GopherProxy

	tAdd vertical scrolling - ve - a minimal text editor (work in progress)
	git clone git://src.adamsgaard.dk/ve
	Log
	Files
	Refs
	README
	LICENSE
	---
	commit 65a91ff9999be9f55f6f57b1ca91afc65f8bdbf6
	parent fd944c194e43e14db7bf4fdaf5c5fbc726683c5e
	Author: Anders Damsgaard <[email protected]>
	Date: Tue, 6 Aug 2019 12:29:55 +0200

	Add vertical scrolling

	Diffstat:
	M byote.h \| 1 +
	M input.c \| 2 +-
	M output.c \| 32 ++++++++++++++++++++---------…
	M terminal.c \| 1 +

	4 files changed, 24 insertions(+), 12 deletions(-)
	---
	diff --git a/byote.h b/byote.h
	t@@ -17,6 +17,7 @@ struct editor_config {
	int screen_rows, screen_cols;
	int num_rows;
	eRow *row;
	+ int row_offset;
	struct termios orig_termios;
	int status_height;
	int mode; /* 0: normal, 1: insert, 2: visual */
	diff --git a/input.c b/input.c
	t@@ -14,7 +14,7 @@ editor_move_cursor(char key)
	E.cursor_x--;
	break;
	case 'j':
	- if (E.cursor_y < E.screen_rows - 1 - E.status_height)
	+ if (E.cursor_y < E.num_rows - E.status_height)
	E.cursor_y++;
	break;
	case 'k':
	diff --git a/output.c b/output.c
	t@@ -68,25 +68,32 @@ draw_status(struct abuf *ab)
	}
	}

	+void
	+editor_scroll()
	+{
	+ if (E.cursor_y < E.row_offset)
	+ E.row_offset = E.cursor_y;
	+ else if (E.cursor_y >= E.row_offset + E.screen_rows - E.status_height)
	+ E.row_offset = E.cursor_y - E.screen_rows + 1;
	+}
	+
	/* draw editor screen.
	* show tilde characters after EOF, and show status on last line */
	void
	editor_draw_rows(struct abuf *ab)
	{
	- int y, len;
	+ int y, len, file_row;
	for (y = 0; y < E.screen_rows; ++y) {
	-
	- if (y < E.num_rows) {
	- len = E.row[y].size;
	+ file_row = y + E.row_offset;
	+ if (y == E.screen_rows-1) {
	+ draw_status(ab);
	+ } else if (file_row < E.num_rows) {
	+ len = E.row[file_row].size;
	if (len > E.screen_cols)
	len = E.screen_cols;
	- ab_append(ab, E.row[y].chars, len);
	-
	+ ab_append(ab, E.row[file_row].chars, len);
	} else {
	- if (y == E.screen_rows-1)
	- draw_status(ab);
	- else
	- ab_append(ab, "~", 1);
	+ ab_append(ab, "~", 1);
	}

	ab_append(ab, "\x1b[K", 3); /* erase to end of line */
	t@@ -104,6 +111,8 @@ editor_draw_rows(struct abuf *ab)
	void
	editor_refresh_screen()
	{
	+ editor_scroll();
	+
	struct abuf ab = ABUF_INIT;
	ab_append(&ab, "\x1b[?25l", 6); /* hide cursor */
	ab_append(&ab, "\x1b[H", 3); /* cursor to home */
	t@@ -111,7 +120,8 @@ editor_refresh_screen()
	editor_draw_rows(&ab);

	char buf[32];
	- snprintf(buf, sizeof(buf), "\x1b[%d;%dH", E.cursor_y+1, E.cursor_x+1);
	+ snprintf(buf, sizeof(buf), "\x1b[%d;%dH", (E.cursor_y - E.row_offset)+…
	+ E.cursor_x+1);
	ab_append(&ab, buf, strlen(buf));

	ab_append(&ab, "\x1b[?25h", 6); /* show cursor */
	diff --git a/terminal.c b/terminal.c
	t@@ -113,6 +113,7 @@ init_editor() {
	E.mode = 0;
	E.num_rows = 0;
	E.row = NULL;
	+ E.row_offset = 0;
	if (get_window_size(&E.screen_rows, &E.screen_cols) == -1)
	die("get_window_size");
	}