Files @ r28616:1df48a6fd940
Branch filter:

Location: cpp/openttd-patchpack/source/src/textfile_gui.cpp

glx22
Fix 48b6b18: Increase MAX_VALUATE_OPS to match the previous limit
  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
/*
 * This file is part of OpenTTD.
 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */

/** @file textfile_gui.cpp Implementation of textfile window. */

#include "stdafx.h"
#include "core/backup_type.hpp"
#include "fileio_func.h"
#include "fontcache.h"
#include "gfx_type.h"
#include "gfx_func.h"
#include "string_func.h"
#include "textfile_gui.h"
#include "widgets/dropdown_type.h"
#include "gfx_layout.h"
#include "debug.h"
#include "openttd.h"

#include "widgets/misc_widget.h"

#include "table/strings.h"
#include "table/control_codes.h"

#if defined(WITH_ZLIB)
#include <zlib.h>
#endif

#if defined(WITH_LIBLZMA)
#include <lzma.h>
#endif

#include <regex>

#include "safeguards.h"

/** Widgets for the textfile window. */
static constexpr NWidgetPart _nested_textfile_widgets[] = {
	NWidget(NWID_HORIZONTAL),
		NWidget(WWT_CLOSEBOX, COLOUR_MAUVE),
		NWidget(WWT_PUSHARROWBTN, COLOUR_MAUVE, WID_TF_NAVBACK), SetFill(0, 1), SetMinimalSize(15, 1), SetDataTip(AWV_DECREASE, STR_TEXTFILE_NAVBACK_TOOLTIP),
		NWidget(WWT_PUSHARROWBTN, COLOUR_MAUVE, WID_TF_NAVFORWARD), SetFill(0, 1), SetMinimalSize(15, 1), SetDataTip(AWV_INCREASE, STR_TEXTFILE_NAVFORWARD_TOOLTIP),
		NWidget(WWT_CAPTION, COLOUR_MAUVE, WID_TF_CAPTION), SetDataTip(STR_NULL, STR_TOOLTIP_WINDOW_TITLE_DRAG_THIS),
		NWidget(WWT_TEXTBTN, COLOUR_MAUVE, WID_TF_WRAPTEXT), SetDataTip(STR_TEXTFILE_WRAP_TEXT, STR_TEXTFILE_WRAP_TEXT_TOOLTIP),
		NWidget(WWT_DEFSIZEBOX, COLOUR_MAUVE),
	EndContainer(),
	NWidget(NWID_SELECTION, INVALID_COLOUR, WID_TF_SEL_JUMPLIST),
		NWidget(WWT_PANEL, COLOUR_MAUVE),
			NWidget(NWID_HORIZONTAL), SetPIP(WidgetDimensions::unscaled.frametext.left, 0, WidgetDimensions::unscaled.frametext.right),
				/* As this widget can be toggled, it needs to be a multiplier of FS_MONO. So add a spacer that ensures this. */
				NWidget(NWID_SPACER), SetMinimalSize(1, 0), SetMinimalTextLines(2, 0, FS_MONO),
				NWidget(NWID_VERTICAL),
					NWidget(NWID_SPACER), SetFill(1, 1), SetResize(1, 0),
					NWidget(WWT_DROPDOWN, COLOUR_MAUVE, WID_TF_JUMPLIST), SetDataTip(STR_TEXTFILE_JUMPLIST, STR_TEXTFILE_JUMPLIST_TOOLTIP), SetFill(1, 0), SetResize(1, 0),
					NWidget(NWID_SPACER), SetFill(1, 1), SetResize(1, 0),
				EndContainer(),
			EndContainer(),
		EndContainer(),
	EndContainer(),
	NWidget(NWID_HORIZONTAL),
		NWidget(WWT_PANEL, COLOUR_MAUVE, WID_TF_BACKGROUND), SetMinimalSize(200, 125), SetResize(1, 12), SetScrollbar(WID_TF_VSCROLLBAR),
		EndContainer(),
		NWidget(NWID_VERTICAL),
			NWidget(NWID_VSCROLLBAR, COLOUR_MAUVE, WID_TF_VSCROLLBAR),
		EndContainer(),
	EndContainer(),
	NWidget(NWID_HORIZONTAL),
		NWidget(NWID_HSCROLLBAR, COLOUR_MAUVE, WID_TF_HSCROLLBAR),
		NWidget(WWT_RESIZEBOX, COLOUR_MAUVE),
	EndContainer(),
};

