The Order Form example shows how to generate rich text documents by combining a simple template with data input by the user in a dialog.
The
DetailsDialog
类是子类化的
QDialog
, implementing a slot
verify()
to allow contents of the
DetailsDialog
to be verified later. This is further explained in
DetailsDialog
Implementation.
class DetailsDialog : public QDialog { Q_OBJECT public: DetailsDialog(const QString &title, QWidget *parent); public slots: void verify(); public: QList<QPair<QString, int> > orderItems(); QString senderName() const; QString senderAddress() const; bool sendOffers(); private: void setupItemsTable(); QLabel *nameLabel; QLabel *addressLabel; QCheckBox *offersCheckBox; QLineEdit *nameEdit; QStringList items; QTableWidget *itemsTable; QTextEdit *addressEdit; QDialogButtonBox *buttonBox; };
The constructor of
DetailsDialog
accepts parameters
title
and
parent
. The class defines four
getter
functions:
orderItems()
,
senderName()
,
senderAddress()
,和
sendOffers()
to allow data to be accessed externally.
The class definition includes input widgets for the required fields,
nameEdit
and
addressEdit
. Also, a
QCheckBox
和
QDialogButtonBox
are defined; the former to provide the user with the option to receive information on products and offers, and the latter to ensure that buttons used are arranged according to the user's native platform. In addition, a
QTableWidget
,
itemsTable
, is used to hold order details.
The screenshot below shows the
DetailsDialog
we intend to create.
The constructor of
DetailsDialog
instantiates the earlier defined fields and their respective labels. The label for
offersCheckBox
is set and the
setupItemsTable()
function is invoked to setup and populate
itemsTable
。
QDialogButtonBox
对象,
buttonBox
, is instantiated with
OK
and
Cancel
buttons. This
buttonBox
's
accepted()
and
rejected()
signals are connected to the
verify()
and
reject()
slots in
DetailsDialog
.
DetailsDialog::DetailsDialog(const QString &title, QWidget *parent) : QDialog(parent) { nameLabel = new QLabel(tr("Name:")); addressLabel = new QLabel(tr("Address:")); addressLabel->setAlignment(Qt::AlignLeft | Qt::AlignTop); nameEdit = new QLineEdit; addressEdit = new QTextEdit; offersCheckBox = new QCheckBox(tr("Send information about products and " "special offers")); setupItemsTable(); buttonBox = new QDialogButtonBox(QDialogButtonBox::Ok | QDialogButtonBox::Cancel); connect(buttonBox, &QDialogButtonBox::accepted, this, &DetailsDialog::verify); connect(buttonBox, &QDialogButtonBox::rejected, this, &DetailsDialog::reject);
A
QGridLayout
is used to place all the objects on the
DetailsDialog
.
QGridLayout *mainLayout = new QGridLayout; mainLayout->addWidget(nameLabel, 0, 0); mainLayout->addWidget(nameEdit, 0, 1); mainLayout->addWidget(addressLabel, 1, 0); mainLayout->addWidget(addressEdit, 1, 1); mainLayout->addWidget(itemsTable, 0, 2, 2, 1); mainLayout->addWidget(offersCheckBox, 2, 1, 1, 2); mainLayout->addWidget(buttonBox, 3, 0, 1, 3); setLayout(mainLayout); setWindowTitle(title); }
The
setupItemsTable()
function instantiates the
QTableWidget
对象,
itemsTable
, and sets the number of rows based on the
QStringList
对象,
项
, which holds the type of items ordered. The number of columns is set to 2, providing a "name" and "quantity" layout. A
for
loop is used to populate the
itemsTable
和
名称
item's flag is set to
Qt::ItemIsEnabled
or
Qt::ItemIsSelectable
. For demonstration purposes, the
quantity
item is set to a 1 and all items in the
itemsTable
have this value for quantity; but this can be modified by editing the contents of the cells at run time.
void DetailsDialog::setupItemsTable() { items << tr("T-shirt") << tr("Badge") << tr("Reference book") << tr("Coffee cup"); itemsTable = new QTableWidget(items.count(), 2); for (int row = 0; row < items.count(); ++row) { QTableWidgetItem *name = new QTableWidgetItem(items[row]); name->setFlags(Qt::ItemIsEnabled | Qt::ItemIsSelectable); itemsTable->setItem(row, 0, name); QTableWidgetItem *quantity = new QTableWidgetItem("1"); itemsTable->setItem(row, 1, quantity); } }
The
orderItems()
function extracts data from the
itemsTable
and returns it in the form of a
QList
<
QPair
<
QString
,int>> where each
QPair
corresponds to an item and the quantity ordered.
