QT学习笔记之十五 BooleanParser 基于Qt4的逻辑表达式分析工具

貌似好久没写了,最近比较忙的说,这个主要练习Model的设计,部分代码是参考别人的,大牛们不要鄙视啊….

源码最后附上。

部分核心代码如下:

booleanmodel.h

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#ifndef BOOLEANMODEL_H
#define BOOLEANMODEL_H
#include <QAbstractItemModel>
class Node;
class BooleanModel : public QAbstractItemModel
{
Q_OBJECT
public:
BooleanModel(QObject *parent = 0);
~BooleanModel();
void setRootNode(Node *node);
QModelIndex index(int row, int column, const QModelIndex &parent) const;
QModelIndex parent(const QModelIndex &child) const;
int rowCount(const QModelIndex &parent) const;
int columnCount(const QModelIndex &parent) const;
QVariant data(const QModelIndex &index, int role) const;
QVariant headerData(int section,Qt::Orientation orientation, int role) const;
private:
Node *nodeFromIndex(const QModelIndex &index) const;
Node *rootNode;
};
#endif // BOOLEANMODEL_H

booleanmodel.cpp

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#include <QtCore>
#include "booleanmodel.h"
#include "booleanparser.h"
/**
构造函数,初始化根结点为空
*/
BooleanModel::BooleanModel(QObject *parent) :QAbstractItemModel(parent)
{
rootNode = 0;
}
/**
析构函数,删除根结点
*/
BooleanModel::~BooleanModel()
{
delete rootNode;
}
/**
设置根结点,删除原来根结点,重新设置根结点
*/
void BooleanModel::setRootNode(Node *node)
{
delete rootNode;
rootNode = node;
reset(); //刷新表格数据
}
/**
返回索引,这个是virtual函数所以一定要重载
*/
QModelIndex BooleanModel::index(int row,int column,const QModelIndex &parent) const
{
if (!rootNode || row < 0 || column < 0)
return QModelIndex(); //非法情况
Node *parentNode = nodeFromIndex(parent);
Node *childNode = parentNode->children.value(row);
if (!childNode)
return QModelIndex();
return createIndex(row,column, childNode);
}
/**
返回父亲结点
*/
QModelIndex BooleanModel::parent(const QModelIndex &child) const
{
Node *node = nodeFromIndex(child);
if (!node)
return QModelIndex(); //结点无效
Node *parentNode = node->parent;
if (!parentNode)
return QModelIndex(); //父结点无效
Node *grandparentNode = parentNode->parent;
if(!grandparentNode)
return QModelIndex(); //父结点的父结点无效
int row = grandparentNode->children.indexOf(parentNode);
return createIndex(row,0,parentNode);
}
/**
返回行数,这个也是virtual函数,要重载
*/
int BooleanModel::rowCount(const QModelIndex &parent) const
{
if (parent.column() > 0)
return 0;
Node *parentNode = nodeFromIndex(parent);
if(!parentNode)
return 0;
return parentNode->children.count();
}
/**
返回列数,固定只有2,这个也是virtual函数,要重载
*/
int BooleanModel::columnCount(const QModelIndex & /*parent*/) const
{
return 2;
}
/**
返回数据,这个也是virtual函数,要重载
*/
QVariant BooleanModel::data(const QModelIndex &index, int role) const
{
if (role != Qt::DisplayRole)
return QVariant(); //不是显示角色,认为是无效数据
Node *node = nodeFromIndex(index);
if (!node)
return QVariant(); //结点无效
if(index.column() == 0) {
switch (node->type) {
case Node::Root:
return tr("Root");
case Node::OrExpression:
return tr("OR Expression");
case Node::AndExpression:
return tr("AND Expression");
case Node::NotExpression:
return tr("NOT Expression");
case Node::Atom:
return tr("Atom");
case Node::Identifier:
return tr("Identifier");
case Node::Operator:
return tr("Operator");
case Node::Punctuator:
return tr("Punctuator");
default:
return tr("Unknown"); //默认为未知
}
} else if(index.column() == 1) {
return node->str;
}
return QVariant();
}
/**
返回表头
*/
QVariant BooleanModel::headerData(int section, Qt::Orientation orientation, int role) const
{
if (orientation == Qt::Horizontal && role == Qt::DisplayRole) {
if (section == 0) {
return tr("Node");
} else if (section == 1) {
return tr("Value");
}
}
return QVariant();
}
/**
从索引返回结点
*/
Node *BooleanModel::nodeFromIndex(const QModelIndex &index) const
{
if (index.isValid()) {
return static_cast<Node *>(index.internalPointer());
} else {
return rootNode;
}
}