/** Window definition for the textfile window */
static WindowDesc _textfile_desc(__FILE__, __LINE__,
	WDP_CENTER, "textfile", 630, 460,
	WC_TEXTFILE, WC_NONE,
	0,
	std::begin(_nested_textfile_widgets), std::end(_nested_textfile_widgets)
);

TextfileWindow::TextfileWindow(TextfileType file_type) : Window(&_textfile_desc), file_type(file_type)
{
	/* Init of nested tree is deferred.
	 * TextfileWindow::ConstructWindow must be called by the inheriting window. */
}

void TextfileWindow::ConstructWindow()
{
	this->CreateNestedTree();
	this->vscroll = this->GetScrollbar(WID_TF_VSCROLLBAR);
	this->hscroll = this->GetScrollbar(WID_TF_HSCROLLBAR);
	this->GetWidget<NWidgetCore>(WID_TF_CAPTION)->SetDataTip(STR_TEXTFILE_README_CAPTION + this->file_type, STR_TOOLTIP_WINDOW_TITLE_DRAG_THIS);
	this->GetWidget<NWidgetStacked>(WID_TF_SEL_JUMPLIST)->SetDisplayedPlane(SZSP_HORIZONTAL);
	this->FinishInitNested(this->file_type);

	this->DisableWidget(WID_TF_NAVBACK);
	this->DisableWidget(WID_TF_NAVFORWARD);
	this->hscroll->SetStepSize(10); // Speed up horizontal scrollbar
}

/**
 * Get the total height of the content displayed in this window, if wrapping is disabled.
 * @return the height in pixels
 */
uint TextfileWindow::ReflowContent()
{
	uint height = 0;
	if (!IsWidgetLowered(WID_TF_WRAPTEXT)) {
		for (auto &line : this->lines) {
			line.top = height;
			height++;
			line.bottom = height;
		}
	} else {
		int max_width = this->GetWidget<NWidgetCore>(WID_TF_BACKGROUND)->current_x - WidgetDimensions::scaled.frametext.Horizontal();
		for (auto &line : this->lines) {
			line.top = height;
			height += GetStringHeight(line.text, max_width, FS_MONO) / GetCharacterHeight(FS_MONO);
			line.bottom = height;
		}
	}

	return height;
}

uint TextfileWindow::GetContentHeight()
{
	if (this->lines.empty()) return 0;
	return this->lines.back().bottom;
}

/* virtual */ void TextfileWindow::UpdateWidgetSize(WidgetID widget, Dimension *size, [[maybe_unused]] const Dimension &padding, [[maybe_unused]] Dimension *fill, [[maybe_unused]] Dimension *resize)
{
	switch (widget) {
		case WID_TF_BACKGROUND:
			resize->height = GetCharacterHeight(FS_MONO);

			size->height = 4 * resize->height + WidgetDimensions::scaled.frametext.Vertical(); // At least 4 lines are visible.
			size->width = std::max(200u, size->width); // At least 200 pixels wide.
			break;
	}
}

/** Set scrollbars to the right lengths. */
void TextfileWindow::SetupScrollbars(bool force_reflow)
{
	if (IsWidgetLowered(WID_TF_WRAPTEXT)) {
		/* Reflow is mandatory if text wrapping is on */
		uint height = this->ReflowContent();
		this->vscroll->SetCount(ClampTo<uint16_t>(height));
		this->hscroll->SetCount(0);
	} else {
		uint height = force_reflow ? this->ReflowContent() : this->GetContentHeight();
		this->vscroll->SetCount(ClampTo<uint16_t>(height));
		this->hscroll->SetCount(this->max_length + WidgetDimensions::scaled.frametext.Horizontal());
	}

	this->SetWidgetDisabledState(WID_TF_HSCROLLBAR, IsWidgetLowered(WID_TF_WRAPTEXT));
}


/** Regular expression that searches for Markdown links. */
static const std::regex _markdown_link_regex{"\\[(.+?)\\]\\((.+?)\\)", std::regex_constants::ECMAScript | std::regex_constants::optimize};

/** Types of link we support in markdown files. */
enum class HyperlinkType {
	Internal, ///< Internal link, or "anchor" in HTML language.
	Web,      ///< Link to an external website.
	File,     ///< Link to a local file.
	Unknown,  ///< Unknown link.
};

