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Codechange: C++-ify the Layouter and related functions

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They all now access a std::string_view, instead of a "const char *"
or std::string (in some cases).

Additionally, GetCharAtPosition and friends now return an index
instead of a "const char *", as it makes for a more clear interface.
This commit is contained in:
Patric Stout
2023-05-06 19:53:02 +02:00
committed by Patric Stout
parent 61d1b330d1
commit 60399e17bd
10 changed files with 84 additions and 157 deletions
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88
src/gfx_layout.cpp
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@@ -59,7 +59,7 @@ Font::Font(FontSize size, TextColour colour) :
* @tparam T The type of layouter we want.
*/
template <typename T>
static inline void GetLayouter(Layouter::LineCacheItem &line, const char *&str, FontState &state)
static inline void GetLayouter(Layouter::LineCacheItem &line, std::string_view str, FontState &state)
{
if (line.buffer != nullptr) free(line.buffer);
@@ -72,15 +72,18 @@ static inline void GetLayouter(Layouter::LineCacheItem &line, const char *&str,
line.buffer = buff_begin;
fontMapping.clear();
auto cur = str.begin();
/*
* Go through the whole string while adding Font instances to the font map
* whenever the font changes, and convert the wide characters into a format
* usable by ParagraphLayout.
*/
for (; buff < buffer_last;) {
WChar c = Utf8Consume(const_cast<const char **>(&str));
for (; buff < buffer_last && cur != str.end();) {
WChar c = Utf8Consume(cur);
if (c == '\0' || c == '\n') {
break;
/* Caller should already have filtered out these characters. */
NOT_REACHED();
} else if (c >= SCC_BLUE && c <= SCC_BLACK) {
state.SetColour((TextColour)(c - SCC_BLUE));
} else if (c == SCC_PUSH_COLOUR) {
@@ -123,65 +126,51 @@ static inline void GetLayouter(Layouter::LineCacheItem &line, const char *&str,
* @param colour The colour of the font.
* @param fontsize The size of font to use.
*/
Layouter::Layouter(const char *str, int maxw, TextColour colour, FontSize fontsize) : string(str)
Layouter::Layouter(std::string_view str, int maxw, TextColour colour, FontSize fontsize) : string(str)
{
FontState state(colour, fontsize);
WChar c = 0;
do {
/* Scan string for end of line */
const char *lineend = str;
for (;;) {
size_t len = Utf8Decode(&c, lineend);
if (c == '\0' || c == '\n') break;
lineend += len;
}
while (true) {
auto line_length = str.find_first_of('\n');
auto str_line = str.substr(0, line_length);
LineCacheItem& line = GetCachedParagraphLayout(str, lineend - str, state);
LineCacheItem &line = GetCachedParagraphLayout(str_line, state);
if (line.layout != nullptr) {
/* Line is in cache */
str = lineend + 1;
state = line.state_after;
line.layout->Reflow();
} else {
/* Line is new, layout it */
FontState old_state = state;
#if (defined(WITH_ICU_I18N) && defined(WITH_HARFBUZZ)) || defined(WITH_UNISCRIBE) || defined(WITH_COCOA)
const char *old_str = str;
#endif
#if defined(WITH_ICU_I18N) && defined(WITH_HARFBUZZ)
if (line.layout == nullptr) {
GetLayouter<ICUParagraphLayoutFactory>(line, str, state);
GetLayouter<ICUParagraphLayoutFactory>(line, str_line, state);
if (line.layout == nullptr) {
state = old_state;
str = old_str;
}
}
#endif
#ifdef WITH_UNISCRIBE
if (line.layout == nullptr) {
GetLayouter<UniscribeParagraphLayoutFactory>(line, str, state);
GetLayouter<UniscribeParagraphLayoutFactory>(line, str_line, state);
if (line.layout == nullptr) {
state = old_state;
str = old_str;
}
}
#endif
#ifdef WITH_COCOA
if (line.layout == nullptr) {
GetLayouter<CoreTextParagraphLayoutFactory>(line, str, state);
GetLayouter<CoreTextParagraphLayoutFactory>(line, str_line, state);
if (line.layout == nullptr) {
state = old_state;
str = old_str;
}
}
#endif
if (line.layout == nullptr) {
GetLayouter<FallbackParagraphLayoutFactory>(line, str, state);
GetLayouter<FallbackParagraphLayoutFactory>(line, str_line, state);
}
}
@@ -191,7 +180,15 @@ Layouter::Layouter(const char *str, int maxw, TextColour colour, FontSize fontsi
if (l == nullptr) break;
this->push_back(std::move(l));
}
} while (c != '\0');
/* Break out if this was the last line. */
if (line_length == std::string_view::npos) {
break;
}
/* Go to the next line. */
str.remove_prefix(line_length + 1);
}
}
/**
@@ -210,21 +207,18 @@ Dimension Layouter::GetBounds()
/**
* Get the position of a character in the layout.
