(C++) QTreeViewExample2

February 24, 2017 · View on GitHub

 

 

 

 

 

(C++) QTreeViewExample2

 

QtQt CreatorLubuntu

 

QTreeView example 2: add a row and undo/redo this is an example to use a QTreeView.

 

Technical facts

 

Application type(s)

Operating system(s) or programming environment(s)

IDE(s):

Project type:

C++ standard:

Compiler(s):

Libraries used:

  • Qt Qt: version 5.4.1 (32 bit)
  • STL STL: GNU ISO C++ Library, version 4.9.2

 

 

 

 

 

Qt project file: ./CppQTreeViewExample2/CppQTreeViewExample2.pro

 

QT       += core gui greaterThan(QT_MAJOR_VERSION, 4): QT += widgets TEMPLATE = app SOURCES += \     qtdialog.cpp \     qtmain.cpp \     qtaddrowcommand.cpp HEADERS  += qtdialog.h \     qtaddrowcommand.h FORMS    += qtdialog.ui

 

 

 

 

 

./CppQTreeViewExample2/qtaddrowcommand.h

 

#ifndef QTADDROWCOMMAND_H #define QTADDROWCOMMAND_H #include <QUndoCommand> struct QStandardItemModel; struct QAbstractItemView; struct QtAddRowCommand : public QUndoCommand {   QtAddRowCommand(     QStandardItemModel * const model,     QAbstractItemView * const view);   void redo();   void undo();   private:   std::string m_text;   QStandardItemModel * const m_model;   QAbstractItemView  * const m_view; }; #endif // QTADDROWCOMMAND_H

 

 

 

 

 

./CppQTreeViewExample2/qtaddrowcommand.cpp

 

#include "qtaddrowcommand.h" #include <QAbstractItemModel> #include <QAbstractItemView> #include <QStandardItem> #include <QStandardItemModel> QtAddRowCommand::QtAddRowCommand(   QStandardItemModel * const model,   QAbstractItemView * const view)   : m_model(model), m_view(view) { } void QtAddRowCommand::redo() {   QStandardItem * const item = new QStandardItem;   item->setText(m_text.c_str());   m_model->appendRow(item);   m_view->setCurrentIndex(item->index()); } void QtAddRowCommand::undo() {   const int n_rows = m_model->rowCount();   QStandardItem * const item = m_model->item(n_rows - 1);   if (item) m_text = item->text().toStdString();   m_model->removeRow(n_rows - 1); }

 

 

 

 

 

./CppQTreeViewExample2/qtdialog.h

 

#ifndef QTDIALOG_H #define QTDIALOG_H #include <QDialog> namespace Ui {   class QtDialog; } struct QStandardItemModel; struct QUndoStack; class QtDialog : public QDialog {   Q_OBJECT    public:   explicit QtDialog(QWidget *parent = 0);   ~QtDialog(); protected:   void keyPressEvent(QKeyEvent *);    private slots:   void on_button_clicked(); private:   Ui::QtDialog *ui;   QStandardItemModel * const m_model;   QUndoStack * const m_undo_stack; }; #endif // QTDIALOG_H

 

 

 

 

 

./CppQTreeViewExample2/qtdialog.cpp

 

#include "qtdialog.h" #include <QKeyEvent> #include <QStandardItemModel> #include <QStyledItemDelegate> #include <QUndoStack> #include "qtaddrowcommand.h" #include "ui_qtdialog.h" QtDialog::QtDialog(QWidget *parent) :   QDialog(parent),   ui(new Ui::QtDialog),   m_model(new QStandardItemModel),   m_undo_stack(new QUndoStack) {   ui->setupUi(this);   ui->tree->setModel(m_model);   ui->tree->setItemDelegate(new QStyledItemDelegate); } QtDialog::~QtDialog() {   delete ui;   delete m_undo_stack; } void QtDialog::keyPressEvent(QKeyEvent * e) {   if ( (e->modifiers() & Qt::ControlModifier)     && !(e->modifiers() & Qt::ShiftModifier)     && e->key() == Qt::Key_Z)   {     m_undo_stack->undo();   }   if ( (e->modifiers() & Qt::ControlModifier)     && (e->modifiers() & Qt::ShiftModifier)     && e->key() == Qt::Key_Z)   {     m_undo_stack->redo();   } } void QtDialog::on_button_clicked() {   QtAddRowCommand * const cmd = new QtAddRowCommand(m_model,ui->tree);   m_undo_stack->push(cmd);   ui->tree->scrollToBottom();   const int n_rows = m_model->rowCount();   QStandardItem * const item = m_model->item(n_rows - 1);   ui->tree->edit(item->index()); }

 

 

 

 

 

./CppQTreeViewExample2/qtmain.cpp

 

#include <QApplication> #include "qtdialog.h" int main(int argc, char *argv[]) {   QApplication a(argc, argv);   QtDialog w;   w.show();      return a.exec(); }