src/html/m_layout.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        src/html/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 #ifdef __BORLANDC__
  13     #pragma hdrstop
  14 #endif
  15
  16 #if wxUSE_HTML && wxUSE_STREAMS
  17
  18 #ifndef WXPRECOMP
  19     #include "wx/image.h"
  20 #endif
  21
  22 #include "wx/html/forcelnk.h"
  23 #include "wx/html/m_templ.h"
  24
  25 #include "wx/html/htmlwin.h"
  26
  27 FORCE_LINK_ME(m_layout)
  28
  29 #ifdef __WXWINCE__
  30     #include "wx/msw/wince/missing.h"       // for bsearch()
  31 #else
  32     #include <stdlib.h>                     // bsearch()
  33 #endif
  34
  35 //-----------------------------------------------------------------------------
  36 // wxHtmlPageBreakCell
  37 //-----------------------------------------------------------------------------
  38
  39 // Since html isn't a page-layout language, it doesn't support page
  40 // page breaks directly--that requires CSS2 support. But a page-break
  41 // facility is handy, and has been requested more than once on the
  42 // mailing lists. This wxHtml tag handler implements just enough of
  43 // CSS2 to support a page break by recognizing only
  44 //   <div style="page-break-before:always">
  45 //
  46 // wxHtml maintains page breaks in wxHtmlPrintout::m_PageBreaks. The
  47 // tag handler below adds appropriate offsets to that array member.
  48 // wxHtmlDCRenderer::Render() accesses that array and makes a new page
  49 // begin after each page-break tag.
  50
  51 // The page-break handler does all its work in AdjustPagebreak(). For
  52 // all tag handlers, that function adjusts the page-break position.
  53 // For other tags, it determines whether the html element can fit on
  54 // the remainder of the page; if it cannot fit, but must not be split,
  55 // then the function moves the page break provided in the argument up,
  56 // and returns 'true' to inform the caller that the argument was
  57 // modified.
  58 //
  59 // Due to its special purpose, the page-break facility differs from
  60 // other tags. It takes up no space, but it behaves as though there is
  61 // never enough room to fit it on the remainder of the page--it always
  62 // forces a page break. Therefore, unlike other elements that trigger
  63 // a page break, it would never 'fit' on the following page either.
  64 // Therefore it's necessary to compare each pagebreak candidate to the
  65 // array wxHtmlPrintout::m_PageBreaks of pagebreaks already set, and
  66 // set a new one only if it's not in that array.
  67
  68 class wxHtmlPageBreakCell : public wxHtmlCell
  69 {
  70 public:
  71     wxHtmlPageBreakCell() {}
  72
  73     bool AdjustPagebreak(int* pagebreak,
  74                          wxArrayInt& known_pagebreaks) const;
  75
  76     void Draw(wxDC& WXUNUSED(dc),
  77               int WXUNUSED(x), int WXUNUSED(y),
  78               int WXUNUSED(view_y1), int WXUNUSED(view_y2),
  79               wxHtmlRenderingInfo& WXUNUSED(info)) {}
  80
  81 private:
  82     DECLARE_NO_COPY_CLASS(wxHtmlPageBreakCell)
  83 };
  84
  85 // Comparison routine for bsearch into an int* array of pagebreaks.
  86 extern "C" int wxCMPFUNC_CONV wxInteger_compare(void const* i0, void const* i1)
  87 {
  88     return *(int*)i0 - *(int*)i1;
  89 }
  90
  91 bool wxHtmlPageBreakCell::AdjustPagebreak(int* pagebreak, wxArrayInt& known_pagebreaks) const
  92 {
  93     // When we are counting pages, 'known_pagebreaks' is non-NULL.
  94     // That's the only time we change 'pagebreak'. Otherwise, pages
  95     // were already counted, 'known_pagebreaks' is NULL, and we don't
  96     // do anything except return false.
  97     //
  98     // We also simply return false if the 'pagebreak' argument is
  99     // less than (vertically above) or the same as the current
 100     // vertical position. Otherwise we'd be setting a pagebreak above
 101     // the current cell, which is incorrect, or duplicating a
 102     // pagebreak that has already been set.
