src/apps/haikudepot/textview/TextDocumentLayout.cpp

   1 /*
   2  * Copyright 2013-2015, Stephan Aßmus <superstippi@gmx.de>.
   3  * All rights reserved. Distributed under the terms of the MIT License.
   4  */
   5
   6 #include "TextDocumentLayout.h"
   7
   8 #include <new>
   9 #include <stdio.h>
  10
  11 #include <View.h>
  12
  13
  14 class LayoutTextListener : public TextListener {
  15 public:
  16         LayoutTextListener(TextDocumentLayout* layout)
  17                 :
  18                 fLayout(layout)
  19         {
  20         }
  21
  22         virtual void TextChanging(TextChangingEvent& event)
  23         {
  24         }
  25
  26         virtual void TextChanged(const TextChangedEvent& event)
  27         {
  28                 printf("TextChanged(%" B_PRIi32 ", %" B_PRIi32 ")\n",
  29                         event.FirstChangedParagraph(),
  30                         event.ChangedParagraphCount());
  31                 // TODO: The event does not contain useful data. Make the event
  32                 // system work so only the affected paragraphs are updated.
  33                 // I think we need "first affected", "last affected" (both relative
  34                 // to the original paragraph count), and than how many new paragraphs
  35                 // are between these. From the difference in old number of paragraphs
  36                 // inbetween and the new count, we know how many new paragraphs are
  37                 // missing, and the rest in the range needs to be updated.
  38 //              fLayout->InvalidateParagraphs(event.FirstChangedParagraph(),
  39 //                      event.ChangedParagraphCount());
  40                 fLayout->Invalidate();
  41         }
  42
  43 private:
  44         TextDocumentLayout*     fLayout;
  45 };
  46
  47
  48
  49 TextDocumentLayout::TextDocumentLayout()
  50         :
  51         fWidth(0.0f),
  52         fLayoutValid(false),
  53
  54         fDocument(),
  55         fTextListener(new(std::nothrow) LayoutTextListener(this), true),
  56         fParagraphLayouts()
  57 {
  58 }
  59
  60
  61 TextDocumentLayout::TextDocumentLayout(const TextDocumentRef& document)
  62         :
  63         fWidth(0.0f),
  64         fLayoutValid(false),
  65
  66         fDocument(),
  67         fTextListener(new(std::nothrow) LayoutTextListener(this), true),
  68         fParagraphLayouts()
  69 {
  70         SetTextDocument(document);
  71 }
  72
  73
  74 TextDocumentLayout::TextDocumentLayout(const TextDocumentLayout& other)
  75         :
  76         fWidth(other.fWidth),
  77         fLayoutValid(other.fLayoutValid),
  78
  79         fDocument(other.fDocument),
  80         fTextListener(new(std::nothrow) LayoutTextListener(this), true),
  81         fParagraphLayouts(other.fParagraphLayouts)
  82 {
  83         if (fDocument.Get() != NULL)
  84                 fDocument->AddListener(fTextListener);
  85 }
  86
  87
  88 TextDocumentLayout::~TextDocumentLayout()
  89 {
  90         SetTextDocument(NULL);
  91 }
  92
  93
  94 void
  95 TextDocumentLayout::SetTextDocument(const TextDocumentRef& document)
  96 {
  97         if (fDocument == document)
  98                 return;
  99
 100         if (fDocument.Get() != NULL)
 101                 fDocument->RemoveListener(fTextListener);
 102
 103         fDocument = document;
 104         _Init();
 105         fLayoutValid = false;
 106
 107         if (fDocument.Get() != NULL)
 108                 fDocument->AddListener(fTextListener);
 109 }
 110
 111
 112 void
 113 TextDocumentLayout::Invalidate()
 114 {
 115         if (fDocument.Get() != NULL)
 116                 InvalidateParagraphs(0, fDocument->Paragraphs().CountItems());
 117 }
 118
 119
 120 void
 121 TextDocumentLayout::InvalidateParagraphs(int32 start, int32 count)
 122 {
 123         if (start < 0 || count == 0 || fDocument.Get() == NULL)
 124                 return;
 125
 126         fLayoutValid = false;
 127
 128         const ParagraphList& paragraphs = fDocument->Paragraphs();
 129
 130         while (count > 0) {
 131                 if (start >= paragraphs.CountItems())
 132                         break;
 133                 const Paragraph& paragraph = paragraphs.ItemAtFast(start);
 134                 if (start >= fParagraphLayouts.CountItems()) {
 135                         ParagraphLayoutRef layout(new(std::nothrow) ParagraphLayout(
 136                                 paragraph), true);
 137                         if (layout.Get() == NULL
 138                                 || !fParagraphLayouts.Add(ParagraphLayoutInfo(0.0f, layout))) {
 139                                 fprintf(stderr, "TextDocumentLayout::InvalidateParagraphs() - "
 140                                         "out of memory\n");
 141                                 return;
 142                         }
 143                 } else {
