<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <!-- /home/espenr/tmp/qt-3.3.8-espenr-2499/qt-x11-free-3.3.8/extensions/nsplugin/examples/grapher/grapher.doc:1 --> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>Grapher Plugin</title> <style type="text/css"><!-- fn { margin-left: 1cm; text-indent: -1cm; } a:link { color: #004faf; text-decoration: none } a:visited { color: #672967; text-decoration: none } body { background: #ffffff; color: black; } --></style> </head> <body> <table border="0" cellpadding="0" cellspacing="0" width="100%"> <tr bgcolor="#E5E5E5"> <td valign=center> <a href="index.html"> <font color="#004faf">Home</font></a> | <a href="classes.html"> <font color="#004faf">All Classes</font></a> | <a href="mainclasses.html"> <font color="#004faf">Main Classes</font></a> | <a href="annotated.html"> <font color="#004faf">Annotated</font></a> | <a href="groups.html"> <font color="#004faf">Grouped Classes</font></a> | <a href="functions.html"> <font color="#004faf">Functions</font></a> </td> <td align="right" valign="center"><img src="logo32.png" align="right" width="64" height="32" border="0"></td></tr></table><h1 align=center>Grapher Plugin</h1> <p> This example graphs data from a simple text file. It demonstrates the use of the <a href="qnpinstance.html#writeReady">TQNPInstance::writeReady</a>() and <a href="qnpinstance.html#write">TQNPInstance::write</a>() functions. <p> To build the example, you must first build the <a href=nsplugin.html>TQt Netscape Plugin Extension</a> library. Then type <tt>make</tt> in <tt>extensions/nsplugin/examples/grapher/</tt> and copy the resulting <tt>grapher.so</tt> or <tt>npgrapher.dll</tt> to the Plugins directory of your WWW browser. <p> <EMBED ALIGN=LEFT WIDTH=49% HEIGHT=300 SRC=graph.g1n graphstyle=pie fontfamily=times fontsize=18> <p> The text file it accepts as input has a title line, then a sequence of lines with a number, then a string. The plugin displays a pie chart of the numbers, each segment labelled by the associated string. The user can select a bar chart view of the same data by selecting from the menu that appears when they point at the plugin. <p> The HTML tag used to embed the graph is: <small> <pre> <EMBED SRC=graph.g1n ALIGN=LEFT WIDTH=49% HEIGHT=300 graphstyle=pie fontfamily=times fontsize=18> </pre><p> </small> Note that some HTML arguments (which we have capitalized here) are interpreted by the browser, while others are used by the plugin. <p> <br clear> With the simplicity and cross-platform nature of TQt-based plugins, pages like <a href="http://www.netcraft.com/survey/">Netcraft's Server Graphs</a> can be provided much more efficiently for both the service provider and consumer. Data need not be converted to an image at the server. <p> <br clear> <hr> Implementation: <p> <pre>// Include TQt Netscape Plugin classes. #include "ntqnp.h" // Include other TQt classes. #include <<a href="qpainter-h.html">ntqpainter.h</a>> #include <<a href="qtextstream-h.html">ntqtextstream.h</a>> #include <<a href="qbuffer-h.html">ntqbuffer.h</a>> #include <<a href="qpixmap-h.html">ntqpixmap.h</a>> #include <<a href="qmenubar-h.html">ntqmenubar.h</a>> #include <<a href="qpushbutton-h.html">ntqpushbutton.h</a>> #include <<a href="qptrlist-h.html">ntqptrlist.h</a>> #include <<a href="qmessagebox-h.html">ntqmessagebox.h</a>> // Include some C library functions. #include <math.h> #include <stdlib.h> #ifndef M_PI // Some math.h don't include this. #define M_PI 3.14159265358979323846264338327950288 #endif // // GraphModel is a simple abstract