Move folder

include/editor/visual.h

@@ -0,0 +1,113 @@
+#include "editor/decl.h"
+#include "io/knot.h"
+#include "io/sysio.h"
+#include "utils/utils.h"
+
+struct GraphemeIterator {
+  char *line{nullptr};
+  uint32_t len{0};
+
+  GraphemeIterator(char *line, uint32_t len) : line(line), len(len) {}
+
+  char *next(uint32_t *o_len, uint32_t *o_width) {
+    if (!line || len == 0)
+      return nullptr;
+    char *cur = line;
+    uint32_t g = grapheme_next_character_break_utf8(cur, len);
+    if (o_width)
+      *o_width = display_width(cur, g);
+    if (o_len)
+      *o_len = g;
+    line += g;
+    len -= g;
+    return cur;
+  }
+};
+
+struct VisualIterator {
+  LineIterator *it{nullptr};
+  uint32_t line_index{UINT32_MAX};
+  uint32_t offset{0};
+  uint32_t len{0};
+  bool first{true};
+  char *line{nullptr};
+  uint32_t render_width{io::cols};
+  std::stack<std::pair<Coord, Coord>> prev_stack;
+
+  VisualIterator(Knot *root, Coord pos, uint32_t width)
+      : it(begin_l_iter(root, pos.row)), offset(pos.col),
+        line_index(pos.row - 1), render_width(width) {}
+
+  std::pair<Coord, Coord> prev() {
+    if (!it)
+      return {{UINT32_MAX, UINT32_MAX}, {UINT32_MAX, UINT32_MAX}};
+    if (prev_stack.empty())
+      return _prev();
+    auto ret = prev_stack.top();
+    offset = ret.first.col;
+    prev_stack.pop();
+    return ret;
+  }
+
+  std::pair<Coord, Coord> _prev() {
+    if (!it)
+      return {{UINT32_MAX, UINT32_MAX}, {UINT32_MAX, UINT32_MAX}};
+    line_index--;
+    line = prev_line(it, &len);
+    if (!line)
+      return {{UINT32_MAX, UINT32_MAX}, {UINT32_MAX, UINT32_MAX}};
+    if (len > 0 && line[len - 1] == '\n')
+      len--;
+    offset = first ? offset : 0;
+    first = false;
+    GraphemeIterator g(line + offset, len - offset);
+    uint32_t o_len, o_width, rendered = 0, advance = 0;
+    while (g.next(&o_len, &o_width)) {
+      if (rendered + o_width > render_width) {
+        prev_stack.push({{line_index, offset}, {line_index, offset + advance}});
+        offset += advance;
+        rendered = 0;
+        advance = 0;
+      }
+      advance += o_len;
+      rendered += o_width;
+    }
+    return {{line_index, offset}, {line_index, offset + advance}};
+  }
+
+  std::pair<Coord, Coord> next() {
+    if (!it)
+      return {{UINT32_MAX, UINT32_MAX}, {UINT32_MAX, UINT32_MAX}};
+    if (!line) {
+      line_index++;
+      line = next_line(it, &len);
+      if (!line)
+        return {{UINT32_MAX, UINT32_MAX}, {UINT32_MAX, UINT32_MAX}};
+      if (len > 0 && line[len - 1] == '\n')
+        len--;
+      offset = first ? offset : 0;
+      first = false;
+    }
+    GraphemeIterator g(line + offset, len - offset);
+    uint32_t o_len, o_width, rendered = 0, advance = 0;
+    while (g.next(&o_len, &o_width)) {
+      if (rendered + o_width > render_width) {
+        offset += advance;
+        return {{line_index, offset - advance}, {line_index, offset}};
+      }
+      advance += o_len;
+      rendered += o_width;
+    }
+    offset += advance;
+    if (offset >= len)
+      line = nullptr;
+    return {{line_index, offset}, {line_index, offset + advance}};
+  }
+
+  ~VisualIterator() {
+    if (!it)
+      return;
+    free(it->buffer);
+    free(it);
+  }
+};