skia2/experimental/editor/editor.cpp
Hal Canary e73aa75732 experimental/editor: up,down preserves x-coordinate
Bug: skia:9020
Change-Id: I009dead2e47d4d7d27ea383697a28c7569ffeaac
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/234318
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Hal Canary <halcanary@google.com>
2019-08-13 17:46:08 +00:00

513 lines
20 KiB
C++

// Copyright 2019 Google LLC.
// Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
#include "experimental/editor/editor.h"
#include "include/core/SkCanvas.h"
#include "include/core/SkExecutor.h"
#include "include/core/SkPath.h"
#include "src/utils/SkUTF.h"
#include "experimental/editor/shape.h"
#include <algorithm>
using namespace editor;
static inline SkRect offset(SkRect r, SkIPoint p) {
return r.makeOffset((float)p.x(), (float)p.y());
}
static constexpr SkRect kUnsetRect{-FLT_MAX, -FLT_MAX, -FLT_MAX, -FLT_MAX};
static bool valid_utf8(const char* ptr, size_t size) { return SkUTF::CountUTF8(ptr, size) >= 0; }
// Kind of like Python's readlines(), but without any allocation.
// Calls f() on each line.
// F is [](const char*, size_t) -> void
template <typename F>
static void readlines(const void* data, size_t size, F f) {
const char* start = (const char*)data;
const char* end = start + size;
const char* ptr = start;
while (ptr < end) {
while (*ptr++ != '\n' && ptr < end) {}
size_t len = ptr - start;
SkASSERT(len > 0);
f(start, len);
start = ptr;
}
}
static const StringSlice remove_newline(const char* str, size_t len) {
return SkASSERT((str != nullptr) || (len == 0)),
StringSlice(str, (len > 0 && str[len - 1] == '\n') ? len - 1 : len);
}
void Editor::markDirty(TextLine* line) {
line->fBlob = nullptr;
line->fShaped = false;
line->fWordBoundaries = std::vector<bool>();
}
void Editor::setFont(SkFont font) {
if (font != fFont) {
fFont = std::move(font);
fNeedsReshape = true;
for (auto& l : fLines) { this->markDirty(&l); }
}
}
void Editor::setWidth(int w) {
if (fWidth != w) {
fWidth = w;
fNeedsReshape = true;
for (auto& l : fLines) { this->markDirty(&l); }
}
}
static SkPoint to_point(SkIPoint p) { return {(float)p.x(), (float)p.y()}; }
Editor::TextPosition Editor::getPosition(SkIPoint xy) {
Editor::TextPosition approximatePosition;
this->reshapeAll();
for (size_t j = 0; j < fLines.size(); ++j) {
const TextLine& line = fLines[j];
SkIRect lineRect = {0,
line.fOrigin.y(),
fWidth,
j + 1 < fLines.size() ? fLines[j + 1].fOrigin.y() : INT_MAX};
if (const SkTextBlob* b = line.fBlob.get()) {
SkIRect r = b->bounds().roundOut();
r.offset(line.fOrigin);
lineRect.join(r);
}
if (!lineRect.contains(xy.x(), xy.y())) {
continue;
}
SkPoint pt = to_point(xy - line.fOrigin);
const std::vector<SkRect>& pos = line.fCursorPos;
for (size_t i = 0; i < pos.size(); ++i) {
if (pos[i] != kUnsetRect && pos[i].contains(pt.x(), pt.y())) {
return Editor::TextPosition{i, j};
}
}
approximatePosition = {xy.x() <= line.fOrigin.x() ? 0 : line.fText.size(), j};
}
return approximatePosition;
}
static inline bool is_utf8_continuation(char v) {
return ((unsigned char)v & 0b11000000) ==
