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             wxCSConv conv(m_WParser->GetInputEncoding());
 297             title = wxString(title.wc_str(conv), wxConvLocal);
 298 #endif
 299             title = m_WParser->GetEntitiesParser()->Parse(title);
 300
 301             winIface->SetHTMLWindowTitle(title);
 302         }
 303         return true;
 304     }
 305
 306 TAG_HANDLER_END(TITLE)
 307
 308
 309
 310
 311 TAG_HANDLER_BEGIN(BODY, "BODY")
 312     TAG_HANDLER_CONSTR(BODY) { }
 313
 314     TAG_HANDLER_PROC(tag)
 315     {
 316         wxColour clr;
 317
 318         if (tag.GetParamAsColour(wxT("TEXT"), &clr))
 319         {
 320             m_WParser->SetActualColor(clr);
 321             m_WParser->GetContainer()->InsertCell(new wxHtmlColourCell(clr));
 322         }
 323
 324         if (tag.GetParamAsColour(wxT("LINK"), &clr))
 325             m_WParser->SetLinkColor(clr);
 326
 327         wxHtmlWindowInterface *winIface = m_WParser->GetWindowInterface();
 328         // the rest of this function requires a window:
 329         if ( !winIface )
 330             return false;
 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 #if !defined(__WXMSW__) || wxUSE_WXDIB
 345                     wxImage image(*is);
 346                     if ( image.Ok() )
 347                         winIface->SetHTMLBackgroundImage(image);
 348 #endif
 349                 }
 350             }
 351         }
 352
 353         if (tag.GetParamAsColour(wxT("BGCOLOR"), &clr))
 354         {
 355             m_WParser->GetContainer()->InsertCell(
 356                 new wxHtmlColourCell(clr, wxHTML_CLR_BACKGROUND));
 357             winIface->SetHTMLBackgroundColour(clr);
 358         }
 359
 360         return false;
 361     }
 362
 363 TAG_HANDLER_END(BODY)
 364
 365
 366
 367 TAG_HANDLER_BEGIN(BLOCKQUOTE, "BLOCKQUOTE")
 368     TAG_HANDLER_CONSTR(BLOCKQUOTE) { }
 369
 370     TAG_HANDLER_PROC(tag)
 371     {
 372         wxHtmlContainerCell *c;
 373
 374         m_WParser->CloseContainer();
 375         c = m_WParser->OpenContainer();
 376
 377         if (c->GetAlignHor() == wxHTML_ALIGN_RIGHT)
 378             c->SetIndent(5 * m_WParser->GetCharWidth(), wxHTML_INDENT_RIGHT);
 379         else
 380             c->SetIndent(5 * m_WParser->GetCharWidth(), wxHTML_INDENT_LEFT);
 381
 382         c->SetIndent(m_WParser->GetCharHeight(), wxHTML_INDENT_TOP);
 383         m_WParser->OpenContainer();
 384         ParseInner(tag);
 385         c = m_WParser->CloseContainer();
 386         c->SetIndent(m_WParser->GetCharHeight(), wxHTML_INDENT_BOTTOM);
 387         m_WParser->CloseContainer();
 388         m_WParser->OpenContainer();
 389         return true;
 390     }
 391
 392 TAG_HANDLER_END(BLOCKQUOTE)
 393
 394
 395
 396 TAG_HANDLER_BEGIN(SUBSUP, "SUB,SUP")
 397
 398     TAG_HANDLER_PROC(tag)
 399     {
 400         bool issub = (tag.GetName() == wxT("SUB"));
 401         wxHtmlScriptMode oldmode = m_WParser->GetScriptMode();
 402         int oldbase = m_WParser->GetScriptBaseline();
 403         int oldsize = m_WParser->GetFontSize();
 404
 405         wxHtmlContainerCell *cont = m_WParser->GetContainer();
 406         wxHtmlCell *c = cont->GetLastChild();
 407
 408         m_WParser->SetScriptMode(issub ? wxHTML_SCRIPT_SUB : wxHTML_SCRIPT_SUP);
 409         m_WParser->SetScriptBaseline(oldbase + c->GetScriptBaseline());
 410
 411         // select smaller font
 412         m_WParser->SetFontSize(m_WParser->GetFontSize()-2);
 413         cont->InsertCell(new wxHtmlFontCell(m_WParser->CreateCurrentFont()));
 414
 415         ParseInner(tag);
 416
 417         // restore font size
 418         m_WParser->SetFontSize(oldsize);
 419         m_WParser->GetContainer()->InsertCell(
 420             new wxHtmlFontCell(m_WParser->CreateCurrentFont()));
 421
 422         // restore base and alignment
 423         m_WParser->SetScriptBaseline(oldbase);
 424         m_WParser->SetScriptMode(oldmode);
 425
 426         return true;
 427     }
 428
 429 TAG_HANDLER_END(SUBSUP)
 430
 431
 432 // Tag handler for tags that we have to ignore, otherwise non-text data
 433 // would show up as text:
 434 TAG_HANDLER_BEGIN(DoNothing, "SCRIPT")
 435     TAG_HANDLER_CONSTR(DoNothing) { }
 436
 437     TAG_HANDLER_PROC(WXUNUSED(tag))
 438     {
 439         return true;
 440     }
 441 TAG_HANDLER_END(DoNothing)
 442
 443
 444
 445
 446
 447 TAGS_MODULE_BEGIN(Layout)
 448
 449     TAGS_MODULE_ADD(P)
 450     TAGS_MODULE_ADD(BR)
 451     TAGS_MODULE_ADD(CENTER)
 452     TAGS_MODULE_ADD(DIV)
 453     TAGS_MODULE_ADD(TITLE)
 454     TAGS_MODULE_ADD(BODY)
 455     TAGS_MODULE_ADD(BLOCKQUOTE)
 456     TAGS_MODULE_ADD(SUBSUP)
 457     TAGS_MODULE_ADD(DoNothing)
 458
 459 TAGS_MODULE_END(Layout)
 460
 461 #endif