QMainWindow : unable to position widget to extreme left

dan1973

Hi,
I am unable to position the Widget to extreme left of main window. there is a gap on the left of the screen.

Here is my code:

DTSMain::DTSMain(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::DTSMain)
{
    ui->setupUi(this);

    QFont fntGgia10( "Georgia", 10, QFont::Bold);
    QFont fntGgia12( "Georgia", 12, QFont::Bold);
    QFont fntGgia12N( "Georgia", 12, QFont::Normal);
    QFont fntGgia16( "Georgia", 16, QFont::Bold);

    QString tabStyle = "QTabBar {background-color: #0B6C87; color:#ffffff;}"
                       "QTabBar::tab:!selected {height: 60px; width: 125px;background-color: #0B6C87; color:#ffffff;font-size:11pt;}"
                       "QTabBar::tab:selected {height: 60px; width: 125px;background-color: #0BAFF2; color:#ffffff;font-size:12pt; font-weight: bold;}";

    tw1= new QTabWidget;
//    tw1->setStyleSheet("QTabBar::tab { height: 40px; width: 100px; font-size:12pt;}");
    tw1->setStyleSheet(tabStyle);
    tw1->setMinimumWidth(1000);
    tw1->setMinimumHeight(700);
    tw1->addTab(new MainTab(), tr("MAIN"));
    tw1->addTab(new UtilitiesTab(), tr("UTILITIES"));
    tw1->addTab(new HCTab(), tr("HEALTH \nCHECK"));
    tw1->addTab(new LVTab(), tr("LOG \nVIEW"));
    tw1->addTab(new GRTab(), tr("GENERATE \nREPORT"));
    tw1->addTab(new HelpTab(), tr("HELP"));
    tw1->addTab(new AboutTab(), tr("ABOUT"));
    tw1->addTab(new ExitTab(), tr("EXIT"));

    connect(tw1, SIGNAL(currentChanged(int)), this, SLOT(onTabChanged(int)));

    // Debug Window 1
    dbgWdw1 = new DebugPortMainWgt(this, "Debug1");
    dbgWdw1->setMaximumHeight(150);
    dbgWdw1->setMaximumWidth(250);

    // Debug Window 2
    dbgWdw2 = new DebugPortMainWgt(this, "Debug2");
    dbgWdw2->setMaximumHeight(150);
    dbgWdw2->setMaximumWidth(250);

    // Debug Window 3
    dbgWdw3 = new DebugPortMainWgt(this, "Debug3");
    dbgWdw3->setMaximumHeight(150);
    dbgWdw3->setMaximumWidth(250);

    // VBox for Debug Windows
    vbxDebug = new QVBoxLayout;
    vbxDebug->addWidget(dbgWdw1);
    vbxDebug->addWidget(dbgWdw2);
    vbxDebug->addWidget(dbgWdw3);
    vbxDebug->addStretch(1);

    // LRU Power Widget
    lblLRUPwr = new QLabel("LRU POWER");
    lblLRUPwr->setAlignment(Qt::AlignHCenter);
    lblLRUPwr->setContentsMargins(10, 0, 0, 0);
    lblLRUPwr->setFont(fntGgia10);

    LPW1 = new LRUPwrWgt;
    vbxLRU = new QVBoxLayout;
    vbxLRU->addStretch(1);
    vbxLRU->addWidget(lblLRUPwr);
    vbxLRU->addWidget(LPW1);

    // SMFD1 Card Status
    lblSCS1 = new QLabel("SMFD1 CARD STATUS");
    lblSCS1->setAlignment(Qt::AlignHCenter);
    lblSCS1->setContentsMargins(10, 0, 0, 0);
    lblSCS1->setFont(fntGgia10);
    SCS1 = new SMFDCardStatusWgt;
    vbxSCS1 = new QVBoxLayout;
    vbxSCS1->addStretch(1);
    vbxSCS1->addWidget(lblSCS1);
    vbxSCS1->addWidget(SCS1);

