QT Layout display - c++

Question

I am new to Qt application programming, I have a task to complete i.e
I need to create a paint like application
Based on left side panel objects Right side List must display..
PFA
so now i am stuck with displaying right side panel
To be more clear...
I used left side QGroupBox with Push Buttons.
Right side i used QGridLayout to show specific objects.
Center graphics view ( ignore this point).
now when I am calling the function after push button clicked Button 1 : should display only numbered objects Button 2 : should display only other objects Button 3 : should display empty plane Button N : should display all objects
could some one suggest me with small code for it.... like
ui->gridLayout_1->... ( to hide previous options )
when called second time ui->gridLayout_1->addWidget(label0,0,0); should display relevant
when called for third time display all objects ui->gridLayout_1->addWidget(label0,0,0);

Answer 1

Edit: After seeing a better example of what you were trying to accomplish I threw this together using QStackedWidget. I think the below code mimics the behavior you are looking for. This has replaced my old answer as I didn't want to add any unnecessary confusion.
mainwindow.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QGridLayout>
#include <QHBoxLayout>
#include <QLabel>
#include <QLineEdit>
#include <QMainWindow>
#include <QPushButton>
#include <QStackedWidget>
#include <QWidget>
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
MainWindow(QWidget *parent = 0);
~MainWindow();
QWidget *central_widget = new QWidget(this);
QHBoxLayout *central_layout = new QHBoxLayout();
QVBoxLayout *ctl_btn_layout = new QVBoxLayout();
QPushButton *ctl_btn_1 = new QPushButton("1", central_widget);
QPushButton *ctl_btn_2 = new QPushButton("2", central_widget);
QStackedWidget *widget_stack = new QStackedWidget(central_widget);
QWidget *page_0 = new QWidget();
QWidget *page_1 = new QWidget();
QGridLayout *page_1_layout = new QGridLayout();
QPushButton *r_btn = new QPushButton("R", page_1);
QPushButton *j_btn = new QPushButton("J", page_1);
QPushButton *l_btn = new QPushButton("L", page_1);
QPushButton *o_btn = new QPushButton("O", page_1);
QPushButton *v_btn = new QPushButton("V", page_1);
QPushButton *f_btn = new QPushButton("F", page_1);
QWidget *page_2 = new QWidget();
QVBoxLayout *page_2_layout = new QVBoxLayout();
QPushButton *btn_1 = new QPushButton("1", page_2);
QPushButton *btn_2 = new QPushButton("2", page_2);
QPushButton *btn_3 = new QPushButton("3", page_2);
QPushButton *btn_4 = new QPushButton("4", page_2);
QPushButton *btn_5 = new QPushButton("5", page_2);
QPushButton *btn_6 = new QPushButton("6", page_2);
QLabel *r = new QLabel("R", central_widget);
QLabel *j = new QLabel("J", central_widget);
QLabel *id = new QLabel("ID", central_widget);
QLabel *x = new QLabel("X", central_widget);
QLabel *y = new QLabel("Y", central_widget);
QLineEdit *r_line = new QLineEdit(central_widget);
QLineEdit *j_line = new QLineEdit(central_widget);
QLineEdit *id_line = new QLineEdit(central_widget);
QLineEdit *x_line = new QLineEdit(central_widget);
QLineEdit *y_line = new QLineEdit(central_widget);
QVBoxLayout *lines_layout = new QVBoxLayout();
public slots:
void ctl_btn_1_clicked();
void ctl_btn_2_clicked();
};
#endif // MAINWINDOW_H
mainwindow.cpp
#include "mainwindow.h"
MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
{
ctl_btn_layout->addWidget(ctl_btn_1);
connect(ctl_btn_1, SIGNAL(clicked(bool)), this, SLOT(ctl_btn_1_clicked()));
ctl_btn_layout->addWidget(ctl_btn_2);
connect(ctl_btn_2, SIGNAL(clicked(bool)), this, SLOT(ctl_btn_2_clicked()));
central_layout->addLayout(ctl_btn_layout);
page_1_layout->addWidget(r_btn, 0, 0, 1, 1);
page_1_layout->addWidget(j_btn, 1, 1, 1, 1);
page_1_layout->addWidget(l_btn, 2, 0, 1, 1);
page_1_layout->addWidget(o_btn, 3, 1, 1, 1);
page_1_layout->addWidget(v_btn, 4, 2, 1, 1);
page_1_layout->addWidget(f_btn, 5, 3, 1, 1);
page_1->setLayout(page_1_layout);
page_2_layout->addWidget(btn_1);
page_2_layout->addWidget(btn_2);
page_2_layout->addWidget(btn_3);
page_2_layout->addWidget(btn_4);
page_2_layout->addWidget(btn_5);
page_2_layout->addWidget(btn_6);
page_2->setLayout(page_2_layout);
widget_stack->addWidget(page_0); //Empty QWidget.
widget_stack->addWidget(page_1);
widget_stack->addWidget(page_2);
central_layout->addWidget(widget_stack);
lines_layout->addWidget(r);
r->hide();
lines_layout->addWidget(r_line);
r_line->hide();
lines_layout->addWidget(j);
j->hide();
lines_layout->addWidget(j_line);
j_line->hide();
lines_layout->addWidget(id);
id->hide();
lines_layout->addWidget(id_line);
id_line->hide();
lines_layout->addWidget(x);
x->hide();
lines_layout->addWidget(x_line);
x_line->hide();
lines_layout->addWidget(y);
y->hide();
lines_layout->addWidget(y_line);
y_line->hide();
central_layout->addLayout(lines_layout);
central_widget->setLayout(central_layout);
setCentralWidget(central_widget);
}
MainWindow::~MainWindow()
{
}
void MainWindow::ctl_btn_1_clicked()
{
if (j->isVisible())
{
j->hide();
j_line->hide();
}
r->show();
r_line->show();
if (!id->isVisible())
{
id->show();
id_line->show();
x->show();
x_line->show();
y->show();
y_line->show();
}
widget_stack->setCurrentIndex(1);
}
void MainWindow::ctl_btn_2_clicked()
{
if (r->isVisible())
{
r->hide();
r_line->hide();
}
j->show();
j_line->show();
if (!id->isVisible())
{
id->show();
id_line->show();
x->show();
x_line->show();
y->show();
y_line->show();
}
widget_stack->setCurrentIndex(2);
}
This works by using a QStackedWidget, which is populated with 3 QWidgets. The first widget is completely empty to mimic the empty page from your example. The second and third widgets have layouts that hold your different button configurations, and the QStackedWidget will flip between pages through functions connected to the button slots.
Note that I tend not to use the form designer that comes w/ Qt Creator, preferring pure C++ UI design. It doesn't matter how you set it up, with or without the form, I just find it easier this way. Main.cpp was left as default from a new Qt GUI project with the generate form box unchecked.