The code in this example compares the three built in GUI widgets which are used to edit text. Each of these controls offers slightly different functionality and features.<\/p>\n\n\n
\n#include <QtCore>\n#include <QtGui>\n\nclass MainWindow : public QWidget\n{\n public:\n MainWindow();\n};\n<\/pre><\/div>\n\n\nThe only required declaration is the MainWindow() constructor.<\/p>\n\n\n
\nMainWindow::MainWindow()\n{\n setMinimumSize(600, 400);\n\n \/\/\n QLabel *label_1 = new QLabel("Line Edit:");\n\n QLineEdit *text_1 = new QLineEdit();\n text_1->setText("Single line of text");\n\n \/\/\n QLabel *label_2 = new QLabel("Text Edit:");\n\n QTextEdit *text_2 = new QTextEdit();\n text_2->setText(\n "Multiple lines using html text formatting."\n "<br>"\n "<span style=\\"color:#aa00ff;\\">"\n "Show text in magenta<\/span>"\n "<br>"\n "<span style=\\"font-size:10pt;\\">"\n "Set 10 pt font<\/span>");\n text_2->setMaximumHeight(100);\n\n \/\/\n QLabel *label_3 = new QLabel("Plain Text:");\n\n QPlainTextEdit *text_3 = new QPlainTextEdit();\n text_3->setPlainText("Multiple lines, no formatting");\n text_3->setMaximumHeight(100);\n\n QPushButton *pb_1 = new QPushButton();\n pb_1->setText("Close");\n\n QGridLayout *layout1 = new QGridLayout();\n layout1->setVerticalSpacing(20);\n\n layout1->addWidget(label_1, 0, 1);\n layout1->addWidget(text_1, 0, 2);\n layout1->addWidget(label_2, 1, 1, Qt::AlignTop);\n layout1->addWidget(text_2, 1, 2);\n layout1->addWidget(label_3, 2, 1, Qt::AlignTop);\n layout1->addWidget(text_3, 2, 2);\n\n QHBoxLayout *layout2 = new QHBoxLayout();\n layout2->addStretch();\n layout2->addWidget(pb_1);\n layout2->addStretch();\n\n QVBoxLayout *layoutMain = new QVBoxLayout(this);\n layoutMain->setContentsMargins(45, 35, 45, 15);\n\n layoutMain->addLayout(layout1);\n layoutMain->addSpacing(20);\n layoutMain->addLayout(layout2);\n\n connect(pb_1, &QPushButton::clicked, \n this, &QWidget::close);\n} \n<\/pre><\/div>\n\n\nThere are three different widgets which can be used to add or edit text in a GUI application. The QLineEdit class declared on line 8 is the most basic control. It allows the user to enter a single line of non-formatted text. This is the most commonly used text edit control. <\/p>\n\n\n\n
On line 14 is the declaration for a QTextEdit widget. This control offers the most features and flexibility. It supports multiple lines of text and a subset of HTML tags like line breaks, span, lists, and tables. For a full list of the supported formatting commands, refer to the API documentation<\/a>.
The QPlainTextEdit declared on line 28 is also multi line however you can not specify any formatting commands. <\/p>\n\n\n\nThese widgets can be used on any user interface form in any combination. <\/p>\n\n\n\n
Main Function<\/h3>\n\n\n\n
Since the source code for main() has not changed there is no need to show it again. Refer to example 3 or download the full source for this example.<\/p>\n\n\n\n
Running the Example<\/h3>\n\n\n\n
To build and run this example use the same CMake build file and commands as we showed for the first example. The only suggested modification is on line 2 of the CMakeLists.txt file, change “example_1” to “example_18”. <\/p>\n\n\n\n