0b10000000;
}
static const char* next_utf8(const char* p, const char* end) {
if (p < end) {
do {
++p;
} while (p < end && is_utf8_continuation(*p));
}
return p;
}
static const char* align_utf8(const char* p, const char* begin) {
while (p > begin && is_utf8_continuation(*p)) {
--p;
}
return p;
}
static const char* prev_utf8(const char* p, const char* begin) {
return p > begin ? align_utf8(p - 1, begin) : begin;
}
SkRect Editor::getLocation(Editor::TextPosition cursor) {
this->reshapeAll();
cursor = this->move(Editor::Movement::kNowhere, cursor);
if (fLines.size() > 0) {
const TextLine& cLine = fLines[cursor.fParagraphIndex];
SkRect pos = {0, 0, 0, 0};
if (cursor.fTextByteIndex < cLine.fCursorPos.size()) {
pos = cLine.fCursorPos[cursor.fTextByteIndex];
}
pos.fRight = pos.fLeft + 1;
pos.fLeft -= 1;
return offset(pos, cLine.fOrigin);
}
return SkRect{0, 0, 0, 0};
}
static size_t count_char(const StringSlice& string, char value) {
size_t count = 0;
for (char c : string) { if (c == value) { ++count; } }
return count;
}
Editor::TextPosition Editor::insert(TextPosition pos, const char* utf8Text, size_t byteLen) {
if (!valid_utf8(utf8Text, byteLen) || 0 == byteLen) {
return pos;
}
pos = this->move(Editor::Movement::kNowhere, pos);
fNeedsReshape = true;
if (pos.fParagraphIndex < fLines.size()) {
fLines[pos.fParagraphIndex].fText.insert(pos.fTextByteIndex, utf8Text, byteLen);
this->markDirty(&fLines[pos.fParagraphIndex]);
} else {
SkASSERT(pos.fParagraphIndex == fLines.size());
SkASSERT(pos.fTextByteIndex == 0);
fLines.push_back(Editor::TextLine(StringSlice(utf8Text, byteLen)));
}
pos = Editor::TextPosition{pos.fTextByteIndex + byteLen, pos.fParagraphIndex};
size_t newlinecount = count_char(fLines[pos.fParagraphIndex].fText, '\n');
if (newlinecount > 0) {
StringSlice src = std::move(fLines[pos.fParagraphIndex].fText);
std::vector<TextLine>::const_iterator next = fLines.begin() + pos.fParagraphIndex + 1;
fLines.insert(next, newlinecount, TextLine());
TextLine* line = &fLines[pos.fParagraphIndex];
readlines(src.begin(), src.size(), [&line](const char* str, size_t l) {
(line++)->fText = remove_newline(str, l);
});
}
return pos;
}
Editor::TextPosition Editor::remove(TextPosition pos1, TextPosition pos2) {
pos1 = this->move(Editor::Movement::kNowhere, pos1);
pos2 = this->move(Editor::Movement::kNowhere, pos2);
auto cmp = [](const Editor::TextPosition& u, const Editor::TextPosition& v) { return u < v; };
Editor::TextPosition start = std::min(pos1, pos2, cmp);
Editor::TextPosition end = std::max(pos1, pos2, cmp);
if (start == end || start.fParagraphIndex == fLines.size()) {
return start;
}
fNeedsReshape = true;
if (start.fParagraphIndex == end.fParagraphIndex) {
SkASSERT(end.fTextByteIndex > start.fTextByteIndex);
fLines[start.fParagraphIndex].fText.remove(
start.fTextByteIndex, end.fTextByteIndex - start.fTextByteIndex);
this->markDirty(&fLines[start.fParagraphIndex]);
} else {
SkASSERT(end.fParagraphIndex < fLines.size());
auto& line = fLines[start.fParagraphIndex];
line.fText.remove(start.fTextByteIndex,
