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QNPlugin Class Reference


The plugin central factory. This class is part of the Qt NSPlugin Extension. More...

#include <qnp.h>

List of all member functions.

Public Members

Static Public Members

Protected Members


Detailed Description

This class is defined in the Qt NSPlugin Extension, which can be found in the qt/extensions directory. It is not included in the main Qt API.

The plugin central factory.

This class is the heart of the plugin. One instance of this object is created when the plugin is first needed, by calling QNPlugin::create(), which must be implemented in your plugin code to return some derived class of QNPlugin. The one QNPlugin object creates all instances for a single running Web-browser process.

Additionally, if Qt is linked to the plugin as a dynamic library, only one instance of QApplication will exist across all plugins that have been made with Qt. So, your plugin should tread lightly on global settings - do not for example, use QApplication::setFont() - that will change the font in every widget of every Qt-based plugin currently loaded!.

Examples: qtimage/qtimage.cpp grapher/grapher.cpp trivial/trivial.cpp


Member Function Documentation

QNPlugin::QNPlugin() [protected]

Creates a QNPlugin. This may only be used by the constructor derived class returned by plugin's implementation of the QNPlugin::create() function.

QNPlugin::~QNPlugin() [virtual]

Destroys the QNPlugin. This is called by the plugin binding code just before the plugin is about to be unloaded from memory. If newWindow() has been called, a QApplication will still exist at this time, but will be deleted shortly after before the plugin is deleted.

QNPlugin*QNPlugin::actual() [static]

Returns the plugin most recently returns by QNPlugin::create().

QNPlugin*QNPlugin::create() [static]

This must be implemented by your plugin code. It should return a derived class of QNPlugin.

void*QNPlugin::getJavaClass() [virtual]

Override to return a reference to the Java class that represents the plugin. The default returns 0, indicating no class.

If you override this class, you must also override QNPlugin::unuseJavaClass().

The return value is actually a jref we use void* so as to avoid burdening plugins which do not require Java.

See also: getJavaEnv() and QNPInstance::getJavaPeer().

void*QNPlugin::getJavaEnv()const

Returns a pointer to the Java execution environment, or 0 if Java is disabled or an error occurred.

The return value is actually a JRIEnv* we use void* so as to avoid burdening plugins which do not require Java.

See also: getJavaClass() and QNPInstance::getJavaPeer().

constchar*QNPlugin::getMIMEDescription()const [virtual]

Override this to return the MIME description of the data formats supported by your plugin. The format of this string is described by the following example:

    const char* getMIMEDescription() const
    {
        return "image/x-png:png:PNG Image;"
               "image/png:png:PNG Image;"
               "image/x-portable-bitmap:pbm:PBM Image;"
               "image/x-portable-graymap:pgm:PGM Image;"
               "image/x-portable-pixmap:ppm:PPM Image;"
               "image/bmp:bmp:BMP Image;"
               "image/x-ms-bmp:bmp:BMP Image;"
               "image/x-xpixmap:xpm:XPM Image;"
               "image/xpm:xpm:XPM Image";
    }

constchar*QNPlugin::getPluginDescriptionString()const [virtual]

Returns a plain-text description of the plugin.

constchar*QNPlugin::getPluginNameString()const [virtual]

Returns the plain-text name of the plugin.

voidQNPlugin::getVersionInfo(int&plugin_major, int&plugin_minor, int&browser_major, int&browser_minor)

Returns the version information - the version of the plugin API, and the version of the browser.

QNPInstance*QNPlugin::newInstance() [virtual]

Override this to return an appropriate derived class of QNPInstance.

voidQNPlugin::unuseJavaClass() [virtual]

This function is called when the plugin is shutting down, with jc set to the value returned earlier by getJavaClass(). The function should unuse the Java class and return 0.

See also: Netscape: Associating a Class with your Plug-in


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Qt version 2.0.2