add keyboard command ^L to switch windows

3 files changed, 54 insertions, 3 deletions

diff --git a/vicmd.w b/vicmd.w
index 4df8c66..113f9c8 100644
--- a/vicmd.w
+++ b/vicmd.w
@@ -1118,8 +1118,27 @@ keyboard driven editor with minimal visual footprint.
 static int a_tag(char buf, Cmd c, Cmd mc)
 {
 	(void)buf; @+(void)c; @+(void)mc;
-	chwin(win_tag_toggle(curwin));
-	return 0;
+	return chwin(win_tag_toggle(curwin)), 0;
+}
+
+@ Switching between windows is done by clicks.  One can also use
+the keyboard command \.{\^L} followed by any of the basic line
+motions \.h, \.j, \.k, and \.l to jump directly to a neighbor
+window.
+
+@<Subr...@>=
+static int a_swtch(char buf, Cmd c, Cmd mc)
+{
+	(void)buf; @+(void)mc;
+	switch (c.arg) {
+	default:
+		return 1;
+	case 'h':
+	case 'j':
+	case 'k':
+	case 'l':
+		return chwin(win_edge(curwin, c.arg)), 0;
+	}
 }
 
 @ Still from Acme, the editor allows the user to run arbitrary
@@ -1281,7 +1300,7 @@ typedef int @[@] cmd_t(char, Cmd, Cmd);
 array below.
 
 @<Predecl...@>=
-static cmd_t a_d, a_c, a_y, a_pP, a_m, a_ins, a_run, a_scroll, a_tag, a_write, a_exit;
+static cmd_t a_d, a_c, a_y, a_pP, a_m, a_ins, a_run, a_scroll, a_swtch, a_tag, a_write, a_exit;
 
 @ @<Other key fields@>=
 union {
@@ -1320,6 +1339,7 @@ union {
 [CTRL('U')] = Act(CZeroCount, a_scroll),@/
 [CTRL('E')] = Act(0, a_scroll), [CTRL('Y')] = Act(0, a_scroll),@/
 [CTRL('T')] = Act(0, a_tag), [CTRL('I')] = Act(0, a_run),@/
+[CTRL('L')] = Act(CHasArg, a_swtch),@/
 [CTRL('W')] = Act(0, a_write), [CTRL('Q')] = Act(0, a_exit),
 
 @** Index.
diff --git a/win.c b/win.c
index ee5bd66..eae4b13 100644
--- a/win.c
+++ b/win.c
@@ -166,6 +166,36 @@ win_which(int x1, int y1)
 	return w;
 }
 
+/* win_edge - Find the edge window in the specified direction.
+ */
+W *
+win_edge(W *w, int dir)
+{
+	W *w1;
+	int i;
+
+	w1 = win_text(w);
+	if (dir == 'j' || dir == 'k') {
+		if (tag.visible && w == tag.owner)
+			return &tag.win;
+		return w1;
+	}
+	for (i=0; w1 != screen[i]; i++)
+		;
+	switch (dir) {
+	case 'h':
+		if (--i < 0)
+		while (screen[i+1])
+			i++;
+		break;
+	case 'l':
+		if (!screen[++i])
+			i = 0;
+		break;
+	}
+	return screen[i];
+}
+
 /* win_move - Resize or move a window to approximately set its
  * upper-left corner to the specified location.
  */
diff --git a/win.h b/win.h
index 1faaab0..bf2f913 100644
--- a/win.h
+++ b/win.h
@@ -36,6 +36,7 @@ W *win_new(void);
 W *win_kill(W *);
 unsigned win_at(W *w, int x, int y);
 W *win_which(int x, int y);
+W *win_edge(W *, int dir);
 void win_move(W *, int x, int y);
 void win_resize_frame(int w, int h);
 void win_redraw_frame(W *focus, int insert);