line.fText.size() - start.fTextByteIndex);
line.fText.insert(start.fTextByteIndex,
fLines[end.fParagraphIndex].fText.begin() + end.fTextByteIndex,
fLines[end.fParagraphIndex].fText.size() - end.fTextByteIndex);
this->markDirty(&line);
fLines.erase(fLines.begin() + start.fParagraphIndex + 1,
fLines.begin() + end.fParagraphIndex + 1);
}
return start;
}
static void append(char** dst, size_t* count, const char* src, size_t n) {
if (*dst) {
::memcpy(*dst, src, n);
*dst += n;
}
*count += n;
}
size_t Editor::copy(TextPosition pos1, TextPosition pos2, char* dst) const {
size_t size = 0;
pos1 = this->move(Editor::Movement::kNowhere, pos1);
pos2 = this->move(Editor::Movement::kNowhere, pos2);
auto cmp = [](const Editor::TextPosition& u, const Editor::TextPosition& v) { return u < v; };
Editor::TextPosition start = std::min(pos1, pos2, cmp);
Editor::TextPosition end = std::max(pos1, pos2, cmp);
if (start == end || start.fParagraphIndex == fLines.size()) {
return size;
}
if (start.fParagraphIndex == end.fParagraphIndex) {
SkASSERT(end.fTextByteIndex > start.fTextByteIndex);
auto& str = fLines[start.fParagraphIndex].fText;
append(&dst, &size, str.begin() + start.fTextByteIndex,
end.fTextByteIndex - start.fTextByteIndex);
return size;
}
SkASSERT(end.fParagraphIndex < fLines.size());
const std::vector<TextLine>::const_iterator firstP = fLines.begin() + start.fParagraphIndex;
const std::vector<TextLine>::const_iterator lastP = fLines.begin() + end.fParagraphIndex;
const auto& first = firstP->fText;
const auto& last = lastP->fText;
append(&dst, &size, first.begin() + start.fTextByteIndex, first.size() - start.fTextByteIndex);
for (auto line = firstP + 1; line < lastP; ++line) {
append(&dst, &size, "\n", 1);
append(&dst, &size, line->fText.begin(), line->fText.size());
}
append(&dst, &size, "\n", 1);
append(&dst, &size, last.begin(), end.fTextByteIndex);
return size;
}
static inline const char* begin(const StringSlice& s) { return s.begin(); }
static inline const char* end(const StringSlice& s) { return s.end(); }
static size_t align_column(const StringSlice& str, size_t p) {
if (p >= str.size()) {
return str.size();
}
return align_utf8(begin(str) + p, begin(str)) - begin(str);
}
// returns smallest i such that list[i] > value. value > list[i-1]
// Use a binary search since list is monotonic
template <typename T>
static size_t find_first_larger(const std::vector<T>& list, T value) {
return (size_t)(std::upper_bound(list.begin(), list.end(), value) - list.begin());
}
static size_t find_closest_x(const std::vector<SkRect>& bounds, float x, size_t b, size_t e) {
if (b >= e) {
return b;
}
SkASSERT(e <= bounds.size());
size_t best_index = b;
float best_diff = ::fabsf(bounds[best_index].x() - x);
for (size_t i = b + 1; i < e; ++i) {
float d = ::fabsf(bounds[i].x() - x);
if (d < best_diff) {
best_diff = d;
best_index = i;
}
}
return best_index;
}
Editor::TextPosition Editor::move(Editor::Movement move, Editor::TextPosition pos) const {
if (fLines.empty()) {
return {0, 0};
}
// First thing: fix possible bad input values.
