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 #endif
  20
  21 #include "wx/image.h"
  22
  23 #include "wx/html/forcelnk.h"
  24 #include "wx/html/m_templ.h"
  25
  26 #include "wx/html/htmlwin.h"
  27
  28 FORCE_LINK_ME(m_layout)
  29
  30 #ifdef __WXWINCE__
  31     #include "wx/msw/wince/missing.h"       // for bsearch()
  32 #else
  33     #include <stdlib.h>                     // bsearch()
  34 #endif
  35
  36 //-----------------------------------------------------------------------------
  37 // wxHtmlPageBreakCell
  38 //-----------------------------------------------------------------------------
  39
  40 // Since html isn't a page-layout language, it doesn't support page
  41 // page breaks directly--that requires CSS2 support. But a page-break
  42 // facility is handy, and has been requested more than once on the
  43 // mailing lists. This wxHtml tag handler implements just enough of
  44 // CSS2 to support a page break by recognizing only
  45 //   <div style="page-break-before:always">
  46 //
  47 // wxHtml maintains page breaks in wxHtmlPrintout::m_PageBreaks. The
  48 // tag handler below adds appropriate offsets to that array member.
  49 // wxHtmlDCRenderer::Render() accesses that array and makes a new page
  50 // begin after each page-break tag.
  51
  52 // The page-break handler does all its work in AdjustPagebreak(). For
  53 // all tag handlers, that function adjusts the page-break position.
  54 // For other tags, it determines whether the html element can fit on
  55 // the remainder of the page; if it cannot fit, but must not be split,
  56 // then the function moves the page break provided in the argument up,
  57 // and returns 'true' to inform the caller that the argument was
  58 // modified.
  59 //
  60 // Due to its special purpose, the page-break facility differs from
  61 // other tags. It takes up no space, but it behaves as though there is
  62 // never enough room to fit it on the remainder of the page--it always
  63 // forces a page break. Therefore, unlike other elements that trigger
  64 // a page break, it would never 'fit' on the following page either.
  65 // Therefore it's necessary to compare each pagebreak candidate to the
  66 // array wxHtmlPrintout::m_PageBreaks of pagebreaks already set, and
  67 // set a new one only if it's not in that array.
  68
  69 class wxHtmlPageBreakCell : public wxHtmlCell
  70 {
  71 public:
  72     wxHtmlPageBreakCell() {}
  73
  74     bool AdjustPagebreak(int* pagebreak,
  75                          wxArrayInt& known_pagebreaks) const;
  76
  77     void Draw(wxDC& WXUNUSED(dc),
  78               int WXUNUSED(x), int WXUNUSED(y),
  79               int WXUNUSED(view_y1), int WXUNUSED(view_y2),
  80               wxHtmlRenderingInfo& WXUNUSED(info)) {}
  81
  82 private:
  83     DECLARE_NO_COPY_CLASS(wxHtmlPageBreakCell)
  84 };
  85
  86 // Comparison routine for bsearch into an int* array of pagebreaks.
  87 extern "C" int wxCMPFUNC_CONV wxInteger_compare(void const* i0, void const* i1)
  88 {
  89     return *(int*)i0 - *(int*)i1;
  90 }
  91
  92 bool wxHtmlPageBreakCell::AdjustPagebreak(int* pagebreak, wxArrayInt& known_pagebreaks) const
  93 {
  94     // When we are counting pages, 'known_pagebreaks' is non-NULL.
  95     // That's the only time we change 'pagebreak'. Otherwise, pages
  96     // were already counted, 'known_pagebreaks' is NULL, and we don't
  97     // do anything except return false.
  98     //
  99     // We also simply return false if the 'pagebreak' argument is
 100     // less than (vertically above) or the same as the current
 101     // vertical position. Otherwise we'd be setting a pagebreak above
 102     // the current cell, which is incorrect, or duplicating a
 103     // pagebreak that has already been set.
 104     if( known_pagebreaks.Count() == 0 || *pagebreak <= m_PosY)
 105     {
 106         return false;
 107     }
 108
 109     // m_PosY is only the vertical offset from the parent. The pagebreak
 110     // required here is the total page offset, so m_PosY must be added
 111     // to the parent's offset and height.
