moz_main.c

来自「SumatraPDF是一款小型开源的pdf阅读工具。虽然玲珑小巧（只有800多K」· C语言 代码 · 共 882 行 · 第 1/2 页

#include "fitz.h"
#include "mupdf.h"

#include <windows.h>
#include <windowsx.h>

#include "npapi.h"
#include "npupp.h"

#define PAD 5

#define MSG(s) MessageBox(0,s,"MuPDF Debug",MB_OK)

typedef struct pdfmoz_s pdfmoz_t;
typedef struct page_s page_t;

struct page_s
{
    fz_obj *ref;
    fz_obj *obj;
    pdf_page *page;
    fz_pixmap *image;
    int w, h;	/* page size in units */
    int px; /* pixel height */
};

struct pdfmoz_s
{
    NPP inst;
    HWND hwnd;
    HWND sbar;
    WNDPROC winproc;
    HCURSOR arrow, hand, wait;
    BITMAPINFO *dibinf;
    HBRUSH graybrush;

    int scrollpage;	/* scrollbar -> page (n) */
    int scrollyofs;	/* scrollbar -> page offset in pixels */

    int pagecount;
    page_t *pages;

    char *filename;
    char *doctitle;

    pdf_xref *xref;
    fz_renderer *rast;

    char error[1024];	/* empty if no error has occured */
};

void pdfmoz_warn(pdfmoz_t *moz, const char *fmt, ...)
{
    char buf[1024];
    va_list ap;
    va_start(ap, fmt);
    vsprintf(buf, fmt, ap);
    va_end(ap);
    strcpy(moz->error, buf);
    InvalidateRect(moz->hwnd, NULL, FALSE);
    NPN_Status(moz->inst, moz->error);
}

void pdfmoz_error(pdfmoz_t *moz, fz_error *error)
{
    strcpy(moz->error, error->msg);
    InvalidateRect(moz->hwnd, NULL, FALSE);
    NPN_Status(moz->inst, moz->error);
}

void pdfmoz_open(pdfmoz_t *moz, char *filename)
{
    SCROLLINFO si;
    fz_error *error;
    fz_obj *obj;
    char *password = "";
    pdf_pagetree *pages;
    fz_irect bbox;
    int rot;
    int i;

    strcpy(moz->error, "");

    error = fz_newrenderer(&moz->rast, pdf_devicergb, 0, 1024 * 512);
    if (error)
	pdfmoz_error(moz, error);

    /*
     * Open PDF and load xref table
     */

    moz->filename = filename;

    error = pdf_newxref(&moz->xref);
    if (error)
	pdfmoz_error(moz, error);

    error = pdf_loadxref(moz->xref, filename);
    if (error)
    {
	if (!strncmp(error->msg, "ioerror", 7))
	    pdfmoz_error(moz, error);
	error = pdf_repairxref(moz->xref, filename);
	if (error)
	    pdfmoz_error(moz, error);
    }

    /*
     * Handle encrypted PDF files
     */

    error = pdf_decryptxref(moz->xref);
    if (error)
	pdfmoz_error(moz, error);

    if (moz->xref->crypt)
    {
	int okay = pdf_setpassword(moz->xref->crypt, password);
	if (!okay)
	    pdfmoz_warn(moz, "Invalid password.");
    }

    /*
     * Load page tree
     */

    error = pdf_loadpagetree(&pages, moz->xref);
    if (error)
	pdfmoz_error(moz, error);

    moz->pagecount = pdf_getpagecount(pages);
    moz->pages = fz_malloc(sizeof(page_t) * moz->pagecount);

    for (i = 0; i < moz->pagecount; i++)
    {
	moz->pages[i].ref = fz_keepobj(pages->pref[i]);
	moz->pages[i].obj = fz_keepobj(pdf_getpageobject(pages, i));
	moz->pages[i].page = nil;
	moz->pages[i].image = nil;

	obj = fz_dictgets(moz->pages[i].obj, "CropBox");
	if (!obj)
	    obj = fz_dictgets(moz->pages[i].obj, "MediaBox");
	bbox = fz_roundrect(pdf_torect(obj));
	moz->pages[i].w = bbox.x1 - bbox.x0;
	moz->pages[i].h = bbox.y1 - bbox.y0;

	rot = fz_toint(fz_dictgets(moz->pages[i].obj, "Rotate"));
	if ((rot / 90) % 2)
	{
	    int t = moz->pages[i].w;
	    moz->pages[i].w = moz->pages[i].h;
	    moz->pages[i].h = t;
	}

	moz->pages[i].px = 1 + PAD;
    }

    pdf_droppagetree(pages);