QList<QPair<QString, int> > DetailsDialog::orderItems() { QList<QPair<QString, int> > orderList; for (int row = 0; row < items.count(); ++row) { QPair<QString, int> item; item.first = itemsTable->item(row, 0)->text(); int quantity = itemsTable->item(row, 1)->data(Qt::DisplayRole).toInt(); item.second = qMax(0, quantity); orderList.append(item); } return orderList; }
The
senderName()
function is used to return the value of the
QLineEdit
used to store the name field for the order form.
QString DetailsDialog::senderName() const { return nameEdit->text(); }
The
senderAddress()
function is used to return the value of the
QTextEdit
containing the address for the order form.
QString DetailsDialog::senderAddress() const { return addressEdit->toPlainText(); }
The
sendOffers()
function is used to return a
true
or
false
value that is used to determine if the customer in the order form wishes to receive more information on the company's offers and promotions.
bool DetailsDialog::sendOffers() { return offersCheckBox->isChecked(); }
The
verify()
function is an additionally implemented slot used to verify the details entered by the user into the
DetailsDialog
. If the details entered are incomplete, a
QMessageBox
is displayed providing the user the option to discard the
DetailsDialog
. Otherwise, the details are accepted and the
accept()
function is invoked.
void DetailsDialog::verify() { if (!nameEdit->text().isEmpty() && !addressEdit->toPlainText().isEmpty()) { accept(); return; } QMessageBox::StandardButton answer; answer = QMessageBox::warning(this, tr("Incomplete Form"), tr("The form does not contain all the necessary information.\n" "Do you want to discard it?"), QMessageBox::Yes | QMessageBox::No); if (answer == QMessageBox::Yes) reject(); }
The
MainWindow
类是子类化的
QMainWindow
, implementing two slots -
openDialog()
and
printFile()
. It also contains a private instance of
QTabWidget
,
letters
.
class MainWindow : public QMainWindow { Q_OBJECT public: MainWindow(); void createSample(); public slots: void openDialog(); void printFile(); private: void createLetter(const QString &name, const QString &address, QList<QPair<QString,int> > orderItems, bool sendOffers); QAction *printAction; QTabWidget *letters; };
The
MainWindow
constructor sets up the
fileMenu
and the required actions,
newAction
and
printAction
. These actions'
triggered()
signals are connected to the additionally implemented openDialog() slot and the default close() slot. The
QTabWidget
,
letters
, is instantiated and set as the window's central widget.
MainWindow::MainWindow() { QMenu *fileMenu = new QMenu(tr("&File"), this); QAction *newAction = fileMenu->addAction(tr("&New...")); newAction->setShortcuts(QKeySequence::New); printAction = fileMenu->addAction(tr("&Print..."), this, &MainWindow::printFile); printAction->setShortcuts(QKeySequence::Print); printAction->setEnabled(false); QAction *quitAction = fileMenu->addAction(tr("E&xit")); quitAction->setShortcuts(QKeySequence::Quit); menuBar()->addMenu(fileMenu); letters = new QTabWidget; connect(newAction, &QAction::triggered, this, &MainWindow::openDialog); connect(quitAction, &QAction::triggered, this, &MainWindow::close); setCentralWidget(letters); setWindowTitle(tr("Order Form")); }
The
createLetter()
function creates a new
QTabWidget
采用
QTextEdit
,
editor
, as the parent. This function accepts four parameters that correspond to we obtained through
DetailsDialog
, in order to "fill" the
editor
.
void MainWindow::createLetter(const QString &name, const QString &address, QList<QPair<QString,int> > orderItems, bool sendOffers) { QTextEdit *editor = new QTextEdit; int tabIndex = letters->addTab(editor, name); letters->setCurrentIndex(tabIndex);
We then obtain the cursor for the
editor
使用
QTextEdit::textCursor
()。
cursor
is then moved to the start of the document using
QTextCursor::Start
.
