[Solved] Dynamic Layout should be better then that what I've done

casisto

Hi there,

I'm very new to QT (using 5.4). First, I get trough the zetcode Tutorial (for QT 4) and now I try to develop my very first own Application with QT.

My problem: to get the UI Dynamic Layout in a nice behaviour (I mean a behaviour where it looks good when its small and when its big), I think I've used more lines then necessary.

My Code:
mainwindow.cpp
@#include "mainwindow.h"

MainWindow::MainWindow(QWidget *parent) : QWidget(parent)
{
/VBox deklarieren - nur einmal QLayout definieren/
QVBoxLayout *vbox = new QVBoxLayout(this);
vbox->setMargin(20);
/HBoxes deklarieren/
QHBoxLayout *hbox_1 = new QHBoxLayout();
QHBoxLayout *hbox_2 = new QHBoxLayout();
QHBoxLayout *hbox_3 = new QHBoxLayout();

/*Strings definieren*/
QLabel *l_title    = new QLabel("Titel", this);
QLabel *l_subtitle = new QLabel("Subtitel", this);

/*Strings formatieren*/
l_title->setAlignment(Qt::AlignCenter);
l_title->setFont(QFont("Calibri", 36, QFont::Bold));
l_title->setStyleSheet("QLabel {color: green}");

l_subtitle->setAlignment(Qt::AlignCenter);

/*Buttons definieren*/
QPushButton *b_1 = new QPushButton("Button 1 ", this);
    b_1->setMaximumWidth(200);
QPushButton *b_2 = new QPushButton("Button 2", this);
    b_2->setMaximumWidth(200);
QPushButton *b_3  = new QPushButton("Button 3", this);
    b_3 ->setMaximumWidth(200);

/*Layout definieren*/
    /*HBox1*/
vbox->addStretch(1);
hbox_1->addWidget(b_1, 0, Qt::AlignVCenter);
vbox->addStretch(1);

    /*HBox2*/
vbox->addStretch(1);
hbox_2->addWidget(b_2, 0, Qt::AlignVCenter);
vbox->addStretch(1);

    /*HBox3*/
vbox->addStretch(1);
hbox_3->addWidget(b_3,  0, Qt::AlignVCenter);
vbox->addStretch(1);

    /*VBox*/
vbox->addStretch(1);
vbox->addWidget(l_title,    0, Qt::AlignHCenter);
vbox->addStretch(1);
vbox->addWidget(l_subtitle, 0, Qt::AlignHCenter);
vbox->addStretch(5);
vbox->addLayout(hbox_1);
vbox->addStretch(1);
vbox->addLayout(hbox_2);
vbox->addStretch(1);
vbox->addLayout(hbox_3);
vbox->addStretch(10);
vbox->addSpacing(50);

/*Layout setzen*/
setLayout(vbox);

}@

It would be nice If someone can give me some hints.
greetings
-casisto

casisto

Sure? I had asked for help, not for a jester...

SGaist

Hi and welcome to devnet,

Spam removed

Your code doesn't look bad, you could use a loop to create and setup your three buttons since you do three times the exact the same thing

casisto

Hi sGaist,

thanks, and thanks for removing the Spam.

I've now edited my Layout with a loop. But I get the error:
"QLayout::addChildLayout: layout "" already has a parent"

The arrays a declared in mainwindow.h and lang.h:
QPushButton *btn[2];
QHBoxLayout *hbox[2];
QString str_btn[] = {"btn1", "btn2", "btn3"};

@#include "mainwindow.h"
#include "lang.h"

MainWindow::MainWindow(QWidget *parent) : QWidget(parent)
{
/VBox deklarieren - nur einmal QLayout definieren/
QVBoxLayout *vbox = new QVBoxLayout(this);
vbox->setMargin(20);

/*Strings definieren*/
QLabel *l_title    = new QLabel("Titel", this);
QLabel *l_subtitle = new QLabel("Subtitel", this);

/*Strings formatieren*/
l_title->setAlignment(Qt::AlignCenter);
l_title->setFont(QFont("Calibri", 36, QFont::Bold));
l_title->setStyleSheet("QLabel {color: green}");

l_subtitle->setAlignment(Qt::AlignCenter);

for(int i = 0; i < 3; i++)
{
    /*Buttons definieren*/
    btn[i] = new QPushButton(str_btn[i], this);

    /*Hboxes definieren*/
    hbox[i] = new QHBoxLayout();

    /*HBoxLayout definieren*/
    hbox[i]->addStretch(1);
    hbox[i]->addWidget(btn[i], 0, Qt::AlignVCenter);
    hbox[i]->addStretch(1);
}

vbox->addStretch(1);
vbox->addWidget(l_title,    0, Qt::AlignHCenter);
vbox->addStretch(1);
vbox->addWidget(l_subtitle, 0, Qt::AlignHCenter);
vbox->addStretch(5);
vbox->addLayout(hbox[0]);
vbox->addStretch(1);
vbox->addLayout(hbox[1]);
vbox->addStretch(1);
vbox->addLayout(hbox[2]);
vbox->addStretch(1);

/*Layout setzen*/
setLayout(vbox);

}
@

It would be great if you could give me hint what throw the warning? (Also, I get the first button in the upper left corner, but I think the first error conditioned the second...)

SGaist

I've missed that one so:

@QVBoxLayout *vbox = new QVBoxLayout(this);@

Here you already set vbox as layout of your widget so the call to

@setLayout(vbox);@

is causing the warning.

casisto

Ok,

now I've get it.
Funny thing, I had change the first line to this:
@ QVBoxLayout *vbox = new QVBoxLayout;@

Comment out the
@setLayout(vbox);@

has finished in an "unexpected close".

Thanks, Samuel