 103     if( known_pagebreaks.Count() == 0 || *pagebreak <= m_PosY)
 104     {
 105         return false;
 106     }
 107
 108     // m_PosY is only the vertical offset from the parent. The pagebreak
 109     // required here is the total page offset, so m_PosY must be added
 110     // to the parent's offset and height.
 111     int total_height = m_PosY + GetParent()->GetPosY() + GetParent()->GetHeight();
 112
 113     // Search the array of pagebreaks to see whether we've already set
 114     // a pagebreak here. The standard bsearch() function is appropriate
 115     // because the array of pagebreaks through known_pagebreaks[number_of_pages]
 116     // is known to be sorted in strictly increasing order. '1 + number_of_pages'
 117     // is used as a bsearch() argument because the array contains a leading
 118     // zero plus one element for each page.
 119     int where = known_pagebreaks.Index( total_height);
 120     // Add a pagebreak only if there isn't one already set here.
 121     if( wxNOT_FOUND != where)
 122     {
 123         return false;
 124     }
 125     else
 126     {
 127         *pagebreak = m_PosY;
 128         return true;
 129     }
 130 }
 131
 132
 133
 134 TAG_HANDLER_BEGIN(P, "P")
 135     TAG_HANDLER_CONSTR(P) { }
 136
 137     TAG_HANDLER_PROC(tag)
 138     {
 139         if (m_WParser->GetContainer()->GetFirstChild() != NULL)
 140         {
 141             m_WParser->CloseContainer();
 142             m_WParser->OpenContainer();
 143         }
 144         m_WParser->GetContainer()->SetIndent(m_WParser->GetCharHeight(), wxHTML_INDENT_TOP);
 145         m_WParser->GetContainer()->SetAlign(tag);
 146         return false;
 147     }
 148
 149 TAG_HANDLER_END(P)
 150
 151
 152
 153 TAG_HANDLER_BEGIN(BR, "BR")
 154     TAG_HANDLER_CONSTR(BR) { }
 155
 156     TAG_HANDLER_PROC(tag)
 157     {
 158         int al = m_WParser->GetContainer()->GetAlignHor();
 159         wxHtmlContainerCell *c;
 160
 161         m_WParser->CloseContainer();
 162         c = m_WParser->OpenContainer();
 163         c->SetAlignHor(al);
 164         c->SetAlign(tag);
 165         c->SetMinHeight(m_WParser->GetCharHeight());
 166         return false;
 167     }
 168
 169 TAG_HANDLER_END(BR)
 170
 171
 172
 173 TAG_HANDLER_BEGIN(CENTER, "CENTER")
 174     TAG_HANDLER_CONSTR(CENTER) { }
 175
 176     TAG_HANDLER_PROC(tag)
 177     {
 178         int old = m_WParser->GetAlign();
 179         wxHtmlContainerCell *c = m_WParser->GetContainer();
 180
 181         m_WParser->SetAlign(wxHTML_ALIGN_CENTER);
 182         if (c->GetFirstChild() != NULL)
 183         {
 184             m_WParser->CloseContainer();
 185             m_WParser->OpenContainer();
 186         }
 187         else
 188             c->SetAlignHor(wxHTML_ALIGN_CENTER);
 189
 190         if (tag.HasEnding())
 191         {
 192             ParseInner(tag);
 193
 194             m_WParser->SetAlign(old);
 195             if (c->GetFirstChild() != NULL)
 196             {
 197                 m_WParser->CloseContainer();
 198                 m_WParser->OpenContainer();
 199             }
 200             else
 201                 c->SetAlignHor(old);
 202
 203             return true;
 204         }
 205         else return false;
 206     }
 207
 208 TAG_HANDLER_END(CENTER)
 209
 210
 211
 212 TAG_HANDLER_BEGIN(DIV, "DIV")
 213     TAG_HANDLER_CONSTR(DIV) { }
 214
 215     TAG_HANDLER_PROC(tag)
 216     {
 217         if(tag.HasParam(wxT("STYLE")))
 218         {
 219             if(tag.GetParam(wxT("STYLE")).IsSameAs(wxT("PAGE-BREAK-BEFORE:ALWAYS"), false))
 220             {
 221                 m_WParser->CloseContainer();
 222                 m_WParser->OpenContainer()->InsertCell(new wxHtmlPageBreakCell);
 223                 m_WParser->CloseContainer();
 224                 m_WParser->OpenContainer();
 225                 return false;
 226             }
 227             else
 228             {
 229                 // Treat other STYLE parameters here when they're supported.