/**
 * Classify the type of hyperlink the destination describes.
 *
 * @param destination The hyperlink destination.
 * @param trusted Whether we trust the content of this file.
 * @return HyperlinkType The classification of the link.
 */
static HyperlinkType ClassifyHyperlink(const std::string &destination, bool trusted)
{
	if (destination.empty()) return HyperlinkType::Unknown;
	if (destination.starts_with("#")) return HyperlinkType::Internal;

	/* Only allow external / internal links for sources we trust. */
	if (!trusted) return HyperlinkType::Unknown;

	if (destination.starts_with("http://")) return HyperlinkType::Web;
	if (destination.starts_with("https://")) return HyperlinkType::Web;
	if (destination.starts_with("./")) return HyperlinkType::File;
	return HyperlinkType::Unknown;
}

/**
 * Create a valid slug for the anchor.
 *
 * @param line The line to create the slug for.
 * @return std::string The slug.
 */
static std::string MakeAnchorSlug(const std::string &line)
{
	std::string r = "#";
	uint state = 0;
	for (char c : line) {
		if (state == 0) {
			/* State 0: Skip leading hashmarks and spaces. */
			if (c == '#') continue;
			if (c == ' ') continue;
			state = 1;
		}
		if (state == 2) {
			/* State 2: Wait for a non-space/dash character.
			 * When found, output a dash and that character. */
			if (c == ' ' || c == '-') continue;
			r += '-';
			state = 1;
		}
		if (state == 1) {
			/* State 1: Normal text.
			 * Lowercase alphanumerics,
			 * spaces and dashes become dashes,
			 * everything else is removed. */
			if (isalnum(c)) {
				r += tolower(c);
			} else if (c == ' ' || c == '-') {
				state = 2;
			}
		}
	}

	return r;
}

/**
 * Find any hyperlinks in a given line.
 *
 * @param line The line to search for hyperlinks.
 * @param line_index The index of the line.
 */
void TextfileWindow::FindHyperlinksInMarkdown(Line &line, size_t line_index)
{
	std::string::const_iterator last_match_end = line.text.cbegin();
	std::string fixed_line;
	char ccbuf[5];

	std::sregex_iterator matcher{ line.text.cbegin(), line.text.cend(), _markdown_link_regex};
	while (matcher != std::sregex_iterator()) {
		std::smatch match = *matcher;

		Hyperlink link;
		link.line = line_index;
		link.destination = match[2].str();
		this->links.push_back(link);

		HyperlinkType link_type = ClassifyHyperlink(link.destination, this->trusted);
		StringControlCode link_colour;
		switch (link_type) {
			case HyperlinkType::Internal:
				link_colour = SCC_GREEN;
				break;
			case HyperlinkType::Web:
				link_colour = SCC_LTBLUE;
				break;
			case HyperlinkType::File:
				link_colour = SCC_LTBROWN;
				break;
			default:
				/* Don't make other link types fancy as they aren't handled (yet). */
				link_colour = SCC_CONTROL_END;
				break;
		}

		if (link_colour != SCC_CONTROL_END) {
			/* Format the link to look like a link. */
			fixed_line += std::string(last_match_end, match[0].first);
			this->links.back().begin = fixed_line.length();
			fixed_line += std::string(ccbuf, Utf8Encode(ccbuf, SCC_PUSH_COLOUR));
			fixed_line += std::string(ccbuf, Utf8Encode(ccbuf, link_colour));
			fixed_line += match[1].str();
			this->links.back().end = fixed_line.length();
			fixed_line += std::string(ccbuf, Utf8Encode(ccbuf, SCC_POP_COLOUR));
			last_match_end = match[0].second;
		}

		/* Find next link. */
		++matcher;
	}
	if (last_match_end == line.text.cbegin()) return; // nothing found

	/* Add remaining text on line. */
	fixed_line += std::string(last_match_end, line.text.cend());

	/* Overwrite original line text with "fixed" line text. */
	line.text = fixed_line;
}

/**
 * Check if the user clicked on a hyperlink, and handle it if so.
 *
 * @param pt The loation the user clicked.
 */
void TextfileWindow::CheckHyperlinkClick(Point pt)
{
	if (this->links.empty()) return;