class that describes // a table of numeric and text data. // class GraphModel { public: enum ColType { Numeric, Label }; union Datum { double dbl; <a href="ntqstring.html">TQString</a>* str; }; virtual TQPtrList<Datum>& graphData()=0; virtual ColType colType(int col) const=0; virtual int nCols() const=0; }; // // Graph is a widget subclass that displays a GraphModel. // Since the widget is a TQNPWidget, it can be used as a plugin window, // returned by Grapher::newWindow() below. // class Graph : public <a href="qnpwidget.html">TQNPWidget</a> { <a href="metaobjects.html#TQ_OBJECT">TQ_OBJECT</a> public: // Constructs a Graph to display a GraphModel // Graph(GraphModel&); ~Graph(); // Two styles are available - Pie and Bar graph // enum Style { Pie, Bar }; static const char* styleName[]; void setStyle(Style); void setStyle(const char*); // Timer event processing rotates the pie graph // void timerEvent(TQTimerEvent*); // These functions are provided by TQNPWidget - we override // them to hide and show the plugin menubar. // void enterInstance(); void leaveInstance(); // Paint the graph... // void paintEvent(TQPaintEvent*); // // ... as either a "Loading" message, a Bar graph, a Pie graph, // or an error message. // void paintWait(TQPaintEvent*); void paintBar(TQPaintEvent*); void paintPie(TQPaintEvent*); void paintError(const char*); signals: // Signals emitted when the Help menus are selected. void aboutPlugin(); void aboutData(); private: GraphModel& model; <a href="ntqmenubar.html">TQMenuBar</a> *menubar; Style style; <a href="ntqpopupmenu.html">TQPopupMenu</a>* stylemenu; int pieRotationTimer; int pieRotation; <a href="ntqpixmap.html">TQPixmap</a> pm; private slots: void setStyleFromMenu(int id); }; <a name="f564"></a>Graph::Graph( GraphModel& mdl ) : model(mdl), <a href="ntqwidget.html#style">style</a>(Bar), pieRotationTimer(0), pieRotation(0) { // Create a menubar for the widget // menubar = new <a href="ntqmenubar.html">TQMenuBar</a>( this ); stylemenu = new <a href="ntqpopupmenu.html">TQPopupMenu</a>; <a name="x2768"></a> stylemenu-><a href="ntqpopupmenu.html#setCheckable">setCheckable</a>(TRUE); for ( Style s = Pie; styleName[s]; s = Style(s+1)) { stylemenu-><a href="ntqmenudata.html#insertItem">insertItem</a>(styleName[s], s+100); } <a name="x2767"></a> <a href="ntqobject.html#connect">connect</a>(stylemenu, SIGNAL(<a href="ntqpopupmenu.html#activated">activated</a>(int)), this, SLOT(setStyleFromMenu(int))); <a href="ntqwidget.html#setStyle">setStyle</a>(Pie); menubar-><a href="ntqmenudata.html#insertItem">insertItem</a>("Style", stylemenu); menubar-><a href="ntqmenudata.html#insertSeparator">insertSeparator</a>(); <a href="ntqpopupmenu.html">TQPopupMenu</a>* help = new <a href="ntqpopupmenu.html">TQPopupMenu</a>; help-><a href="ntqmenudata.html#insertItem">insertItem</a>( "About plugin...", this, SIGNAL(aboutPlugin()) ); help-><a href="ntqmenudata.html#insertItem">insertItem</a>( "About data...", this, SIGNAL(aboutData()) ); menubar-><a href="ntqmenudata.html#insertItem">insertItem</a>("Help", help); <a name="x2745"></a> menubar-><a href="ntqmenubar.html#hide">hide</a>(); } Graph::~Graph() { } <a name="x2778"></a>void Graph::<a href="ntqwidget.html#setStyle">setStyle</a>(Style s) { if (style != s) { if (pieRotationTimer) <a href="ntqobject.html#killTimer">killTimer</a>(pieRotationTimer); <a name="x2749"></a> stylemenu-><a href="ntqmenudata.html#setItemChecked">setItemChecked</a>(100+style, FALSE); style = s; if ( style == Pie ) pieRotationTimer = <a href="ntqobject.html#startTimer">startTimer</a>( 