 230                 return false;
 231             }
 232         }
 233         else if(tag.HasParam(wxT("ALIGN")))
 234         {
 235             int old = m_WParser->GetAlign();
 236             wxHtmlContainerCell *c = m_WParser->GetContainer();
 237             if (c->GetFirstChild() != NULL)
 238             {
 239                 m_WParser->CloseContainer();
 240                 m_WParser->OpenContainer();
 241                 c = m_WParser->GetContainer();
 242                 c->SetAlign(tag);
 243                 m_WParser->SetAlign(c->GetAlignHor());
 244             }
 245             else
 246             {
 247                 c->SetAlign(tag);
 248                 m_WParser->SetAlign(c->GetAlignHor());
 249             }
 250
 251             ParseInner(tag);
 252
 253             m_WParser->SetAlign(old);
 254             if (c->GetFirstChild() != NULL)
 255             {
 256                 m_WParser->CloseContainer();
 257                 m_WParser->OpenContainer();
 258             }
 259             else
 260                 c->SetAlignHor(old);
 261
 262             return true;
 263         }
 264         else
 265         {
 266             // Same as BR
 267             int al = m_WParser->GetContainer()->GetAlignHor();
 268             wxHtmlContainerCell *c;
 269
 270             m_WParser->CloseContainer();
 271             c = m_WParser->OpenContainer();
 272             c->SetAlignHor(al);
 273             c->SetAlign(tag);
 274             c->SetMinHeight(m_WParser->GetCharHeight());
 275             return false;
 276         }
 277     }
 278
 279 TAG_HANDLER_END(DIV)
 280
 281
 282
 283
 284 TAG_HANDLER_BEGIN(TITLE, "TITLE")
 285     TAG_HANDLER_CONSTR(TITLE) { }
 286
 287     TAG_HANDLER_PROC(tag)
 288     {
 289         wxHtmlWindowInterface *winIface = m_WParser->GetWindowInterface();
 290         if (winIface)
 291         {
 292             wxString title = m_WParser->GetSource()->Mid(
 293                                     tag.GetBeginPos(),
 294                                     tag.GetEndPos1()-tag.GetBeginPos());
 295 #if !wxUSE_UNICODE && wxUSE_WCHAR_T
 296             const wxFontEncoding enc = m_WParser->GetInputEncoding();
 297             if ( enc != wxFONTENCODING_DEFAULT )
 298             {
 299                 // need to convert to the current one
 300                 title = wxString(title.wc_str(wxCSConv(enc)), wxConvLocal);
 301             }
 302 #endif // !wxUSE_UNICODE
 303
 304             title = m_WParser->GetEntitiesParser()->Parse(title);
 305
 306             winIface->SetHTMLWindowTitle(title);
 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         wxHtmlWindowInterface *winIface = m_WParser->GetWindowInterface();
 333         // the rest of this function requires a window:
 334         if ( !winIface )
 335             return false;
 336
 337         if (tag.HasParam(wxT("BACKGROUND")))
 338         {
 339             wxFSFile *fileBgImage = m_WParser->OpenURL
 340                                                (
 341                                                 wxHTML_URL_IMAGE,
 342                                                 tag.GetParam(wxT("BACKGROUND"))
 343                                                );
 344             if ( fileBgImage )
 345             {
 346                 wxInputStream *is = fileBgImage->GetStream();
 347                 if ( is )
 348                 {
 349 #if !defined(__WXMSW__) || wxUSE_WXDIB
 350                     wxImage image(*is);
