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                          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.GetCount() == 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;
 112     for ( wxHtmlCell *parent = GetParent(); parent; parent = parent->GetParent() )
 113     {
 114         total_height += parent->GetPosY();
 115     }
 116
 117
 118     // Search the array of pagebreaks to see whether we've already set
 119     // a pagebreak here. The standard bsearch() function is appropriate
 120     // because the array of pagebreaks through known_pagebreaks[number_of_pages]
 121     // is known to be sorted in strictly increasing order. '1 + number_of_pages'
 122     // is used as a bsearch() argument because the array contains a leading
 123     // zero plus one element for each page.
 124     int where = known_pagebreaks.Index( total_height);
 125     // Add a pagebreak only if there isn't one already set here.
 126     if( wxNOT_FOUND != where)
 127     {
 128         return false;
 129     }
 130     else
 131     {
 132         *pagebreak = m_PosY;
 133         return true;
 134     }
 135 }
 136
 137
 138
 139 TAG_HANDLER_BEGIN(P, "P")
 140     TAG_HANDLER_CONSTR(P) { }
 141
 142     TAG_HANDLER_PROC(tag)
 143     {
 144         if (m_WParser->GetContainer()->GetFirstChild() != NULL)
 145         {
 146             m_WParser->CloseContainer();
 147             m_WParser->OpenContainer();
 148         }
 149         m_WParser->GetContainer()->SetIndent(m_WParser->GetCharHeight(), wxHTML_INDENT_TOP);
 150         m_WParser->GetContainer()->SetAlign(tag);
 151         return false;
 152     }
 153
 154 TAG_HANDLER_END(P)
 155
 156
 157
 158 TAG_HANDLER_BEGIN(BR, "BR")
 159     TAG_HANDLER_CONSTR(BR) { }
 160
 161     TAG_HANDLER_PROC(tag)
 162     {
 163         int al = m_WParser->GetContainer()->GetAlignHor();
 164         wxHtmlContainerCell *c;
 165
 166         m_WParser->CloseContainer();
 167         c = m_WParser->OpenContainer();
 168         c->SetAlignHor(al);
 169         c->SetAlign(tag);
 170         c->SetMinHeight(m_WParser->GetCharHeight());
 171         return false;
 172     }
 173
 174 TAG_HANDLER_END(BR)
 175
 176
 177
 178 TAG_HANDLER_BEGIN(CENTER, "CENTER")
 179     TAG_HANDLER_CONSTR(CENTER) { }
 180
 181     TAG_HANDLER_PROC(tag)
 182     {
 183         int old = m_WParser->GetAlign();
 184         wxHtmlContainerCell *c = m_WParser->GetContainer();
 185
 186         m_WParser->SetAlign(wxHTML_ALIGN_CENTER);
 187         if (c->GetFirstChild() != NULL)
 188         {
 189             m_WParser->CloseContainer();
 190             m_WParser->OpenContainer();
 191         }
 192         else
 193             c->SetAlignHor(wxHTML_ALIGN_CENTER);
 194
 195         if (tag.HasEnding())
 196         {
 197             ParseInner(tag);
 198
 199             m_WParser->SetAlign(old);
 200             if (c->GetFirstChild() != NULL)
 201             {
 202                 m_WParser->CloseContainer();
 203                 m_WParser->OpenContainer();
 204             }
 205             else
 206                 c->SetAlignHor(old);
 207
 208             return true;
 209         }
 210         else return false;
 211     }
 212
 213 TAG_HANDLER_END(CENTER)
 214
 215
 216
 217 TAG_HANDLER_BEGIN(DIV, "DIV")
 218     TAG_HANDLER_CONSTR(DIV) { }
 219
 220     TAG_HANDLER_PROC(tag)
 221     {
 222         if(tag.HasParam(wxT("STYLE")))
 223         {
 224             if(tag.GetParam(wxT("STYLE")).IsSameAs(wxT("PAGE-BREAK-BEFORE:ALWAYS"), false))
 225             {
 226                 m_WParser->CloseContainer();
 227                 m_WParser->OpenContainer()->InsertCell(new wxHtmlPageBreakCell);
 228                 m_WParser->CloseContainer();
 229                 m_WParser->OpenContainer();
 230                 return false;
 231             }
 232             else
 233             {
 234                 // Treat other STYLE parameters here when they're supported.