80 ); else pieRotationTimer = 0; stylemenu-><a href="ntqmenudata.html#setItemChecked">setItemChecked</a>(100+style, TRUE); <a href="ntqwidget.html#update">update</a>(); } } <a name="x2755"></a>void Graph::<a href="ntqobject.html#timerEvent">timerEvent</a>(TQTimerEvent*) { pieRotation = ( pieRotation + 6 ) % 360; repaint(FALSE); } void Graph::<a href="ntqwidget.html#setStyle">setStyle</a>(const char* stext) { for ( Style s = Pie; styleName[s]; s = Style(s+1) ) { if ( <a href="ntqcstring.html#qstricmp">tqstricmp</a>(stext,styleName[s])==0 ) { <a href="ntqwidget.html#setStyle">setStyle</a>(s); return; } } } <a name="x2753"></a>void Graph::<a href="qnpwidget.html#enterInstance">enterInstance</a>() { <a name="x2746"></a> menubar-><a href="ntqmenubar.html#show">show</a>(); } <a name="x2754"></a>void Graph::<a href="qnpwidget.html#leaveInstance">leaveInstance</a>() { menubar-><a href="ntqmenubar.html#hide">hide</a>(); } void <a name="f565"></a>Graph::paintError(const char* e) { <a href="ntqpainter.html">TQPainter</a> p(this); int w = <a href="ntqwidget.html#width">width</a>(); <a name="x2760"></a> p.<a href="ntqpainter.html#drawText">drawText</a>(w/8, 0, w-w/4, height(), AlignCenter|WordBreak, e); } void <a name="f566"></a>Graph::paintBar(TQPaintEvent* event) { if ( model.colType(0) != GraphModel::Numeric ) { paintError("First column not numeric, cannot draw bar graph\n"); return; } <a href="ntqptrlist.html">TQPtrList</a><GraphModel::Datum>& data = model.graphData(); double max = 0.0; <a name="x2772"></a> for (GraphModel::Datum* rowdata = data.<a href="ntqptrlist.html#first">first</a>(); <a name="x2773"></a> rowdata; rowdata = data.<a href="ntqptrlist.html#next">next</a>()) { if (rowdata[0].dbl > max) max = rowdata[0].dbl; } const uint w = <a href="ntqwidget.html#width">width</a>(); const uint h = <a href="ntqwidget.html#height">height</a>(); <a href="ntqpainter.html">TQPainter</a> p(this); <a name="x2762"></a> p.<a href="ntqpainter.html#setClipRect">setClipRect</a>(event->rect()); <a name="x2771"></a> if ( w > data.<a href="ntqptrlist.html#count">count</a>() ) { // More pixels than data int x = 0; int i = 0; <a href="ntqfontmetrics.html">TQFontMetrics</a> fm=<a href="ntqwidget.html#fontMetrics">fontMetrics</a>(); <a name="x2741"></a> int fh = fm.<a href="ntqfontmetrics.html#height">height</a>(); for (GraphModel::Datum* rowdata = data.<a href="ntqptrlist.html#first">first</a>(); rowdata; rowdata = data.<a href="ntqptrlist.html#next">next</a>()) { <a href="ntqcolor.html">TQColor</a> c; <a name="x2740"></a> c.<a href="ntqcolor.html#setHsv">setHsv</a>( (i * 255)/data.<a href="ntqptrlist.html#count">count</a>(), 255, 255 );// rainbow effect p.<a href="ntqpainter.html#setBrush">setBrush</a>(c); int bw = (w-w/4-x)/(data.<a href="ntqptrlist.html#count">count</a>()-i); int bh = int((h-h/4-1)*rowdata[0].dbl/max); p.<a href="ntqpainter.html#drawRect">drawRect</a>( w/8+x, h-h/8-1-bh, bw, bh ); i++; x+=bw; } } else { // More data than pixels int x = 0; int i = 0; double av = 0.0; int n = 0; for (GraphModel::Datum* rowdata = data.<a href="ntqptrlist.html#first">first</a>(); rowdata; rowdata = data.<a href="ntqptrlist.html#next">next</a>()) { int bx = i*w/data.<a href="ntqptrlist.html#count">count</a>(); if (bx > x) { <a href="ntqcolor.html">TQColor</a> c; c.<a href="ntqcolor.html#setHsv">setHsv</a>( (x * 255)/w, 255, 255 );// rainbow effect p.<a href="ntqpainter.html#setPen">setPen</a>(c); int bh = int(h*av/n/max); p.