Dispaly three items of QStringList in one QtableWidget element - qt

I have a binary vector (it is in hex)
For Example -
x={0x06, 0xfc, 0x47}
I want to save it in a QStringList and then read it from the list and display all of them in one element of QTableWidget. How can I do this? I did this previously with a for loop but it only displays the last vector element (0x47) in the table.
Thanks.

You can do it like this:
QStringList list;
for(int i = 0; i < vector.size(); ++i)
{
list.append(QString::number(vector[i], 16));
}
// i - row, j - column in function join put your separator(for example "\n" if you want all items in new row)
ui->tableWidget->setItem(i,j, new QTableWidgetItem(list.join("\n"));

Related

How to set data source for a list view to contain custom data ? (and associate with QTableView)

I am trying to get listview and tableview working together.
The listview must be used for display, the tableview must be used for editing data. The tableview is created on demand in a popup widget (and it may never be needed).
I populate the listview, on start, from a text file - each row a line, with 2 entries separated by a tab. Easy.
The tableview will have to edit 2 columns separately... also, on listview click, I must be able to retrieve the first part of the split...
I have created a model subclass of QStringListModel.
QListView *m_myView = new QListView();
StringList *m_myList = new StringList();
QTextStream in(&myFile);
while (!in.atEnd())
{
QString temp = in.readLine();
if(!temp.isEmpty())
m_myList->append(temp);
}
myFile.close();
m_myView->setModel(m_myList);
where
class StringList : public QStringListModel
{
public:
void append (const QString& string)
{
insertRows(rowCount(), 1);
QModelIndex m = index(rowCount() - 1);
setData(m, string, Qt::EditRole);
QStringList splist = string.split('\t');
setData(m, splist.at(0), Qt::ToolTipRole);
if(splist.size() > 1)
setData(m, splist.at(1), Qt::StatusTipRole);
else
setData(m, "", Qt::StatusTipRole);
qDebug() << data(m, Qt::EditRole).toString()
<< data(m, Qt::ToolTipRole).toString()
<< data(m, Qt::StatusTipRole).toString();
}
};
The EditRole displays correctly, the others display empty strings.
It seems that QStringListModel is incapable of storing anything except EditRole.
So I am left with 2 options - either do the split on each selection, and also when creating the table view, or - what I would like to try but don't know how - create a QStandardItemModel that can act as data sources for both the listview and the tableview, and can easily retrieve the partial data I require on click.
I thought I can simply use it to set the data on listview (like they do here).
QListView *m_myView = new QListView();
QStandardItemModel *m_myList = new QStandardItemModel();
QTextStream in(&myFile);
int r = 0;
while (!in.atEnd())
{
QString temp = in.readLine();
if(!temp.isEmpty())
{
QStringList splist = temp.split('\t'); // assume I know there will be 2 strings always
QStandardItem *item = new QStandardItem(splist.at(0));
m_myList->setItem(r, 0, item);
QStandardItem *item1 = new QStandardItem(splist.at(1));
m_myList->setItem(r, 1, item1);
++r;
}
}
myFile.close();
m_myView->setModel(m_myList);
connect(m_myListView, SIGNAL(clicked(QModelIndex)),
this, SLOT(listChangedSlot(QModelIndex)));
But this will only set the first string in the listview, I really need both, and I still don't know how to retrieve the data
void listChangedSlot(QModelIndex index)
{
qDebug() << m_myList->item(index.row(), 0)->data().toString()
<< m_myList->item(index.row(), 1)->data().toString();
} // shows empty strings
Or...
In the loading section, try:
if(!temp.isEmpty())
{
QStringList splist = temp.split('\t');
splist.append(QString()); // so I don't need to test
QStandardItem *item = new QStandardItem(temp);
m_myList->setItem(r, 0, item);
QModelIndex idx = m_myList->index(r, 0);
QMap<int, QVariant> roles;
roles.insert(Qt::UserRole + 1, QVariant(splist.at(0)));
roles.insert(Qt::UserRole + 2, QVariant(splist.at(1)));
roles.insert(Qt::DisplayRole, QVariant(temp));
m_myList->setItemData(idx, roles);
++r;
}
This works - displays fine and gets the correct content on click - but seems to be unusable for the tableview.
(And seems I am doing twice the work, with setItem and setItemData - so technically storing the content 3 times).
How can I get my listview have a datasource with 2 string items, show both, be able to set it on a tableview, and be able to retrieve the first item on click ?
I figured out a way to share the data source between the listview and tableview:
I create 3 columns - column 0 with the combined components, and columns 1 and 2 with the separated components.
The listview will display only column 0. For tableview, I will hide column 0.
The data I require for processing will be stored in columns 1 and 2. user edit of the data in tableview will require, upon accepting changes, the edit of corresponding column 0.

