Browser Side Plug-in API

This chapter describes methods in the plug-in API that are available from the browser. The names of all of these methods begin with NPN_ to indicate that they are implemented by the browser and called by the plug-in. For an overview of how these two sides of the plug-in API interact, see the How Plug-ins Work and Overview of Plug-in Structure sections in the introduction.

Warning: You must only call these from the main thread; calling them from other threads is not supported and may have unpredictable results.

Netscape Plug-in Method Summary

NPN_DestroyStream

Closes and deletes a stream.

NPN_ForceRedraw

Forces a paint message for a windowless plug-in.

NPN_GetAuthenticationInfo

This function is called by plug-ins to get HTTP authentication information from the browser.

NPN_GetURL

Asks the browser to create a stream for the specified URL.

NPN_GetURLNotify

Requests creation of a new stream with the contents of the specified URL; gets notification of the result.

NPN_GetValue

Allows the plug-in to query the browser for information.

NPN_GetValueForURL

Provides information to a plug-in which is associated with a given URL, for example the cookies or preferred proxy.

NPN_InvalidateRect

Invalidates specified drawing area prior to repainting or refreshing a windowless plug-in.

NPN_InvalidateRegion

Invalidates specified drawing region prior to repainting or refreshing a windowless plug-in.

NPN_MemAlloc

Allocates memory from the browser's memory space.

NPN_MemFlush

Requests that the browser free a specified amount of memory.

NPN_MemFree

Deallocates a block of allocated memory.

NPN_NewStream

Requests the creation of a new data stream produced by the plug-in and consumed by the browser.

NPN_PluginThreadAsyncCall

Thread-safe way to request that the browser calls a plug-in function on the browser or plug-in thread (the thread on which the plug-in was initiated).

NPN_PopPopupsEnabledState

Pops the popups-enabled state.

NPN_PostURL

Posts data to a URL.

NPN_PostURLNotify

Posts data to a URL, and receives notification of the result.

NPN_PushPopupsEnabledState

Pushes the popups-enabled state.

NPN_ReloadPlugins

Reloads all plug-ins in the Plugins directory.

NPN_RequestRead

Requests a range of bytes for a seekable stream.

NPN_SetValue

Sets windowless plug-in as transparent or opaque.

NPN_SetValueForURL

Allows a plug-in to change the stored information associated with a URL, in particular its cookies.

NPN_Status

Displays a message on the status line of the browser window.

NPN_UserAgent

Returns the browser's user agent field.

NPN_Version

Returns version information for the Plug-in API.

NPN_Write

Pushes data into a stream produced by the plug-in and consumed by the browser.