	/* Which line was clicked. */
	const int clicked_row = this->GetRowFromWidget(pt.y, WID_TF_BACKGROUND, WidgetDimensions::scaled.frametext.top, GetCharacterHeight(FS_MONO)) + this->GetScrollbar(WID_TF_VSCROLLBAR)->GetPosition();
	size_t line_index;
	size_t subline;
	if (IsWidgetLowered(WID_TF_WRAPTEXT)) {
		auto it = std::find_if(std::begin(this->lines), std::end(this->lines), [clicked_row](const Line &l) { return l.top <= clicked_row && l.bottom > clicked_row; });
		if (it == this->lines.cend()) return;
		line_index = it - this->lines.cbegin();
		subline = clicked_row - it->top;
		Debug(misc, 4, "TextfileWindow check hyperlink: clicked_row={}, line_index={}, line.top={}, subline={}", clicked_row, line_index, it->top, subline);
	} else {
		line_index = clicked_row / GetCharacterHeight(FS_MONO);
		subline = 0;
	}

	/* Find hyperlinks in this line. */
	std::vector<Hyperlink> found_links;
	for (const auto &link : this->links) {
		if (link.line == line_index) found_links.push_back(link);
	}
	if (found_links.empty()) return;

	/* Build line layout to figure out character position that was clicked. */
	uint window_width = IsWidgetLowered(WID_TF_WRAPTEXT) ? this->GetWidget<NWidgetCore>(WID_TF_BACKGROUND)->current_x - WidgetDimensions::scaled.frametext.Horizontal() : INT_MAX;
	Layouter layout(this->lines[line_index].text, window_width, this->lines[line_index].colour, FS_MONO);
	assert(subline < layout.size());
	ptrdiff_t char_index = layout.GetCharAtPosition(pt.x - WidgetDimensions::scaled.frametext.left, subline);
	if (char_index < 0) return;
	Debug(misc, 4, "TextfileWindow check hyperlink click: line={}, subline={}, char_index={}", line_index, subline, (int)char_index);

	/* Found character index in line, check if any links are at that position. */
	for (const auto &link : found_links) {
		Debug(misc, 4, "Checking link from char {} to {}", link.begin, link.end);
		if ((size_t)char_index >= link.begin && (size_t)char_index < link.end) {
			Debug(misc, 4, "Activating link with destination: {}", link.destination);
			this->OnHyperlinkClick(link);
			return;
		}
	}
}

/**
 * Append the new location to the history, so the user can go back.
 *
 * @param filepath The location the user is navigating to.
 */
void TextfileWindow::AppendHistory(const std::string &filepath)
{
	this->history.erase(this->history.begin() + this->history_pos + 1, this->history.end());
	this->UpdateHistoryScrollpos();
	this->history.push_back(HistoryEntry{ filepath, 0 });
	this->EnableWidget(WID_TF_NAVBACK);
	this->DisableWidget(WID_TF_NAVFORWARD);
	this->history_pos = this->history.size() - 1;
}

/**
 * Update the scroll position to the current, so we can restore there if we go back.
 */
void TextfileWindow::UpdateHistoryScrollpos()
{
	this->history[this->history_pos].scrollpos = this->GetScrollbar(WID_TF_VSCROLLBAR)->GetPosition();
}

/**
 * Navigate through the history, either forward or backward.
 *
 * @param delta The direction to navigate.
 */
void TextfileWindow::NavigateHistory(int delta)
{
	if (delta == 0) return;
	if (delta < 0 && static_cast<int>(this->history_pos) < -delta) return;
	if (delta > 0 && this->history_pos + delta >= this->history.size()) return;

	this->UpdateHistoryScrollpos();
	this->history_pos += delta;

	if (this->history[this->history_pos].filepath != this->filepath) {
		this->filepath = this->history[this->history_pos].filepath;
		this->filename = this->filepath.substr(this->filepath.find_last_of(PATHSEP) + 1);
		this->LoadTextfile(this->filepath, NO_DIRECTORY);
	}

	this->SetWidgetDisabledState(WID_TF_NAVFORWARD, this->history_pos + 1 >= this->history.size());
	this->SetWidgetDisabledState(WID_TF_NAVBACK, this->history_pos == 0);
	this->GetScrollbar(WID_TF_VSCROLLBAR)->SetPosition(this->history[this->history_pos].scrollpos);
	this->GetScrollbar(WID_TF_HSCROLLBAR)->SetPosition(0);
	this->SetDirty();
}

