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     wxDECLARE_NO_COPY_CLASS(wxHtmlPageBreakCell);
  83 };
  84
  85 bool wxHtmlPageBreakCell::AdjustPagebreak(int* pagebreak, wxArrayInt& known_pagebreaks) const
  86 {
  87     // When we are counting pages, 'known_pagebreaks' is non-NULL.
  88     // That's the only time we change 'pagebreak'. Otherwise, pages
  89     // were already counted, 'known_pagebreaks' is NULL, and we don't
  90     // do anything except return false.
  91     //
  92     // We also simply return false if the 'pagebreak' argument is
  93     // less than (vertically above) or the same as the current
  94     // vertical position. Otherwise we'd be setting a pagebreak above
  95     // the current cell, which is incorrect, or duplicating a
  96     // pagebreak that has already been set.
  97     if( known_pagebreaks.GetCount() == 0 || *pagebreak <= m_PosY)
  98     {
  99         return false;
 100     }
 101
 102     // m_PosY is only the vertical offset from the parent. The pagebreak
 103     // required here is the total page offset, so m_PosY must be added
 104     // to the parent's offset and height.
 105     int total_height = m_PosY;
 106     for ( wxHtmlCell *parent = GetParent(); parent; parent = parent->GetParent() )
 107     {
 108         total_height += parent->GetPosY();
 109     }
 110
 111
 112     // Search the array of pagebreaks to see whether we've already set
 113     // a pagebreak here.
 114     int where = known_pagebreaks.Index( total_height);
 115     // Add a pagebreak only if there isn't one already set here.
 116     if( wxNOT_FOUND != where)
 117     {
 118         return false;
 119     }
 120     else
 121     {
 122         *pagebreak = m_PosY;
 123         return true;
 124     }
 125 }
 126
 127
 128
 129 TAG_HANDLER_BEGIN(P, "P")
 130     TAG_HANDLER_CONSTR(P) { }
 131
 132     TAG_HANDLER_PROC(tag)
 133     {
 134         if (m_WParser->GetContainer()->GetFirstChild() != NULL)
 135         {
 136             m_WParser->CloseContainer();
 137             m_WParser->OpenContainer();
 138         }
 139         m_WParser->GetContainer()->SetIndent(m_WParser->GetCharHeight(), wxHTML_INDENT_TOP);
 140         m_WParser->GetContainer()->SetAlign(tag);
 141         return false;
 142     }
 143
 144 TAG_HANDLER_END(P)
 145
 146
 147
 148 TAG_HANDLER_BEGIN(BR, "BR")
 149     TAG_HANDLER_CONSTR(BR) { }
 150
 151     TAG_HANDLER_PROC(tag)
 152     {
 153         int al = m_WParser->GetContainer()->GetAlignHor();
 154         wxHtmlContainerCell *c;
 155
 156         m_WParser->CloseContainer();
 157         c = m_WParser->OpenContainer();
 158         c->SetAlignHor(al);
 159         c->SetAlign(tag);
 160         c->SetMinHeight(m_WParser->GetCharHeight());
 161         return false;
 162     }
 163
 164 TAG_HANDLER_END(BR)
 165
 166
 167
 168 TAG_HANDLER_BEGIN(CENTER, "CENTER")
 169     TAG_HANDLER_CONSTR(CENTER) { }
 170
 171     TAG_HANDLER_PROC(tag)
 172     {
 173         int old = m_WParser->GetAlign();
 174         wxHtmlContainerCell *c = m_WParser->GetContainer();
 175
 176         m_WParser->SetAlign(wxHTML_ALIGN_CENTER);
 177         if (c->GetFirstChild() != NULL)
 178         {
 179             m_WParser->CloseContainer();
 180             m_WParser->OpenContainer();
 181         }
 182         else
 183             c->SetAlignHor(wxHTML_ALIGN_CENTER);
 184
 185         if (tag.HasEnding())
 186         {
 187             ParseInner(tag);
 188
 189             m_WParser->SetAlign(old);
 190             if (c->GetFirstChild() != NULL)
 191             {
 192                 m_WParser->CloseContainer();
 193                 m_WParser->OpenContainer();
 194             }
 195             else
 196                 c->SetAlignHor(old);
 197
 198             return true;
 199         }
 200         else return false;
 201     }
 202
 203 TAG_HANDLER_END(CENTER)
 204
 205
 206
 207 TAG_HANDLER_BEGIN(DIV, "DIV")
 208     TAG_HANDLER_CONSTR(DIV) { }
 209
 210     TAG_HANDLER_PROC(tag)
 211     {
 212         if(tag.HasParam(wxT("STYLE")))
 213         {
 214             if(tag.GetParam(wxT("STYLE")).IsSameAs(wxT("PAGE-BREAK-BEFORE:ALWAYS"), false))
 215             {
 216                 m_WParser->CloseContainer();
 217                 m_WParser->OpenContainer()->InsertCell(new wxHtmlPageBreakCell);
 218                 m_WParser->CloseContainer();
 219                 m_WParser->OpenContainer();
 220                 return false;
 221             }
 222             else
 223             {
 224                 // Treat other STYLE parameters here when they're supported.
