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39
40#ifndef QQMLEXPRESSION_H
41#define QQMLEXPRESSION_H
42
43#include <QtQml/qqmlerror.h>
44#include <QtQml/qqmlscriptstring.h>
45
46#include <QtCore/qobject.h>
47#include <QtCore/qvariant.h>
48
49QT_BEGIN_NAMESPACE
50
51
52class QString;
53class QQmlRefCount;
54class QQmlEngine;
55class QQmlContext;
56class QQmlExpressionPrivate;
57class QQmlContextData;
58class Q_QML_EXPORT QQmlExpression : public QObject
59{
60 Q_OBJECT
61public:
62 QQmlExpression();
63 QQmlExpression(QQmlContext *, QObject *, const QString &, QObject * = nullptr);
64 explicit QQmlExpression(const QQmlScriptString &, QQmlContext * = nullptr, QObject * = nullptr, QObject * = nullptr);
65 ~QQmlExpression() override;
66
67 QQmlEngine *engine() const;
68 QQmlContext *context() const;
69
70 QString expression() const;
71 void setExpression(const QString &);
72
73 bool notifyOnValueChanged() const;
74 void setNotifyOnValueChanged(bool);
75
76 QString sourceFile() const;
77 int lineNumber() const;
78 int columnNumber() const;
79 void setSourceLocation(const QString &fileName, int line, int column = 0);
80
81 QObject *scopeObject() const;
82
83 bool hasError() const;
84 void clearError();
85 QQmlError error() const;
86
87 QVariant evaluate(bool *valueIsUndefined = nullptr);
88
89Q_SIGNALS:
90 void valueChanged();
91
92private:
93 QQmlExpression(QQmlContextData *, QObject *, const QString &);
94
95 Q_DISABLE_COPY(QQmlExpression)
96 Q_DECLARE_PRIVATE(QQmlExpression)
97 friend class QQmlDebugger;
98 friend class QQmlContext;
99};
100
101QT_END_NAMESPACE
102
103#endif // QQMLEXPRESSION_H
104
105

source code of qtdeclarative/src/qml/qml/qqmlexpression.h