<a href="ntqpainter.html#drawLine">drawLine</a>(x,h-1,x,h-bh); av = 0.0; n = 0; x = bx; } av += rowdata[0].dbl; n++; i++; } } } void <a name="f567"></a>Graph::paintPie(TQPaintEvent* event) { if ( model.colType(0) != GraphModel::Numeric ) { paintError("First column not numeric, cannot draw pie graph\n"); return; } <a href="ntqptrlist.html">TQPtrList</a><GraphModel::Datum>& data = model.graphData(); double total = 0.0; GraphModel::Datum* rowdata; for (rowdata = data.<a href="ntqptrlist.html#first">first</a>(); rowdata; rowdata = data.<a href="ntqptrlist.html#next">next</a>()) { total += rowdata[0].dbl; } // Only use first column for pie chart if ( !total ) return; int apos = (pieRotation-90)*16; const int w = <a href="ntqwidget.html#width">width</a>(); const int h = <a href="ntqwidget.html#height">height</a>(); const int xd = w - w/5; const int yd = h - h/5; <a name="x2766"></a> pm.<a href="ntqpixmap.html#resize">resize</a>(<a href="ntqwidget.html#width">width</a>(),height()); <a name="x2765"></a> pm.<a href="ntqpixmap.html#fill">fill</a>(<a href="ntqwidget.html#backgroundColor">backgroundColor</a>()); <a href="ntqpainter.html">TQPainter</a> p(&pm); <a name="x2763"></a> p.<a href="ntqpainter.html#setFont">setFont</a>(<a href="ntqwidget.html#font">font</a>()); p.<a href="ntqpainter.html#setClipRect">setClipRect</a>(event->rect()); int i = 0; for (rowdata = data.<a href="ntqptrlist.html#first">first</a>(); rowdata; rowdata = data.<a href="ntqptrlist.html#next">next</a>()) { <a href="ntqcolor.html">TQColor</a> c; c.<a href="ntqcolor.html#setHsv">setHsv</a>( ( i * 255)/data.<a href="ntqptrlist.html#count">count</a>(), 255, 255 );// rainbow effect p.<a href="ntqpainter.html#setBrush">setBrush</a>( c ); // solid fill with color c int a = int(( rowdata[0].dbl * 360.0 ) / total * 16.0 + 0.5); <a name="x2757"></a> p.<a href="ntqpainter.html#drawPie">drawPie</a>( w/10, h/10, xd, yd, -apos, -a ); apos += a; i++; } if (model.colType(1) == GraphModel::Label) { double apos = (pieRotation-90)*M_PI/180; for (rowdata = data.<a href="ntqptrlist.html#first">first</a>(); rowdata; rowdata = data.<a href="ntqptrlist.html#next">next</a>()) { double a = rowdata[0].dbl * 360 / total * M_PI / 180; int x = int(cos(apos+a/2)*w*5/16 + w/2 + 0.5); int y = int(sin(apos+a/2)*h*5/16 + h/2 + 0.5); // ### This causes a crash, so comment out for now /*p.<a href="ntqpainter.html#drawText">drawText</a>(x-w/8, y-h/8, w/4, h/4, WordBreak|AlignCenter, *rowdata[1].str);*/ apos += a; } } <a href="ntqpainter.html">TQPainter</a> p2(this); p2.<a href="ntqpainter.html#setClipRect">setClipRect</a>(event->rect()); <a name="x2758"></a> p2.<a href="ntqpainter.html#drawPixmap">drawPixmap</a>(0,0,pm); } void <a name="f568"></a>Graph::paintWait(TQPaintEvent*) { <a href="ntqpainter.html">TQPainter</a> p(this); p.<a href="ntqpainter.html#drawText">drawText</a>(rect(), AlignCenter, "Loading..."); } void Graph::<a href="ntqwidget.html#paintEvent">paintEvent</a>(TQPaintEvent* event) { if (!model.nCols()) { paintWait(event); } else { switch (style) { case Pie: paintPie(event); break; case Bar: paintBar(event); break; } } } void <a name="f569"></a>Graph::setStyleFromMenu(int id) { setStyle(Style(id-100)); } const char* Graph::styleName[] = { "Pie", "Bar", 0 }; // // Grapher is a subclass of TQNPInstance, and so it can be returned // by GrapherPlugin::newInstance(). A TQNPInstance represents the // plugin, distinctly from the plugin window. // // Grapher is also a GraphModel, because it loads graph data from // the net. When Grapher creates a window in newWindow(), it creates // a Graph widget to display the GraphModel that is the