QTextCursor cursor(editor->textCursor()); cursor.movePosition(QTextCursor::Start);
Recall the structure of a Rich Text Document , where sequences of frames and tables are always separated by text blocks, some of which may contain no information.
In the case of the Order Form Example, the document structure for this portion is described by the table below:
frame with referenceFrameFormat | |
block |
A company
|
block | |
block |
321 City Street
|
block | |
block |
Industry Park
|
block | |
block |
Another country
|
This is accomplished with the following code:
QTextFrame *topFrame = cursor.currentFrame(); QTextFrameFormat topFrameFormat = topFrame->frameFormat(); topFrameFormat.setPadding(16); topFrame->setFrameFormat(topFrameFormat); QTextCharFormat textFormat; QTextCharFormat boldFormat; boldFormat.setFontWeight(QFont::Bold); QTextFrameFormat referenceFrameFormat; referenceFrameFormat.setBorder(1); referenceFrameFormat.setPadding(8); referenceFrameFormat.setPosition(QTextFrameFormat::FloatRight); referenceFrameFormat.setWidth(QTextLength(QTextLength::PercentageLength, 40)); cursor.insertFrame(referenceFrameFormat); cursor.insertText("A company", boldFormat); cursor.insertBlock(); cursor.insertText("321 City Street"); cursor.insertBlock(); cursor.insertText("Industry Park"); cursor.insertBlock(); cursor.insertText("Another country");
注意,
topFrame
是
editor
's top-level frame and is not shown in the document structure.
We then set the
cursor
's position back to its last position in
topFrame
and fill in the customer's name (provided by the constructor) and address - using a range-based for loop to traverse the
QString
,
address
.
cursor.setPosition(topFrame->lastPosition()); cursor.insertText(name, textFormat); const QStringList lines = address.split('\n'); for (const QString &line : lines) { cursor.insertBlock(); cursor.insertText(line); }
The
cursor
is now back in
topFrame
and the document structure for the above portion of code is:
block |
Donald
|
block |
47338 Park Avenue
|
block |
Big City
|
For spacing purposes, we invoke
insertBlock()
twice. The
currentDate()
is obtained and displayed. We use
setWidth()
to increase the width of
bodyFrameFormat
and we insert a new frame with that width.
cursor.insertBlock(); cursor.insertBlock(); QDate date = QDate::currentDate(); cursor.insertText(tr("Date: %1").arg(date.toString("d MMMM yyyy")), textFormat); cursor.insertBlock(); QTextFrameFormat bodyFrameFormat; bodyFrameFormat.setWidth(QTextLength(QTextLength::PercentageLength, 100)); cursor.insertFrame(bodyFrameFormat);
The following code inserts standard text into the order form.
cursor.insertText(tr("I would like to place an order for the following " "items:"), textFormat); cursor.insertBlock(); cursor.insertBlock();
This part of the document structure now contains the date, a frame with
bodyFrameFormat
, as well as the standard text.
block | |
block | |
block |
Date: 25 May 2007
|
block | |
frame with bodyFrameFormat | |
block |
I would like to place an order for the following items:
|
block | |
block |
A
QTextTableFormat
对象,
orderTableFormat
, is used to hold the type of item and the quantity ordered.
QTextTableFormat orderTableFormat; orderTableFormat.setAlignment(Qt::AlignHCenter); QTextTable *orderTable = cursor.insertTable(1, 2, orderTableFormat); QTextFrameFormat orderFrameFormat = cursor.currentFrame()->frameFormat(); orderFrameFormat.setBorder(1); cursor.currentFrame()->setFrameFormat(orderFrameFormat);
使用
cellAt()
to set the headers for the
orderTable
.
cursor = orderTable->cellAt(0, 0).firstCursorPosition(); cursor.insertText(tr("Product"), boldFormat); cursor = orderTable->cellAt(0, 1).firstCursorPosition(); cursor.insertText(tr("Quantity"), boldFormat);
Then, we iterate through the
QList
of
QPair
objects to populate
orderTable
.
