[Qt5] Set Default Suffix

[Salads]

I made a small program that saves a file, but people who use Ubuntu say that they can't properly save the file without manually putting a file extension in the save file name. I tried using the setDefaultSuffix function though I don't see how it would fit with the getSaveFileName function that I'm using.

Here's my code for the save button:

void MainWindow::on_save_clicked()
{
    if (pngData.isEmpty())
    {
        QPixmap noSaveData(":/graphic/noSaveData.png");
        ui->preview->setStyleSheet("background: transparent ;");
        ui->preview->setPixmap(noSaveData);
        return;
    }
    QString filename = QFileDialog::getSaveFileName(this, ("Save Skin"), "C:/Users/", ("PNG Image (*.png)"));
    QFile file(filename);
    file.open(QIODevice::WriteOnly);
    file.write(pngData);
    file.close();
}

void MainWindow::on_save_clicked()
{
    if (pngData.isEmpty())
    {
        QPixmap noSaveData(":/graphic/noSaveData.png");
        ui->preview->setStyleSheet("background: transparent ;");
        ui->preview->setPixmap(noSaveData);
        return;
    }
    QString filename = QFileDialog::getSaveFileName(this, ("Save Skin"), "C:/Users/", ("PNG Image (*.png)"));
    QFile file(filename);
    file.open(QIODevice::WriteOnly);
    file.write(pngData);
    file.close();
}

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[alrawab]

QFileDialog::getSaveFileName(0,"Save Skin",QDir::homePath(),"PNG Image (*.png)");

QFileDialog::getSaveFileName(0,"Save Skin",QDir::homePath(),"PNG Image (*.png)");

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there is no C:/Users in Linux ...read The Current Directory and Other Special Paths
http://doc.qt.io/qt-4.8/QDir

[Salads]

Thanks for the tip, the save function now goes to the directory I want, however I get weird error output since I added it in:
output.jpg

QFSFileEngine::open: No file name specified
Cannot create accessible interface for object:  MainWindow(0x33fbd4, name = "MainWindow") 
Cannot create accessible interface for object:  QPushButton(0x8f4880, name = "save") 
Cannot create accessible interface for object:  MainWindow(0x33fbd4, name = "MainWindow") 
Cannot create accessible interface for object:  MainWindow(0x33fbd4, name = "MainWindow") 
Cannot create accessible interface for object:  QPushButton(0x8f4880, name = "save") 
Cannot create accessible interface for object:  QPushButton(0xa77478, name = "dLoad") 
Cannot create accessible interface for object:  QLineEdit(0xa774d8, name = "lineEdit") 
Cannot create accessible interface for object:  QPushButton(0x8f4880, name = "save") 
Cannot create accessible interface for object:  QLabel(0x8f4900, name = "preview") 
Cannot create accessible interface for object:  QPushButton(0x8f4960, name = "clear") 
Cannot create accessible interface for object:  QWidget(0xa77418, name = "centralWidget") 
Cannot create accessible interface for object:  MainWindow(0x33fbd4, name = "MainWindow") 
Cannot create accessible interface for object:  MainWindow(0x33fbd4, name = "MainWindow")

QFSFileEngine::open: No file name specified
Cannot create accessible interface for object:  MainWindow(0x33fbd4, name = "MainWindow") 
Cannot create accessible interface for object:  QPushButton(0x8f4880, name = "save") 
Cannot create accessible interface for object:  MainWindow(0x33fbd4, name = "MainWindow") 
Cannot create accessible interface for object:  MainWindow(0x33fbd4, name = "MainWindow") 
Cannot create accessible interface for object:  QPushButton(0x8f4880, name = "save") 
Cannot create accessible interface for object:  QPushButton(0xa77478, name = "dLoad") 
Cannot create accessible interface for object:  QLineEdit(0xa774d8, name = "lineEdit") 
Cannot create accessible interface for object:  QPushButton(0x8f4880, name = "save") 
Cannot create accessible interface for object:  QLabel(0x8f4900, name = "preview") 
Cannot create accessible interface for object:  QPushButton(0x8f4960, name = "clear") 
Cannot create accessible interface for object:  QWidget(0xa77418, name = "centralWidget") 
Cannot create accessible interface for object:  MainWindow(0x33fbd4, name = "MainWindow") 
Cannot create accessible interface for object:  MainWindow(0x33fbd4, name = "MainWindow")

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Everything seems to be working regardless, besides the missing extensions that Linux users have.

EDIT: The errors don't seem related to QDir, as I changed it back just to check and had the same result.