* @param ch Character to get the position of.
* @param ch Character to get the position of. Must be an iterator of the string passed to the constructor.
* @return Upper left corner of the character relative to the start of the string.
* @note Will only work right for single-line strings.
*/
Point Layouter::GetCharPosition(const char *ch) const
Point Layouter::GetCharPosition(std::string_view::const_iterator ch) const
{
/* Find the code point index which corresponds to the char
* pointer into our UTF-8 source string. */
size_t index = 0;
const char *str = this->string;
while (str < ch) {
WChar c;
size_t len = Utf8Decode(&c, str);
if (c == '\0' || c == '\n') break;
str += len;
auto str = this->string.begin();
while (str < ch && str != this->string.end()) {
WChar c = Utf8Consume(str);
index += this->front()->GetInternalCharLength(c);
}
@@ -233,7 +227,7 @@ Point Layouter::GetCharPosition(const char *ch) const
const auto &line = this->front();
/* Pointer to the end-of-string/line marker? Return total line width. */
if (*ch == '\0' || *ch == '\n') {
if (ch == this->string.end() || *ch == '\0' || *ch == '\n') {
Point p = { line->GetWidth(), 0 };
return p;
}
@@ -259,9 +253,9 @@ Point Layouter::GetCharPosition(const char *ch) const
/**
* Get the character that is at a position.
* @param x Position in the string.
* @return Pointer to the character at the position or nullptr if no character is at the position.
* @return Index of the position or -1 if no character is at the position.
*/
const char *Layouter::GetCharAtPosition(int x) const
ptrdiff_t Layouter::GetCharAtPosition(int x) const
{
const auto &line = this->front();
@@ -280,17 +274,18 @@ const char *Layouter::GetCharAtPosition(int x) const
size_t index = run.GetGlyphToCharMap()[i];
size_t cur_idx = 0;
for (const char *str = this->string; *str != '\0'; ) {
if (cur_idx == index) return str;
int char_index = 0;
for (auto str = this->string.begin(); str != this->string.end(); char_index++) {
if (cur_idx == index) return char_index;
WChar c = Utf8Consume(&str);
WChar c = Utf8Consume(str);
cur_idx += line->GetInternalCharLength(c);
}
}
}
}
return nullptr;
return -1;
}
/**
@@ -332,18 +327,17 @@ void Layouter::ResetFontCache(FontSize size)
* Get reference to cache item.
* If the item does not exist yet, it is default constructed.
* @param str Source string of the line (including colour and font size codes).
* @param len Length of \a str in bytes (no termination).
* @param state State of the font at the beginning of the line.
* @return Reference to cache item.
*/
Layouter::LineCacheItem &Layouter::GetCachedParagraphLayout(const char *str, size_t len, const FontState &state)
Layouter::LineCacheItem &Layouter::GetCachedParagraphLayout(std::string_view str, const FontState &state)
{
if (linecache == nullptr) {
/* Create linecache on first access to avoid trouble with initialisation order of static variables. */
linecache = new LineCache();
}
if (auto match = linecache->find(LineCacheQuery{state, std::string_view{str, len}});
if (auto match = linecache->find(LineCacheQuery{state, str});
match != linecache->end()) {
return match->second;
}
@@ -351,7 +345,7 @@ Layouter::LineCacheItem &Layouter::GetCachedParagraphLayout(const char *str, siz
/* Create missing entry */
LineCacheKey key;
key.state_before = state;
key.str.assign(str, len);
key.str.assign(str);
return (*linecache)[key];
}