    // SMFD2 Card Status
    lblSCS2 = new QLabel("SMFD2 CARD STATUS");
    lblSCS2->setAlignment(Qt::AlignHCenter);
    lblSCS2->setContentsMargins(10, 0, 0, 0);
    lblSCS2->setFont(fntGgia10);
    SCS2 = new SMFDCardStatusWgt;
    vbxSCS2 = new QVBoxLayout;
    vbxSCS2->addStretch(1);
    vbxSCS2->addWidget(lblSCS2);
    vbxSCS2->addWidget(SCS2);

    // SMFD3 Card Status
    lblSCS3 = new QLabel("SMFD3 CARD STATUS");
    lblSCS3->setAlignment(Qt::AlignHCenter);
    lblSCS3->setContentsMargins(10, 0, 0, 0);
    lblSCS3->setFont(fntGgia10);
    SCS3 = new SMFDCardStatusWgt;
    vbxSCS3 = new QVBoxLayout;
    vbxSCS3->addStretch(1);
    vbxSCS3->addWidget(lblSCS3);
    vbxSCS3->addWidget(SCS3);

    hbxBottom = new QHBoxLayout;
    hbxBottom->addLayout(vbxLRU);
    hbxBottom->addLayout(vbxSCS1);
    hbxBottom->addLayout(vbxSCS2);
    hbxBottom->addLayout(vbxSCS3);
    hbxBottom->addStretch(1);

    glMain = new QGridLayout;
    glMain->addWidget(tw1, 0, 0);
    glMain->addLayout(vbxDebug, 0, 1, 3, 1, Qt::AlignRight);
    glMain->setRowStretch(0, 1);
    glMain->addItem(new QSpacerItem(0, 200, QSizePolicy::Expanding, QSizePolicy::Expanding), 1, 0);
//    glMain->addWidget(lblLRUPwr, 2, 0, Qt::AlignLeft | Qt::AlignBottom);
//    glMain->addItem(new QSpacerItem(200, 0, QSizePolicy::Expanding, QSizePolicy::Expanding), 2, 1);
    glMain->addLayout(hbxBottom, 4, 0, Qt::AlignLeft | Qt::AlignBottom);


    QWidget *wgt1 = new QWidget();
    wgt1->setLayout(glMain);

    setCentralWidget(wgt1);
    setWindowTitle("Display Test Setup - Software Version 1.0");
}

Any suggestions on aligning my widgets to left??

jsulm

@dan1973 said in QMainWindow : unable to position widget to extreme left:

lblLRUPwr->setContentsMargins(10, 0, 0, 0);

Set left margins also to 0

Pl45m4

@dan1973

The layouts also have a margin by default (depending on OS/platform, style and layout used)

By default, QLayout uses the values provided by the style. On most platforms, the margin is 11 pixels in all directions.

(https://doc.qt.io/qt-5/qlayout.html#setContentsMargins)

Try setting setContentsMargins(0,top,right,bot) to your main layout. Then everything should move to the left by approx 11px.

To not change everything else, you could get the QMargin from your QLayout / QWidget first and then just change the left value.
https://doc.qt.io/qt-5/qlayout.html#contentsMargins

Just theorycrafting... haven't tested it and don't know how it will look like... ;-)

dan1973

@jsulm I had set left margins of all my widgets to 0.
tw1->setContentsMargins(0, 0, 0, 0);
...
lblLRUPwr->setContentsMargins(0, 0, 0, 0);
....

No effect. I still see the gap between screen edge and the widget in Main Window.
![alt text]( image url)

mrjj

Hi
Make sure your glMain layout also is set to zero.

dan1973

@mrjj Thank you. It worked finally. Thanks again. Now in my updated code i had used VBox instead of GL. and i reduced left margin of VBox to 0.

Pl45m4

@Pl45m4 said in QMainWindow : unable to position widget to extreme left:

Try setting setContentsMargins(0,top,right,bot) to your main layout. Then everything should move to the left by approx 11px.

I already said it here :-)
You must have missed it

But good to hear that it worked :-)

It seems quite tempting to use GridLayouts every time, but I would say in most cases cascading VBox and HBox layouts work better