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 WX_PRECOMP
  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                          const wxArrayInt& known_pagebreaks,
  75                          int pageHeight) 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     wxDECLARE_NO_COPY_CLASS(wxHtmlPageBreakCell);
  84 };
  85
  86 bool
  87 wxHtmlPageBreakCell::AdjustPagebreak(int* pagebreak,
  88                                      const wxArrayInt& known_pagebreaks,
  89                                      int WXUNUSED(pageHeight)) const
  90 {
  91     // When we are counting pages, 'known_pagebreaks' is non-NULL.
  92     // That's the only time we change 'pagebreak'. Otherwise, pages
  93     // were already counted, 'known_pagebreaks' is NULL, and we don't
  94     // do anything except return false.
  95     //
  96     // We also simply return false if the 'pagebreak' argument is
  97     // less than (vertically above) or the same as the current
  98     // vertical position. Otherwise we'd be setting a pagebreak above
  99     // the current cell, which is incorrect, or duplicating a
 100     // pagebreak that has already been set.
 101     if( known_pagebreaks.GetCount() == 0 || *pagebreak <= m_PosY)
 102     {
 103         return false;
 104     }
 105
 106     // m_PosY is only the vertical offset from the parent. The pagebreak
 107     // required here is the total page offset, so m_PosY must be added
 108     // to the parent's offset and height.
 109     int total_height = m_PosY;
 110     for ( wxHtmlCell *parent = GetParent(); parent; parent = parent->GetParent() )
 111     {
 112         total_height += parent->GetPosY();
 113     }
 114
 115
 116     // Search the array of pagebreaks to see whether we've already set
 117     // a pagebreak here.
 118     int where = known_pagebreaks.Index( total_height);
 119     // Add a pagebreak only if there isn't one already set here.
 120     if( wxNOT_FOUND != where)
 121     {
 122         return false;
 123     }
 124     else
 125     {
 126         *pagebreak = m_PosY;
 127         return true;
 128     }
 129 }
 130
 131
 132
 133 TAG_HANDLER_BEGIN(P, "P")
 134     TAG_HANDLER_CONSTR(P) { }
 135
 136     TAG_HANDLER_PROC(tag)
 137     {
 138         if (m_WParser->GetContainer()->GetFirstChild() != NULL)
 139         {
 140             m_WParser->CloseContainer();
 141             m_WParser->OpenContainer();
 142         }
 143         m_WParser->GetContainer()->SetIndent(m_WParser->GetCharHeight(), wxHTML_INDENT_TOP);
 144         m_WParser->GetContainer()->SetAlign(tag);
 145         return false;
 146     }
 147
 148 TAG_HANDLER_END(P)
 149
 150
 151
 152 TAG_HANDLER_BEGIN(BR, "BR")
 153     TAG_HANDLER_CONSTR(BR) { }
 154
 155     TAG_HANDLER_PROC(tag)
 156     {
 157         int al = m_WParser->GetContainer()->GetAlignHor();
 158         wxHtmlContainerCell *c;
 159
 160         m_WParser->CloseContainer();
 161         c = m_WParser->OpenContainer();
 162         c->SetAlignHor(al);
 163         c->SetAlign(tag);
 164         c->SetMinHeight(m_WParser->GetCharHeight());
 165         return false;
 166     }
 167
 168 TAG_HANDLER_END(BR)
 169
 170
 171
 172 TAG_HANDLER_BEGIN(CENTER, "CENTER")
 173     TAG_HANDLER_CONSTR(CENTER) { }
 174
 175     TAG_HANDLER_PROC(tag)
 176     {
 177         int old = m_WParser->GetAlign();
 178         wxHtmlContainerCell *c = m_WParser->GetContainer();
 179
 180         m_WParser->SetAlign(wxHTML_ALIGN_CENTER);
 181         if (c->GetFirstChild() != NULL)
 182         {
 183             m_WParser->CloseContainer();
 184             m_WParser->OpenContainer();
 185         }
 186         else
 187             c->SetAlignHor(wxHTML_ALIGN_CENTER);
 188
 189         if (tag.HasEnding())
 190         {
 191             ParseInner(tag);
 192
 193             m_WParser->SetAlign(old);
 194             if (c->GetFirstChild() != NULL)
 195             {
 196                 m_WParser->CloseContainer();
 197                 m_WParser->OpenContainer();
 198             }
 199             else
 200                 c->SetAlignHor(old);
 201
 202             return true;
 203         }
 204         else return false;
 205     }
 206
 207 TAG_HANDLER_END(CENTER)
 208
 209
 210
 211 TAG_HANDLER_BEGIN(DIV, "DIV")
 212     TAG_HANDLER_CONSTR(DIV) { }
 213
 214     TAG_HANDLER_PROC(tag)
 215     {
 216         if(tag.HasParam(wxT("STYLE")))
 217         {
 218             if(tag.GetParam(wxT("STYLE")).IsSameAs(wxT("PAGE-BREAK-BEFORE:ALWAYS"), false))
 219             {
 220                 m_WParser->CloseContainer();
 221                 m_WParser->OpenContainer()->InsertCell(new wxHtmlPageBreakCell);
 222                 m_WParser->CloseContainer();
 223                 m_WParser->OpenContainer();
 224                 return false;
 225             }
 226             else
 227             {
 228                 // Treat other STYLE parameters here when they're supported.
