src/html/m_layout.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        m_layout.cpp
   3 // Purpose:     wxHtml module for basic paragraphs/layout handling
   4 // Author:      Vaclav Slavik
   5 // RCS-ID:      $Id$
   6 // Copyright:   (c) 1999 Vaclav Slavik
   7 // Licence:     wxWindows licence
   8 /////////////////////////////////////////////////////////////////////////////
   9
  10 #include "wx/wxprec.h"
  11
  12 #include "wx/defs.h"
  13
  14 #if wxUSE_HTML && wxUSE_STREAMS
  15
  16 #ifdef __BORLANDC__
  17     #pragma hdrstop
  18 #endif
  19
  20 #ifndef WXPRECOMP
  21 #endif
  22
  23 #include "wx/image.h"
  24
  25 #include "wx/html/forcelnk.h"
  26 #include "wx/html/m_templ.h"
  27
  28 #include "wx/html/htmlwin.h"
  29
  30 FORCE_LINK_ME(m_layout)
  31
  32 #ifdef __WXWINCE__
  33     #include "wx/msw/wince/missing.h"       // for bsearch()
  34 #else
  35     #include <stdlib.h>                     // bsearch()
  36 #endif
  37
  38 //-----------------------------------------------------------------------------
  39 // wxHtmlPageBreakCell
  40 //-----------------------------------------------------------------------------
  41
  42 // Since html isn't a page-layout language, it doesn't support page
  43 // page breaks directly--that requires CSS2 support. But a page-break
  44 // facility is handy, and has been requested more than once on the
  45 // mailing lists. This wxHtml tag handler implements just enough of
  46 // CSS2 to support a page break by recognizing only
  47 //   <div style="page-break-before:always">
  48 //
  49 // wxHtml maintains page breaks in wxHtmlPrintout::m_PageBreaks. The
  50 // tag handler below adds appropriate offsets to that array member.
  51 // wxHtmlDCRenderer::Render() accesses that array and makes a new page
  52 // begin after each page-break tag.
  53
  54 // The page-break handler does all its work in AdjustPagebreak(). For
  55 // all tag handlers, that function adjusts the page-break position.
  56 // For other tags, it determines whether the html element can fit on
  57 // the remainder of the page; if it cannot fit, but must not be split,
  58 // then the function moves the page break provided in the argument up,
  59 // and returns 'true' to inform the caller that the argument was
  60 // modified.
  61 //
  62 // Due to its special purpose, the page-break facility differs from
  63 // other tags. It takes up no space, but it behaves as though there is
  64 // never enough room to fit it on the remainder of the page--it always
  65 // forces a page break. Therefore, unlike other elements that trigger
  66 // a page break, it would never 'fit' on the following page either.
  67 // Therefore it's necessary to compare each pagebreak candidate to the
  68 // array wxHtmlPrintout::m_PageBreaks of pagebreaks already set, and
  69 // set a new one only if it's not in that array.
  70
  71 class wxHtmlPageBreakCell : public wxHtmlCell
  72 {
  73 public:
  74     wxHtmlPageBreakCell() {}
  75
  76     bool AdjustPagebreak(int* pagebreak,
  77                          int* known_pagebreaks = NULL,
  78                          int number_of_pages = 0) const;
  79     void Draw(wxDC& WXUNUSED(dc),
  80               int WXUNUSED(x), int WXUNUSED(y),
  81               int WXUNUSED(view_y1), int WXUNUSED(view_y2),
  82               wxHtmlRenderingInfo& WXUNUSED(info)) {}
  83
  84 private:
  85     DECLARE_NO_COPY_CLASS(wxHtmlPageBreakCell)
  86 };
  87
  88 // Comparison routine for bsearch into an int* array of pagebreaks.
  89 extern "C" int wxCMPFUNC_CONV wxInteger_compare(void const* i0, void const* i1)
  90 {
  91     return *(int*)i0 - *(int*)i1;
  92 }
  93
  94 bool wxHtmlPageBreakCell::AdjustPagebreak(int* pagebreak, int* known_pagebreaks, int number_of_pages) const
  95 {
  96     // When we are counting pages, 'known_pagebreaks' is non-NULL.
