popularurls.h

LINUX 下, 以 QT/KDE 写的档案管理员

#ifndef POPULARURLS_H
#define POPULARURLS_H

#include <qobject.h>
#include <kurl.h>
#include <qdict.h>
#include <kdialogbase.h>

// the class holds a list of most popular links in a dual data structure
// * linked list, with head and tail: for fast append/prepend support
// * dictionary that maps urls to list nodes: to save the need to iterate
//   over the list in order to find the correct node for each new url
// 
// also, the class holds a maximum number of urls. two variables affect this:
// * maxUrls - the num. of urls the user can see
// * hardLimit - the actual number of urls kept.
// when the number of urls reaches hardLimit, a garbage collection is done and
// the bottom (hardLimit-maxUrls) entries are removed from the list
typedef struct _UrlNode* UrlNodeP;
typedef struct _UrlNode {
	UrlNodeP prev;
	KURL url;
	int rank;
	UrlNodeP next;
} UrlNode;

class PopularUrlsDlg;

class PopularUrls : public QObject {
	Q_OBJECT
public:
	PopularUrls(QObject *parent = 0, const char *name = 0);
	~PopularUrls();
	void save();
	void load();
	void addUrl(const KURL& url);
	KURL::List getMostPopularUrls(int max);

public slots:	
	void showDialog(); 

protected:
	// NOTE: the following methods append/insert/remove a node to the list 
	// but NEVER free memory or allocate memory!
	void appendNode(UrlNodeP node);
	void insertNode(UrlNodeP node, UrlNodeP after);
	void removeNode(UrlNodeP node);
	void relocateIfNeeded(UrlNodeP node);
	void clearList();
	void dumpList();
	void decreaseRanks();
	
private:
	UrlNodeP head, tail;
	QDict<UrlNode> ranks; // actually holds UrlNode*
	int count;
	static const int maxUrls = 30; 
	PopularUrlsDlg *dlg;
};

class KListView;
class KListViewSearchLine;

class PopularUrlsDlg: public KDialogBase {
	Q_OBJECT
public:
	PopularUrlsDlg();
	~PopularUrlsDlg();
	void run(KURL::List list); // use this to open the dialog
	inline int result() const { return selection; } // returns index 0 - topmost, or -1
	

protected slots:
	void slotSearchReturnPressed(const QString&);
	void slotItemSelected(QListViewItem *it);
	
private:
	KListView *urls;
	KListViewSearchLine *search;
	int selection;
};


#endif