I work with A QTableWidget in my app. To calculate the max. Columns to show I need to get the real width of the QTableWidget. I tried different ways:
this (QTableWidget)
this->geometry()->width() = Will always report 640.
this->horizontalHeader()->length() = Will always report 1660 here in case of the amount of columns.
But the QTableWidget has a size of exact 1000 pixel. This confuse me.
My first Idea wa, ok you ask the app at the wrong position about the size.
SO I also asked after the MDIChild was build.
QVBoxLayout * dlgSplitter = new QVBoxLayout(this);
QHBoxLayout * topNav = new QHBoxLayout(this);
QWidget * wdgSplitter = new QWidget(this);
QLabel *labelTopNav = new QLabel(this);
labelTopNav->setText(tr("This is a header"));
topNav->addWidget(labelTopNav);
topNav->setContentsMargins(1,8,1,0);
dlgSplitter->setContentsMargins(0,0,0,0);
dlgSplitter->setSpacing(0);
dlgSplitter->setMargin(0);
dlgSplitter->addLayout(topNav);
scanBoard = new QScanBoard(200, 83); //This ist he "this->" control from above
//scrollArea->setWidget(scanBoard);
dlgSplitter->addWidget(scanBoard);
wdgSplitter->setLayout(dlgSplitter);
this->setCentralWidget(wdgSplitter);
int nWidth = scanBoard->geometry().width();
qDebug("Breite: %d ",nWidth);
But this also throws the same data as the class itself do.
Do anybody know a way to read the size of the QTableWidget without its contents, just its frame?
Related
I am working on Qt applicaction. There I have QMainWindow. Inside it I have added QTableView. When I run the application I see that I need to scroll to display the whole table and also blank space shows up below it.
I would like main window to resize horizontally in order to use space needed by the table. Also I would like it to resize vertically to not having space unused. How could I achieve that?
This is my code so far:
void MainWindow::initUi() {
setWindowTitle(tr("Main Window"));
QWidget* centralWidget = new QWidget(this);
QVBoxLayout *mainLayout = new QVBoxLayout(centralWidget);
QFormLayout *upperLayout = new QFormLayout;
// Default layout appearance of QMacStyle
upperLayout->setRowWrapPolicy(QFormLayout::DontWrapRows);
upperLayout->setFieldGrowthPolicy(QFormLayout::FieldsStayAtSizeHint);
upperLayout->setFormAlignment(Qt::AlignHCenter | Qt::AlignTop);
upperLayout->setLabelAlignment(Qt::AlignLeft);
QVBoxLayout *resultsLayout = new QVBoxLayout;
QTableView* table = new QTableView(centralWidget);
table->verticalHeader()->hide();
QStandardItemModel* model= new QStandardItemModel(4, 4);
for (int row = 0; row < 4; ++row) {
for (int column = 0; column < 4; ++column) {
QStandardItem *item = new QStandardItem(QString("row %0, column %1").arg(row).arg(column));
model->setItem(row, column, item);
}
}
table->setModel(model);
QLabel* upperLabel = new QLabel(tr("Label:"), centralWidget);
upperLabel->setAlignment(Qt::AlignLeft);
resultLabel = new QLabel(tr("Result goes here"), centralWidget);
mainLayout->addLayout(resultsLayout);
resultsLayout->addLayout(upperLayout);
resultsLayout->addWidget(table);
upperLayout->addRow(upperLabel, resultLabel);
centralWidget->setLayout(mainLayout);
setCentralWidget(centralWidget);
this->adjustSize();
}
Set the sizeAdjustPolicy of the table to AdjustToContents view, then set the size policy to Fixed in both horizontal and vertical directions.
AdjustToContents might incur a slight performance penalty for dynamic contents in the view, since every data change may change the layout.
The Qt Designer is a really nifty tool to figure layout issues out quickly; the {table,list,tree} widgets behave exactly the same as the views do (because they're the same) and the widgets can be quickly filled with dummy data in Qt Designer.
I have a QWidget rzadKontener that represents a row in a QListWidget.