  97     // That's the only time we change 'pagebreak'. Otherwise, pages
  98     // were already counted, 'known_pagebreaks' is NULL, and we don't
  99     // do anything except return false.
 100     //
 101     // We also simply return false if the 'pagebreak' argument is
 102     // less than (vertically above) or the same as the current
 103     // vertical position. Otherwise we'd be setting a pagebreak above
 104     // the current cell, which is incorrect, or duplicating a
 105     // pagebreak that has already been set.
 106     if(NULL == known_pagebreaks || *pagebreak <= m_PosY)
 107         {
 108         return false;
 109         }
 110
 111     // m_PosY is only the vertical offset from the parent. The pagebreak
 112     // required here is the total page offset, so m_PosY must be added
 113     // to the parent's offset and height.
 114     int total_height = m_PosY + GetParent()->GetPosY() + GetParent()->GetHeight();
 115
 116     // Search the array of pagebreaks to see whether we've already set
 117     // a pagebreak here. The standard bsearch() function is appropriate
 118     // because the array of pagebreaks through known_pagebreaks[number_of_pages]
 119     // is known to be sorted in strictly increasing order. '1 + number_of_pages'
 120     // is used as a bsearch() argument because the array contains a leading
 121     // zero plus one element for each page.
 122     int* where = (int*) bsearch(&total_height, known_pagebreaks,
 123                                 1 + number_of_pages, sizeof(int),
 124                                 wxInteger_compare);
 125     // Add a pagebreak only if there isn't one already set here.
 126     if(NULL != where)
 127         {
 128         return false;
 129         }
 130     else
 131         {
 132         *pagebreak = m_PosY;
 133         return true;
 134         }
 135 }
 136
 137 TAG_HANDLER_BEGIN(P, "P")
 138     TAG_HANDLER_CONSTR(P) { }
 139
 140     TAG_HANDLER_PROC(tag)
 141     {
 142         if (m_WParser->GetContainer()->GetFirstChild() != NULL)
 143         {
 144             m_WParser->CloseContainer();
 145             m_WParser->OpenContainer();
 146         }
 147         m_WParser->GetContainer()->SetIndent(m_WParser->GetCharHeight(), wxHTML_INDENT_TOP);
 148         m_WParser->GetContainer()->SetAlign(tag);
 149         return false;
 150     }
 151
 152 TAG_HANDLER_END(P)
 153
 154
 155
 156 TAG_HANDLER_BEGIN(BR, "BR")
 157     TAG_HANDLER_CONSTR(BR) { }
 158
 159     TAG_HANDLER_PROC(tag)
 160     {
 161         int al = m_WParser->GetContainer()->GetAlignHor();
 162         wxHtmlContainerCell *c;
 163
 164         m_WParser->CloseContainer();
 165         c = m_WParser->OpenContainer();
 166         c->SetAlignHor(al);
 167         c->SetAlign(tag);
 168         c->SetMinHeight(m_WParser->GetCharHeight());
 169         return false;
 170     }
 171
 172 TAG_HANDLER_END(BR)
 173
 174
 175
 176 TAG_HANDLER_BEGIN(CENTER, "CENTER")
 177     TAG_HANDLER_CONSTR(CENTER) { }
 178
 179     TAG_HANDLER_PROC(tag)
 180     {
 181         int old = m_WParser->GetAlign();
 182         wxHtmlContainerCell *c = m_WParser->GetContainer();
 183
 184         m_WParser->SetAlign(wxHTML_ALIGN_CENTER);
 185         if (c->GetFirstChild() != NULL)
 186         {
 187             m_WParser->CloseContainer();
 188             m_WParser->OpenContainer();
 189         }
 190         else
 191             c->SetAlignHor(wxHTML_ALIGN_CENTER);
 192
 193         if (tag.HasEnding())
 194         {
 195             ParseInner(tag);
 196
 197             m_WParser->SetAlign(old);
 198             if (c->GetFirstChild() != NULL)
 199             {
 200                 m_WParser->CloseContainer();
 201                 m_WParser->OpenContainer();
 202             }
 203             else
 204                 c->SetAlignHor(old);
 205
 206             return true;
 207         }
 208         else return false;
 209     }
 210
 211 TAG_HANDLER_END(CENTER)
 212
 213
 214
 215 TAG_HANDLER_BEGIN(DIV, "DIV")
 216     TAG_HANDLER_CONSTR(DIV) { }
 217
 218     TAG_HANDLER_PROC(tag)
 219     {
 220         if(tag.HasParam(wxT("STYLE")))
 221         {
 222             if(tag.GetParam(wxT("STYLE")).IsSameAs(wxT("PAGE-BREAK-BEFORE:ALWAYS"), false))
 223             {
 224                 m_WParser->CloseContainer();
 225                 m_WParser->OpenContainer()->InsertCell(new wxHtmlPageBreakCell);
 226                 m_WParser->CloseContainer();
 227                 m_WParser->OpenContainer();
 228                 return false;
 229             }
 230             else
 231             {
 232                 // Treat other STYLE parameters here when they're supported.
