Qt Script学习笔记(二)

Qt Script学习笔记(二)

2010-11-21 15:33

在script脚本中，使用 QObject及其派生类的属性、信号、槽。

练习一界面

将Widget的导出到脚本中，名字为widget。

为了将该Widget的3个Children作为属性导出到脚本环境中，需要设置Child的QObject::objectName()

• 界面中两个按钮，button1 和 button2。导出到脚本中的名字：btn1和btn2
• 界面中的文本框，textEdit。导出到脚本中的名字：textEdit

Widget 定义两个参数类型不同的同名信号函数。

• void sig1(const QString& text);

• void sig1(int number);

script

设置按钮的Text属性

"widget.btn1.text = 'add number'\n"
"widget.btn2.text = 'add string'\n"

定义4个函数

"var func1 = function(){widget.textEdit.appendPlainText(Math.random())}\n"
"var func2 = function(){widget.textEdit.appendPlainText('hello')}\n"
"var slot1 = function(text){print(text)}\n"
"var slot2 = function(num){print(num)}\n"

连接信号与槽

"widget.btn1.clicked.connect(func1)\n"
"widget.btn2.clicked.connect(func2)\n"
"widget['sig1(QString)'].connect(slot1)\n"
"widget['sig1(int)'].connect(slot2)\n"

发射信号

"widget.sig1('from sig1(QString)')\n"
"widget['sig1(QString)']('from sig1(QString) too')\n"
"widget.sig1(798)\n"完整代码

#include
#include
#include

const char script[]="widget.btn1.text = 'add number'\n"
"widget.btn2.text = 'add string'\n"
"var func1 = function(){widget.textEdit.appendPlainText(Math.random())}\n"
"var func2 = function(){widget.textEdit.appendPlainText('hello')}\n"
"var slot1 = function(text){print(text)}\n"
"var slot2 = function(num){print(num)}\n"
"widget.btn1.clicked.connect(func1)\n"
"widget.btn2.clicked.connect(func2)\n"
"widget['sig1(QString)'].connect(slot1)\n"
"widget['sig1(int)'].connect(slot2)\n"
"widget.sig1('from sig1(QString)')\n"
"widget['sig1(QString)']('from sig1(QString) too')\n"
"widget.sig1(798)\n";

class Widget:public QWidget
{
Q_OBJECT
public:
Widget(QWidget * parent=NULL):QWidget(parent)
{
button1 = new QPushButton;
button1->setObjectName("btn1");
button2 = new QPushButton;
button2->setObjectName("btn2");
QHBoxLayout * hbox = new QHBoxLayout;
hbox->addWidget(button1);
hbox->addWidget(button2);
textEdit = new QPlainTextEdit;
textEdit->setObjectName("textEdit");
QVBoxLayout * vbox = new QVBoxLayout(this);
vbox->addLayout(hbox);
vbox->addWidget(textEdit);
}
signals:
void sig1(const QString& text);
void sig1(int number);
private:
QPushButton * button1;
QPushButton * button2;
QPlainTextEdit * textEdit;
};
#include "main.moc"
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
Widget widget;
QScriptEngine engine;
QScriptValue w = engine.newQObject(&widget);
engine.globalObject().setProperty("widget", w);
engine.evaluate(script);
widget.show();
return app.exec();
}

练习二

• 对成员函数，信号和槽可直接在脚本中访问，对其他成员函数，需要加 Q_INVOKABLE
• 依赖Qt的 Q_PROPERTY 提供的自省，可以在脚本中使用属性

#include /QCoreApplication>
#include /QDebug>
#include

const char script[]="print(obj.text)\n"
"obj.setText('second')\n"
"print(obj.getText())\n"
"obj.text = 'third'\n"
"print(obj.text)\n";

class HelloObject:public QObject
{
Q_OBJECT
Q_PROPERTY(QString text READ text WRITE setText)
public:
HelloObject(QObject* parent=NULL)
:QObject(parent), m_text("first")
{}
Q_INVOKABLE QString getText() const {
return m_text;
}
QString text() const {
return m_text;
}
public slots:
void setText(const QString& t) {
m_text = t;
}

private:
QString m_text;
};

#include "main.moc"
int main(int argc, char *argv[])
{
QCoreApplication a(argc, argv);
HelloObject obj;
QScriptEngine engine;
QScriptValue o = engine.newQObject(&obj);
engine.globalObject().setProperty("obj", o);
engine.evaluate(script);
if (engine.hasUncaughtException()){
qDebug()<<engine.uncaughtException().toString();
qDebug()<<engine.uncaughtExceptionBacktrace().join("\n");
}
return a.exec();
}

程序输出

first
second
third