
  QObject::connect(&watcher,SIGNAL(progressRangeChanged(int,int)),&pDialog,SLOT(setRange(int,int)));
  QObject::connect(&watcher,SIGNAL(progressValueChanged(int)),&pDialog,SLOT(setValue(int)));

  watcher.setFuture(QtConcurrent::map(files,&Widget::compress));
  pDialog.exec();
  if(watcher.isCanceled()){
    QMessageBox::information(this,qApp->applicationName(),"You canceled.");
  }else{
    QMessageBox::information(this,qApp->applicationName(),"All done.");
  }
}

void Widget::compress(QStringList &files)
{

  if(!JlCompress::compressFiles("C:/Users/Lincoln/Desktop/iconos.zip",files)){
    QMessageBox::warning(this,qApp->applicationName(),"Error al comprimir la carpeta.");
    return;
  }

}

[jsulm]

@lincoln said in How? I show a message, while the task is running:

box.deleteLater();

Don't delete stack allocated objects!
box will be deleted automatically as soon as on_pushButton_5_clicked() finishes.

[lincoln]

@jsulm
Already remove deletelater and the message box is stuck, not responding.

[SGaist]

Hi,

What do you mean by not responding ?

[lincoln]

@SGaist
I mean when removing box.deleteLater (); as @jsulm mentions, it does not close, and stays there. And I can't close the application either, the entire App is frozen.

It seems to me that it is best to do it with QFutureWatcher, as I put in the code below, but it does not work either.

[SGaist]

Are you sure that compress is called ?
How many times ?
How fast ?
Any runtime warning related to signals and slots ?
Why are you using map since your compress method takes a list as parameter ?

[J.Hilk]

@Lincoln remove the

QMessageBox::warning(this,qApp->applicationName(),"Error al comprimir la carpeta.");

from compress

no gui stuff in other threads.

[lincoln]

@J-Hilk
ok It gives me the same result