if (pos.fParagraphIndex >= fLines.size()) {
pos.fParagraphIndex = fLines.size() - 1;
pos.fTextByteIndex = fLines[pos.fParagraphIndex].fText.size();
} else {
pos.fTextByteIndex = align_column(fLines[pos.fParagraphIndex].fText, pos.fTextByteIndex);
}
SkASSERT(pos.fParagraphIndex < fLines.size());
SkASSERT(pos.fTextByteIndex <= fLines[pos.fParagraphIndex].fText.size());
SkASSERT(pos.fTextByteIndex == fLines[pos.fParagraphIndex].fText.size() ||
!is_utf8_continuation(fLines[pos.fParagraphIndex].fText.begin()[pos.fTextByteIndex]));
switch (move) {
case Editor::Movement::kNowhere:
break;
case Editor::Movement::kLeft:
if (0 == pos.fTextByteIndex) {
if (pos.fParagraphIndex > 0) {
--pos.fParagraphIndex;
pos.fTextByteIndex = fLines[pos.fParagraphIndex].fText.size();
}
} else {
const auto& str = fLines[pos.fParagraphIndex].fText;
pos.fTextByteIndex =
prev_utf8(begin(str) + pos.fTextByteIndex, begin(str)) - begin(str);
}
break;
case Editor::Movement::kRight:
if (fLines[pos.fParagraphIndex].fText.size() == pos.fTextByteIndex) {
if (pos.fParagraphIndex + 1 < fLines.size()) {
++pos.fParagraphIndex;
pos.fTextByteIndex = 0;
}
} else {
const auto& str = fLines[pos.fParagraphIndex].fText;
pos.fTextByteIndex =
next_utf8(begin(str) + pos.fTextByteIndex, end(str)) - begin(str);
}
break;
case Editor::Movement::kHome:
{
const std::vector<size_t>& list = fLines[pos.fParagraphIndex].fLineEndOffsets;
size_t f = find_first_larger(list, pos.fTextByteIndex);
pos.fTextByteIndex = f > 0 ? list[f - 1] : 0;
}
break;
case Editor::Movement::kEnd:
{
const std::vector<size_t>& list = fLines[pos.fParagraphIndex].fLineEndOffsets;
size_t f = find_first_larger(list, pos.fTextByteIndex);
if (f < list.size()) {
pos.fTextByteIndex = list[f] > 0 ? list[f] - 1 : 0;
} else {
pos.fTextByteIndex = fLines[pos.fParagraphIndex].fText.size();
}
}
break;
case Editor::Movement::kUp:
{
SkASSERT(pos.fTextByteIndex < fLines[pos.fParagraphIndex].fCursorPos.size());
float x = fLines[pos.fParagraphIndex].fCursorPos[pos.fTextByteIndex].left();
const std::vector<size_t>& list = fLines[pos.fParagraphIndex].fLineEndOffsets;
size_t f = find_first_larger(list, pos.fTextByteIndex);
// list[f] > value. value > list[f-1]
if (f > 0) {
// not the first line in paragraph.
pos.fTextByteIndex = find_closest_x(fLines[pos.fParagraphIndex].fCursorPos, x,
(f == 1) ? 0 : list[f - 2],
list[f - 1]);
} else if (pos.fParagraphIndex > 0) {
--pos.fParagraphIndex;
const auto& newLine = fLines[pos.fParagraphIndex];
size_t r = newLine.fLineEndOffsets.size();
if (r > 0) {
pos.fTextByteIndex = find_closest_x(newLine.fCursorPos, x,
newLine.fLineEndOffsets[r - 1],
newLine.fCursorPos.size());
} else {
pos.fTextByteIndex = find_closest_x(newLine.fCursorPos, x, 0,
newLine.fCursorPos.size());
}
}
pos.fTextByteIndex =
align_column(fLines[pos.fParagraphIndex].fText, pos.fTextByteIndex);
}
break;
case Editor::Movement::kDown:
{
const std::vector<size_t>& list = fLines[pos.fParagraphIndex].fLineEndOffsets;
float x = fLines[pos.fParagraphIndex].fCursorPos[pos.fTextByteIndex].left();
size_t f = find_first_larger(list, pos.fTextByteIndex);
if (f < list.size()) {
const auto& bounds = fLines[pos.fParagraphIndex].fCursorPos;
pos.fTextByteIndex = find_closest_x(bounds, x, list[f],
f + 1 < list.size() ? list[f + 1]
: bounds.size());
} else if (pos.fParagraphIndex + 1 < fLines.size()) {
++pos.fParagraphIndex;
const auto& bounds = fLines[pos.fParagraphIndex].fCursorPos;
const std::vector<size_t>& l2 = fLines[pos.fParagraphIndex].fLineEndOffsets;