/* virtual */ void TextfileWindow::OnHyperlinkClick(const Hyperlink &link)
{
	switch (ClassifyHyperlink(link.destination, this->trusted)) {
		case HyperlinkType::Internal:
		{
			auto it = std::find_if(this->link_anchors.cbegin(), this->link_anchors.cend(), [&](const Hyperlink &other) { return link.destination == other.destination; });
			if (it != this->link_anchors.cend()) {
				this->AppendHistory(this->filepath);
				this->ScrollToLine(it->line);
				this->UpdateHistoryScrollpos();
			}
			break;
		}

		case HyperlinkType::Web:
			OpenBrowser(link.destination);
			break;

		case HyperlinkType::File:
			this->NavigateToFile(link.destination, 0);
			break;

		default:
			/* Do nothing */
			break;
	}
}

/**
 * Navigate to the requested file.
 *
 * @param newfile The file to navigate to.
 * @param line The line to scroll to.
 */
void TextfileWindow::NavigateToFile(std::string newfile, size_t line)
{
	/* Double-check that the file link begins with ./ as a relative path. */
	if (!newfile.starts_with("./")) return;

	/* Get the path portion of the current file path. */
	std::string newpath = this->filepath;
	size_t pos = newpath.find_last_of(PATHSEPCHAR);
	if (pos == std::string::npos) {
		newpath.clear();
	} else {
		newpath.erase(pos + 1);
	}

	/* Check and remove for anchor in link. Do this before we find the filename, as people might have a / after the hash. */
	size_t anchor_pos = newfile.find_first_of('#');
	std::string anchor;
	if (anchor_pos != std::string::npos) {
		anchor = newfile.substr(anchor_pos);
		newfile.erase(anchor_pos);
	}

	/* Now the anchor is gone, check if this is a markdown or textfile. */
	if (!StrEndsWithIgnoreCase(newfile, ".md") && !StrEndsWithIgnoreCase(newfile, ".txt")) return;

	/* Convert link destination to acceptable local filename (replace forward slashes with correct path separator). */
	newfile = newfile.substr(2);
	if (PATHSEPCHAR != '/') {
		for (char &c : newfile) {
			if (c == '/') c = PATHSEPCHAR;
		}
	}

	/* Paste the two together and check file exists. */
	newpath = newpath + newfile;
	if (!FioCheckFileExists(newpath, NO_DIRECTORY)) return;

	/* Update history. */
	this->AppendHistory(newpath);

	/* Load the new file. */
	this->filepath = newpath;
	this->filename = newpath.substr(newpath.find_last_of(PATHSEP) + 1);

	this->LoadTextfile(this->filepath, NO_DIRECTORY);

	this->GetScrollbar(WID_TF_HSCROLLBAR)->SetPosition(0);
	this->GetScrollbar(WID_TF_VSCROLLBAR)->SetPosition(0);

	if (anchor.empty() || line != 0) {
		this->ScrollToLine(line);
	} else {
		auto anchor_dest = std::find_if(this->link_anchors.cbegin(), this->link_anchors.cend(), [&](const Hyperlink &other) { return anchor == other.destination; });
		if (anchor_dest != this->link_anchors.cend()) {
			this->ScrollToLine(anchor_dest->line);
			this->UpdateHistoryScrollpos();
		} else {
			this->ScrollToLine(0);
		}
	}
}

/* virtual */ void TextfileWindow::AfterLoadText()
{
	this->link_anchors.clear();

	if (StrEndsWithIgnoreCase(this->filename, ".md")) this->AfterLoadMarkdown();

	if (this->GetWidget<NWidgetStacked>(WID_TF_SEL_JUMPLIST)->SetDisplayedPlane(this->jumplist.empty() ? SZSP_HORIZONTAL : 0)) this->ReInit();
}

/**
 * Post-processing of markdown files.
 */
void TextfileWindow::AfterLoadMarkdown()
{
	for (size_t line_index = 0; line_index < this->lines.size(); ++line_index) {
		Line &line = this->lines[line_index];

		/* Find and mark all hyperlinks in the line. */
		this->FindHyperlinksInMarkdown(line, line_index);

		/* All lines beginning with # are headings. */
		if (!line.text.empty() && line.text[0] == '#') {
			this->jumplist.push_back(line_index);
			this->lines[line_index].colour = TC_GOLD;
			this->link_anchors.emplace_back(Hyperlink{ line_index, 0, 0, MakeAnchorSlug(line.text) });
		}
	}
}