Grapher itself. // class Grapher : public <a href="qnpinstance.html">TQNPInstance</a>, GraphModel { TQ_OBJECT public: // Create a Grapher - all Grapher plugins are created // by one GrapherPlugin object. // Grapher(); ~Grapher(); // We override this TQNPInstance function to create our // own subclass of TQNPWidget, a Graph widget. // <a href="qnpwidget.html">TQNPWidget</a>* newWindow(); // We override this TQNPInstance function to process the // incoming graph data. // int write(TQNPStream* /*str*/, int /*offset*/, int len, void* buffer); private: // Grapher is a GraphModel, so it implements the pure virtual // functions of that class. // <a href="ntqptrlist.html">TQPtrList</a><Datum>& graphData(); ColType colType(int col) const; int nCols() const; void consumeLine(); <a href="ntqptrlist.html">TQPtrList</a><Datum> data; <a href="ntqbuffer.html">TQBuffer</a> line; int ncols; ColType *coltype; private slots: // Slots that are connected to the Graph menu items. // void aboutPlugin(); void aboutData(); }; <a name="f570"></a>Grapher::Grapher() { <a name="x2769"></a> data.<a href="ntqptrcollection.html#setAutoDelete">setAutoDelete</a>(TRUE); ncols = 0; <a name="x2743"></a> line.<a href="ntqiodevice.html#open">open</a>(IO_WriteOnly|IO_Truncate); } Grapher::~Grapher() { } TQPtrList<GraphModel::Datum>& <a name="f571"></a>Grapher::graphData() { return data; } GraphModel::ColType <a name="f572"></a>Grapher::colType(int col) const { return coltype[col]; } int <a name="f573"></a>Grapher::nCols() const { return ncols; } <a name="x2751"></a>TQNPWidget* Grapher::<a href="qnpinstance.html#newWindow">newWindow</a>() { // Create a Graph - our subclass of TQNPWidget. Graph *graph = new Graph(*this); // Look at the arguments from the EMBED tag. // GRAPHSTYLE chooses pie or bar // FONTFAMILY and FONTSIZE choose the font // const char* style = <a href="qnpinstance.html#arg">arg</a>("GRAPHSTYLE"); if ( style ) graph-><a href="ntqwidget.html#setStyle">setStyle</a>(style); const char* fontfamily = <a href="qnpinstance.html#arg">arg</a>("FONTFAMILY"); const char* fontsize = <a href="qnpinstance.html#arg">arg</a>("FONTSIZE"); <a name="x2775"></a> int ptsize = fontsize ? atoi(fontsize) : graph-><a href="ntqwidget.html#font">font</a>().pointSize(); if (fontfamily) graph-><a href="ntqwidget.html#setFont">setFont</a>(TQFont(fontfamily, ptsize)); <a href="ntqobject.html#connect">connect</a>(graph, SIGNAL(aboutPlugin()), this, SLOT(aboutPlugin())); <a href="ntqobject.html#connect">connect</a>(graph, SIGNAL(aboutData()), this, SLOT(aboutData())); return graph; } void <a name="f574"></a>Grapher::consumeLine() { <a name="x2742"></a> line.<a href="ntqiodevice.html#close">close</a>(); line.<a href="ntqiodevice.html#open">open</a>(IO_ReadOnly); <a href="ntqtextstream.html">TQTextStream</a> ts( &line ); if (ncols == 0 ) { ncols=0; <a href="ntqptrlist.html">TQPtrList</a><ColType> typelist; typelist.<a href="ntqptrcollection.html#setAutoDelete">setAutoDelete</a>(TRUE); do { <a href="ntqstring.html">TQString</a> typestr; ts >> typestr >> ws; ColType* t = 0; if ( typestr == "num" ) { t = new ColType(Numeric); } else if ( typestr == "label" ) { t = new ColType(Label); } <a name="x2770"></a> if (t) typelist.<a href="ntqptrlist.html#append">append</a>(t); <a name="x2774"></a> } while (!ts.<a href="ntqtextstream.html#atEnd">atEnd</a>()); coltype = new ColType[ncols]; for (ColType* t = typelist.<a href="ntqptrlist.html#first">first</a>(); t; t = typelist.<a href="ntqptrlist.html#next">next</a>()) { coltype[ncols++] = *t; } } else { int col=0; Datum *rowdata = new Datum[ncols]; while ( col < ncols && !ts.