Firefox Plugins-II

最新推荐文章于 2025-12-30 10:06:08 发布

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#firefox #printing #browser #structure #methods #dialog

Chapter 3：Plug-in API

5: typedef struct _NPWindow

6: NPError NPP_SetWindow(NPP instance, NPWindow *window);

The NPWindow Structure

When a plug-in is loaded, it is drawn into a target area. This target is either the windowed plug-in's native window, or the drawable of a windowless plug-in. The NPWindow structure represents either the native window or a drawable. This structure contains information about coordinate position, size, the state of the plug-in (windowed or windowless), and some platform-specific information.

NOTE: When a plug-in is drawn to a window, the plug-in is responsible for preserving state information and ensuring that the original state is restored.

For windowless plug-ins, the browser calls the NPP_SetWindow method with an NPWindow structure that represents a drawable. For windowed plug-ins, the browser calls the NPP_SetWindow method with an NPWindow structure that represents a window.

//The NPWindow Structure





typedef enum {



NPWindowTypeWindow = 1,

NPWindowTypeDrawable



} NPWindowType;





 

typedef struct _NPWindow

{

void*   window;   /* Platform-specific handle      */

uint32  x;        /* Position of top-left corner   */

uint32  y;        /*   relative to a Netscape page */

uint32  width;    /* Maximum window size           */

uint32  height;

NPRect  clipRect; /* Clipping rectangle in port coordinates */



#ifdef XP_UNIX

void *  ws_info;  /* Platform-dependent additional data     */

#endif /* XP_UNIX */

 

NPWindowType  type;   /* Whether this is a window or a drawable */

} NPWindow;

The type field indicates the NPWindow type of the target area:

NPWindowType Window: Windowed plug-in. The window field holds a platform-specific handle to a window.
NPWindowType Drawable: Windowless plug-in. The window field holds a platform-specific handle to a drawable

由type来决定这个Plugin是一个windowed还是一个windowless

Drawing Plug-ins

This section describes the methods and processes you use in drawing both windowed and windowless plug-ins. Processes that apply to only one of these plug-in types are described in the following sections.

The plug-in uses these methods to draw plug-ins and to handle events:

Plug-in methods, called by the browser:

NPP_HandleEvent : Deliver a platform-specific event to the instance.
NPP_Print : Request a platform-specific print operation for the instance.
NPP_SetWindow : Set the window in which a plug-in draws.

Browser-side methods, called by the plug-in:

NPN_ForceRedraw : Force a paint message to a windowless plug-in.
NPN_InvalidateRect : Invalidate an area in a windowless plug-in before repainting or refreshing.
NPN_InvalidateRegion : Invalidate a region in a windowless plug-in before repainting or refreshing.

Printing the Plug-in

The browser calls the NPP_Print method to ask the plug-in instance to print itself.

void NPP_Print(NPP instance, NPPrint *printInfo);

The PrintInfo parameter determines the print mode. It is set to either NP_FULL to indicate full-page plug-in printing, or NP_EMBED if this is an embedded plug-in printed as part of the window in which it is embedded.

An embedded plug-in shares printing with the browser. The plug-in prints the part of the page it occupies, and the browser handles the rest of the printing process, including displaying print dialog boxes, getting the printer device context, and, of course, printing the rest of the page.

An embedded plug-in can set the pluginPrinted field in its PrintInfo parameter to false (the default). This is a field of the _NPFullPrint substructure of the NPPrint structure. The browser displays the necessary print dialog boxes and calls NPP_Print again. This time, PrintInfo->mode should be set to NP_EMBED .

A full-page plug-in handles the print dialog boxes and printing process as it sees fit. In this case, before the browser displays any print dialog boxes, NPP_Print is called with PrintInfo->mode equal to NP_FULL . On Mac OS, full-page printing requires that the field PrintInfo contain a standard Mac OS THPrint (see Printing.h ).

Of course, NPP_Print is also called with PrintInfo->mode equal to NP_EMBED when the instance is embedded. In this case, platformPrint->embedPrint.window contains the window in which the plug-in should print.

NPP_Print这个函数内部看情形应该对传入的printInfo进行详细的分析然后做出不同的事情来才行。

For windowed plug-ins on MS Windows and Unix, the window->window
 field is a handle to a subwindow of the Netscape window hierarchy.



之前说送入window，再回过头来看，这个Window还得是浏览器所属的才行？是这个意思吧