[alrawab]

its works fine if we supposed pngData is correct data type

#include <QApplication>
#include <QFileDialog>
 
int main(int argc, char **argv)
{
 QApplication app(argc,argv);
        QString filename =QFileDialog::getSaveFileName(0,"Save Skin",QDir::homePath(),"PNG Image (*.png)");
        QFile file(filename);
        file.open(QIODevice::WriteOnly);
        file.write("Foo");//change Foo to your data
 
        file.close();
        return 0;
}

#include <QApplication>
#include <QFileDialog>

int main(int argc, char **argv)
{
 QApplication app(argc,argv);
        QString filename =QFileDialog::getSaveFileName(0,"Save Skin",QDir::homePath(),"PNG Image (*.png)");
        QFile file(filename);
        file.open(QIODevice::WriteOnly);
        file.write("Foo");//change Foo to your data

        file.close();
        return 0;
}

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QPixmap::save

[Salads]

---

Added after 4 minutes:

I think I want to keep it as a QByteArray because I use the .clear() functions for a clear button in the downloader. (It's a small minecraft skin downloader)
Would the QFileDialog::setDefaultSuffix work here? How would I implement it?

Here's my full code:

header:

#ifndef MAINWINDOW_H
#define MAINWINDOW_H
 
#include <QMainWindow>
#include <QNetworkReply>
 
namespace Ui {
class MainWindow;
}
 
class MainWindow : public QMainWindow
{
    Q_OBJECT
 
public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();
    QByteArray pngData;
    QNetworkAccessManager *manager;
 
 
private slots:
    void on_dLoad_clicked();
 
    void replyFinished(QNetworkReply *reply);
 
    void on_save_clicked();
 
    void on_clear_clicked();
 
    void on_lineEdit_returnPressed();
 
private:
    Ui::MainWindow *ui;
};
 
#endif // MAINWINDOW_H

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QNetworkReply>

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT
    
public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();
    QByteArray pngData;
    QNetworkAccessManager *manager;

    
private slots:
    void on_dLoad_clicked();

    void replyFinished(QNetworkReply *reply);

    void on_save_clicked();

    void on_clear_clicked();

    void on_lineEdit_returnPressed();

private:
    Ui::MainWindow *ui;
};

#endif // MAINWINDOW_H

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mainwindow.cpp

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QIcon>
#include <QNetworkAccessManager>
#include <QNetworkRequest>
#include <QNetworkReply>
#include <QDebug>
#include <QFileDialog>
#include <QFile>
#include <QDir>
 
MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    setWindowTitle("Minecraft Skin Downloader v0.7"); //Version
    QIcon icon(":/graphic/ico.png");
    setWindowIcon(icon);
    setFixedSize(400, 200);
    setStyleSheet("QMainWindow { background-image: url( :/graphic/bg.png); } ");
    setWindowFlags(windowFlags() ^ Qt::WindowMaximizeButtonHint);
    ui->lineEdit->setToolTip("Username (Case Sensitive)");
 
    manager = new QNetworkAccessManager(this);
    connect(manager, SIGNAL(finished(QNetworkReply *)), this, SLOT(replyFinished(QNetworkReply *)));
}
 
MainWindow::~MainWindow()
{
    delete ui;
}
 
void MainWindow::on_dLoad_clicked()
{
    //s3.amazonaws.com/MinecraftSkins/NICKNAME.png
    QString prefix = "http://s3.amazonaws.com/MinecraftSkins/";
    QString usrl = prefix += ui->lineEdit->text() += ".png";
 
    QUrl url(usrl);
    QNetworkRequest request(url);
 
    manager->get(request);
}
 
void MainWindow::replyFinished(QNetworkReply *reply)
{
    if(reply->error() != QNetworkReply::NoError)
    {
        qDebug() <<"Error in" << reply->url() << ":" << reply->errorString();
        QPixmap noUsr(":/graphic/voidUser.png");
        ui->preview->setStyleSheet("background: transparent ;");
        ui->preview->setPixmap(noUsr);
        pngData.clear();
        return;
    }
 
    pngData = reply->readAll();
    QPixmap srcPic;
    srcPic.loadFromData(pngData);
    QPixmap scaled = srcPic.scaled(128, 64, Qt::KeepAspectRatio, Qt::FastTransformation);
    ui->preview->setStyleSheet("QLabel { background-color: white ;}");
    ui->preview->setPixmap(scaled);
 
