QGridLayout does not stretch the homemade QWidget over the workspace.

[timob256]

QGridLayout does not stretch the homemade QWidget over the workspace.

I don't know how to fix.

displays part of the widget, moreover, a small part, how to fix it so that it does display in the entire application.

here is the code:

CMakeLists.txt

cmake_minimum_required(VERSION 3.5)

project(vikroika VERSION 0.1 LANGUAGES CXX)

set(CMAKE_INCLUDE_CURRENT_DIR ON)

set(CMAKE_AUTOUIC ON)
set(CMAKE_AUTOMOC ON)
set(CMAKE_AUTORCC ON)

set(CMAKE_CXX_STANDARD 11)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

find_package(QT NAMES Qt6 Qt5 COMPONENTS Widgets REQUIRED)
find_package(Qt${QT_VERSION_MAJOR} COMPONENTS Widgets REQUIRED)

set(PROJECT_SOURCES
        main.cpp
        rascroika.cpp
        rascroika.h
        tochkabutton.cpp
        tochkabutton.h
)

if(${QT_VERSION_MAJOR} GREATER_EQUAL 6)
    qt_add_executable(vikroika
        MANUAL_FINALIZATION
        ${PROJECT_SOURCES}
    )
# Define target properties for Android with Qt 6 as:
#    set_property(TARGET vikroika APPEND PROPERTY QT_ANDROID_PACKAGE_SOURCE_DIR
#                 ${CMAKE_CURRENT_SOURCE_DIR}/android)
# For more information, see https://doc.qt.io/qt-6/qt-add-executable.html#target-creation
else()
    if(ANDROID)
        add_library(vikroika SHARED
            ${PROJECT_SOURCES}
        )
# Define properties for Android with Qt 5 after find_package() calls as:
#    set(ANDROID_PACKAGE_SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/android")
    else()
        add_executable(vikroika
            ${PROJECT_SOURCES}
        )
    endif()
endif()

target_link_libraries(vikroika PRIVATE Qt${QT_VERSION_MAJOR}::Widgets)

set_target_properties(vikroika PROPERTIES
    MACOSX_BUNDLE_GUI_IDENTIFIER my.example.com
    MACOSX_BUNDLE_BUNDLE_VERSION ${PROJECT_VERSION}
    MACOSX_BUNDLE_SHORT_VERSION_STRING ${PROJECT_VERSION_MAJOR}.${PROJECT_VERSION_MINOR}
)

if(QT_VERSION_MAJOR EQUAL 6)
    qt_finalize_executable(vikroika)
endif()

main.cpp

#include "rascroika.h"

#include <QApplication>
#include <QScreen>
#include <QDebug>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    Rascroika w;

    QSize screenSize = qApp->screens().at(0)->availableSize();
    const int width = screenSize.width() / 2.5;
    const int height = screenSize.height() * 0.5;
    w.setGeometry((screenSize.width() - width) / 2.0,
                  (screenSize.height() - height) / 2.0,
                  width,
                  height);

    w.setWindowTitle("Раскройка");

    w.show();
    return a.exec();
}

rascroika.h

#ifndef RASCROIKA_H
#define RASCROIKA_H

#include <QMainWindow>
#include <QVBoxLayout>
#include <QGridLayout>

#include "tochkabutton.h"

class Rascroika : public QMainWindow
{
    Q_OBJECT

public:
    Rascroika(QWidget *parent = nullptr);
    ~Rascroika();

private:

    TochkaButton *_tochkab;
    QGridLayout  *_vbox;
};
#endif // RASCROIKA_H

rascroika.cpp

#include "rascroika.h"

Rascroika::Rascroika(QWidget *parent)
    : QMainWindow(parent)
    , _vbox(new QGridLayout(this))
    , _tochkab(new TochkaButton(this))
{
     _vbox->addWidget(_tochkab,0,0,Qt::AlignJustify);

//    _tochkab->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
    _tochkab->setPosition(this->x(),this->y());
    _tochkab->setScale(this->width(),this->height());

//    _tochkab->setPosition(10,10);
//    _tochkab->setScale(100,200);

    this->setLayout(_vbox);
    this->show();
}

Rascroika::~Rascroika()
{
}

tochkabutton.h

#ifndef TOCKABUTTON_H
#define TOCKABUTTON_H

#include <QWidget>
#include <QPainter>
#include <QColor>
#include <QDebug>


class TochkaButton : public QWidget {
    Q_OBJECT
public:
    using QWidget::QWidget;

    // туту сетеры  гетеры
    ///
    /// \brief setColor выбор цвета
    ///
    void setColor(int r, int g, int b, int a);

    ///
    /// \brief setColor выбор цвета "основной" линии
    ///
    void setColorLine(int r, int g, int b, int a);

    ///
    /// \brief setScaleFactor установить коэффициент масштаба
    ///
    void setScale(float height, float width);

