list_window: added list_window_scroll_cmd()

It is similar to list_window_cmd(), but it scrolls the window instead
of moving the selection.  It is used by the "lyrics" and the "help"
screen.

4 files changed, 62 insertions, 69 deletions

diff --git a/src/list_window.c b/src/list_window.c
index 88f0a690c..f26088da4 100644
--- a/src/list_window.c
+++ b/src/list_window.c
@@ -296,6 +296,56 @@ list_window_cmd(struct list_window *lw, unsigned rows, command_t cmd)
 	return 1;
 }
 
+int
+list_window_scroll_cmd(struct list_window *lw, unsigned rows, command_t cmd)
+{
+	switch (cmd) {
+	case CMD_LIST_PREVIOUS:
+		if (lw->start > 0)
+			lw->start--;
+		break;
+
+	case CMD_LIST_NEXT:
+		if (lw->start + lw->rows < rows)
+			lw->start++;
+		break;
+
+	case CMD_LIST_FIRST:
+		lw->start = 0;
+		break;
+
+	case CMD_LIST_LAST:
+		if (rows > lw->rows)
+			lw->start = rows - lw->rows;
+		else
+			lw->start = 0;
+		break;
+
+	case CMD_LIST_NEXT_PAGE:
+		lw->start += lw->rows - 1;
+		if (lw->start + lw->rows > rows) {
+			if (rows > lw->rows)
+				lw->start = rows - lw->rows;
+			else
+				lw->start = 0;
+		}
+		break;
+
+	case CMD_LIST_PREVIOUS_PAGE:
+		if (lw->start > lw->rows)
+			lw->start -= lw->rows;
+		else
+			lw->start = 0;
+		break;
+
+	default:
+		return 0;
+	}
+
+	lw->repaint = lw->clear = 1;
+	return 1;
+}
+
 list_window_state_t *
 list_window_init_state(void)
 {
diff --git a/src/list_window.h b/src/list_window.h
index 2efff8a5c..ab02f4bdd 100644
--- a/src/list_window.h
+++ b/src/list_window.h
@@ -49,6 +49,13 @@ void list_window_paint(struct list_window *lw,
 /* perform basic list window commands (movement) */
 int list_window_cmd(struct list_window *lw, unsigned rows, command_t cmd);
 
+/**
+ * Scroll the window.  Returns non-zero if the command has been
+ * consumed.
+ */
+int
+list_window_scroll_cmd(struct list_window *lw, unsigned rows, command_t cmd);
+
 
 /* select functions */
 void list_window_set_selected(struct list_window *lw, unsigned n);
diff --git a/src/screen_help.c b/src/screen_help.c
index 7c5134fc6..850608181 100644
--- a/src/screen_help.c
+++ b/src/screen_help.c
@@ -240,44 +240,8 @@ help_update(mpd_unused screen_t *screen, mpd_unused mpdclient_t *c)
 static int
 help_cmd(screen_t *screen, mpd_unused mpdclient_t *c, command_t cmd)
 {
-	lw->repaint=1;
-	lw->clear=1;
-	switch(cmd) {
-	case CMD_LIST_NEXT:
-		if (lw->start + lw->rows < (unsigned)help_text_rows)
-			lw->start++;
+	if (list_window_scroll_cmd(lw, help_text_rows, cmd))
 		return 1;
-	case CMD_LIST_PREVIOUS:
-		if (lw->start > 0)
-			lw->start--;
-		return 1;
-	case CMD_LIST_FIRST:
-		lw->start = 0;
-		return 1;
-	case CMD_LIST_LAST:
-		if ((unsigned)help_text_rows > lw->rows)
-			lw->start = help_text_rows - lw->rows;
-		else
-			lw->start = 0;
-		return 1;
-	case CMD_LIST_NEXT_PAGE:
-		lw->start = lw->start + lw->rows;
-		if (lw->start + lw->rows >= (unsigned)help_text_rows) {
-			if ((unsigned)help_text_rows > lw->rows)
-				lw->start = help_text_rows - lw->rows;
-			else
-				lw->start = 0;
-		}
-		return 1;
-	case CMD_LIST_PREVIOUS_PAGE:
-		if (lw->start > lw->rows)
-			lw->start -= lw->rows;
-		else
-			lw->start = 0;
-		return 1;
-	default:
-		break;
-	}
 
 	lw->selected = lw->start+lw->rows;
 	if (screen_find(screen,
diff --git a/src/screen_lyrics.c b/src/screen_lyrics.c
index e6e2cf0df..5356548c9 100644
--- a/src/screen_lyrics.c
+++ b/src/screen_lyrics.c
@@ -289,40 +289,12 @@ lyrics_update(mpd_unused screen_t *screen, mpd_unused mpdclient_t *c)
 static int
 lyrics_cmd(screen_t *screen, mpdclient_t *c, command_t cmd)
 {
+	if (list_window_scroll_cmd(lw, current.lines->len, cmd))
+		return 1;
+
 	lw->repaint=1;
+
 	switch(cmd) {
-	case CMD_LIST_NEXT:
-		if (current.lines != NULL && lw->start+lw->rows < current.lines->len+1)
-			lw->start++;
-		return 1;
-	case CMD_LIST_PREVIOUS:
-		if( lw->start >0 )
-			lw->start--;
-		return 1;
-	case CMD_LIST_FIRST:
-		lw->start = 0;
-		return 1;
-	case CMD_LIST_LAST:
-		if ((unsigned)lyrics_text_rows > lw->rows)
-			lw->start = lyrics_text_rows - lw->rows;
-		else
-			lw->start = 0;
-		return 1;
-	case CMD_LIST_NEXT_PAGE:
-		lw->start = lw->start + lw->rows - 1;
-		if (lw->start + lw->rows >= (unsigned)lyrics_text_rows + 1) {
-			if ((unsigned)lyrics_text_rows + 1 > lw->rows)
-				lw->start = lyrics_text_rows + 1 - lw->rows;
-			else
-				lw->start = 0;
-		}
-		return 1;
-	case CMD_LIST_PREVIOUS_PAGE:
-		if (lw->start > lw->rows)
-			lw->start -= lw->rows;
-		else
-			lw->start = 0;
-		return 1;
 	case CMD_SELECT:
 		/* XXX */
 		if (current.loader != NULL) {