 112     int total_height = m_PosY + GetParent()->GetPosY() + GetParent()->GetHeight();
 113
 114     // Search the array of pagebreaks to see whether we've already set
 115     // a pagebreak here. The standard bsearch() function is appropriate
 116     // because the array of pagebreaks through known_pagebreaks[number_of_pages]
 117     // is known to be sorted in strictly increasing order. '1 + number_of_pages'
 118     // is used as a bsearch() argument because the array contains a leading
 119     // zero plus one element for each page.
 120     int where = known_pagebreaks.Index( total_height);
 121     // Add a pagebreak only if there isn't one already set here.
 122     if( wxNOT_FOUND != where)
 123     {
 124         return false;
 125     }
 126     else
 127     {
 128         *pagebreak = m_PosY;
 129         return true;
 130     }
 131 }
 132
 133
 134
 135 TAG_HANDLER_BEGIN(P, "P")
 136     TAG_HANDLER_CONSTR(P) { }
 137
 138     TAG_HANDLER_PROC(tag)
 139     {
 140         if (m_WParser->GetContainer()->GetFirstChild() != NULL)
 141         {
 142             m_WParser->CloseContainer();
 143             m_WParser->OpenContainer();
 144         }
 145         m_WParser->GetContainer()->SetIndent(m_WParser->GetCharHeight(), wxHTML_INDENT_TOP);
 146         m_WParser->GetContainer()->SetAlign(tag);
 147         return false;
 148     }
 149
 150 TAG_HANDLER_END(P)
 151
 152
 153
 154 TAG_HANDLER_BEGIN(BR, "BR")
 155     TAG_HANDLER_CONSTR(BR) { }
 156
 157     TAG_HANDLER_PROC(tag)
 158     {
 159         int al = m_WParser->GetContainer()->GetAlignHor();
 160         wxHtmlContainerCell *c;
 161
 162         m_WParser->CloseContainer();
 163         c = m_WParser->OpenContainer();
 164         c->SetAlignHor(al);
 165         c->SetAlign(tag);
 166         c->SetMinHeight(m_WParser->GetCharHeight());
 167         return false;
 168     }
 169
 170 TAG_HANDLER_END(BR)
 171
 172
 173
 174 TAG_HANDLER_BEGIN(CENTER, "CENTER")
 175     TAG_HANDLER_CONSTR(CENTER) { }
 176
 177     TAG_HANDLER_PROC(tag)
 178     {
 179         int old = m_WParser->GetAlign();
 180         wxHtmlContainerCell *c = m_WParser->GetContainer();
 181
 182         m_WParser->SetAlign(wxHTML_ALIGN_CENTER);
 183         if (c->GetFirstChild() != NULL)
 184         {
 185             m_WParser->CloseContainer();
 186             m_WParser->OpenContainer();
 187         }
 188         else
 189             c->SetAlignHor(wxHTML_ALIGN_CENTER);
 190
 191         if (tag.HasEnding())
 192         {
 193             ParseInner(tag);
 194
 195             m_WParser->SetAlign(old);
 196             if (c->GetFirstChild() != NULL)
 197             {
 198                 m_WParser->CloseContainer();
 199                 m_WParser->OpenContainer();
 200             }
 201             else
 202                 c->SetAlignHor(old);
 203
 204             return true;
 205         }
 206         else return false;
 207     }
 208
 209 TAG_HANDLER_END(CENTER)
 210
 211
 212
 213 TAG_HANDLER_BEGIN(DIV, "DIV")
 214     TAG_HANDLER_CONSTR(DIV) { }
 215
 216     TAG_HANDLER_PROC(tag)
 217     {
 218         if(tag.HasParam(wxT("STYLE")))
 219         {
 220             if(tag.GetParam(wxT("STYLE")).IsSameAs(wxT("PAGE-BREAK-BEFORE:ALWAYS"), false))
 221             {
 222                 m_WParser->CloseContainer();
 223                 m_WParser->OpenContainer()->InsertCell(new wxHtmlPageBreakCell);
 224                 m_WParser->CloseContainer();
 225                 m_WParser->OpenContainer();
 226                 return false;
 227             }
 228             else
 229             {
 230                 // Treat other STYLE parameters here when they're supported.