/* virtual */ void TextfileWindow::OnClick([[maybe_unused]] Point pt, WidgetID widget, [[maybe_unused]] int click_count)
{
	switch (widget) {
		case WID_TF_WRAPTEXT:
			this->ToggleWidgetLoweredState(WID_TF_WRAPTEXT);
			this->InvalidateData();
			break;

		case WID_TF_JUMPLIST: {
			DropDownList list;
			for (size_t line : this->jumplist) {
				SetDParamStr(0, this->lines[line].text);
				list.push_back(std::make_unique<DropDownListStringItem>(STR_TEXTFILE_JUMPLIST_ITEM, (int)line, false));
			}
			ShowDropDownList(this, std::move(list), -1, widget);
			break;
		}

		case WID_TF_NAVBACK:
			this->NavigateHistory(-1);
			break;

		case WID_TF_NAVFORWARD:
			this->NavigateHistory(+1);
			break;

		case WID_TF_BACKGROUND:
			this->CheckHyperlinkClick(pt);
			break;
	}
}

/* virtual */ void TextfileWindow::DrawWidget(const Rect &r, WidgetID widget) const
{
	if (widget != WID_TF_BACKGROUND) return;

	Rect fr = r.Shrink(WidgetDimensions::scaled.frametext);

	DrawPixelInfo new_dpi;
	if (!FillDrawPixelInfo(&new_dpi, fr)) return;
	AutoRestoreBackup dpi_backup(_cur_dpi, &new_dpi);

	/* Draw content (now coordinates given to DrawString* are local to the new clipping region). */
	fr = fr.Translate(-fr.left, -fr.top);
	int line_height = GetCharacterHeight(FS_MONO);
	int pos = this->vscroll->GetPosition();
	int cap = this->vscroll->GetCapacity();

	for (auto &line : this->lines) {
		if (line.bottom < pos) continue;
		if (line.top > pos + cap) break;

		int y_offset = (line.top - pos) * line_height;
		if (IsWidgetLowered(WID_TF_WRAPTEXT)) {
			DrawStringMultiLine(0, fr.right, y_offset, fr.bottom, line.text, line.colour, SA_TOP | SA_LEFT, false, FS_MONO);
		} else {
			DrawString(-this->hscroll->GetPosition(), fr.right, y_offset, line.text, line.colour, SA_TOP | SA_LEFT, false, FS_MONO);
		}
	}
}

/* virtual */ void TextfileWindow::OnResize()
{
	this->vscroll->SetCapacityFromWidget(this, WID_TF_BACKGROUND, WidgetDimensions::scaled.frametext.Vertical());
	this->hscroll->SetCapacityFromWidget(this, WID_TF_BACKGROUND);

	this->SetupScrollbars(false);
}

/* virtual */ void TextfileWindow::OnInvalidateData([[maybe_unused]] int data, [[maybe_unused]] bool gui_scope)
{
	if (!gui_scope) return;

	this->SetupScrollbars(true);
}

void TextfileWindow::OnDropdownSelect(WidgetID widget, int index)
{
	if (widget != WID_TF_JUMPLIST) return;

	this->ScrollToLine(index);
}

void TextfileWindow::ScrollToLine(size_t line)
{
	Scrollbar *sb = this->GetScrollbar(WID_TF_VSCROLLBAR);
	int newpos;
	if (this->IsWidgetLowered(WID_TF_WRAPTEXT)) {
		newpos = this->lines[line].top;
	} else {
		newpos = static_cast<int>(line);
	}
	sb->SetPosition(std::min(newpos, sb->GetCount() - sb->GetCapacity()));
	this->SetDirty();
}

/* virtual */ void TextfileWindow::Reset()
{
	this->search_iterator = 0;
}

/* virtual */ FontSize TextfileWindow::DefaultSize()
{
	return FS_MONO;
}

/* virtual */ std::optional<std::string_view> TextfileWindow::NextString()
{
	if (this->search_iterator >= this->lines.size()) return std::nullopt;

	return this->lines[this->search_iterator++].text;
}

/* virtual */ bool TextfileWindow::Monospace()
{
	return true;
}

/* virtual */ void TextfileWindow::SetFontNames([[maybe_unused]] FontCacheSettings *settings, [[maybe_unused]] const char *font_name, [[maybe_unused]] const void *os_data)
{
#if defined(WITH_FREETYPE) || defined(_WIN32) || defined(WITH_COCOA)
	settings->mono.font = font_name;
	settings->mono.os_handle = os_data;
#endif
}