 229                 return false;
 230             }
 231         }
 232         else if(tag.HasParam(wxT("ALIGN")))
 233         {
 234             int old = m_WParser->GetAlign();
 235             wxHtmlContainerCell *c = m_WParser->GetContainer();
 236             if (c->GetFirstChild() != NULL)
 237             {
 238                 m_WParser->CloseContainer();
 239                 m_WParser->OpenContainer();
 240                 c = m_WParser->GetContainer();
 241                 c->SetAlign(tag);
 242                 m_WParser->SetAlign(c->GetAlignHor());
 243             }
 244             else
 245             {
 246                 c->SetAlign(tag);
 247                 m_WParser->SetAlign(c->GetAlignHor());
 248             }
 249
 250             ParseInner(tag);
 251
 252             m_WParser->SetAlign(old);
 253             if (c->GetFirstChild() != NULL)
 254             {
 255                 m_WParser->CloseContainer();
 256                 m_WParser->OpenContainer();
 257             }
 258             else
 259                 c->SetAlignHor(old);
 260
 261             return true;
 262         }
 263         else
 264         {
 265             // Same as BR
 266             int al = m_WParser->GetContainer()->GetAlignHor();
 267             wxHtmlContainerCell *c;
 268
 269             m_WParser->CloseContainer();
 270             c = m_WParser->OpenContainer();
 271             c->SetAlignHor(al);
 272             c->SetAlign(tag);
 273             c->SetMinHeight(m_WParser->GetCharHeight());
 274             return false;
 275         }
 276     }
 277
 278 TAG_HANDLER_END(DIV)
 279
 280
 281
 282
 283 TAG_HANDLER_BEGIN(TITLE, "TITLE")
 284     TAG_HANDLER_CONSTR(TITLE) { }
 285
 286     TAG_HANDLER_PROC(tag)
 287     {
 288         wxHtmlWindowInterface *winIface = m_WParser->GetWindowInterface();
 289         if (winIface)
 290         {
 291             wxString title(tag.GetBeginIter(), tag.GetEndIter1());
 292 #if !wxUSE_UNICODE
 293             const wxFontEncoding enc = m_WParser->GetInputEncoding();
 294             if ( enc != wxFONTENCODING_DEFAULT )
 295             {
 296                 // need to convert to the current one
 297                 title = wxString(title.wc_str(wxCSConv(enc)), wxConvLocal);
 298             }
 299 #endif // !wxUSE_UNICODE
 300
 301             title = m_WParser->GetEntitiesParser()->Parse(title);
 302
 303             winIface->SetHTMLWindowTitle(title);
 304         }
 305         return true;
 306     }
 307
 308 TAG_HANDLER_END(TITLE)
 309
 310
 311
 312
 313 TAG_HANDLER_BEGIN(BODY, "BODY")
 314     TAG_HANDLER_CONSTR(BODY) { }
 315
 316     TAG_HANDLER_PROC(tag)
 317     {
 318         wxColour clr;
 319
 320         if (tag.GetParamAsColour(wxT("TEXT"), &clr))
 321         {
 322             m_WParser->SetActualColor(clr);
 323             m_WParser->GetContainer()->InsertCell(new wxHtmlColourCell(clr));
 324         }
 325
 326         if (tag.GetParamAsColour(wxT("LINK"), &clr))
 327             m_WParser->SetLinkColor(clr);
 328
 329         wxHtmlWindowInterface *winIface = m_WParser->GetWindowInterface();
 330         // the rest of this function requires a window:
 331         if ( !winIface )
 332             return false;
 333
 334         if (tag.HasParam(wxT("BACKGROUND")))
 335         {
 336             wxFSFile *fileBgImage = m_WParser->OpenURL
 337                                                (
 338                                                 wxHTML_URL_IMAGE,
 339                                                 tag.GetParam(wxT("BACKGROUND"))
 340                                                );
 341             if ( fileBgImage )
 342             {