 231                 return false;
 232             }
 233         }
 234         else if(tag.HasParam(wxT("ALIGN")))
 235         {
 236             int old = m_WParser->GetAlign();
 237             wxHtmlContainerCell *c = m_WParser->GetContainer();
 238             if (c->GetFirstChild() != NULL)
 239             {
 240                 m_WParser->CloseContainer();
 241                 m_WParser->OpenContainer();
 242                 c = m_WParser->GetContainer();
 243                 c->SetAlign(tag);
 244                 m_WParser->SetAlign(c->GetAlignHor());
 245             }
 246             else
 247             {
 248                 c->SetAlign(tag);
 249                 m_WParser->SetAlign(c->GetAlignHor());
 250             }
 251
 252             ParseInner(tag);
 253
 254             m_WParser->SetAlign(old);
 255             if (c->GetFirstChild() != NULL)
 256             {
 257                 m_WParser->CloseContainer();
 258                 m_WParser->OpenContainer();
 259             }
 260             else
 261                 c->SetAlignHor(old);
 262
 263             return true;
 264         }
 265         else
 266         {
 267             // Same as BR
 268             int al = m_WParser->GetContainer()->GetAlignHor();
 269             wxHtmlContainerCell *c;
 270
 271             m_WParser->CloseContainer();
 272             c = m_WParser->OpenContainer();
 273             c->SetAlignHor(al);
 274             c->SetAlign(tag);
 275             c->SetMinHeight(m_WParser->GetCharHeight());
 276             return false;
 277         }
 278     }
 279
 280 TAG_HANDLER_END(DIV)
 281
 282
 283
 284
 285 TAG_HANDLER_BEGIN(TITLE, "TITLE")
 286     TAG_HANDLER_CONSTR(TITLE) { }
 287
 288     TAG_HANDLER_PROC(tag)
 289     {
 290         wxHtmlWindowInterface *winIface = m_WParser->GetWindowInterface();
 291         if (winIface)
 292         {
 293             wxString title = m_WParser->GetSource()->Mid(
 294                                     tag.GetBeginPos(),
 295                                     tag.GetEndPos1()-tag.GetBeginPos());
 296 #if !wxUSE_UNICODE && wxUSE_WCHAR_T
 297             wxCSConv conv(m_WParser->GetInputEncoding());
 298             title = wxString(title.wc_str(conv), wxConvLocal);
 299 #endif
 300             title = m_WParser->GetEntitiesParser()->Parse(title);
 301
 302             winIface->SetHTMLWindowTitle(title);
 303         }
 304         return true;
 305     }
 306
 307 TAG_HANDLER_END(TITLE)
 308
 309
 310
 311
 312 TAG_HANDLER_BEGIN(BODY, "BODY")
 313     TAG_HANDLER_CONSTR(BODY) { }
 314
 315     TAG_HANDLER_PROC(tag)
 316     {
 317         wxColour clr;
 318
 319         if (tag.GetParamAsColour(wxT("TEXT"), &clr))
 320         {
 321             m_WParser->SetActualColor(clr);
 322             m_WParser->GetContainer()->InsertCell(new wxHtmlColourCell(clr));
 323         }
 324
 325         if (tag.GetParamAsColour(wxT("LINK"), &clr))
 326             m_WParser->SetLinkColor(clr);
 327
 328         wxHtmlWindowInterface *winIface = m_WParser->GetWindowInterface();
 329         // the rest of this function requires a window:
 330         if ( !winIface )
 331             return false;
 332
 333         if (tag.HasParam(wxT("BACKGROUND")))
 334         {
 335             wxFSFile *fileBgImage = m_WParser->OpenURL
 336                                                (
 337                                                 wxHTML_URL_IMAGE,
 338                                                 tag.GetParam(wxT("BACKGROUND"))
 339                                                );
 340             if ( fileBgImage )
 341             {
 342                 wxInputStream *is = fileBgImage->GetStream();