#if defined(WITH_ZLIB)

/**
 * Do an in-memory gunzip operation. This works on a raw deflate stream,
 * or a file with gzip or zlib header.
 * @param bufp  A pointer to a buffer containing the input data. This
 *              buffer will be freed and replaced by a buffer containing
 *              the uncompressed data.
 * @param sizep A pointer to the buffer size. Before the call, the value
 *              pointed to should contain the size of the input buffer.
 *              After the call, it contains the size of the uncompressed
 *              data.
 *
 * When decompressing fails, *bufp is set to nullptr and *sizep to 0. The
 * compressed buffer passed in is still freed in this case.
 */
static void Gunzip(byte **bufp, size_t *sizep)
{
	static const int BLOCKSIZE  = 8192;
	byte             *buf       = nullptr;
	size_t           alloc_size = 0;
	z_stream         z;
	int              res;

	memset(&z, 0, sizeof(z));
	z.next_in = *bufp;
	z.avail_in = (uInt)*sizep;

	/* window size = 15, add 32 to enable gzip or zlib header processing */
	res = inflateInit2(&z, 15 + 32);
	/* Z_BUF_ERROR just means we need more space */
	while (res == Z_OK || (res == Z_BUF_ERROR && z.avail_out == 0)) {
		/* When we get here, we're either just starting, or
		 * inflate is out of output space - allocate more */
		alloc_size += BLOCKSIZE;
		z.avail_out += BLOCKSIZE;
		buf = ReallocT(buf, alloc_size);
		z.next_out = buf + alloc_size - z.avail_out;
		res = inflate(&z, Z_FINISH);
	}

	free(*bufp);
	inflateEnd(&z);

	if (res == Z_STREAM_END) {
		*bufp = buf;
		*sizep = alloc_size - z.avail_out;
	} else {
		/* Something went wrong */
		*bufp = nullptr;
		*sizep = 0;
		free(buf);
	}
}
#endif

#if defined(WITH_LIBLZMA)

/**
 * Do an in-memory xunzip operation. This works on a .xz or (legacy)
 * .lzma file.
 * @param bufp  A pointer to a buffer containing the input data. This
 *              buffer will be freed and replaced by a buffer containing
 *              the uncompressed data.
 * @param sizep A pointer to the buffer size. Before the call, the value
 *              pointed to should contain the size of the input buffer.
 *              After the call, it contains the size of the uncompressed
 *              data.
 *
 * When decompressing fails, *bufp is set to nullptr and *sizep to 0. The
 * compressed buffer passed in is still freed in this case.
 */
static void Xunzip(byte **bufp, size_t *sizep)
{
	static const int BLOCKSIZE  = 8192;
	byte             *buf       = nullptr;
	size_t           alloc_size = 0;
	lzma_stream      z = LZMA_STREAM_INIT;
	int              res;

	z.next_in = *bufp;
	z.avail_in = *sizep;

	res = lzma_auto_decoder(&z, UINT64_MAX, LZMA_CONCATENATED);
	/* Z_BUF_ERROR just means we need more space */
	while (res == LZMA_OK || (res == LZMA_BUF_ERROR && z.avail_out == 0)) {
		/* When we get here, we're either just starting, or
		 * inflate is out of output space - allocate more */
		alloc_size += BLOCKSIZE;
		z.avail_out += BLOCKSIZE;
		buf = ReallocT(buf, alloc_size);
		z.next_out = buf + alloc_size - z.avail_out;
		res = lzma_code(&z, LZMA_FINISH);
	}

	free(*bufp);
	lzma_end(&z);

	if (res == LZMA_STREAM_END) {
		*bufp = buf;
		*sizep = alloc_size - z.avail_out;
	} else {
		/* Something went wrong */
		*bufp = nullptr;
		*sizep = 0;
		free(buf);
	}
}
#endif


/**
 * Loads the textfile text from file and setup #lines.
 */
/* virtual */ void TextfileWindow::LoadTextfile(const std::string &textfile, Subdirectory dir)
{
	this->lines.clear();
	this->jumplist.clear();

	if (this->GetWidget<NWidgetStacked>(WID_TF_SEL_JUMPLIST)->SetDisplayedPlane(SZSP_HORIZONTAL)) this->ReInit();

	if (textfile.empty()) return;

