diff --git a/README.md b/README.md index bace049..f994af7 100644 --- a/README.md +++ b/README.md @@ -2,3 +2,6 @@ Tyrel's Text Editor https://viewsourcecode.org/snaptoken/kilo/04.aTextViewer.html#vertical-scrolling +https://viewsourcecode.org/snaptoken/kilo/04.aTextViewer.html#horizontal-scrolling +https://viewsourcecode.org/snaptoken/kilo/04.aTextViewer.html#tabs-and-the-cursor +https://viewsourcecode.org/snaptoken/kilo/04.aTextViewer.html#scrolling-with-page-up-and-page-down diff --git a/tted.c b/tted.c index 035ada6..c2380e2 100644 --- a/tted.c +++ b/tted.c @@ -16,6 +16,7 @@ /** defines */ #define TTED_VERSION "0.0.1" #define CTRL_KEY(k) ((k) & 0x1f) +#define TTED_TAB_STOP 8 enum editorKey { ARROW_LEFT = 1000, @@ -33,12 +34,16 @@ enum editorKey { /** data */ typedef struct erow { int size; + int rsize; char *chars; + char *render; } erow; struct editorConfig { int cx, cy; + int rx; int rowoff; + int coloff; int screenrows; int screencols; int numrows; @@ -168,6 +173,43 @@ int getWindowSize(int *rows, int *cols) { } /** Row operations */ +int editorRowCxToRx(erow *row, int cx) { + int rx = 0; + int j; + for (j=0; j < cx; j++){ + if (row->chars[j] == '\t') { + rx += (TTED_TAB_STOP -1) - (rx % TTED_TAB_STOP); + } + rx++; + } + return rx; +} +void editorUpdateRow(erow *row) { + int tabs = 0; + int j; + for (j = 0; j < row->size; j++) { + if (row->chars[j] == '\t') { + tabs++; + } + } + + free(row->render); + row->render = malloc(row->size + tabs*(TTED_TAB_STOP - 1) + 1); + + int idx = 0; + for (j = 0; j < row->size; j++) { + if (row->chars[j] == '\t') { + row->render[idx++] = ' '; + while (idx % TTED_TAB_STOP != 0) row->render[idx++] = ' '; + } else { + row->render[idx++] = row->chars[j]; + } + } + row->render[idx] = '\0'; + row->rsize = idx; +} + + void editorAppendRow(char *s, size_t len) { E.row = realloc(E.row, sizeof(erow) * (E.numrows + 1)); @@ -176,6 +218,9 @@ void editorAppendRow(char *s, size_t len) { E.row[at].chars = malloc(len + 1); memcpy(E.row[at].chars, s, len); E.row[at].chars[len] = '\0'; + E.row[at].rsize = 0; + E.row[at].render = NULL; + editorUpdateRow(&E.row[at]); E.numrows++; } @@ -221,11 +266,23 @@ void abFree(struct abuf *ab) { /** output */ void editorScroll() { - if (E.cy < E.rowoff){ + E.rx = 0; + if (E.cy < E.numrows){ + E.rx = editorRowCxToRx(&E.row[E.cy], E.cx); + } + + + if (E.cy < E.rowoff) { E.rowoff = E.cy; } if (E.cy >= E.rowoff + E.screenrows) { - E.rowoff = E.cy - E.screenrows +1; + E.rowoff = E.cy - E.screenrows + 1; + } + if (E.rx < E.coloff) { + E.coloff = E.rx; + } + if (E.rx >= E.coloff + E.screencols) { + E.coloff = E.rx - E.screencols + 1; } } @@ -250,9 +307,10 @@ void editorDrawRows(struct abuf *ab) { abAppend(ab, "~", 1); } } else { // draw buffer - int len = E.row[filerow].size; + int len = E.row[filerow].rsize - E.coloff; + if (len < 0) len = 0; if (len > E.screencols) len = E.screencols; // truncate if further than columns - abAppend(ab, E.row[filerow].chars, len); + abAppend(ab, &E.row[filerow].render[E.coloff], len); } abAppend(ab, "\x1b[K", 3); @@ -271,7 +329,7 @@ void editorRefreshScreen() { editorDrawRows(&ab); char buf[32]; - snprintf(buf, sizeof(buf), "\x1b[%d;%dH", (E.cy - E.rowoff) +1, E.cx + 1); + snprintf(buf, sizeof(buf), "\x1b[%d;%dH", (E.cy - E.rowoff) + 1, (E.rx - E.coloff) + 1); abAppend(&ab, buf, strlen(buf)); abAppend(&ab, "\x1b[?25h", 6); @@ -282,15 +340,23 @@ void editorRefreshScreen() { /** input */ void editorMoveCursor(int key) { + erow *row = (E.cy >= E.numrows) ? NULL : &E.row[E.cy]; + switch (key) { case ARROW_LEFT: if (E.cx != 0) { E.cx--; + } else if (E.cy > 0) { + E.cy--; + E.cx = E.row[E.cy].size; } break; case ARROW_RIGHT: - if (E.cx != E.screencols - 1) { + if (row && E.cx < row->size) { E.cx++; + } else if (row && E.cx == row->size) { + E.cy++; + E.cx = 0; } break; case ARROW_UP: @@ -304,6 +370,13 @@ void editorMoveCursor(int key) { } break; } + + // Snap cursor + row = (E.cy >= E.numrows) ? NULL : &E.row[E.cy]; + int rowlen = row ? row->size : 0; + if (E.cx > rowlen) { + E.cx = rowlen; + } } void editorProcessKeypress() { @@ -343,7 +416,9 @@ void editorProcessKeypress() { void initEditor() { E.cx = 0; E.cy = 0; + E.rx = 0; E.rowoff = 0; + E.coloff = 0; E.numrows = 0; E.row = NULL; if (getWindowSize(&E.screenrows, &E.screencols) == -1) die("getWindowSize");