 144                         const ParagraphLayoutInfo& info = fParagraphLayouts.ItemAtFast(
 145                                 start);
 146                         info.layout->SetParagraph(paragraph);
 147                 }
 148
 149                 start++;
 150                 count--;
 151         }
 152
 153         // Remove any extra paragraph layouts
 154         while (paragraphs.CountItems() < fParagraphLayouts.CountItems())
 155                 fParagraphLayouts.Remove(fParagraphLayouts.CountItems() - 1);
 156 }
 157
 158
 159 void
 160 TextDocumentLayout::SetWidth(float width)
 161 {
 162         if (fWidth != width) {
 163                 fWidth = width;
 164                 fLayoutValid = false;
 165         }
 166 }
 167
 168
 169 float
 170 TextDocumentLayout::Height()
 171 {
 172         _ValidateLayout();
 173
 174         float height = 0.0f;
 175
 176         if (fParagraphLayouts.CountItems() > 0) {
 177                 const ParagraphLayoutInfo& lastLayout = fParagraphLayouts.LastItem();
 178                 height = lastLayout.y + lastLayout.layout->Height();
 179         }
 180
 181         return height;
 182 }
 183
 184
 185 void
 186 TextDocumentLayout::Draw(BView* view, const BPoint& offset,
 187         const BRect& updateRect)
 188 {
 189         _ValidateLayout();
 190
 191         int layoutCount = fParagraphLayouts.CountItems();
 192         for (int i = 0; i < layoutCount; i++) {
 193                 const ParagraphLayoutInfo& layout = fParagraphLayouts.ItemAtFast(i);
 194                 BPoint location(offset.x, offset.y + layout.y);
 195                 if (location.y > updateRect.bottom)
 196                         break;
 197                 if (location.y + layout.layout->Height() > updateRect.top)
 198                         layout.layout->Draw(view, location);
 199         }
 200 }
 201
 202
 203 int32
 204 TextDocumentLayout::LineIndexForOffset(int32 textOffset)
 205 {
 206         int32 index = _ParagraphLayoutIndexForOffset(textOffset);
 207         if (index >= 0) {
 208                 int32 lineIndex = 0;
 209                 for (int32 i = 0; i < index; i++) {
 210                         lineIndex += fParagraphLayouts.ItemAtFast(i).layout->CountLines();
 211                 }
 212
 213                 const ParagraphLayoutInfo& info = fParagraphLayouts.ItemAtFast(index);
 214                 return lineIndex + info.layout->LineIndexForOffset(textOffset);
 215         }
 216
 217         return 0;
 218 }
 219
 220
 221 int32
 222 TextDocumentLayout::FirstOffsetOnLine(int32 lineIndex)
 223 {
 224         int32 paragraphOffset;
 225         int32 index = _ParagraphLayoutIndexForLineIndex(lineIndex, paragraphOffset);
 226         if (index >= 0) {
 227                 const ParagraphLayoutInfo& info = fParagraphLayouts.ItemAtFast(index);
 228                 return info.layout->FirstOffsetOnLine(lineIndex) + paragraphOffset;
 229         }
 230
 231         return 0;
 232 }
 233
 234
 235 int32
 236 TextDocumentLayout::LastOffsetOnLine(int32 lineIndex)
 237 {
 238         int32 paragraphOffset;
 239         int32 index = _ParagraphLayoutIndexForLineIndex(lineIndex, paragraphOffset);
 240         if (index >= 0) {
 241                 const ParagraphLayoutInfo& info = fParagraphLayouts.ItemAtFast(index);
 242                 return info.layout->LastOffsetOnLine(lineIndex) + paragraphOffset;
 243         }
 244
 245         return 0;
 246 }
 247
 248
 249 int32
 250 TextDocumentLayout::CountLines()
 251 {
 252         _ValidateLayout();
 253
 254         int32 lineCount = 0;
 255
 256         int32 count = fParagraphLayouts.CountItems();
 257         for (int32 i = 0; i < count; i++) {
 258                 const ParagraphLayoutInfo& info = fParagraphLayouts.ItemAtFast(i);
 259                 lineCount += info.layout->CountLines();
 260         }
 261
 262         return lineCount;
 263 }
 264
 265
 266 void
 267 TextDocumentLayout::GetLineBounds(int32 lineIndex, float& x1, float& y1,
 268         float& x2, float& y2)
 269 {
 270         int32 paragraphOffset;
 271         int32 index = _ParagraphLayoutIndexForLineIndex(lineIndex, paragraphOffset);
 272         if (index >= 0) {
 273                 const ParagraphLayoutInfo& info = fParagraphLayouts.ItemAtFast(index);
 274                 info.layout->GetLineBounds(lineIndex, x1, y1, x2, y2);
 275                 y1 += info.y;
 276                 y2 += info.y;
 277                 return;
 278         }
 279
 280         x1 = 0.0f;
 281         y1 = 0.0f;
 282         x2 = 0.0f;
 283         y2 = 0.0f;
 284 }
 285
 286
 287 void
 288 TextDocumentLayout::GetTextBounds(int32 textOffset, float& x1, float& y1,
 289         float& x2, float& y2)
 290 {
 291         int32 index = _ParagraphLayoutIndexForOffset(textOffset);
 292         if (index >= 0) {
 293                 const ParagraphLayoutInfo& info = fParagraphLayouts.ItemAtFast(index);