    /*
     * Load meta information
     * TODO: move this into mupdf library
     */

    obj = fz_dictgets(moz->xref->trailer, "Root");
    if (!obj)
	pdfmoz_error(moz, fz_throw("syntaxerror: missing Root object"));

    error = pdf_loadindirect(&moz->xref->root, moz->xref, obj);
    if (error)
	pdfmoz_error(moz, error);

    obj = fz_dictgets(moz->xref->trailer, "Info");
    if (obj)
    {
	error = pdf_loadindirect(&moz->xref->info, moz->xref, obj);
	if (error)
	    pdfmoz_error(moz, error);
    }

    error = pdf_loadnametrees(moz->xref);
    if (error)
	pdfmoz_error(moz, error);

    moz->doctitle = filename;
    if (strrchr(moz->doctitle, '\\'))
	moz->doctitle = strrchr(moz->doctitle, '\\') + 1;
    if (strrchr(moz->doctitle, '/'))
	moz->doctitle = strrchr(moz->doctitle, '/') + 1;
    if (moz->xref->info)
    {
	obj = fz_dictgets(moz->xref->info, "Title");
	if (obj)
	{
	    error = pdf_toutf8(&moz->doctitle, obj);
	    if (error)
		pdfmoz_error(moz, error);
	}
    }

    /*
     * Start at first page
     */

    si.cbSize = sizeof(si);
    si.fMask = SIF_POS | SIF_RANGE; // XXX | SIF_PAGE;
    si.nPos = 0;
    si.nMin = 0;
    si.nMax = 1;
    si.nPage = 1;
    SetScrollInfo(moz->hwnd, SB_VERT, &si, TRUE);

    moz->scrollpage = 0;
    moz->scrollyofs = 0;

    InvalidateRect(moz->hwnd, NULL, FALSE);
}

static void decodescroll(pdfmoz_t *moz, int spos)
{
    int i, y = 0;
    moz->scrollpage = 0;
    moz->scrollyofs = 0;
    for (i = 0; i < moz->pagecount; i++)
    {
	if (spos >= y && spos < y + moz->pages[i].px)
	{
	    moz->scrollpage = i;
	    moz->scrollyofs = spos - y;
	    return;
	}
	y += moz->pages[i].px;
    }
}

fz_matrix pdfmoz_pagectm(pdfmoz_t *moz, int pagenum)
{
    page_t *page = moz->pages + pagenum;
    fz_matrix ctm;
    float zoom;
    RECT rc;

    GetClientRect(moz->hwnd, &rc);

    zoom = (rc.right - rc.left) / (float) page->w;

    ctm = fz_identity();
    ctm = fz_concat(ctm, fz_translate(0, -page->page->mediabox.y1));
    ctm = fz_concat(ctm, fz_scale(zoom, -zoom));
    ctm = fz_concat(ctm, fz_rotate(page->page->rotate));

    return ctm;
}

void pdfmoz_loadpage(pdfmoz_t *moz, int pagenum)
{
    page_t *page = moz->pages + pagenum;
    fz_error *error;

    if (page->page)
	return;

    error = pdf_loadpage(&page->page, moz->xref, page->obj);
    if (error)
	pdfmoz_error(moz, error);
}

void pdfmoz_drawpage(pdfmoz_t *moz, int pagenum)
{
    page_t *page = moz->pages + pagenum;
    fz_error *error;
    fz_matrix ctm;
    fz_rect bbox;

    if (page->image)
	return;

    ctm = pdfmoz_pagectm(moz, pagenum);
    bbox = fz_transformaabb(ctm, page->page->mediabox);

    error = fz_rendertree(&page->image, moz->rast, page->page->tree,
	    ctm, fz_roundrect(bbox), 1);
    if (error)
	pdfmoz_error(moz, error);
}

void pdfmoz_gotouri(pdfmoz_t *moz, fz_obj *uri)
{
    char buf[2048];
    memcpy(buf, fz_tostrbuf(uri), fz_tostrlen(uri));
    buf[fz_tostrlen(uri)] = 0;
    NPN_GetURL(moz->inst, buf, "_blank");
}