 343                 wxInputStream *is = fileBgImage->GetStream();
 344                 if ( is )
 345                 {
 346                     wxImage image(*is);
 347                     if ( image.IsOk() )
 348                         winIface->SetHTMLBackgroundImage(image);
 349                 }
 350
 351                 delete fileBgImage;
 352             }
 353         }
 354
 355         if (tag.GetParamAsColour(wxT("BGCOLOR"), &clr))
 356         {
 357             m_WParser->GetContainer()->InsertCell(
 358                 new wxHtmlColourCell(clr, wxHTML_CLR_TRANSPARENT_BACKGROUND));
 359             winIface->SetHTMLBackgroundColour(clr);
 360         }
 361
 362         return false;
 363     }
 364
 365 TAG_HANDLER_END(BODY)
 366
 367
 368
 369 TAG_HANDLER_BEGIN(BLOCKQUOTE, "BLOCKQUOTE")
 370     TAG_HANDLER_CONSTR(BLOCKQUOTE) { }
 371
 372     TAG_HANDLER_PROC(tag)
 373     {
 374         wxHtmlContainerCell *c;
 375
 376         m_WParser->CloseContainer();
 377         c = m_WParser->OpenContainer();
 378
 379         if (c->GetAlignHor() == wxHTML_ALIGN_RIGHT)
 380             c->SetIndent(5 * m_WParser->GetCharWidth(), wxHTML_INDENT_RIGHT);
 381         else
 382             c->SetIndent(5 * m_WParser->GetCharWidth(), wxHTML_INDENT_LEFT);
 383
 384         c->SetIndent(m_WParser->GetCharHeight(), wxHTML_INDENT_TOP);
 385         m_WParser->OpenContainer();
 386         ParseInner(tag);
 387         c = m_WParser->CloseContainer();
 388         c->SetIndent(m_WParser->GetCharHeight(), wxHTML_INDENT_BOTTOM);
 389         m_WParser->CloseContainer();
 390         m_WParser->OpenContainer();
 391         return true;
 392     }
 393
 394 TAG_HANDLER_END(BLOCKQUOTE)
 395
 396
 397
 398 TAG_HANDLER_BEGIN(SUBSUP, "SUB,SUP")
 399
 400     TAG_HANDLER_PROC(tag)
 401     {
 402         bool issub = (tag.GetName() == wxT("SUB"));
 403         wxHtmlScriptMode oldmode = m_WParser->GetScriptMode();
 404         int oldbase = m_WParser->GetScriptBaseline();
 405         int oldsize = m_WParser->GetFontSize();
 406
 407         wxHtmlContainerCell *cont = m_WParser->GetContainer();
 408         wxHtmlCell *c = cont->GetLastChild();
 409
 410         m_WParser->SetScriptMode(issub ? wxHTML_SCRIPT_SUB : wxHTML_SCRIPT_SUP);
 411         m_WParser->SetScriptBaseline(
 412                 oldbase + c ? c->GetScriptBaseline() : 0);
 413
 414         // select smaller font
 415         m_WParser->SetFontSize(m_WParser->GetFontSize()-2);
 416         cont->InsertCell(new wxHtmlFontCell(m_WParser->CreateCurrentFont()));
 417
 418         ParseInner(tag);
 419
 420         // restore font size
 421         m_WParser->SetFontSize(oldsize);
 422         m_WParser->GetContainer()->InsertCell(
 423             new wxHtmlFontCell(m_WParser->CreateCurrentFont()));
 424
 425         // restore base and alignment
 426         m_WParser->SetScriptBaseline(oldbase);
 427         m_WParser->SetScriptMode(oldmode);
 428
 429         return true;
 430     }
 431
 432 TAG_HANDLER_END(SUBSUP)
 433
 434
 435 // Tag handler for tags that we have to ignore, otherwise non-text data
 436 // would show up as text:
 437 TAG_HANDLER_BEGIN(DoNothing, "SCRIPT")
 438     TAG_HANDLER_CONSTR(DoNothing) { }
 439
 440     TAG_HANDLER_PROC(WXUNUSED(tag))
 441     {
 442         return true;
 443     }
 444 TAG_HANDLER_END(DoNothing)
 445
 446
 447
 448
 449
 450 TAGS_MODULE_BEGIN(Layout)
 451
 452     TAGS_MODULE_ADD(P)
 453     TAGS_MODULE_ADD(BR)
 454     TAGS_MODULE_ADD(CENTER)
 455     TAGS_MODULE_ADD(DIV)
 456     TAGS_MODULE_ADD(TITLE)
 457     TAGS_MODULE_ADD(BODY)
 458     TAGS_MODULE_ADD(BLOCKQUOTE)
 459     TAGS_MODULE_ADD(SUBSUP)
 460     TAGS_MODULE_ADD(DoNothing)
 461
 462 TAGS_MODULE_END(Layout)
 463
 464 #endif