flowtop: Add horizontal scrolling over flows table

Add left/right scrolling for flows list table to make
possible see all the columns with a smaller display size.

Handle 'Left' & 'Right' keypress to scroll left or right.

Signed-off-by: Vadim Kochan <vadim4j@gmail.com>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>

3 files changed, 46 insertions, 19 deletions

diff --git a/flowtop.c b/flowtop.c
index d98a7b6..1052e08 100644
--- a/flowtop.c
+++ b/flowtop.c
@@ -1190,22 +1190,24 @@ static void draw_help(void)
 
 	mvaddnstr(row + 4, col + 3, "Up, u, k      Move up", -1);
 	mvaddnstr(row + 5, col + 3, "Down, d, j    Move down", -1);
-	mvaddnstr(row + 6, col + 3, "?             Toggle help window", -1);
-	mvaddnstr(row + 7, col + 3, "q, Ctrl+C     Quit", -1);
+	mvaddnstr(row + 6, col + 3, "Left,l        Scroll left", -1);
+	mvaddnstr(row + 7, col + 3, "Right,h       Scroll right", -1);
+	mvaddnstr(row + 8, col + 3, "?             Toggle help window", -1);
+	mvaddnstr(row + 9, col + 3, "q, Ctrl+C     Quit", -1);
 
 	attron(A_BOLD | A_UNDERLINE);
-	mvaddnstr(row + 9, col + 2, "Display Settings", -1);
+	mvaddnstr(row + 11, col + 2, "Display Settings", -1);
 	attroff(A_BOLD | A_UNDERLINE);
 
-	mvaddnstr(row + 11, col + 3, "b     Toggle rate units (bits/bytes)", -1);
-	mvaddnstr(row + 12, col + 3, "a     Toggle display of active flows (rate > 0) only", -1);
-	mvaddnstr(row + 13, col + 3, "s     Toggle show source peer info", -1);
+	mvaddnstr(row + 13, col + 3, "b     Toggle rate units (bits/bytes)", -1);
+	mvaddnstr(row + 14, col + 3, "a     Toggle display of active flows (rate > 0) only", -1);
+	mvaddnstr(row + 15, col + 3, "s     Toggle show source peer info", -1);
 
-	mvaddnstr(row + 15, col + 3, "T     Toggle display TCP flows", -1);
-	mvaddnstr(row + 16, col + 3, "U     Toggle display UDP flows", -1);
-	mvaddnstr(row + 17, col + 3, "D     Toggle display DCCP flows", -1);
-	mvaddnstr(row + 18, col + 3, "I     Toggle display ICMP flows", -1);
-	mvaddnstr(row + 19, col + 3, "S     Toggle display SCTP flows", -1);
+	mvaddnstr(row + 17, col + 3, "T     Toggle display TCP flows", -1);
+	mvaddnstr(row + 18, col + 3, "U     Toggle display UDP flows", -1);
+	mvaddnstr(row + 19, col + 3, "D     Toggle display DCCP flows", -1);
+	mvaddnstr(row + 20, col + 3, "I     Toggle display ICMP flows", -1);
+	mvaddnstr(row + 21, col + 3, "S     Toggle display SCTP flows", -1);
 }
 
 static void draw_header(WINDOW *screen)
@@ -1332,6 +1334,14 @@ static void presenter(void)
 			if (skip_lines > SCROLL_MAX)
 				skip_lines = SCROLL_MAX;
 			break;
+		case KEY_LEFT:
+		case 'h':
+			ui_table_event_send(&flows_tbl, UI_EVT_SCROLL_LEFT);
+			break;
+		case KEY_RIGHT:
+		case 'l':
+			ui_table_event_send(&flows_tbl, UI_EVT_SCROLL_RIGHT);
+			break;
 		case 'b':
 			if (rate_type == RATE_BYTES)
 				rate_type = RATE_BITS;
diff --git a/ui.c b/ui.c
index 23a2293..1ab56af 100644
--- a/ui.c
+++ b/ui.c
@@ -154,7 +154,7 @@ void ui_table_clear(struct ui_table *tbl)
 
 void ui_table_row_show(struct ui_table *tbl)
 {
-	mvaddchstr(tbl->rows_y, tbl->x, tbl->row->str);
+	mvaddchstr(tbl->rows_y, tbl->x, tbl->row->str + tbl->scroll_x);
 	ui_text_len_set(tbl->row, 0);
 }
 
@@ -190,19 +190,28 @@ void ui_table_height_set(struct ui_table *tbl, int height)
 void ui_table_header_print(struct ui_table *tbl)
 {
 	struct ui_col *col;
-	int max_width = tbl->width;
-	int width = 0;
+
+	attron(tbl->hdr_color);
+	mvprintw(tbl->y, tbl->x, "%*s", tbl->width, " ");
+	attroff(tbl->hdr_color);
 
 	list_for_each_entry(col, &tbl->cols, entry) {
 		__ui_table_row_print(tbl, col, tbl->hdr_color, col->name);
 
-		if (width + col->len + tbl->col_pad < max_width)
-			width += col->len + tbl->col_pad;
 	}
 
 	ui_table_row_show(tbl);
+}
 
-	attron(tbl->hdr_color);
-	mvprintw(tbl->y, width, "%*s", max_width - width, " ");
-	attroff(tbl->hdr_color);
+#define SCROLL_X_STEP 10
+
+void ui_table_event_send(struct ui_table *tbl, enum ui_event_id evt_id)
+{
+	if (evt_id == UI_EVT_SCROLL_RIGHT) {
+		tbl->scroll_x += SCROLL_X_STEP;
+	} else if (evt_id == UI_EVT_SCROLL_LEFT) {
+		tbl->scroll_x -= SCROLL_X_STEP;
+		if (tbl->scroll_x < 0)
+			tbl->scroll_x = 0;
+	}
 }
diff --git a/ui.h b/ui.h
index 7f4814c..65338d1 100644
--- a/ui.h
+++ b/ui.h
@@ -6,6 +6,11 @@
 
 #include "list.h"
 
+enum ui_event_id {
+	UI_EVT_SCROLL_LEFT,
+	UI_EVT_SCROLL_RIGHT,
+};
+
 enum ui_align {
 	UI_ALIGN_LEFT,
 	UI_ALIGN_RIGHT,
@@ -37,6 +42,7 @@ struct ui_table {
 	int col_pad;
 	int width;
 	int height;
+	int scroll_x;
 };
 
 extern void ui_table_init(struct ui_table *tbl);
@@ -58,4 +64,6 @@ extern void ui_table_row_print(struct ui_table *tbl, uint32_t col_id,
 extern void ui_table_header_color_set(struct ui_table *tbl, int color);
 extern void ui_table_header_print(struct ui_table *tbl);
 
+extern void ui_table_event_send(struct ui_table *tbl, enum ui_event_id id);
+
 #endif /* UI_H */