booleanparser.h

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#ifndef BOOLEANPARSER_H
#define BOOLEANPARSER_H
#include "node.h"
class BooleanParser
{
public:
BooleanParser();
Node *parse(const QString &expr);
private:
Node *parseOrExpression();
Node *parseAndExpression();
Node *parseNotExpression();
Node *parseAtom();
Node *parseIdentifier();
void addChild(Node *parent, Node *child);
void addToken(Node *parent, const QString &str, Node::Type type);
bool matchToken(const QString &str) const;
QString in;
int pos;
};
#endif // BOOLEANPARSER_H

booleanparser.cpp

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#include <QtCore>
#include "booleanparser.h"
#include "node.h"
BooleanParser::BooleanParser()
{
}
Node *BooleanParser::parse(const QString &expr)
{
in = expr;
in.replace(" ", "");
pos = 0;
Node *node = new Node(Node::Root);
addChild(node, parseOrExpression());
return node;
}
/**
解析或表达式
*/
Node *BooleanParser::parseOrExpression()
{
Node *childNode = parseAndExpression();
if (matchToken("||")) {
Node *node = new Node(Node::OrExpression);
addChild(node,childNode);
while (matchToken("||")) {
addToken(node,"||", Node::Operator);
addChild(node, parseAndExpression());
}
return node;
} else {
return childNode;
}
}
/**
解析与表达式
*/
Node *BooleanParser::parseAndExpression()
{
Node *childNode = parseNotExpression();
if (matchToken("&&")) {
Node *node = new Node(Node::AndExpression);
addChild(node, childNode);
while (matchToken("&&")) {
addToken(node, "&&", Node::Operator);
addChild(node, parseNotExpression());
}
return node;
} else {
return childNode;
}
}
/**
解析非表达式
*/
Node *BooleanParser::parseNotExpression()
{
if (matchToken("!")) {
Node *node = new Node(Node::NotExpression);
while (matchToken("!"))
addToken(node, "!", Node::Operator);
addChild(node, parseAtom());
return node;
} else {
return parseAtom();
}
}
/**
解析一个项
*/
Node *BooleanParser::parseAtom()
{
if (matchToken("(")) {
Node *node = new Node(Node::Atom);
addToken(node, "(", Node::Punctuator);
addChild(node, parseOrExpression());
addToken(node, ")", Node::Punctuator);
return node;
} else {
return parseIdentifier();
}
}
/**
解析标识符
*/
Node *BooleanParser::parseIdentifier()
{
int startPos = pos;
while (pos < in.length() && in[pos].isLetterOrNumber())
++pos;
if (pos > startPos) {
return new Node(Node::Identifier,
in.mid(startPos, pos - startPos));
} else {
return 0;
}
}
/**
添加子结点
*/
void BooleanParser::addChild(Node *parent, Node *child)
{
if (child) {
parent->children += child;
parent->str += child->str;
child->parent = parent;
}
}
/**
添加token
*/
void BooleanParser::addToken(Node *parent, const QString &str,
Node::Type type)
{
if (in.mid(pos, str.length()) == str) {
addChild(parent, new Node(type, str));
pos += str.length();
}
}
/**
token匹配
*/
bool BooleanParser::matchToken(const QString &str) const
{
return in.mid(pos, str.length()) == str;
}

booleanwindow.h

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#ifndef BOOLEANWINDOW_H
#define BOOLEANWINDOW_H
#include <QWidget>
class QLabel;
class QLineEdit;
class QTreeView;
class BooleanModel;
class BooleanWindow : public QWidget
{
Q_OBJECT
public:
BooleanWindow();
private slots:private slots:
void booleanExpressionChanged(const QString &expr);
private:
QLabel *label;
QLineEdit *lineEdit;
BooleanModel *booleanModel;
QTreeView *treeView;
};
#endif // BOOLEANWINDOW_H

booleanwindow.cpp

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#include <QtGui>
#include "booleanwindow.h"
#include "booleanmodel.h"
#include "booleanparser.h"
BooleanWindow::BooleanWindow()
{
//Label
label = new QLabel(tr("Boolean expression:"));
//LineEdit
lineEdit = new QLineEdit;
//BooleanModel
booleanModel = new BooleanModel(this);
//TreeView
treeView = new QTreeView;
treeView->setModel(booleanModel);
//signal and slot
connect(lineEdit, SIGNAL(textChanged(QString)), this,SLOT(booleanExpressionChanged(QString)));
//Layout
QGridLayout *layout = new QGridLayout;
layout->addWidget(label, 0 ,0);
layout->addWidget(lineEdit, 0 , 1);
layout->addWidget(treeView, 1, 0, 1, 2);
setLayout(layout);
setWindowTitle(tr("Boolean Parser"));
}
void BooleanWindow::booleanExpressionChanged(const QString &expr)
{
BooleanParser parser;
Node *rootNode = parser.parse(expr);
booleanModel->setRootNode(rootNode);
}

其他的可以去下载

下载地址:http://download.csdn.net/source/1529790”>http://download.csdn.net/source/1529790

软件截图:

image

PS:最近比较郁闷…..

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