 351                     if ( image.Ok() )
 352                         winIface->SetHTMLBackgroundImage(image);
 353 #endif
 354                 }
 355             }
 356         }
 357
 358         if (tag.GetParamAsColour(wxT("BGCOLOR"), &clr))
 359         {
 360             m_WParser->GetContainer()->InsertCell(
 361                 new wxHtmlColourCell(clr, wxHTML_CLR_BACKGROUND));
 362             winIface->SetHTMLBackgroundColour(clr);
 363         }
 364
 365         return false;
 366     }
 367
 368 TAG_HANDLER_END(BODY)
 369
 370
 371
 372 TAG_HANDLER_BEGIN(BLOCKQUOTE, "BLOCKQUOTE")
 373     TAG_HANDLER_CONSTR(BLOCKQUOTE) { }
 374
 375     TAG_HANDLER_PROC(tag)
 376     {
 377         wxHtmlContainerCell *c;
 378
 379         m_WParser->CloseContainer();
 380         c = m_WParser->OpenContainer();
 381
 382         if (c->GetAlignHor() == wxHTML_ALIGN_RIGHT)
 383             c->SetIndent(5 * m_WParser->GetCharWidth(), wxHTML_INDENT_RIGHT);
 384         else
 385             c->SetIndent(5 * m_WParser->GetCharWidth(), wxHTML_INDENT_LEFT);
 386
 387         c->SetIndent(m_WParser->GetCharHeight(), wxHTML_INDENT_TOP);
 388         m_WParser->OpenContainer();
 389         ParseInner(tag);
 390         c = m_WParser->CloseContainer();
 391         c->SetIndent(m_WParser->GetCharHeight(), wxHTML_INDENT_BOTTOM);
 392         m_WParser->CloseContainer();
 393         m_WParser->OpenContainer();
 394         return true;
 395     }
 396
 397 TAG_HANDLER_END(BLOCKQUOTE)
 398
 399
 400
 401 TAG_HANDLER_BEGIN(SUBSUP, "SUB,SUP")
 402
 403     TAG_HANDLER_PROC(tag)
 404     {
 405         bool issub = (tag.GetName() == wxT("SUB"));
 406         wxHtmlScriptMode oldmode = m_WParser->GetScriptMode();
 407         int oldbase = m_WParser->GetScriptBaseline();
 408         int oldsize = m_WParser->GetFontSize();
 409
 410         wxHtmlContainerCell *cont = m_WParser->GetContainer();
 411         wxHtmlCell *c = cont->GetLastChild();
 412
 413         m_WParser->SetScriptMode(issub ? wxHTML_SCRIPT_SUB : wxHTML_SCRIPT_SUP);
 414         m_WParser->SetScriptBaseline(
 415                 oldbase + c ? c->GetScriptBaseline() : 0);
 416
 417         // select smaller font
 418         m_WParser->SetFontSize(m_WParser->GetFontSize()-2);
 419         cont->InsertCell(new wxHtmlFontCell(m_WParser->CreateCurrentFont()));
 420
 421         ParseInner(tag);
 422
 423         // restore font size
 424         m_WParser->SetFontSize(oldsize);
 425         m_WParser->GetContainer()->InsertCell(
 426             new wxHtmlFontCell(m_WParser->CreateCurrentFont()));
 427
 428         // restore base and alignment
 429         m_WParser->SetScriptBaseline(oldbase);
 430         m_WParser->SetScriptMode(oldmode);
 431
 432         return true;
 433     }
 434
 435 TAG_HANDLER_END(SUBSUP)
 436
 437
 438 // Tag handler for tags that we have to ignore, otherwise non-text data
 439 // would show up as text:
 440 TAG_HANDLER_BEGIN(DoNothing, "SCRIPT")
 441     TAG_HANDLER_CONSTR(DoNothing) { }
 442
 443     TAG_HANDLER_PROC(WXUNUSED(tag))
 444     {
 445         return true;
 446     }
 447 TAG_HANDLER_END(DoNothing)
 448
 449
 450
 451
 452
 453 TAGS_MODULE_BEGIN(Layout)
 454
 455     TAGS_MODULE_ADD(P)
 456     TAGS_MODULE_ADD(BR)
 457     TAGS_MODULE_ADD(CENTER)
 458     TAGS_MODULE_ADD(DIV)
 459     TAGS_MODULE_ADD(TITLE)
 460     TAGS_MODULE_ADD(BODY)
 461     TAGS_MODULE_ADD(BLOCKQUOTE)
 462     TAGS_MODULE_ADD(SUBSUP)
 463     TAGS_MODULE_ADD(DoNothing)
 464
 465 TAGS_MODULE_END(Layout)
 466
 467 #endif