int pdfmoz_getpagenum(pdfmoz_t *moz, fz_obj *obj)
{
    int oid = fz_tonum(obj);
    int i;
    for (i = 0; i < moz->pagecount; i++)
	if (fz_tonum(moz->pages[i].ref) == oid)
	    return i;
    return 0;
}

void pdfmoz_gotopage(pdfmoz_t *moz, fz_obj *obj)
{
    int oid = fz_tonum(obj);
    int i, y = 0;
    for (i = 0; i < moz->pagecount; i++)
    {
	if (fz_tonum(moz->pages[i].ref) == oid)
	{
	    SetScrollPos(moz->hwnd, SB_VERT, y, TRUE);
	    InvalidateRect(moz->hwnd, NULL, FALSE);
	    return;
	}
	y += moz->pages[i].px;
    }
}

void pdfmoz_onmouse(pdfmoz_t *moz, int x, int y, int click)
{
    char buf[512];
    pdf_link *link;
    fz_matrix ctm;
    fz_point p;
    int pi;
    int py;

    if (!moz->pages)
	return;

    pi = moz->scrollpage;
    py = -moz->scrollyofs;
    while (pi < moz->pagecount)
    {
	if (!moz->pages[pi].image)
	    return;
	if (y > py && y < moz->pages[pi].px)
	    break;
	py += moz->pages[pi].px;
	pi ++;
    }
    if (pi == moz->pagecount)
	return;

    p.x = x + moz->pages[pi].image->x;
    p.y = y + moz->pages[pi].image->y - py;

    ctm = pdfmoz_pagectm(moz, pi);
    ctm = fz_invertmatrix(ctm);

    p = fz_transformpoint(ctm, p);

    for (link = moz->pages[pi].page->links; link; link = link->next)
    {
	if (p.x >= link->rect.x0 && p.x <= link->rect.x1)
	    if (p.y >= link->rect.y0 && p.y <= link->rect.y1)
		break;
    }

    if (link)
    {
	SetCursor(moz->hand);
	if (click)
	{
	    if (fz_isstring(link->dest))
		pdfmoz_gotouri(moz, link->dest);
	    if (fz_isindirect(link->dest))
		pdfmoz_gotopage(moz, link->dest);
	    return;
	}
	else
	{
	    if (fz_isstring(link->dest))
	    {
		memcpy(buf, fz_tostrbuf(link->dest), fz_tostrlen(link->dest));
		buf[fz_tostrlen(link->dest)] = 0;
		NPN_Status(moz->inst, buf);
	    }
	    else if (fz_isindirect(link->dest))
	    {
		sprintf(buf, "Go to page %d",
			pdfmoz_getpagenum(moz, link->dest) + 1);
		NPN_Status(moz->inst, buf);
	    }
	    else
		NPN_Status(moz->inst, "Say what?");
	}
    }
    else
    {
	sprintf(buf, "Page %d of %d", moz->scrollpage + 1, moz->pagecount);
	NPN_Status(moz->inst, buf);
	SetCursor(moz->arrow);
    }
}

static void drawimage(HDC hdc, pdfmoz_t *moz, fz_pixmap *image, int yofs)
{
    int bmpstride = ((image->w * 3 + 3) / 4) * 4;
    char *bmpdata = fz_malloc(image->h * bmpstride);
    int x, y;

    if (!bmpdata)
	return;

    for (y = 0; y < image->h; y++)
    {
	char *p = bmpdata + y * bmpstride;
	char *s = image->samples + y * image->w * 4;
	for (x = 0; x < image->w; x++)
	{
	    p[x * 3 + 0] = s[x * 4 + 3];
	    p[x * 3 + 1] = s[x * 4 + 2];
	    p[x * 3 + 2] = s[x * 4 + 1];
	}
    }

    moz->dibinf->bmiHeader.biWidth = image->w;
    moz->dibinf->bmiHeader.biHeight = -image->h;
    moz->dibinf->bmiHeader.biSizeImage = image->h * bmpstride;
    SetDIBitsToDevice(hdc,
	    0, /* destx */
	    yofs, /* desty */
	    image->w, /* destw */
	    image->h, /* desth */
	    0, /* srcx */
	    0, /* srcy */
	    0, /* startscan */
	    image->h, /* numscans */
	    bmpdata, /* pBits */
	    moz->dibinf, /* pInfo */
	    DIB_RGB_COLORS /* color use flag */
		     );

    fz_free(bmpdata);
}

LRESULT CALLBACK