pos.fTextByteIndex = find_closest_x(bounds, x, 0,
l2.size() > 0 ? l2[0] : bounds.size());
} else {
pos.fTextByteIndex = fLines[pos.fParagraphIndex].fText.size();
}
pos.fTextByteIndex =
align_column(fLines[pos.fParagraphIndex].fText, pos.fTextByteIndex);
}
break;
case Editor::Movement::kWordLeft:
{
if (pos.fTextByteIndex == 0) {
pos = this->move(Editor::Movement::kLeft, pos);
break;
}
const std::vector<bool>& words = fLines[pos.fParagraphIndex].fWordBoundaries;
SkASSERT(words.size() == fLines[pos.fParagraphIndex].fText.size());
do {
--pos.fTextByteIndex;
} while (pos.fTextByteIndex > 0 && !words[pos.fTextByteIndex]);
}
break;
case Editor::Movement::kWordRight:
{
const StringSlice& text = fLines[pos.fParagraphIndex].fText;
if (pos.fTextByteIndex == text.size()) {
pos = this->move(Editor::Movement::kRight, pos);
break;
}
const std::vector<bool>& words = fLines[pos.fParagraphIndex].fWordBoundaries;
SkASSERT(words.size() == text.size());
do {
++pos.fTextByteIndex;
} while (pos.fTextByteIndex < text.size() && !words[pos.fTextByteIndex]);
}
break;
}
return pos;
}
void Editor::paint(SkCanvas* c, PaintOpts options) {
this->reshapeAll();
if (!c) {
return;
}
c->drawPaint(SkPaint(options.fBackgroundColor));
SkPaint selection = SkPaint(options.fSelectionColor);
auto cmp = [](const Editor::TextPosition& u, const Editor::TextPosition& v) { return u < v; };
for (TextPosition pos = std::min(options.fSelectionBegin, options.fSelectionEnd, cmp),
end = std::max(options.fSelectionBegin, options.fSelectionEnd, cmp);
pos < end;
pos = this->move(Editor::Movement::kRight, pos))
{
SkASSERT(pos.fParagraphIndex < fLines.size());
const TextLine& l = fLines[pos.fParagraphIndex];
c->drawRect(offset(l.fCursorPos[pos.fTextByteIndex], l.fOrigin), selection);
}
if (fLines.size() > 0) {
c->drawRect(Editor::getLocation(options.fCursor), SkPaint(options.fCursorColor));
}
SkPaint foreground = SkPaint(options.fForegroundColor);
for (const TextLine& line : fLines) {
if (line.fBlob) {
c->drawTextBlob(line.fBlob.get(), line.fOrigin.x(), line.fOrigin.y(), foreground);
}
}
}
void Editor::reshapeAll() {
if (fNeedsReshape) {
if (fLines.empty()) {
fLines.push_back(TextLine());
}
float shape_width = (float)(fWidth);
#ifdef SK_EDITOR_GO_FAST
SkSemaphore semaphore;
std::unique_ptr<SkExecutor> executor = SkExecutor::MakeFIFOThreadPool(100);
int jobCount = 0;
for (TextLine& line : fLines) {
if (!line.fShaped) {
executor->add([&]() {
ShapeResult result = Shape(line.fText.begin(), line.fText.size(),
fFont, fLocale, shape_width);
line.fBlob = std::move(result.blob);
line.fLineEndOffsets = std::move(result.lineBreakOffsets);
line.fCursorPos = std::move(result.glyphBounds);
line.fWordBoundaries = std::move(result.wordBreaks);
line.fHeight = result.verticalAdvance;
line.fShaped = true;
semaphore.signal();
}
++jobCount;
});
}
while (jobCount-- > 0) { semaphore.wait(); }
#else
int i = 0;
for (TextLine& line : fLines) {
if (!line.fShaped) {
ShapeResult result = Shape(line.fText.begin(), line.fText.size(),
fFont, fLocale, shape_width);
line.fBlob = std::move(result.blob);
line.fLineEndOffsets = std::move(result.lineBreakOffsets);
line.fCursorPos = std::move(result.glyphBounds);
line.fWordBoundaries = std::move(result.wordBreaks);
line.fHeight = result.verticalAdvance;
line.fShaped = true;
}
++i;
}
#endif
int y = 0;
for (TextLine& line : fLines) {
line.fOrigin = {0, y};
y += line.fHeight;
}
fHeight = y;
fNeedsReshape = false;
}
}