 233                 return false;
 234             }
 235         }
 236         else if(tag.HasParam(wxT("ALIGN")))
 237         {
 238             int old = m_WParser->GetAlign();
 239             wxHtmlContainerCell *c = m_WParser->GetContainer();
 240             if (c->GetFirstChild() != NULL)
 241             {
 242                 m_WParser->CloseContainer();
 243                 m_WParser->OpenContainer();
 244                 c = m_WParser->GetContainer();
 245                 c->SetAlign(tag);
 246                 m_WParser->SetAlign(c->GetAlignHor());
 247             }
 248             else
 249             {
 250                 c->SetAlign(tag);
 251                 m_WParser->SetAlign(c->GetAlignHor());
 252             }
 253
 254             ParseInner(tag);
 255
 256             m_WParser->SetAlign(old);
 257             if (c->GetFirstChild() != NULL)
 258             {
 259                 m_WParser->CloseContainer();
 260                 m_WParser->OpenContainer();
 261             }
 262             else
 263                 c->SetAlignHor(old);
 264
 265             return true;
 266         }
 267         else
 268         {
 269             // Same as BR
 270             int al = m_WParser->GetContainer()->GetAlignHor();
 271             wxHtmlContainerCell *c;
 272
 273             m_WParser->CloseContainer();
 274             c = m_WParser->OpenContainer();
 275             c->SetAlignHor(al);
 276             c->SetAlign(tag);
 277             c->SetMinHeight(m_WParser->GetCharHeight());
 278             return false;
 279         }
 280     }
 281
 282 TAG_HANDLER_END(DIV)
 283
 284
 285
 286
 287 TAG_HANDLER_BEGIN(TITLE, "TITLE")
 288     TAG_HANDLER_CONSTR(TITLE) { }
 289
 290     TAG_HANDLER_PROC(tag)
 291     {
 292         if (m_WParser->GetWindow())
 293         {
 294             wxHtmlWindow *wfr = (wxHtmlWindow*)(m_WParser->GetWindow());
 295             if (wfr)
 296             {
 297                 wxString title = m_WParser->GetSource()->Mid(
 298                                         tag.GetBeginPos(),
 299                                         tag.GetEndPos1()-tag.GetBeginPos());
 300 #if !wxUSE_UNICODE && wxUSE_WCHAR_T
 301                 wxCSConv conv(m_WParser->GetInputEncoding());
 302                 title = wxString(title.wc_str(conv), wxConvLocal);
 303 #endif
 304                 title = m_WParser->GetEntitiesParser()->Parse(title);
 305                 wfr->OnSetTitle(title);
 306             }
 307         }
 308         return true;
 309     }
 310
 311 TAG_HANDLER_END(TITLE)
 312
 313
 314
 315
 316 TAG_HANDLER_BEGIN(BODY, "BODY")
 317     TAG_HANDLER_CONSTR(BODY) { }
 318
 319     TAG_HANDLER_PROC(tag)
 320     {
 321         wxColour clr;
 322
 323         if (tag.GetParamAsColour(wxT("TEXT"), &clr))
 324         {
 325             m_WParser->SetActualColor(clr);
 326             m_WParser->GetContainer()->InsertCell(new wxHtmlColourCell(clr));
 327         }
