src/html/m_layout.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        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 #if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
  10 #pragma implementation
  11 #endif
  12
  13 #include "wx/wxprec.h"
  14
  15 #include "wx/defs.h"
  16
  17 #if wxUSE_HTML && wxUSE_STREAMS
  18
  19 #ifdef __BORLANDC__
  20     #pragma hdrstop
  21 #endif
  22
  23 #ifndef WXPRECOMP
  24 #endif
  25
  26 #include "wx/image.h"
  27
  28 #include "wx/html/forcelnk.h"
  29 #include "wx/html/m_templ.h"
  30
  31 #include "wx/html/htmlwin.h"
  32
  33 FORCE_LINK_ME(m_layout)
  34
  35 #ifdef __WXWINCE__
  36     #include "wx/msw/wince/missing.h"       // for bsearch()
  37 #else
  38     #include <stdlib.h>                     // bsearch()
  39 #endif
  40
  41 //-----------------------------------------------------------------------------
  42 // wxHtmlPageBreakCell
  43 //-----------------------------------------------------------------------------
  44
  45 // Since html isn't a page-layout language, it doesn't support page
  46 // page breaks directly--that requires CSS2 support. But a page-break
  47 // facility is handy, and has been requested more than once on the
  48 // mailing lists. This wxHtml tag handler implements just enough of
  49 // CSS2 to support a page break by recognizing only
  50 //   <div style="page-break-before:always">
  51 //
  52 // wxHtml maintains page breaks in wxHtmlPrintout::m_PageBreaks. The
  53 // tag handler below adds appropriate offsets to that array member.
  54 // wxHtmlDCRenderer::Render() accesses that array and makes a new page
  55 // begin after each page-break tag.
  56
  57 // The page-break handler does all its work in AdjustPagebreak(). For
  58 // all tag handlers, that function adjusts the page-break position.
  59 // For other tags, it determines whether the html element can fit on
  60 // the remainder of the page; if it cannot fit, but must not be split,
  61 // then the function moves the page break provided in the argument up,
  62 // and returns 'true' to inform the caller that the argument was
  63 // modified.
  64 //
  65 // Due to its special purpose, the page-break facility differs from
  66 // other tags. It takes up no space, but it behaves as though there is
  67 // never enough room to fit it on the remainder of the page--it always
  68 // forces a page break. Therefore, unlike other elements that trigger
  69 // a page break, it would never 'fit' on the following page either.
  70 // Therefore it's necessary to compare each pagebreak candidate to the
  71 // array wxHtmlPrintout::m_PageBreaks of pagebreaks already set, and
  72 // set a new one only if it's not in that array.
  73
  74 class wxHtmlPageBreakCell : public wxHtmlCell
  75 {
  76 public:
  77     wxHtmlPageBreakCell() {}
  78
  79     bool AdjustPagebreak(int* pagebreak,
  80                          int* known_pagebreaks = NULL,
  81                          int number_of_pages = 0) const;
  82     void Draw(wxDC& WXUNUSED(dc),
  83               int WXUNUSED(x), int WXUNUSED(y),
  84               int WXUNUSED(view_y1), int WXUNUSED(view_y2),
  85               wxHtmlRenderingInfo& WXUNUSED(info)) {}
  86
  87 private:
  88     DECLARE_NO_COPY_CLASS(wxHtmlPageBreakCell)
  89 };
  90
  91 // Comparison routine for bsearch into an int* array of pagebreaks.
  92 extern "C" int wxCMPFUNC_CONV wxInteger_compare(void const* i0, void const* i1)
  93 {
  94     return *(int*)i0 - *(int*)i1;
  95 }
  96
  97 bool wxHtmlPageBreakCell::AdjustPagebreak(int* pagebreak, int* known_pagebreaks, int number_of_pages) const
  98 {
  99     // When we are counting pages, 'known_pagebreaks' is non-NULL.
 100     // That's the only time we change 'pagebreak'. Otherwise, pages
 101     // were already counted, 'known_pagebreaks' is NULL, and we don't
 102     // do anything except return false.
 103     //
 104     // We also simply return false if the 'pagebreak' argument is
 105     // less than (vertically above) or the same as the current
 106     // vertical position. Otherwise we'd be setting a pagebreak above
 107     // the current cell, which is incorrect, or duplicating a
 108     // pagebreak that has already been set.