 235                 return false;
 236             }
 237         }
 238         else if(tag.HasParam(wxT("ALIGN")))
 239         {
 240             int old = m_WParser->GetAlign();
 241             wxHtmlContainerCell *c = m_WParser->GetContainer();
 242             if (c->GetFirstChild() != NULL)
 243             {
 244                 m_WParser->CloseContainer();
 245                 m_WParser->OpenContainer();
 246                 c = m_WParser->GetContainer();
 247                 c->SetAlign(tag);
 248                 m_WParser->SetAlign(c->GetAlignHor());
 249             }
 250             else
 251             {
 252                 c->SetAlign(tag);
 253                 m_WParser->SetAlign(c->GetAlignHor());
 254             }
 255
 256             ParseInner(tag);
 257
 258             m_WParser->SetAlign(old);
 259             if (c->GetFirstChild() != NULL)
 260             {
 261                 m_WParser->CloseContainer();
 262                 m_WParser->OpenContainer();
 263             }
 264             else
 265                 c->SetAlignHor(old);
 266
 267             return true;
 268         }
 269         else
 270         {
 271             // Same as BR
 272             int al = m_WParser->GetContainer()->GetAlignHor();
 273             wxHtmlContainerCell *c;
 274
 275             m_WParser->CloseContainer();
 276             c = m_WParser->OpenContainer();
 277             c->SetAlignHor(al);
 278             c->SetAlign(tag);
 279             c->SetMinHeight(m_WParser->GetCharHeight());
 280             return false;
 281         }
 282     }
 283
 284 TAG_HANDLER_END(DIV)
 285
 286
 287
 288
 289 TAG_HANDLER_BEGIN(TITLE, "TITLE")
 290     TAG_HANDLER_CONSTR(TITLE) { }
 291
 292     TAG_HANDLER_PROC(tag)
 293     {
 294         wxHtmlWindowInterface *winIface = m_WParser->GetWindowInterface();
 295         if (winIface)
 296         {
 297             wxString title(tag.GetBeginIter(), tag.GetEndIter1());
 298 #if !wxUSE_UNICODE && wxUSE_WCHAR_T
 299             const wxFontEncoding enc = m_WParser->GetInputEncoding();
 300             if ( enc != wxFONTENCODING_DEFAULT )
 301             {
 302                 // need to convert to the current one
 303                 title = wxString(title.wc_str(wxCSConv(enc)), wxConvLocal);
 304             }
 305 #endif // !wxUSE_UNICODE
 306
 307             title = m_WParser->GetEntitiesParser()->Parse(title);
 308
 309             winIface->SetHTMLWindowTitle(title);
 310         }
 311         return true;
 312     }
 313
 314 TAG_HANDLER_END(TITLE)
 315
 316
 317
 318
 319 TAG_HANDLER_BEGIN(BODY, "BODY")
 320     TAG_HANDLER_CONSTR(BODY) { }
 321
 322     TAG_HANDLER_PROC(tag)
 323     {
 324         wxColour clr;
 325
 326         if (tag.GetParamAsColour(wxT("TEXT"), &clr))
 327         {
 328             m_WParser->SetActualColor(clr);
 329             m_WParser->GetContainer()->InsertCell(new wxHtmlColourCell(clr));
 330         }
 331
 332         if (tag.GetParamAsColour(wxT("LINK"), &clr))
 333             m_WParser->SetLinkColor(clr);
 334
 335         wxHtmlWindowInterface *winIface = m_WParser->GetWindowInterface();
 336         // the rest of this function requires a window:
 337         if ( !winIface )
 338             return false;
 339
 340         if (tag.HasParam(wxT("BACKGROUND")))
 341         {
 342             wxFSFile *fileBgImage = m_WParser->OpenURL
 343                                                (
 344                                                 wxHTML_URL_IMAGE,
 345                                                 tag.GetParam(wxT("BACKGROUND"))
 346                                                );
 347             if ( fileBgImage )
 348             {