 225                 return false;
 226             }
 227         }
 228         else if(tag.HasParam(wxT("ALIGN")))
 229         {
 230             int old = m_WParser->GetAlign();
 231             wxHtmlContainerCell *c = m_WParser->GetContainer();
 232             if (c->GetFirstChild() != NULL)
 233             {
 234                 m_WParser->CloseContainer();
 235                 m_WParser->OpenContainer();
 236                 c = m_WParser->GetContainer();
 237                 c->SetAlign(tag);
 238                 m_WParser->SetAlign(c->GetAlignHor());
 239             }
 240             else
 241             {
 242                 c->SetAlign(tag);
 243                 m_WParser->SetAlign(c->GetAlignHor());
 244             }
 245
 246             ParseInner(tag);
 247
 248             m_WParser->SetAlign(old);
 249             if (c->GetFirstChild() != NULL)
 250             {
 251                 m_WParser->CloseContainer();
 252                 m_WParser->OpenContainer();
 253             }
 254             else
 255                 c->SetAlignHor(old);
 256
 257             return true;
 258         }
 259         else
 260         {
 261             // Same as BR
 262             int al = m_WParser->GetContainer()->GetAlignHor();
 263             wxHtmlContainerCell *c;
 264
 265             m_WParser->CloseContainer();
 266             c = m_WParser->OpenContainer();
 267             c->SetAlignHor(al);
 268             c->SetAlign(tag);
 269             c->SetMinHeight(m_WParser->GetCharHeight());
 270             return false;
 271         }
 272     }
 273
 274 TAG_HANDLER_END(DIV)
 275
 276
 277
 278
 279 TAG_HANDLER_BEGIN(TITLE, "TITLE")
 280     TAG_HANDLER_CONSTR(TITLE) { }
 281
 282     TAG_HANDLER_PROC(tag)
 283     {
 284         wxHtmlWindowInterface *winIface = m_WParser->GetWindowInterface();
 285         if (winIface)
 286         {
 287             wxString title(tag.GetBeginIter(), tag.GetEndIter1());
 288 #if !wxUSE_UNICODE
 289             const wxFontEncoding enc = m_WParser->GetInputEncoding();
 290             if ( enc != wxFONTENCODING_DEFAULT )
 291             {
 292                 // need to convert to the current one
 293                 title = wxString(title.wc_str(wxCSConv(enc)), wxConvLocal);
 294             }
 295 #endif // !wxUSE_UNICODE
 296
 297             title = m_WParser->GetEntitiesParser()->Parse(title);
 298
 299             winIface->SetHTMLWindowTitle(title);
 300         }
 301         return true;
 302     }
 303
 304 TAG_HANDLER_END(TITLE)
 305
 306
 307
 308
 309 TAG_HANDLER_BEGIN(BODY, "BODY")
 310     TAG_HANDLER_CONSTR(BODY) { }
 311
 312     TAG_HANDLER_PROC(tag)
 313     {
 314         wxColour clr;
 315
 316         if (tag.GetParamAsColour(wxT("TEXT"), &clr))
 317         {
 318             m_WParser->SetActualColor(clr);
 319             m_WParser->GetContainer()->InsertCell(new wxHtmlColourCell(clr));
 320         }
 321
 322         if (tag.GetParamAsColour(wxT("LINK"), &clr))
 323             m_WParser->SetLinkColor(clr);
 324
 325         wxHtmlWindowInterface *winIface = m_WParser->GetWindowInterface();
 326         // the rest of this function requires a window:
 327         if ( !winIface )
 328             return false;
 329
 330         if (tag.HasParam(wxT("BACKGROUND")))
 331         {
 332             wxFSFile *fileBgImage = m_WParser->OpenURL
 333                                                (
 334                                                 wxHTML_URL_IMAGE,
 335                                                 tag.GetParam(wxT("BACKGROUND"))
 336                                                );
 337             if ( fileBgImage )
 338             {