 109     if(NULL == known_pagebreaks || *pagebreak <= m_PosY)
 110         {
 111         return false;
 112         }
 113
 114     // m_PosY is only the vertical offset from the parent. The pagebreak
 115     // required here is the total page offset, so m_PosY must be added
 116     // to the parent's offset and height.
 117     int total_height = m_PosY + GetParent()->GetPosY() + GetParent()->GetHeight();
 118
 119     // Search the array of pagebreaks to see whether we've already set
 120     // a pagebreak here. The standard bsearch() function is appropriate
 121     // because the array of pagebreaks through known_pagebreaks[number_of_pages]
 122     // is known to be sorted in strictly increasing order. '1 + number_of_pages'
 123     // is used as a bsearch() argument because the array contains a leading
 124     // zero plus one element for each page.
 125     int* where = (int*) bsearch(&total_height, known_pagebreaks,
 126                                 1 + number_of_pages, sizeof(int),
 127                                 wxInteger_compare);
 128     // Add a pagebreak only if there isn't one already set here.
 129     if(NULL != where)
 130         {
 131         return false;
 132         }
 133     else
 134         {
 135         *pagebreak = m_PosY;
 136         return true;
 137         }
 138 }
 139
 140 TAG_HANDLER_BEGIN(P, "P")
 141     TAG_HANDLER_CONSTR(P) { }
 142
 143     TAG_HANDLER_PROC(tag)
 144     {
 145         if (m_WParser->GetContainer()->GetFirstChild() != NULL)
 146         {
 147             m_WParser->CloseContainer();
 148             m_WParser->OpenContainer();
 149         }
 150         m_WParser->GetContainer()->SetIndent(m_WParser->GetCharHeight(), wxHTML_INDENT_TOP);
 151         m_WParser->GetContainer()->SetAlign(tag);
 152         return false;
 153     }
 154
 155 TAG_HANDLER_END(P)
 156
 157
 158
 159 TAG_HANDLER_BEGIN(BR, "BR")
 160     TAG_HANDLER_CONSTR(BR) { }
 161
 162     TAG_HANDLER_PROC(tag)
 163     {
 164         int al = m_WParser->GetContainer()->GetAlignHor();
 165         wxHtmlContainerCell *c;
 166
 167         m_WParser->CloseContainer();
 168         c = m_WParser->OpenContainer();
 169         c->SetAlignHor(al);
 170         c->SetAlign(tag);
 171         c->SetMinHeight(m_WParser->GetCharHeight());
 172         return false;
 173     }
 174
 175 TAG_HANDLER_END(BR)
 176
 177
 178
 179 TAG_HANDLER_BEGIN(CENTER, "CENTER")
 180     TAG_HANDLER_CONSTR(CENTER) { }
 181
 182     TAG_HANDLER_PROC(tag)
 183     {
 184         int old = m_WParser->GetAlign();
 185         wxHtmlContainerCell *c = m_WParser->GetContainer();
 186
 187         m_WParser->SetAlign(wxHTML_ALIGN_CENTER);
 188         if (c->GetFirstChild() != NULL)
 189         {
 190             m_WParser->CloseContainer();
 191             m_WParser->OpenContainer();
 192         }
 193         else
 194             c->SetAlignHor(wxHTML_ALIGN_CENTER);
 195
 196         if (tag.HasEnding())
 197         {
 198             ParseInner(tag);
 199
 200             m_WParser->SetAlign(old);
 201             if (c->GetFirstChild() != NULL)
 202             {
 203                 m_WParser->CloseContainer();
 204                 m_WParser->OpenContainer();
 205             }
 206             else
 207                 c->SetAlignHor(old);
 208
 209             return true;
 210         }
 211         else return false;
 212     }
 213
 214 TAG_HANDLER_END(CENTER)
 215
 216
 217
 218 TAG_HANDLER_BEGIN(DIV, "DIV")
 219     TAG_HANDLER_CONSTR(DIV) { }
 220
 221     TAG_HANDLER_PROC(tag)
 222     {
 223         if(tag.HasParam(wxT("STYLE")))
 224         {
 225             if(tag.GetParam(wxT("STYLE")).IsSameAs(wxT("PAGE-BREAK-BEFORE:ALWAYS"), false))
 226             {
 227                 m_WParser->CloseContainer();
 228                 m_WParser->OpenContainer()->InsertCell(new wxHtmlPageBreakCell);
 229                 m_WParser->CloseContainer();
 230                 m_WParser->OpenContainer();
 231                 return false;
 232             }
 233             else
 234             {
 235                 // Treat other STYLE parameters here when they're supported.