for (int i = 0; i < orderItems.count(); ++i) { QPair<QString,int> item = orderItems[i]; int row = orderTable->rows(); orderTable->insertRows(row, 1); cursor = orderTable->cellAt(row, 0).firstCursorPosition(); cursor.insertText(item.first, textFormat); cursor = orderTable->cellAt(row, 1).firstCursorPosition(); cursor.insertText(QString("%1").arg(item.second), textFormat); }
The resulting document structure for this section is:
orderTable
with
orderTableFormat
|
|
block |
Product
|
block |
Quantity
|
block |
T-shirt
|
block |
4
|
block |
Badge
|
block |
3
|
block |
Reference book
|
block |
2
|
block |
Coffee cup
|
block |
5
|
The
cursor
is then moved back to
topFrame
's
lastPosition()
and more standard text is inserted.
cursor.setPosition(topFrame->lastPosition()); cursor.insertBlock(); cursor.insertText(tr("Please update my records to take account of the " "following privacy information:")); cursor.insertBlock();
Another QTextTable is inserted, to display the customer's preference regarding offers.
QTextTable *offersTable = cursor.insertTable(2, 2); cursor = offersTable->cellAt(0, 1).firstCursorPosition(); cursor.insertText(tr("I want to receive more information about your " "company's products and special offers."), textFormat); cursor = offersTable->cellAt(1, 1).firstCursorPosition(); cursor.insertText(tr("I do not want to receive any promotional information " "from your company."), textFormat); if (sendOffers) cursor = offersTable->cellAt(0, 0).firstCursorPosition(); else cursor = offersTable->cellAt(1, 0).firstCursorPosition(); cursor.insertText("X", boldFormat);
The document structure for this portion is:
block | |
block |
Please update my...
|
block | |
offersTable
|
|
block |
I want to receive...
|
block |
I do not want to receive...
|
block |
X
|
The
cursor
is moved to insert "Sincerely" along with the customer's name. More blocks are inserted for spacing purposes. The
printAction
is enabled to indicate that an order form can now be printed.
cursor.setPosition(topFrame->lastPosition()); cursor.insertBlock(); cursor.insertText(tr("Sincerely,"), textFormat); cursor.insertBlock(); cursor.insertBlock(); cursor.insertBlock(); cursor.insertText(name); printAction->setEnabled(true); }
The bottom portion of the document structure is:
block | |
block |
Sincerely,
|
block | |
block | |
block | |
block |
Donald
|
The
createSample()
function is used for illustration purposes, to create a sample order form.
void MainWindow::createSample() { DetailsDialog dialog("Dialog with default values", this); createLetter("Mr. Smith", "12 High Street\nSmall Town\nThis country", dialog.orderItems(), true); }
The
openDialog()
function opens a
DetailsDialog
object. If the details in
dialog
are accepted, the
createLetter()
function is invoked using the parameters extracted from
dialog
.
void MainWindow::openDialog() { DetailsDialog dialog(tr("Enter Customer Details"), this); if (dialog.exec() == QDialog::Accepted) { createLetter(dialog.senderName(), dialog.senderAddress(), dialog.orderItems(), dialog.sendOffers()); } }
In order to print out the order form, a
printFile()
function is included, as shown below:
void MainWindow::printFile() { #if defined(QT_PRINTSUPPORT_LIB) && QT_CONFIG(printdialog) QTextEdit *editor = static_cast<QTextEdit*>(letters->currentWidget()); QPrinter printer; QPrintDialog dialog(&printer, this); dialog.setWindowTitle(tr("Print Document")); if (editor->textCursor().hasSelection()) dialog.addEnabledOption(QAbstractPrintDialog::PrintSelection); if (dialog.exec() != QDialog::Accepted) { return; } editor->print(&printer); #endif }
This function also allows the user to print a selected area with QTextCursor::hasSelection (), instead of printing the entire document.
main()
函数
The
main()
function instantiates
MainWindow
and sets its size to 640x480 pixels before invoking the
show()
函数和
createSample()
函数。
int main(int argc, char *argv[]) { QApplication app(argc, argv); MainWindow window; window.resize(640, 480); window.show(); window.createSample(); return app.exec(); }