Fix broken link for key implementation since last changes to the filter.

The links have been taken before from the model, now we need to get
them out of the help files, since the help eninge core does not provide
(yet) such functionality. Also return a sensible amount of hits for the
first character, limited for now to 300 for speed reasons.

Reviewed-by: ck

src/plugins/help/helpindexfilter.cpp

@@ -50,19 +50,36 @@ using namespace Help::Internal;
 
 Q_DECLARE_METATYPE(ILocatorFilter*);
 
+static const char linksForKeyQuery[] = "SELECT d.Title, f.Name, e.Name, "
+    "d.Name, a.Anchor FROM IndexTable a, FileNameTable d, FolderTable e, "
+    "NamespaceTable f WHERE a.FileId=d.FileId AND d.FolderId=e.Id AND "
+    "a.NamespaceId=f.Id AND a.Name='%1'";
+
 // -- HelpIndexFilter::HelpFileReader
 
 class HelpIndexFilter::HelpFileReader
 {
+    struct dbCleaner {
+        dbCleaner(const QString &dbName)
+            : name(dbName) {}
+        ~dbCleaner() {
+            QSqlDatabase::removeDatabase(name);
+        }
+        QString name;
+    };
+
 public:
     HelpFileReader();
     ~HelpFileReader();
 
 public:
     void updateHelpFiles();
-    QList<FilterEntry> matchesFor(const QString &entry, ILocatorFilter *locator);
+    QMap<QString, QUrl> linksForKey(const QString &key);
+    QList<FilterEntry> matchesFor(const QString &entry, ILocatorFilter *locator,
+        int maxHits = INT_MAX);
 
 private:
+    QIcon m_icon;
     bool m_initialized;
     QStringList m_helpFiles;
 };
@@ -70,6 +87,7 @@ private:
 HelpIndexFilter::HelpFileReader::HelpFileReader()
     : m_initialized(false)
 {
+    m_icon = QIcon(QLatin1String(":/help/images/bookmark.png"));
 }
 
 HelpIndexFilter::HelpFileReader::~HelpFileReader()
@@ -96,8 +114,55 @@ void HelpIndexFilter::HelpFileReader::updateHelpFiles()
     QSqlDatabase::removeDatabase(id);
 }
 
+QUrl buildQUrl(const QString &nameSpace, const QString &folder,
+    const QString &relFileName, const QString &anchor)
+{
+    QUrl url;
+    url.setScheme(QLatin1String("qthelp"));
+    url.setAuthority(nameSpace);
+    url.setPath(folder + QLatin1Char('/') + relFileName);
+    url.setFragment(anchor);
+    return url;
+}
+
+QMap<QString, QUrl>HelpIndexFilter::HelpFileReader::linksForKey(const QString &key)
+{
+    if (!m_initialized) {
+        updateHelpFiles();
+        m_initialized = true;
+    }
+
+    QMap<QString, QUrl> links;
+    const QLatin1String sqlite("QSQLITE");
+    const QLatin1String name("HelpIndexFilter::HelpFileReader::linksForKey");
+
+    dbCleaner cleaner(name);
+    QSqlDatabase db = QSqlDatabase::addDatabase(sqlite, name);
+    if (db.driver() && db.driver()->lastError().type() == QSqlError::NoError) {
+        foreach(const QString &file, m_helpFiles) {
+            if (!QFile::exists(file))
+                continue;
+            db.setDatabaseName(file);
+            if (db.open()) {
+                QSqlQuery query = QSqlQuery(db);
+                query.setForwardOnly(true);
+                query.exec(QString::fromLatin1(linksForKeyQuery).arg(key));
+                while (query.next()) {
+                    QString title = query.value(0).toString();
+                    if (title.isEmpty()) // generate a title + corresponding path
+                        title = key + QLatin1String(" : ") + query.value(3).toString();
+                    links.insertMulti(title, buildQUrl(query.value(1).toString(),
+                        query.value(2).toString(), query.value(3).toString(),
+                        query.value(4).toString()));
+                }
+            }
+        }
+    }
+    return links;
+}
+
 QList<FilterEntry> HelpIndexFilter::HelpFileReader::matchesFor(const QString &id,
-    ILocatorFilter *locator)
+    ILocatorFilter *locator, int maxHits)
 {
     if (!m_initialized) {
         updateHelpFiles();
@@ -107,31 +172,30 @@ QList<FilterEntry> HelpIndexFilter::HelpFileReader::matchesFor(const QString &id
     QList<FilterEntry> entries;
     const QLatin1String sqlite("QSQLITE");
     const QLatin1String name("HelpIndexFilter::HelpFileReader::matchesFor");
-    foreach(const QString &file, m_helpFiles) {
-        if (!QFile::exists(file))
-            continue;
-        {
-            QSqlDatabase db = QSqlDatabase::addDatabase(sqlite, name);
-            if (db.driver()
-                && db.driver()->lastError().type() == QSqlError::NoError) {
-                db.setDatabaseName(file);
-                if (db.open()) {
-                    QSqlQuery query = QSqlQuery(db);
-                    query.setForwardOnly(true);
-                    query.exec(QString::fromLatin1("SELECT DISTINCT Name FROM "
-                        "IndexTable WHERE Name LIKE '%%1%'").arg(id));
-                    while (query.next()) {
-                        const QString &key = query.value(0).toString();
-                        if (!key.isEmpty()) {
-                            // NOTE: do not use an icon since it is really slow
-                            entries.append(FilterEntry(locator, key, QVariant(),
-                                QIcon()));
-                        }
+
+    dbCleaner cleaner(name);
+    QSqlDatabase db = QSqlDatabase::addDatabase(sqlite, name);
+    if (db.driver() && db.driver()->lastError().type() == QSqlError::NoError) {
+        foreach(const QString &file, m_helpFiles) {
+            if (!QFile::exists(file))
+                continue;
+            db.setDatabaseName(file);
+            if (db.open()) {
+                QSqlQuery query = QSqlQuery(db);
+                query.setForwardOnly(true);
+                query.exec(QString::fromLatin1("SELECT DISTINCT Name FROM "
+                    "IndexTable WHERE Name LIKE '%%1%'").arg(id));
+                while (query.next()) {
+                    const QString &key = query.value(0).toString();
+                    if (!key.isEmpty()) {
+                        entries.append(FilterEntry(locator, key, QVariant(),
+                            m_icon));
+                        if (entries.count() == maxHits)
+                            return entries;
                     }
                 }
             }
         }
-        QSqlDatabase::removeDatabase(name);
     }
     return entries;
 }
@@ -176,18 +240,18 @@ ILocatorFilter::Priority HelpIndexFilter::priority() const
 QList<FilterEntry> HelpIndexFilter::matchesFor(const QString &entry)
 {
     if (entry.length() < 2)
-        return QList<FilterEntry>();
+        return m_fileReader->matchesFor(entry, this, 300);
     return m_fileReader->matchesFor(entry, this);
 }
 
 void HelpIndexFilter::accept(FilterEntry selection) const
 {
-    const QHelpEngineCore &engine = HelpManager::helpEngineCore();
-    QMap<QString, QUrl> links = engine.linksForIdentifier(selection.displayName);
+    const QString &key = selection.displayName;
+    const QMap<QString, QUrl> &links = m_fileReader->linksForKey(key);
     if (links.size() == 1) {
         emit linkActivated(links.begin().value());
     } else if (!links.isEmpty()) {
-        emit linksActivated(links, selection.displayName);
+        emit linksActivated(links, key);
     }
 }