 349                 wxInputStream *is = fileBgImage->GetStream();
 350                 if ( is )
 351                 {
 352                     wxImage image(*is);
 353                     if ( image.Ok() )
 354                         winIface->SetHTMLBackgroundImage(image);
 355                 }
 356
 357                 delete fileBgImage;
 358             }
 359         }
 360
 361         if (tag.GetParamAsColour(wxT("BGCOLOR"), &clr))
 362         {
 363             m_WParser->GetContainer()->InsertCell(
 364                 new wxHtmlColourCell(clr, wxHTML_CLR_BACKGROUND));
 365             winIface->SetHTMLBackgroundColour(clr);
 366         }
 367
 368         return false;
 369     }
 370
 371 TAG_HANDLER_END(BODY)
 372
 373
 374
 375 TAG_HANDLER_BEGIN(BLOCKQUOTE, "BLOCKQUOTE")
 376     TAG_HANDLER_CONSTR(BLOCKQUOTE) { }
 377
 378     TAG_HANDLER_PROC(tag)
 379     {
 380         wxHtmlContainerCell *c;
 381
 382         m_WParser->CloseContainer();
 383         c = m_WParser->OpenContainer();
 384
 385         if (c->GetAlignHor() == wxHTML_ALIGN_RIGHT)
 386             c->SetIndent(5 * m_WParser->GetCharWidth(), wxHTML_INDENT_RIGHT);
 387         else
 388             c->SetIndent(5 * m_WParser->GetCharWidth(), wxHTML_INDENT_LEFT);
 389
 390         c->SetIndent(m_WParser->GetCharHeight(), wxHTML_INDENT_TOP);
 391         m_WParser->OpenContainer();
 392         ParseInner(tag);
 393         c = m_WParser->CloseContainer();
 394         c->SetIndent(m_WParser->GetCharHeight(), wxHTML_INDENT_BOTTOM);
 395         m_WParser->CloseContainer();
 396         m_WParser->OpenContainer();
 397         return true;
 398     }
 399
 400 TAG_HANDLER_END(BLOCKQUOTE)
 401
 402
 403
 404 TAG_HANDLER_BEGIN(SUBSUP, "SUB,SUP")
 405
 406     TAG_HANDLER_PROC(tag)
 407     {
 408         bool issub = (tag.GetName() == wxT("SUB"));
 409         wxHtmlScriptMode oldmode = m_WParser->GetScriptMode();
 410         int oldbase = m_WParser->GetScriptBaseline();
 411         int oldsize = m_WParser->GetFontSize();
 412
 413         wxHtmlContainerCell *cont = m_WParser->GetContainer();
 414         wxHtmlCell *c = cont->GetLastChild();
 415
 416         m_WParser->SetScriptMode(issub ? wxHTML_SCRIPT_SUB : wxHTML_SCRIPT_SUP);
 417         m_WParser->SetScriptBaseline(
 418                 oldbase + c ? c->GetScriptBaseline() : 0);
 419
 420         // select smaller font
 421         m_WParser->SetFontSize(m_WParser->GetFontSize()-2);
 422         cont->InsertCell(new wxHtmlFontCell(m_WParser->CreateCurrentFont()));
 423
 424         ParseInner(tag);
 425
 426         // restore font size
 427         m_WParser->SetFontSize(oldsize);
 428         m_WParser->GetContainer()->InsertCell(
 429             new wxHtmlFontCell(m_WParser->CreateCurrentFont()));
 430
 431         // restore base and alignment
 432         m_WParser->SetScriptBaseline(oldbase);
 433         m_WParser->SetScriptMode(oldmode);
 434
 435         return true;
 436     }
 437
 438 TAG_HANDLER_END(SUBSUP)
 439
 440
 441 // Tag handler for tags that we have to ignore, otherwise non-text data
 442 // would show up as text:
 443 TAG_HANDLER_BEGIN(DoNothing, "SCRIPT")
 444     TAG_HANDLER_CONSTR(DoNothing) { }
 445
 446     TAG_HANDLER_PROC(WXUNUSED(tag))
 447     {
 448         return true;
 449     }
 450 TAG_HANDLER_END(DoNothing)
 451
 452
 453
 454
 455
 456 TAGS_MODULE_BEGIN(Layout)
 457
 458     TAGS_MODULE_ADD(P)
 459     TAGS_MODULE_ADD(BR)
 460     TAGS_MODULE_ADD(CENTER)
 461     TAGS_MODULE_ADD(DIV)
 462     TAGS_MODULE_ADD(TITLE)
 463     TAGS_MODULE_ADD(BODY)
 464     TAGS_MODULE_ADD(BLOCKQUOTE)
 465     TAGS_MODULE_ADD(SUBSUP)
 466     TAGS_MODULE_ADD(DoNothing)
 467
 468 TAGS_MODULE_END(Layout)
 469
 470 #endif