 236                 return false;
 237             }
 238         }
 239         else if(tag.HasParam(wxT("ALIGN")))
 240         {
 241             int old = m_WParser->GetAlign();
 242             wxHtmlContainerCell *c = m_WParser->GetContainer();
 243             if (c->GetFirstChild() != NULL)
 244             {
 245                 m_WParser->CloseContainer();
 246                 m_WParser->OpenContainer();
 247                 c = m_WParser->GetContainer();
 248                 c->SetAlign(tag);
 249                 m_WParser->SetAlign(c->GetAlignHor());
 250             }
 251             else
 252             {
 253                 c->SetAlign(tag);
 254                 m_WParser->SetAlign(c->GetAlignHor());
 255             }
 256
 257             ParseInner(tag);
 258
 259             m_WParser->SetAlign(old);
 260             if (c->GetFirstChild() != NULL)
 261             {
 262                 m_WParser->CloseContainer();
 263                 m_WParser->OpenContainer();
 264             }
 265             else
 266                 c->SetAlignHor(old);
 267
 268             return true;
 269         }
 270         else
 271         {
 272             // Same as BR
 273             int al = m_WParser->GetContainer()->GetAlignHor();
 274             wxHtmlContainerCell *c;
 275
 276             m_WParser->CloseContainer();
 277             c = m_WParser->OpenContainer();
 278             c->SetAlignHor(al);
 279             c->SetAlign(tag);
 280             c->SetMinHeight(m_WParser->GetCharHeight());
 281             return false;
 282         }
 283     }
 284
 285 TAG_HANDLER_END(DIV)
 286
 287
 288
 289
 290 TAG_HANDLER_BEGIN(TITLE, "TITLE")
 291     TAG_HANDLER_CONSTR(TITLE) { }
 292
 293     TAG_HANDLER_PROC(tag)
 294     {
 295         if (m_WParser->GetWindow())
 296         {
 297             wxHtmlWindow *wfr = (wxHtmlWindow*)(m_WParser->GetWindow());
 298             if (wfr)
 299             {
 300                 wxString title = m_WParser->GetSource()->Mid(
 301                                         tag.GetBeginPos(),
 302                                         tag.GetEndPos1()-tag.GetBeginPos());
 303 #if !wxUSE_UNICODE && wxUSE_WCHAR_T
 304                 wxCSConv conv(m_WParser->GetInputEncoding());
 305                 title = wxString(title.wc_str(conv), wxConvLocal);
 306 #endif
 307                 title = m_WParser->GetEntitiesParser()->Parse(title);
 308                 wfr->OnSetTitle(title);
 309             }
 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         if (tag.HasParam(wxT("BACKGROUND")))
 336         {
 337             wxFSFile *fileBgImage = m_WParser->OpenURL
 338                                                (
 339                                                 wxHTML_URL_IMAGE,
 340                                                 tag.GetParam(wxT("BACKGROUND"))
 341                                                );
 342             if ( fileBgImage )
 343             {
 344                 wxInputStream *is = fileBgImage->GetStream();
 345                 if ( is )
 346                 {
 347                     wxImage image(*is);
 348                     if ( image.Ok() )
 349                         m_WParser->GetWindow()->SetBackgroundImage(image);
 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             if (m_WParser->GetWindow() != NULL)
 359                 m_WParser->GetWindow()->SetBackgroundColour(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 for tags that we have to ignore, otherwise non-text data
 399 // would show up as text:
 400 TAG_HANDLER_BEGIN(DoNothing, "SCRIPT")
 401     TAG_HANDLER_CONSTR(DoNothing) { }
 402
 403     TAG_HANDLER_PROC(WXUNUSED(tag))
 404     {
 405         return true;
 406     }
 407 TAG_HANDLER_END(DoNothing)
 408
 409
 410
 411 TAGS_MODULE_BEGIN(Layout)
 412
 413     TAGS_MODULE_ADD(P)
 414     TAGS_MODULE_ADD(BR)
 415     TAGS_MODULE_ADD(CENTER)
 416     TAGS_MODULE_ADD(DIV)
 417     TAGS_MODULE_ADD(TITLE)
 418     TAGS_MODULE_ADD(BODY)
 419     TAGS_MODULE_ADD(BLOCKQUOTE)
 420     TAGS_MODULE_ADD(DoNothing)
 421
 422 TAGS_MODULE_END(Layout)
 423
 424 #endif