	/* Get text from file */
	size_t filesize;
	FILE *handle = FioFOpenFile(textfile, "rb", dir, &filesize);
	if (handle == nullptr) return;
	/* Early return on empty files. */
	if (filesize == 0) return;

	char *buf = MallocT<char>(filesize);
	size_t read = fread(buf, 1, filesize, handle);
	fclose(handle);

	if (read != filesize) {
		free(buf);
		return;
	}

#if defined(WITH_ZLIB)
	/* In-place gunzip */
	if (textfile.ends_with(".gz")) Gunzip((byte**)&buf, &filesize);
#endif

#if defined(WITH_LIBLZMA)
	/* In-place xunzip */
	if (textfile.ends_with(".xz")) Xunzip((byte**)&buf, &filesize);
#endif

	if (buf == nullptr) return;

	std::string_view sv_buf(buf, filesize);

	/* Check for the byte-order-mark, and skip it if needed. */
	if (sv_buf.starts_with("\ufeff")) sv_buf.remove_prefix(3);

	/* Update the filename. */
	this->filepath = textfile;
	this->filename = this->filepath.substr(this->filepath.find_last_of(PATHSEP) + 1);
	/* If it's the first file being loaded, add to history. */
	if (this->history.empty()) this->history.push_back(HistoryEntry{ this->filepath, 0 });

	/* Process the loaded text into lines, and do any further parsing needed. */
	this->LoadText(sv_buf);
	free(buf);
}

/**
 * Load a text into the textfile viewer.
 *
 * This will split the text into newlines and stores it for fast drawing.
 *
 * @param buf The text to load.
 */
void TextfileWindow::LoadText(std::string_view buf)
{
	std::string text = StrMakeValid(buf, SVS_REPLACE_WITH_QUESTION_MARK | SVS_ALLOW_NEWLINE | SVS_REPLACE_TAB_CR_NL_WITH_SPACE);
	this->lines.clear();

	/* Split the string on newlines. */
	std::string_view p(text);
	int row = 0;
	auto next = p.find_first_of('\n');
	while (next != std::string_view::npos) {
		this->lines.emplace_back(row, p.substr(0, next));
		p.remove_prefix(next + 1);

		row++;
		next = p.find_first_of('\n');
	}
	this->lines.emplace_back(row, p);

	/* Calculate maximum text line length. */
	uint max_length = 0;
	for (auto &line : this->lines) {
		max_length = std::max(max_length, GetStringBoundingBox(line.text, FS_MONO).width);
	}
	this->max_length = max_length;

	this->AfterLoadText();

	CheckForMissingGlyphs(true, this);
}

/**
 * Search a textfile file next to the given content.
 * @param type The type of the textfile to search for.
 * @param dir The subdirectory to search in.
 * @param filename The filename of the content to look for.
 * @return The path to the textfile, \c nullptr otherwise.
 */
std::optional<std::string> GetTextfile(TextfileType type, Subdirectory dir, const std::string &filename)
{
	static const char * const prefixes[] = {
		"readme",
		"changelog",
		"license",
	};
	static_assert(lengthof(prefixes) == TFT_CONTENT_END);

	/* Only the generic text file types allowed for this function */
	if (type >= TFT_CONTENT_END) return std::nullopt;

	std::string_view prefix = prefixes[type];

	if (filename.empty()) return std::nullopt;

	auto slash = filename.find_last_of(PATHSEPCHAR);
	if (slash == std::string::npos) return std::nullopt;

	std::string_view base_path(filename.data(), slash + 1);

	static const std::initializer_list<std::string_view> extensions{
		"txt",
		"md",
#if defined(WITH_ZLIB)
		"txt.gz",
		"md.gz",
#endif
#if defined(WITH_LIBLZMA)
		"txt.xz",
		"md.xz",
#endif
	};

	for (auto &extension : extensions) {
		std::string file_path = fmt::format("{}{}_{}.{}", base_path, prefix, GetCurrentLanguageIsoCode(), extension);
		if (FioCheckFileExists(file_path, dir)) return file_path;

		file_path = fmt::format("{}{}_{:.2s}.{}", base_path, prefix, GetCurrentLanguageIsoCode(), extension);
		if (FioCheckFileExists(file_path, dir)) return file_path;

		file_path = fmt::format("{}{}.{}", base_path, prefix, extension);
		if (FioCheckFileExists(file_path, dir)) return file_path;
	}
	return std::nullopt;
}