QWidget* rzadKontener = new QWidget;
QHBoxLayout* rzadKontenerLayout = new QHBoxLayout();
rzadKontenerLayout->setAlignment(Qt::AlignLeft);
rzadKontenerLayout->setAlignment(Qt::AlignTop);
rzadKontener->setObjectName("rzadKontener_" + poziom);
rzadKontener->setFixedHeight(200);
rzadKontener->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
rzadKontener->setLayout(rzadKontenerLayout);
(....)
QListWidgetItem* newItemRzad = new QListWidgetItem;
newItemRzad->setSizeHint(QSize(listSize*225, 200));
QString poziomText = poziom;
newItemRzad->setText(poziomText);
newItemRzad->setTextColor(QColor(Qt::white));
ui->listWidgetZdjeciaModelu->addItem(newItemRzad);
ui->listWidgetZdjeciaModelu->setItemWidget(newItemRzad, rzadKontener);
It contains a number of items, that are QWidgets with pictures, buttons and text. It is then placed in a QListWidget as a row full of these items. When I add 5 items at once, while creating a new rzadKontener, scroll bars in the QListWidget will appear. But if I add 3 and then 2 items later on, they'll go out of bounds without a scrollbar. How can I force the layout to scale to the new rzadKontener's size?
I found an answer. Instead of modifying the QWidget inside the list, I should be modifying the QListWidgetItem it's inside of (the parent...).
QWidget* newPicture = new QWidget;
yadda yadda yadda (....)
int currentRowWidth = ui->listWidgetZdjeciaModelu->findChild<QWidget*>(objectName)->width(); //gets max width of rzadKontener, which fills the entirety of the row - it equals the QListWidgetItem's width
int newWidth = currentRowWidth + 225; //225 is a fixed width of newPicture
ui->listWidgetZdjeciaModelu->item(0)->setSizeHint(QSize(newWidth, 200));
ui->listWidgetZdjeciaModelu->findChild<QWidget*>(objectName)->layout()->addWidget(newPicture );
We can do ui->listWidgetZdjeciaModelu->item(0)->setSizeHint(QSize(newWidth, 200)); instead of a specific row (->item(row)), because the list is a rectangle. Doesn't matter which row we enlarge, the entire thing will stretch anyway.
But, if you want to get the row number, you can do it this way:
int row=0;
//we make a list. Each of my QListWidgetItem has a unique string poziom in it, so I can filter by that.
QList<QListWidgetItem *> items = ui->listWidgetZdjeciaModelu->findItems(poziom, Qt::MatchContains);
if (items.size() > 0) {
//we use the first (and only, in my case) item on this list to get row number
row = ui->listWidgetZdjeciaModelu->row(items[0]);
}
Weird thing is, I already tried this. Must've kept making a typo.
I'm trying to create a GUI with QtCreator. For this GUI, I need to display several images with different sizes next to each other. These images should be touching each other.
I use a QWidget with a QHBoxLayout, where I add the labels (with different sizes) containing the images.
According to related questions, I should use setSpacing and setContentsMargin to remove these spaces, but that won't work; I tried several times.
Here's the code:
QWidget *widget = new QWidget(ui->tagcloud);
QHBoxLayout * l = new QHBoxLayout(widget);
ui->tagcloud->setWidget(widget);
for(int i=0;i<list.size();++i)
{
QLabel *lab = new QLabel;
QPixmap pic((list[i].imgPath).c_str()); //This fetches the image
int sizeChange = 50 + (2*list[i].percent); //Calculates the size of the image
lab->setFixedSize(QSize(sizeChange, sizeChange));
lab->setPixmap(pic);
lab->setScaledContents(true);
l->addWidget(lab);
l->setSpacing(0);
}
However, when I run this, the spacing remains the same (i.e. definitely not zero).
If I add more labels to the layout, the spacing seems to get smaller.
Can anyone explain or help me? Thanks!
