Initial revision

1 files changed, 293 insertions, 0 deletions

diff --git a/noncore/apps/tableviewer/db/datacache.cpp b/noncore/apps/tableviewer/db/datacache.cpp
new file mode 100644
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+++ b/noncore/apps/tableviewer/db/datacache.cpp
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+/**********************************************************************
+** Copyright (C) 2000 Trolltech AS.  All rights reserved.
+**
+** This file is part of Qtopia Environment.
+**
+** This file may be distributed and/or modified under the terms of the
+** GNU General Public License version 2 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.
+**
+** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
+** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+**
+** See http://www.trolltech.com/gpl/ for GPL licensing information.
+**
+** Contact info@trolltech.com if any conditions of this licensing are
+** not clear to you.
+**
+**********************************************************************/ 
+/*
+ * This file is used to load the xml files that represent the database.
+ * The main requirment for said file is each data entry must contain a key,
+ * otherwise any other data headings are allowed.
+ */
+
+#include "datacache.h"
+#include "xmlsource.h"
+#include "csvsource.h"
+#include <stdlib.h>
+#include <qheader.h>
+
+#define INIT_TABLE_SIZE 128
+
+/*!
+    \class DBStore datastore.h
+
+    \brief The DBStore class is the class responsible for storing, sorting and
+    searching the data loaded by the application
+
+*/
+
+/*!
+    Constructs a DBStore item
+*/
+DBStore::DBStore()
+{
+    name = "";
+    number_elems = 0;
+    full = false;
+    kRep = new KeyList();
+    master_table.resize(INIT_TABLE_SIZE);
+    table_size = INIT_TABLE_SIZE;
+
+    current_elem = 0;
+    archive = 0;
+}
+
+//TODO 
+/*!
+    Reinitializes the table to empty (include a resize of the master table, 
+    which should free some memory) 
+*/
+void DBStore::freeTable()
+{
+    name = "";
+    if(archive) {
+        delete archive;
+        archive = 0;
+    }
+    kRep->clear(); /* clear the current key list */
+
+    number_elems = 0;
+    table_size = INIT_TABLE_SIZE;
+    master_table.resize(table_size);
+    full = false;
+    current_elem = 0;
+}
+
+/*!
+    Removes all items from the DBStore and destroys the DBStore
+*/
+DBStore::~DBStore()
+{
+    freeTable();
+}
+
+/*!
+    This function opens the given xml file, loads it and sets up the 
+    appropriate data structures.
+
+    \param file_name A string representing the name of the file to be opened
+    \return true if successful, false otherwise.
+*/
+bool DBStore::openSource(QIODevice *inDev, const QString &source) {
+
+        /* first check if db is already open, if contains data.. then clear */
+    if(number_elems > 0) {
+        freeTable();
+    }
+
+    if (source == "text/x-xml-tableviewer") {
+        archive = new DBXml(this);
+    } else if (source == "text/csv") {
+        archive = new DBCsv(this);
+    } else
+            return false;
+
+    return (archive->openSource(inDev));
+}
+
+bool DBStore::saveSource(QIODevice *outDev, const QString &source) 
+{
+    /* saving a new file */
+    if(!archive) {
+        if (source == "text/x-xml-tableviewer") {
+            archive = new DBXml(this);
+        } else if (source == "text/x-xml-tableviewer") {
+            archive = new DBCsv(this);
+        } else
+            return false;
+    }
+
+    /* changing file type */
+    if(archive->type() != source) {
+        delete archive;
+        if (source == "text/x-xml-tableviewer") {
+            archive = new DBXml(this);
+        } else if (source == "text/x-xml-tableviewer") {
+            archive = new DBCsv(this);
+        } else 
+            return false;
+    }
+
+    return (archive->saveSource(outDev));
+}
+
+/*! 
+    This function is used to add new elements to the database.  If the database
+    has already reached the maximum allowable size this function does not alter
+    the database.
+
+    \param delm An already allocated and initialized data element to be added
+*/
+void DBStore::addItem(DataElem *delem)
+{
+    addItemInternal(delem);
+}
+
+void DBStore::addItemInternal(DataElem *delem)
+{
+    /* if already full, don't over fill, do a qWarning though */
+    if (full) {
+        qWarning("Attempted to add items to already full table");
+        return;
+    }
+
+    master_table.insert(number_elems, delem);
+
+    current_elem = number_elems;
+    number_elems++;
+
+    if(number_elems >= table_size) {
+        /* filled current table, double if we can */
+        table_size = table_size << 1;
+
+        /* check that the new table size is still valid, i.e. that we didn't
+           just shift the 1 bit of the end of the int. */
+        if (!table_size) {
+            full = true;
+            /* no point in doing antying else. */
+            return;
+        }
+        master_table.resize(table_size);
+    }
+}
+
+void DBStore::removeItem(DataElem *r)
+{
+    int position = master_table.findRef(r);
+        if(position != -1) {
+                /* there is at least one item, this is it */
+                /* replace this with the last element, decrease the element count */
+                master_table.insert(position, master_table.at(--number_elems));
+                master_table.remove(number_elems);
+                delete r;
+        }
+}
+
+/*!
+    Sets the name of the database
+
+    \param n A string representing the new name of the database.
+*/
+void DBStore::setName(const QString &n)
+{
+        name = n;
+}
+
+/*!
+    Gets the name of the database
+
+    \return A string representing the name of the database.
+*/
+QString DBStore::getName()
+{
+        return name;
+}
+
+/*!
+    Retrieves a pointer to the key representation of the database for 
+    other classes to use as reference.
+
+    \return a pointer to the databases key representaion
+*/
+KeyList *DBStore::getKeys()
+{
+    return kRep;
+}
+
+/*!
+    sets the database's key representation the passed pointer
+    \param a pointer to a key representaton
+*/
+void DBStore::setKeys(KeyList *k)
+{
+    kRep = k;
+}
+
+/*!
+    Sets the current element to the first element of the database 
+*/
+void DBStore::first()
+{
+    current_elem = 0;
+}
+
+/*!
+    Sets the current element to the last element of the database 
+*/
+void DBStore::last()
+{
+    current_elem = number_elems - 1;
+}
+
+/*!
+    Sets the current element to the next element of the database if
+    there exists an element after the current one.
+*/
+bool DBStore::next()
+{
+    unsigned int new_current_elem = current_elem + 1;
+    if (current_elem < number_elems) 
+        /* was valid before inc (it is possible but unlikely that inc current
+           elem will change it from invalid to valid) */
+        if (new_current_elem < number_elems) {
+            /* is valid after inc */
+            current_elem = new_current_elem;
+            return true;
+        }
+    return false;
+}
+
+/*!
+    Sets the current element to the previous element of the database if
+    there exists an element before the current one.
+*/
+bool DBStore::previous()
+{
+    unsigned int new_current_elem = current_elem -1;
+    if (current_elem < number_elems)
+        /* was valid */
+        if (new_current_elem < number_elems) {
+            /* still is (if was 0, then now -1, but as is unsigned will wrap 
+               and hence be invalid */
+            current_elem = new_current_elem;
+            return true;
+        }
+    return false;
+}
+
+/*!
+    Returns the current data element in the database.  Which element is current
+    is affected by newly added items, findItem, next, previous, first and 
+    last functions
+
+    \return a pointer to the current data element
+*/
+DataElem *DBStore::getCurrentData() 
+{
+    if (current_elem >= number_elems) 
+        return NULL;
+    return master_table[current_elem];
+}