    ///
    /// \brief setPosition установить расположение обьекта
    ///
    void setPosition(float x, float y);

private:
    // туту слоты
    QColor   _color        {220, 220, 0, 227};
    QColor   _color_line   {0, 0, 0, 255}; //  ченый не прозрачный
    float    _height        {0};
    float    _width         {0};
    float    _thickness     {0};        // толщина оучки
    float    _x             {0};
    float    _y             {0};


protected:
    virtual void paintEvent(QPaintEvent *event);          // тут рисуем
//    virtual QSize sizeHint() const;                       // тут задаем размеры (возми из иного прмера)
    virtual void mousePressEvent(QMouseEvent * event);    // тут нажатие клавиши (зажатие)
    virtual void mouseReleaseEvent(QMouseEvent * event);  // тут зажатие клавиши (отддатие  )
};

#endif // TOCKABUTTON_H

tochkabutton.cpp

#include "tochkabutton.h"

void TochkaButton::setColor(int r, int g, int b, int a)
{
    _color.setRgb(r,g,b,a);
}

void TochkaButton::setColorLine(int r, int g, int b, int a)
{
    _color_line.setRgb(r,g,b,a);
}

void TochkaButton::setScale(float height, float width)
{
    _height = height;
    _width = width;

    _thickness = (height+width)/100.0;
}

void TochkaButton::setPosition(float x, float y)
{
    _x = x;
    _y = y;
}

void TochkaButton::paintEvent(QPaintEvent *event)
{
    QPainter painter(this);
    painter.setRenderHint(QPainter::Antialiasing, true);

    painter.setPen(QPen(_color_line, _thickness, Qt::SolidLine));
    painter.setBrush(QBrush(_color));

    qDebug() << "_x" << _x << "_y" << _y << "_width" << _width << "_height" << _height;
    painter.drawRect(_x, _y, _width, _height);

    // проверить несколько вариантов
    painter.setBrush(QBrush(_color_line)); // чтоб центр был круглый
//    painter.drawEllipse(_x+_width/2.0-_thickness, _y+_height/2.0-_thickness, _thickness*2, _thickness*2 );

    // воторой вариант просто точка
    painter.drawPoint(_x+_width/2.0, _y+_height/2.0);
}

void TochkaButton::mousePressEvent(QMouseEvent *event)
{

}

void TochkaButton::mouseReleaseEvent(QMouseEvent *event)
{

}

[SGaist]

Hi,

You are using a QMainWindow as base class for Rascroika. QMainWindow already has a layout that you cannot replace. You likely also have a run time warning printed when you run your application.

Either change the base class or create a central widget and apply your layout on that one.

[Christian Ehrlicher]

You don't return any size() or sizeHint() so how should Qt know how much space wour widget needs?

[SGaist]

Hi,

You are using a QMainWindow as base class for Rascroika. QMainWindow already has a layout that you cannot replace. You likely also have a run time warning printed when you run your application.

Either change the base class or create a central widget and apply your layout on that one.

[timob256]

@SGaist said in QGridLayout does not stretch the homemade QWidget over the workspace.:

Hi,

You are using a QMainWindow as base class for Rascroika. QMainWindow already has a layout that you cannot replace. You likely also have a run time warning printed when you run your application.

yes

QLayout: Attempting to add QLayout "" to Rascroika "", which already has a layout
QWidget::setLayout: Attempting to set QLayout "" on Rascroika "", which already has a layout

Either change the base class or create a central widget and apply your layout on that one.

I don't understand what to do ;_;

i tried to add layouts to rascroika.cpp file, gives the same error.

rascroika.cpp

#include "rascroika.h"

Rascroika::Rascroika(QWidget *parent)
    : QMainWindow(parent)
    , _vbox(new QGridLayout(this))
    , _tochkab(new TochkaButton(this))
{
    QVBoxLayout *vlay = new QVBoxLayout();
    QHBoxLayout *hlay1 = new QHBoxLayout();

     hlay1->addWidget(_tochkab);
     _tochkab->setPosition(this->x(),this->y());
     _tochkab->setScale(this->width(),this->height());

    hlay1->addStretch(1);
    vlay->addItem(hlay1);

    vlay->addStretch(1);

    this->setLayout(vlay);
    this->show();
}

Rascroika::~Rascroika()
{
}

I don't know how to add my _vbox widget to the layout.

this->addWidget(_tochkab);

error: no member named 'addWidget' in 'Rascroika'

please, tell me what i need to write??????

[JonB]

@timob256 said in QGridLayout does not stretch the homemade QWidget over the workspace.:

please, tell me what i need to write??????

@SGaist said in QGridLayout does not stretch the homemade QWidget over the workspace.:

Either change the base class or create a central widget and apply your layout on that one.

@timob256 said in QGridLayout does not stretch the homemade QWidget over the workspace.:

I don't know how to add my _vbox widget to the layout.

To which layout? someLayout->addWidget(_tochkab). Not this->addWidget(_tochkab); ("error: no member named 'addWidget' in 'Rascroika'".)

[timob256]

#include "rascroika.h"

Rascroika::Rascroika(QWidget *parent)
   : QMainWindow(parent)
   , _vbox(new QGridLayout(this))
   , _tochkab(new TochkaButton(this))
{
   _tochkab->setPosition(this->x(),this->y());
   _tochkab->setScale(this->width(),this->height());

   this->setCentralWidget(_tochkab);
   this->show();
}

[SGaist]

You _vbox variable is now useless, you should remove it.

Passing a parent to a layout when creating it automatically applies that layout to the parent. That's not what you want here (beside the fact that there are no use in setting a widget on a QMainWindow object.