Setting spacing to 0 and adding stretch before and after works for me :
l->addStretch();
for(int i = 0; i < list.size(); ++i)
{
QLabel *lab = new QLabel;
QPixmap pic((list[i].imgPath).c_str()); //This fetches the image
int sizeChange = 50 + (2*list[i].percent); //Calculates the size of the image
lab->setFixedSize(QSize(sizeChange, sizeChange));
lab->setPixmap(pic);
lab->setScaledContents(true);
l->addWidget(lab);
}
l->addStretch();
l->setSpacing(0);
Also this works I think
l->setSizeConstraint(QLayout::SetMaximumSize);
Hi guys I have to dynamically create push buttons depending on user inputs, therefore if user gives a large input number the widget containing the push buttons has to have the ability to scroll up and down. For this reason I am using QScrollArea. I generate the template in Qt designer and the UIC generates the code for me after which I add in my part which should handle dynamic creation of push buttons. However, I can not seem to get the vertical scroll bars to appear. Here is the relevant part of the code.
verticalWidget = new QWidget(FWHMWorkflowDialog);
verticalWidget->setObjectName(QString::fromUtf8("verticalWidget"));
verticalWidget->setMinimumSize(QSize(150, 0));
verticalWidget->setMaximumSize(QSize(150, 16777215));
verticalLayout_5 = new QVBoxLayout(verticalWidget);
verticalLayout_5->setObjectName(QString::fromUtf8("verticalLayout_5"));
scrollArea = new QScrollArea(verticalWidget);
scrollArea->setObjectName(QString::fromUtf8("scrollArea"));
scrollArea->setMaximumSize(QSize(150, 16777215));
scrollArea->setWidgetResizable(true);
scrollAreaWidgetContents = new QWidget();
scrollAreaWidgetContents->setObjectName(QString::fromUtf8("scrollAreaWidgetContents"));
scrollAreaWidgetContents->setGeometry(QRect(0, 0, 130, 432));
numberOfSlices = numberSlices;
for (int i = 0; i < numberOfSlices; i++)
{
QWidget *horizontalWidget = new QWidget(scrollAreaWidgetContents);
horizontalWidget->setMaximumSize(150,40);
horizontalWidget->setGeometry(QRect(0, i*40, 150, 40));
hWidgetList.push_back(horizontalWidget);
QHBoxLayout *hLayout = new QHBoxLayout(horizontalWidget);
hLayoutList.push_back(hLayout);
hLayout->setSizeConstraint(QLayout::SetMinimumSize);
hLayout->setContentsMargins(-1, 1, -1, 1);
QPushButton *pushButton = new QPushButton(horizontalWidget);
pushButtonList.push_back(pushButton);
QString temp = QString("m_sliceButton").arg(i);
pushButtonList[i]->setObjectName(temp);
pushButtonList[i]->setGeometry(QRect(10, 20+i*40, 98, 27));
hLayout->addWidget(pushButton);
QCheckBox *checkBox = new QCheckBox(horizontalWidget);
checkBoxList.push_back(checkBox);
temp = QString("m_checkBox").arg(i);
checkBoxList[i]->setObjectName(temp);
checkBoxList[i]->setEnabled(true);
checkBoxList[i]->setGeometry(QRect(110, 20+i*40, 21, 22));
hLayout->addWidget(checkBox);
}
scrollArea->setWidget(scrollAreaWidgetContents);
//scrollArea->setWidgetResizable(true);
verticalLayout_5->addWidget(scrollArea);
The output window always looks like the following.
In this example the input by the user is 25 however you can see that the 21st button is cut off and 4 other buttons are not visible.
The size window problem occurring after scroll functionality started working.
You need to add your horizontalWidget to a vertical widget like so:
QVBoxLayout* vLayout = new QVBoxLayout();
for (int i = 0; i < numberOfSlices; i++)
{
QWidget *horizontalWidget = new QWidget();
vLayout->addWidget(horizontalWidget);
....