 339                 wxInputStream *is = fileBgImage->GetStream();
 340                 if ( is )
 341                 {
 342                     wxImage image(*is);
 343                     if ( image.Ok() )
 344                         winIface->SetHTMLBackgroundImage(image);
 345                 }
 346
 347                 delete fileBgImage;
 348             }
 349         }
 350
 351         if (tag.GetParamAsColour(wxT("BGCOLOR"), &clr))
 352         {
 353             m_WParser->GetContainer()->InsertCell(
 354                 new wxHtmlColourCell(clr, wxHTML_CLR_BACKGROUND));
 355             winIface->SetHTMLBackgroundColour(clr);
 356         }
 357
 358         return false;
 359     }
 360
 361 TAG_HANDLER_END(BODY)
 362
 363
 364
 365 TAG_HANDLER_BEGIN(BLOCKQUOTE, "BLOCKQUOTE")
 366     TAG_HANDLER_CONSTR(BLOCKQUOTE) { }
 367
 368     TAG_HANDLER_PROC(tag)
 369     {
 370         wxHtmlContainerCell *c;
 371
 372         m_WParser->CloseContainer();
 373         c = m_WParser->OpenContainer();
 374
 375         if (c->GetAlignHor() == wxHTML_ALIGN_RIGHT)
 376             c->SetIndent(5 * m_WParser->GetCharWidth(), wxHTML_INDENT_RIGHT);
 377         else
 378             c->SetIndent(5 * m_WParser->GetCharWidth(), wxHTML_INDENT_LEFT);
 379
 380         c->SetIndent(m_WParser->GetCharHeight(), wxHTML_INDENT_TOP);
 381         m_WParser->OpenContainer();
 382         ParseInner(tag);
 383         c = m_WParser->CloseContainer();
 384         c->SetIndent(m_WParser->GetCharHeight(), wxHTML_INDENT_BOTTOM);
 385         m_WParser->CloseContainer();
 386         m_WParser->OpenContainer();
 387         return true;
 388     }
 389
 390 TAG_HANDLER_END(BLOCKQUOTE)
 391
 392
 393
 394 TAG_HANDLER_BEGIN(SUBSUP, "SUB,SUP")
 395
 396     TAG_HANDLER_PROC(tag)
 397     {
 398         bool issub = (tag.GetName() == wxT("SUB"));
 399         wxHtmlScriptMode oldmode = m_WParser->GetScriptMode();
 400         int oldbase = m_WParser->GetScriptBaseline();
 401         int oldsize = m_WParser->GetFontSize();
 402
 403         wxHtmlContainerCell *cont = m_WParser->GetContainer();
 404         wxHtmlCell *c = cont->GetLastChild();
 405
 406         m_WParser->SetScriptMode(issub ? wxHTML_SCRIPT_SUB : wxHTML_SCRIPT_SUP);
 407         m_WParser->SetScriptBaseline(
 408                 oldbase + c ? c->GetScriptBaseline() : 0);
 409
 410         // select smaller font
 411         m_WParser->SetFontSize(m_WParser->GetFontSize()-2);
 412         cont->InsertCell(new wxHtmlFontCell(m_WParser->CreateCurrentFont()));
 413
 414         ParseInner(tag);
 415
 416         // restore font size
 417         m_WParser->SetFontSize(oldsize);
 418         m_WParser->GetContainer()->InsertCell(
 419             new wxHtmlFontCell(m_WParser->CreateCurrentFont()));
 420
 421         // restore base and alignment
 422         m_WParser->SetScriptBaseline(oldbase);
 423         m_WParser->SetScriptMode(oldmode);
 424
 425         return true;
 426     }
 427
 428 TAG_HANDLER_END(SUBSUP)
 429
 430
 431 // Tag handler for tags that we have to ignore, otherwise non-text data
 432 // would show up as text:
 433 TAG_HANDLER_BEGIN(DoNothing, "SCRIPT")
 434     TAG_HANDLER_CONSTR(DoNothing) { }
 435
 436     TAG_HANDLER_PROC(WXUNUSED(tag))
 437     {
 438         return true;
 439     }
 440 TAG_HANDLER_END(DoNothing)
 441
 442
 443
 444
 445
 446 TAGS_MODULE_BEGIN(Layout)
 447
 448     TAGS_MODULE_ADD(P)
 449     TAGS_MODULE_ADD(BR)
 450     TAGS_MODULE_ADD(CENTER)
 451     TAGS_MODULE_ADD(DIV)
 452     TAGS_MODULE_ADD(TITLE)
 453     TAGS_MODULE_ADD(BODY)
 454     TAGS_MODULE_ADD(BLOCKQUOTE)
 455     TAGS_MODULE_ADD(SUBSUP)
 456     TAGS_MODULE_ADD(DoNothing)
 457
 458 TAGS_MODULE_END(Layout)
 459
 460 #endif