 294                 info.layout->GetTextBounds(textOffset, x1, y1, x2, y2);
 295                 y1 += info.y;
 296                 y2 += info.y;
 297                 return;
 298         }
 299
 300         x1 = 0.0f;
 301         y1 = 0.0f;
 302         x2 = 0.0f;
 303         y2 = 0.0f;
 304 }
 305
 306
 307 int32
 308 TextDocumentLayout::TextOffsetAt(float x, float y, bool& rightOfCenter)
 309 {
 310         _ValidateLayout();
 311
 312         int32 textOffset = 0;
 313         rightOfCenter = false;
 314
 315         int32 paragraphs = fParagraphLayouts.CountItems();
 316         for (int32 i = 0; i < paragraphs; i++) {
 317                 const ParagraphLayoutInfo& info = fParagraphLayouts.ItemAtFast(i);
 318                 if (y > info.y + info.layout->Height()) {
 319                         textOffset += info.layout->CountGlyphs();
 320                         continue;
 321                 }
 322
 323                 textOffset += info.layout->TextOffsetAt(x, y - info.y, rightOfCenter);
 324                 break;
 325         }
 326
 327         return textOffset;
 328 }
 329
 330 // #pragma mark - private
 331
 332
 333 void
 334 TextDocumentLayout::_ValidateLayout()
 335 {
 336         if (!fLayoutValid) {
 337                 _Layout();
 338                 fLayoutValid = true;
 339         }
 340 }
 341
 342
 343 void
 344 TextDocumentLayout::_Init()
 345 {
 346         fParagraphLayouts.Clear();
 347
 348         if (fDocument.Get() == NULL)
 349                 return;
 350
 351         const ParagraphList& paragraphs = fDocument->Paragraphs();
 352
 353         int paragraphCount = paragraphs.CountItems();
 354         for (int i = 0; i < paragraphCount; i++) {
 355                 const Paragraph& paragraph = paragraphs.ItemAtFast(i);
 356                 ParagraphLayoutRef layout(new(std::nothrow) ParagraphLayout(paragraph),
 357                         true);
 358                 if (layout.Get() == NULL
 359                         || !fParagraphLayouts.Add(ParagraphLayoutInfo(0.0f, layout))) {
 360                         fprintf(stderr, "TextDocumentLayout::_Layout() - out of memory\n");
 361                         return;
 362                 }
 363         }
 364 }
 365
 366
 367 void
 368 TextDocumentLayout::_Layout()
 369 {
 370         float y = 0.0f;
 371
 372         int layoutCount = fParagraphLayouts.CountItems();
 373         for (int i = 0; i < layoutCount; i++) {
 374                 ParagraphLayoutInfo info = fParagraphLayouts.ItemAtFast(i);
 375                 const ParagraphStyle& style = info.layout->Style();
 376
 377                 if (i > 0)
 378                         y += style.SpacingTop();
 379
 380                 fParagraphLayouts.Replace(i, ParagraphLayoutInfo(y, info.layout));
 381
 382                 info.layout->SetWidth(fWidth);
 383                 y += info.layout->Height() + style.SpacingBottom();
 384         }
 385 }
 386
 387
 388 int32
 389 TextDocumentLayout::_ParagraphLayoutIndexForOffset(int32& textOffset)
 390 {
 391         _ValidateLayout();
 392
 393         int32 paragraphs = fParagraphLayouts.CountItems();
 394         for (int32 i = 0; i < paragraphs - 1; i++) {
 395                 const ParagraphLayoutInfo& info = fParagraphLayouts.ItemAtFast(i);
 396
 397                 int32 length = info.layout->CountGlyphs();
 398                 if (textOffset >= length) {
 399                         textOffset -= length;
 400                         continue;
 401                 }
 402
 403                 return i;
 404         }
 405
 406         if (paragraphs > 0) {
 407                 const ParagraphLayoutInfo& info = fParagraphLayouts.LastItem();
 408
 409                 // Return last paragraph if the textOffset is still within or
 410                 // exactly behind the last valid offset in that paragraph.
 411                 int32 length = info.layout->CountGlyphs();
 412                 if (textOffset <= length)
 413                         return paragraphs - 1;
 414         }
 415
 416         return -1;
 417 }
 418
 419 int32
 420 TextDocumentLayout::_ParagraphLayoutIndexForLineIndex(int32& lineIndex,
 421         int32& paragraphOffset)
 422 {
 423         _ValidateLayout();
 424
 425         paragraphOffset = 0;
 426         int32 paragraphs = fParagraphLayouts.CountItems();
 427         for (int32 i = 0; i < paragraphs; i++) {
 428                 const ParagraphLayoutInfo& info = fParagraphLayouts.ItemAtFast(i);
 429
 430                 int32 lineCount = info.layout->CountLines();
 431                 if (lineIndex >= lineCount) {
 432                         lineIndex -= lineCount;
 433                         paragraphOffset += info.layout->CountGlyphs();
 434                         continue;
 435                 }
 436
 437                 return i;
 438         }
 439
 440         return -1;
 441 }