 328
 329         if (tag.GetParamAsColour(wxT("LINK"), &clr))
 330             m_WParser->SetLinkColor(clr);
 331
 332         if (tag.HasParam(wxT("BACKGROUND")))
 333         {
 334             wxFSFile *fileBgImage = m_WParser->OpenURL
 335                                                (
 336                                                 wxHTML_URL_IMAGE,
 337                                                 tag.GetParam(wxT("BACKGROUND"))
 338                                                );
 339             if ( fileBgImage )
 340             {
 341                 wxInputStream *is = fileBgImage->GetStream();
 342                 if ( is )
 343                 {
 344                     wxImage image(*is);
 345                     if ( image.Ok() )
 346                         m_WParser->GetWindow()->SetBackgroundImage(image);
 347                 }
 348             }
 349         }
 350
 351         if (tag.GetParamAsColour(wxT("BGCOLOR"), &clr))
 352         {
 353             m_WParser->GetContainer()->InsertCell(
 354                 new wxHtmlColourCell(clr, wxHTML_CLR_BACKGROUND));
 355             if (m_WParser->GetWindow() != NULL)
 356                 m_WParser->GetWindow()->SetBackgroundColour(clr);
 357         }
 358
 359         return false;
 360     }
 361
 362 TAG_HANDLER_END(BODY)
 363
 364
 365
 366 TAG_HANDLER_BEGIN(BLOCKQUOTE, "BLOCKQUOTE")
 367     TAG_HANDLER_CONSTR(BLOCKQUOTE) { }
 368
 369     TAG_HANDLER_PROC(tag)
 370     {
 371         wxHtmlContainerCell *c;
 372
 373         m_WParser->CloseContainer();
 374         c = m_WParser->OpenContainer();
 375
 376         if (c->GetAlignHor() == wxHTML_ALIGN_RIGHT)
 377             c->SetIndent(5 * m_WParser->GetCharWidth(), wxHTML_INDENT_RIGHT);
 378         else
 379             c->SetIndent(5 * m_WParser->GetCharWidth(), wxHTML_INDENT_LEFT);
 380
 381         c->SetIndent(m_WParser->GetCharHeight(), wxHTML_INDENT_TOP);
 382         m_WParser->OpenContainer();
 383         ParseInner(tag);
 384         c = m_WParser->CloseContainer();
 385         c->SetIndent(m_WParser->GetCharHeight(), wxHTML_INDENT_BOTTOM);
 386         m_WParser->CloseContainer();
 387         m_WParser->OpenContainer();
 388         return true;
 389     }
 390
 391 TAG_HANDLER_END(BLOCKQUOTE)
 392
 393
 394
 395 // Tag handler for tags that we have to ignore, otherwise non-text data
 396 // would show up as text:
 397 TAG_HANDLER_BEGIN(DoNothing, "SCRIPT")
 398     TAG_HANDLER_CONSTR(DoNothing) { }
 399
 400     TAG_HANDLER_PROC(WXUNUSED(tag))
 401     {
 402         return true;
 403     }
 404 TAG_HANDLER_END(DoNothing)
 405
 406
 407
 408 TAGS_MODULE_BEGIN(Layout)
 409
 410     TAGS_MODULE_ADD(P)
 411     TAGS_MODULE_ADD(BR)
 412     TAGS_MODULE_ADD(CENTER)
 413     TAGS_MODULE_ADD(DIV)
 414     TAGS_MODULE_ADD(TITLE)
 415     TAGS_MODULE_ADD(BODY)
 416     TAGS_MODULE_ADD(BLOCKQUOTE)
 417     TAGS_MODULE_ADD(DoNothing)
 418
 419 TAGS_MODULE_END(Layout)
 420
 421 #endif