<a href="ntqtextstream.html#atEnd">atEnd</a>() ) { switch (coltype[col]) { case Numeric: { double value; ts >> value >> ws; rowdata[col].dbl = value; break; } case Label: { <a href="ntqstring.html">TQString</a>* value = new <a href="ntqstring.html">TQString</a>; ts >> *value >> ws; rowdata[col].str = value; break; } } col++; } data.<a href="ntqptrlist.html#append">append</a>(rowdata); } line.<a href="ntqiodevice.html#close">close</a>(); line.<a href="ntqiodevice.html#open">open</a>(IO_WriteOnly|IO_Truncate); } <a name="x2752"></a>int Grapher::<a href="qnpinstance.html#write">write</a>(TQNPStream* /*str*/, int /*offset*/, int len, void* buffer) { // The browser calls this function when data is available on one // of the streams the plugin has requested. Since we are only // processing one stream - the URL in the SRC argument of the EMBED // tag, we assume the TQNPStream is that one. Also, since we do not // override TQNPInstance::writeReady(), we must accepts ALL the data // that is sent to this function. // char* txt = (char*)buffer; for (int i=0; i<len; i++) { char ch = txt[i]; switch ( ch ) { case '\n': consumeLine(); break; case '\r': // ignore; break; default: <a name="x2744"></a> line.<a href="ntqiodevice.html#putch">putch</a>(ch); } } if ( <a href="qnpinstance.html#widget">widget</a>() ) <a href="qnpinstance.html#widget">widget</a>()->update(); return len; } void <a name="f575"></a>Grapher::aboutPlugin() { <a href="qnpinstance.html#getURL">getURL</a>( "http://doc.trolltech.com/netscape-plugin.html", "_blank" ); } void <a name="f576"></a>Grapher::aboutData() { const char* page = <a href="qnpinstance.html#arg">arg</a>("DATAPAGE"); if (page) <a href="qnpinstance.html#getURL">getURL</a>( page, "_blank" ); else <a name="x2750"></a> TQMessageBox::<a href="ntqmessagebox.html#message">message</a>("Help", "No help for this data"); } // // GrapherPlugin is the start of everything. It is a TQNPlugin subclass, // and it is responsible for describing the plugin to the browser, and // creating instances of the plugin when it appears in web page. // class GrapherPlugin : public <a href="qnplugin.html">TQNPlugin</a> { public: GrapherPlugin() { } <a href="qnpinstance.html">TQNPInstance</a>* newInstance() { // Make a new Grapher, our subclass of TQNPInstance. return new Grapher; } const char* getMIMEDescription() const { // Describe the MIME types which this plugin can // process. Just the concocted "application/x-graphable" // type, with the "g1n" filename extension. // return "application/x-graphable:g1n:Graphable ASCII numeric data"; } const char * getPluginNameString() const { // The name of the plugin. This is the title string used in // the "About Plugins" page of the browser. // return "TQt-based Graph Plugin"; } const char * getPluginDescriptionString() const { // A longer description of the plugin. // return "A TQt-based LiveConnected plug-in that graphs numeric data"; } }; // // Finally, we provide the implementation of TQNPlugin::create(), to // provide our subclass of TQNPlugin. // TQNPlugin* TQNPlugin::create() { return new GrapherPlugin; } #include "grapher.moc" </pre> <p>See also <a href="nsplugin-examples.html">Netscape Plugin Examples</a>. <!-- eof --> <p><address><hr><div align=center> <table width=100% cellspacing=0 border=0><tr> <td>Copyright © 2007 <a href="troll.html">Trolltech</a><td align=center><a href="trademarks.html">Trademarks</a> <td align=right><div align=right>TQt 3.3.8</div> </table></div></address></body> </html>