From: Jeffrey Middleton <jefromi@gmail.com>
Date: Thu, 5 Mar 2009 22:43:02 +0000 (-0600)
Subject: list_window: Added scroll up/down commands
X-Git-Tag: release-0.14~82
X-Git-Url: https://git.tokkee.org/?a=commitdiff_plain;h=01694c3c217403471136792b0730fdd2263ea8ea;p=ncmpc.git

list_window: Added scroll up/down commands

Commands scroll a list window up/down by one line, mapped by default to
Ctrl-N and Ctrl-B (mnemonics next and back).  The scrolling functions can
scroll by an arbitrary amount, so we can use them later for half-screen scroll
commands like Vim's Ctrl-D/U.
---

diff --git a/src/command.c b/src/command.c
index 3a16e80..7182d16 100644
--- a/src/command.c
+++ b/src/command.c
@@ -92,6 +92,10 @@ static command_definition_t cmds[] = {
 	  N_("Page down") },
 	{ { 'v',  0, 0 }, 0, CMD_LIST_VISUAL_SELECT, "visual-select",
 	  N_("Visual selection") },
+	{ { 14,  0, 0 }, 0, CMD_LIST_SCROLL_DOWN_LINE, "scroll-down-line",
+	  N_("Scroll up one line") },
+	{ { 2,  0, 0 }, 0, CMD_LIST_SCROLL_UP_LINE, "scroll-up-line",
+	  N_("Scroll down one line") },
 
 
 	/* basic screens */
diff --git a/src/command.h b/src/command.h
index c7514c4..abfca44 100644
--- a/src/command.h
+++ b/src/command.h
@@ -74,6 +74,8 @@ typedef enum {
 	CMD_LIST_MOVE_UP,
 	CMD_LIST_MOVE_DOWN,
 	CMD_LIST_VISUAL_SELECT,
+	CMD_LIST_SCROLL_UP_LINE,
+	CMD_LIST_SCROLL_DOWN_LINE,
 	CMD_MOUSE_EVENT,
 	CMD_SCREEN_UPDATE,
 	CMD_SCREEN_PREVIOUS,
diff --git a/src/list_window.c b/src/list_window.c
index 8d1a2d5..a127a5b 100644
--- a/src/list_window.c
+++ b/src/list_window.c
@@ -221,6 +221,56 @@ list_window_previous_page(struct list_window *lw)
 		list_window_first(lw);
 }
 
+static void
+list_window_scroll_up(struct list_window *lw, unsigned n)
+{
+	if (lw->start > 0) {
+		if (n > lw->start)
+			lw->start = 0;
+		else
+			lw->start -= n;
+		if (lw->selected > lw->start + lw->rows - 1) {
+			lw->selected = lw->start + lw->rows - 1;
+			if (lw->visual_selection) {
+				if (lw->selected < lw->visual_base) {
+					lw->selected_start = lw->selected;
+					lw->selected_end = lw->visual_base;
+				} else {
+					lw->selected_end = lw->selected;
+				}
+			} else {
+				lw->selected_start = lw->selected;
+				lw->selected_end = lw->selected;
+			}
+		}
+	}
+}
+
+static void
+list_window_scroll_down(struct list_window *lw, unsigned length, unsigned n)
+{
+	if (lw->start + lw->rows < length - 1)
+	{
+		if ( lw->start + lw->rows + n > length - 1)
+			lw->start = length-1;
+		else
+			lw->start += n;
+		if (lw->selected < lw->start) {
+			lw->selected = lw->start;
+			if (lw->visual_selection) {
+				if (lw->selected > lw->visual_base) {
+					lw->selected_end = lw->selected;
+					lw->selected_start = lw->visual_base;
+				} else {
+					lw->selected_start = lw->selected;
+				}
+			} else {
+				lw->selected_start = lw->selected;
+				lw->selected_end = lw->selected;
+			}
+		}
+	}
+}
 
 void
 list_window_paint(struct list_window *lw,
@@ -434,6 +484,12 @@ list_window_cmd(struct list_window *lw, unsigned rows, command_t cmd)
 			lw->visual_selection = true;
 		}
 		break;
+	case CMD_LIST_SCROLL_UP_LINE:
+		list_window_scroll_up(lw, 1);
+		break;
+	case CMD_LIST_SCROLL_DOWN_LINE:
+		list_window_scroll_down(lw, rows, 1);
+		break;
 	default:
 		return false;
 	}
diff --git a/src/screen_help.c b/src/screen_help.c
index 5a0654f..e731664 100644
--- a/src/screen_help.c
+++ b/src/screen_help.c
@@ -47,6 +47,8 @@ static help_text_row_t help_text[] = {
 	{ 0, CMD_LIST_FIRST, NULL },
 	{ 0, CMD_LIST_LAST, NULL },
 	{ 0, CMD_LIST_VISUAL_SELECT, NULL },
+	{ 0, CMD_LIST_SCROLL_UP_LINE, NULL},
+	{ 0, CMD_LIST_SCROLL_DOWN_LINE, NULL},
 	{ 0, CMD_NONE, NULL },
 	{ 0, CMD_SCREEN_PREVIOUS,NULL },
 	{ 0, CMD_SCREEN_NEXT, NULL },