create a table in Qt and fill it by the user

i want to create an Qt application containing a table of 3 columns and n row, the user will choose the number of row by putting it in the edit button and the table will have 3 columns and the number given by the user. then fill it with element
i have search a lot but only found how to fill the able with sql data,
please is anybody having an idea?
here is what i did so far, i have fixed the number of rows and columns but it is not what i want, besides, i want to use either QtableWidget or QtavleViewItem
int n;
n = ui->spinBox->value();
QStandardItemModel *model = new QStandardItemModel(n,3,this); //2 Rows and 3 Columns
model->setHorizontalHeaderItem(0, new QStandardItem(QString("x")));
model->setHorizontalHeaderItem(1, new QStandardItem(QString("y")));
model->setHorizontalHeaderItem(2, new QStandardItem(QString("z")));
ui->tableView->setModel(model);
you can go through the elements in a QTableView and do things with them:
for(int r=0; r<N_ROWS; r++)
{
for(int c=0; c<N_COLS; c++)
{
QModelIndex index = ui->tableView->model()->index(r,c, QModelIndex());
// Do something with the QVariant that index.data() returns
qDebug() << r << c << index.data().toString();
}
}
Regards.

QStringList "index out of range"

I am trying to reverse the words within a QStringList. Below is the code up to now, but I keep on getting a "Index out of Range" error. From the error it would seem that I am trying to use data that is out of scope, but not able to figure out my problem.
QString reversed;
QStringList reversedlist;
QStringlist list = input.split(" ");
for (int i=0;i<list.length(); ++1)
reversedlist[i] = list[list.length() -1 -i];
reversed = reversedlist.join(" ");`
Thanks
As pointed out by #ThorngardSO, the reversedlist is initially empty, and you are trying to access the invalid index in your loop code. You should add values to the list using one of the following functions:
STL-compatible function push_back() (inserts value at the end of the list)
STL-compatible function push_front() (inserts value at the beginning of the list)
Qt function append() (Qt alternative for push_back)
Qt function prepend() (Qt alternative for push_front)
As you see, prepend() inserts the element at the beginning of the list, that is why it makes the reversing of the list very simple:
for (int i = 0; i < list.length(); ++i) {
reversedlist.prepend(list[i]);
}
Also, note that there is a typo in your loop: it should be ++i instead of ++1.
Your reversedList is initially empty. You have to actually append the items, like this:
reversedlist.push_back (list[list.length () - 1 - i]);
Naturally, trying to access non-existing items via reversedList[i] does not work and throws the index-out-out-range error.
You got the index out of range as there is no sting inside the QStringList reversedlist. So when your code reach the line reversedlist[0], it throw the "index out of range" error. And you can read the value using [0] and cant assign.
if you want to assign the value to a particular index of the QStringList.
QString reversed;
QStringList reversedlist;
QString input="123 456 789 000";
QStringList list = input.split(" ");
for (int i=0;i<list.length(); ++i){
//value to particular index
reversedlist.insert(i,list[list.length() -1 -i]);
}
reversed = reversedlist.join(" ");
qDebug() << reversed;

QList<QString> to QString.arg()

I have the following QString:
QString funcProxy = "executeProxy(\"%1\", \"%2\", \"%3\")";
The data for each on is in:
QList<QString> listProxy;
How would I go about adding the data in listProxy to funcProxy using the arg() method?
funcProxy.arg(??);
Thanks
Regarding the answer from #owacoder, you do not actually need the replace function, the following should work correclty:
for (int i = 0; i < listProxy.size(); ++i) {
funcProxy = funcProxy.arg(listProxy.at(i));
}
Why you ask: From the documentation on QString::arg()
Returns a copy of this string with the lowest numbered place marker replaced by string
Thus it replaces the lowest number with the string in the arg call. First iteration contains %1, %2 and %3, so it replaces %1. Next iteration contains %2 and %3, thus replaces %2.
Alternatively if you have control over funcProxy you can do the following given you can change your list to a QStringList:
QString funcProxy = "executeProxy(\"%1\")";
QStringList listProxy{"a", "b", "c"};
funcProxy = funcProxy.arg(listProxy.join("\", \""));
If you know you'll have exactly 3 elements in your list, you can do this:
funcProxy.arg(listProxy.at(0)).arg(listProxy.at(1)).arg(listProxy.at(2));
Otherwise, you could use this:
for (int i = 0; i < listProxy.size(); ++i)
funcProxy.replace(QString("%%1").arg(i+1), listProxy.at(i));

How to get the texts of all items from QListWidget in Qt?

How can I get the texts of all the widgets in a QListWidget as a QList<QString>?
I can get the list of widget items like this:
QList<QListWidgetItem *> items =
ui->listWidget->findItems(QString("*"), Qt::MatchWrap | Qt::MatchWildcard);
But that's not exactly what I want, I'd like the list of the widget text() properties.
There is no built-in function for that, you'll need to do it manually.
QList<QString> texts;
foreach(QListWidgetItem *item, items)
texts.append(item->text());
Or something like that.
int c = ui->listWidget->count();
for (int i = 0; i < c ; ++i){
QString s = QString::number(i);
QModelIndex *model_index = new QModelIndex(ui->listWidget->model()->index(i,0) ); //0th column since we have one cloumn in listwidget
QString q= model_index->data(Qt::DisplayRole).toString();
qDebug()<<q;
}

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