}
scrollAreaWidgetContents->setLayout(vLayout);
You second problem looks like it comes from this line:
scrollArea = new QScrollArea(verticalWidget);
You're adding scrollArea directly to verticalWidget, but to get it to lay out the way you want you need to put it in a layout. Try the following instead:
QVBoxLayout* l = new QVBoxLayout();
l->addWidget(sliceLabel); // or whatever you call it
l->addWidget(scrollArea);
l->addWidget(clearButton); // again, your name here
verticalWidget->setLayout(l);
Try playing around with the QScrollBarPolicy.
http://doc.qt.digia.com/qt/qabstractscrollarea.html#horizontalScrollBarPolicy-prop
I'm guessing that the default behavior isn't working because there is something strange going on with layouts.
All, I am maintaining a QGridLayout of QLabels which show the coefficients of a polynomial. I represent my polynomial using QList<double>.
Each time I update my coefficients, I update my labels. When changing the size of the list, my method does not works well. QGridLayout::rowCount() doesn't update correctly. I am wondering if there's a way to remove rows from a QGridLayout.
Code follows, updating the QGridLayout size with more (or less) QLabels
int count = coefficients->count(); //coefficients is a QList<double> *
if(count != (m_informational->rowCount() - 1)) //m_information is a QGridLayout
{
SetFitMethod(0);
for(int i = 0; i < count; ++i)
{
QLabel * new_coeff = new QLabel(this);
new_coeff->setAlignment(Qt::AlignRight);
m_informational->addWidget(new_coeff, i+1, 0);
QLabel * param = new QLabel(this);
param->setAlignment(Qt::AlignLeft);
param->setText(QString("<b><i>x</i><sup>%2</sup></b>").arg(count-i-1));
m_informational->addWidget(param, i+1, 1);
QSpacerItem * space = new QSpacerItem(0,0,QSizePolicy::Expanding);
m_informational->addItem(space, i+1, 1);
}
m_informational->setColumnStretch(0, 3);
m_informational->setColumnStretch(1, 1);
m_informational->setColumnStretch(2, 1);
}
The SetFitMethod (it's an initial mockup)
void SetFitMethod(int method)
{
ClearInformational();
switch(method)
{
case 0: //Polynomial fit
QLabel * title = new QLabel(this);
title->setText("<b> <u> Coefficients </u> </b>");
title->setAlignment(Qt::AlignHCenter);
m_informational->addWidget(title,0,0,1,3, Qt::AlignHCenter);
}
}
The Clearing Method:
void ClearInformational()
{
while(m_informational->count())
{
QLayoutItem * cur_item = m_informational->takeAt(0);
if(cur_item->widget())
delete cur_item->widget();
delete cur_item;
}
}
The issue is that QGridLayout::rowCount() doesn't actually return the number of rows that you can see, it actually returns the number of rows that QGridLayout has internally allocated for rows of data (yes, this isn't very obvious and isn't documented).
To get around this you can either delete the QGridLayout and recreate it, or if you're convinced that your column count won't change, you can do something like this:
int rowCount = m_informational->count()/m_informational->columnCount();
I solved this by creating a QVBoxLayout (for rows) and within this I was adding QHBoxLayout (for columns). In the QHBoxLayout I was then inserting my widgets (in one row). This way I was able to nicely remove rows - overall row count was working as it should be. Additionally to this I got also an insert method, thanks to which I was able to insert new rows into specific locations (everything was correctly reordered/renumbered).
Example (only from head):
QVBoxLayout *vBox= new QVBoxLayout(this);
//creating row 1
QHBoxLayout *row1 = new QHBoxLayout();
QPushButton *btn1x1 = new QPushButton("1x1");
QPushButton *btn1x2 = new QPushButton("1x2");
row1->addWidget(btn1x1);
row1->addWidget(btn1x2);
//adding to vBox - here you can use also insertLayout() for insert to specific location
vBox->addlayout(row1);
//creating row 2
QHBoxLayout *row2 = new QHBoxLayout();
QPushButton *btn2x1 = new QPushButton("2x1");
QPushButton *btn2x2 = new QPushButton("2x2");
row2->addWidget(btn2x1);
row2->addWidget(btn2x2);
//adding to vBox - here you can use also insertLayout() for insert to specific location
vBox->addlayout(row2);
Well, my solution was to also delete the QGridLayout in ClearInformational