 343                 if ( is )
 344                 {
 345 #if !defined(__WXMSW__) || wxUSE_WXDIB
 346                     wxImage image(*is);
 347                     if ( image.Ok() )
 348                         winIface->SetHTMLBackgroundImage(image);
 349 #endif
 350                 }
 351             }
 352         }
 353
 354         if (tag.GetParamAsColour(wxT("BGCOLOR"), &clr))
 355         {
 356             m_WParser->GetContainer()->InsertCell(
 357                 new wxHtmlColourCell(clr, wxHTML_CLR_BACKGROUND));
 358             winIface->SetHTMLBackgroundColour(clr);
 359         }
 360
 361         return false;
 362     }
 363
 364 TAG_HANDLER_END(BODY)
 365
 366
 367
 368 TAG_HANDLER_BEGIN(BLOCKQUOTE, "BLOCKQUOTE")
 369     TAG_HANDLER_CONSTR(BLOCKQUOTE) { }
 370
 371     TAG_HANDLER_PROC(tag)
 372     {
 373         wxHtmlContainerCell *c;
 374
 375         m_WParser->CloseContainer();
 376         c = m_WParser->OpenContainer();
 377
 378         if (c->GetAlignHor() == wxHTML_ALIGN_RIGHT)
 379             c->SetIndent(5 * m_WParser->GetCharWidth(), wxHTML_INDENT_RIGHT);
 380         else
 381             c->SetIndent(5 * m_WParser->GetCharWidth(), wxHTML_INDENT_LEFT);
 382
 383         c->SetIndent(m_WParser->GetCharHeight(), wxHTML_INDENT_TOP);
 384         m_WParser->OpenContainer();
 385         ParseInner(tag);
 386         c = m_WParser->CloseContainer();
 387         c->SetIndent(m_WParser->GetCharHeight(), wxHTML_INDENT_BOTTOM);
 388         m_WParser->CloseContainer();
 389         m_WParser->OpenContainer();
 390         return true;
 391     }
 392
 393 TAG_HANDLER_END(BLOCKQUOTE)
 394
 395
 396
 397 TAG_HANDLER_BEGIN(SUBSUP, "SUB,SUP")
 398
 399     TAG_HANDLER_PROC(tag)
 400     {
 401         bool issub = (tag.GetName() == wxT("SUB"));
 402         wxHtmlScriptMode oldmode = m_WParser->GetScriptMode();
 403         int oldbase = m_WParser->GetScriptBaseline();
 404         int oldsize = m_WParser->GetFontSize();
 405
 406         wxHtmlContainerCell *cont = m_WParser->GetContainer();
 407         wxHtmlCell *c = cont->GetLastChild();
 408
 409         m_WParser->SetScriptMode(issub ? wxHTML_SCRIPT_SUB : wxHTML_SCRIPT_SUP);
 410         m_WParser->SetScriptBaseline(oldbase + c->GetScriptBaseline());
 411
 412         // select smaller font
 413         m_WParser->SetFontSize(m_WParser->GetFontSize()-2);
 414         cont->InsertCell(new wxHtmlFontCell(m_WParser->CreateCurrentFont()));
 415
 416         ParseInner(tag);
 417
 418         // restore font size
 419         m_WParser->SetFontSize(oldsize);
 420         m_WParser->GetContainer()->InsertCell(
 421             new wxHtmlFontCell(m_WParser->CreateCurrentFont()));
 422
 423         // restore base and alignment
 424         m_WParser->SetScriptBaseline(oldbase);
 425         m_WParser->SetScriptMode(oldmode);
 426
 427         return true;
 428     }
 429
 430 TAG_HANDLER_END(SUBSUP)
 431
 432
 433 // Tag handler for tags that we have to ignore, otherwise non-text data
 434 // would show up as text:
 435 TAG_HANDLER_BEGIN(DoNothing, "SCRIPT")
 436     TAG_HANDLER_CONSTR(DoNothing) { }
 437
 438     TAG_HANDLER_PROC(WXUNUSED(tag))
 439     {
 440         return true;
 441     }
 442 TAG_HANDLER_END(DoNothing)
 443
 444
 445
 446
 447
 448 TAGS_MODULE_BEGIN(Layout)
 449
 450     TAGS_MODULE_ADD(P)
 451     TAGS_MODULE_ADD(BR)
 452     TAGS_MODULE_ADD(CENTER)
 453     TAGS_MODULE_ADD(DIV)
 454     TAGS_MODULE_ADD(TITLE)
 455     TAGS_MODULE_ADD(BODY)
 456     TAGS_MODULE_ADD(BLOCKQUOTE)
 457     TAGS_MODULE_ADD(SUBSUP)
 458     TAGS_MODULE_ADD(DoNothing)
 459
 460 TAGS_MODULE_END(Layout)
 461
 462 #endif