}
 
void MainWindow::on_save_clicked()
{
    if (pngData.isEmpty())
    {
        QPixmap noSaveData(":/graphic/noSaveData.png");
        ui->preview->setStyleSheet("background: transparent ;");
        ui->preview->setPixmap(noSaveData);
        return;
    }
    QString filename = QFileDialog::getSaveFileName(this, tr("Save Skin"), QDir::homePath(), tr("PNG Image(*.png)"));
    QFile file(filename);
 
    file.open(QIODevice::WriteOnly);
    file.write(pngData);
    file.close();
}
 
void MainWindow::on_clear_clicked()
{
    pngData.clear();
    ui->preview->clear();
    ui->preview->setStyleSheet("background: transparent ;");
    ui->lineEdit->clear();
}
 
void MainWindow::on_lineEdit_returnPressed()
{
    on_dLoad_clicked();
}

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QIcon>
#include <QNetworkAccessManager>
#include <QNetworkRequest>
#include <QNetworkReply>
#include <QDebug>
#include <QFileDialog>
#include <QFile>
#include <QDir>

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    setWindowTitle("Minecraft Skin Downloader v0.7"); //Version
    QIcon icon(":/graphic/ico.png");
    setWindowIcon(icon);
    setFixedSize(400, 200);
    setStyleSheet("QMainWindow { background-image: url( :/graphic/bg.png); } ");
    setWindowFlags(windowFlags() ^ Qt::WindowMaximizeButtonHint);
    ui->lineEdit->setToolTip("Username (Case Sensitive)");

    manager = new QNetworkAccessManager(this);
    connect(manager, SIGNAL(finished(QNetworkReply *)), this, SLOT(replyFinished(QNetworkReply *)));
}

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

void MainWindow::on_dLoad_clicked()
{
    //s3.amazonaws.com/MinecraftSkins/NICKNAME.png
    QString prefix = "http://s3.amazonaws.com/MinecraftSkins/";
    QString usrl = prefix += ui->lineEdit->text() += ".png";

    QUrl url(usrl);
    QNetworkRequest request(url);

    manager->get(request);
}

void MainWindow::replyFinished(QNetworkReply *reply)
{
    if(reply->error() != QNetworkReply::NoError)
    {
        qDebug() <<"Error in" << reply->url() << ":" << reply->errorString();
        QPixmap noUsr(":/graphic/voidUser.png");
        ui->preview->setStyleSheet("background: transparent ;");
        ui->preview->setPixmap(noUsr);
        pngData.clear();
        return;
    }

    pngData = reply->readAll();
    QPixmap srcPic;
    srcPic.loadFromData(pngData);
    QPixmap scaled = srcPic.scaled(128, 64, Qt::KeepAspectRatio, Qt::FastTransformation);
    ui->preview->setStyleSheet("QLabel { background-color: white ;}");
    ui->preview->setPixmap(scaled);

}

void MainWindow::on_save_clicked()
{
    if (pngData.isEmpty())
    {
        QPixmap noSaveData(":/graphic/noSaveData.png");
        ui->preview->setStyleSheet("background: transparent ;");
        ui->preview->setPixmap(noSaveData);
        return;
    }
    QString filename = QFileDialog::getSaveFileName(this, tr("Save Skin"), QDir::homePath(), tr("PNG Image(*.png)"));
    QFile file(filename);

    file.open(QIODevice::WriteOnly);
    file.write(pngData);
    file.close();
}

void MainWindow::on_clear_clicked()
{
    pngData.clear();
    ui->preview->clear();
    ui->preview->setStyleSheet("background: transparent ;");
    ui->lineEdit->clear();
}

void MainWindow::on_lineEdit_returnPressed()
{
    on_dLoad_clicked();
}

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---

Added after 47 minutes:

Alright so I may have found a way around it, but I'm not sure if it would work since I don't have a Linux computer.

void MainWindow::on_save_clicked()
{
    if (pngData.isEmpty())
    {
        QPixmap noSaveData(":/graphic/noSaveData.png");
        ui->preview->setStyleSheet("background: transparent ;");
        ui->preview->setPixmap(noSaveData);
        return;
    }
    QString filename = QFileDialog::getSaveFileName(this, tr("Save Skin"), QDir::homePath(), tr("PNG Image(*.png)"));
 
    QFile file(filename);
    QFileInfo fi(file);
    if(fi.suffix().isEmpty())
    {
        fi.suffix() = "png";
    }
 
    file.open(QIODevice::WriteOnly);
    file.write(pngData);
    file.close();
}

void MainWindow::on_save_clicked()
{
    if (pngData.isEmpty())
    {
        QPixmap noSaveData(":/graphic/noSaveData.png");
        ui->preview->setStyleSheet("background: transparent ;");
        ui->preview->setPixmap(noSaveData);
        return;
    }
    QString filename = QFileDialog::getSaveFileName(this, tr("Save Skin"), QDir::homePath(), tr("PNG Image(*.png)"));

    QFile file(filename);
    QFileInfo fi(file);
    if(fi.suffix().isEmpty())
    {
        fi.suffix() = "png";
    }

    file.open(QIODevice::WriteOnly);
    file.write(pngData);
    file.close();
}

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Would this work?