From: Ali Gholami Rudi <ali@rudi.ir>
Date: Fri, 22 Mar 2013 15:51:52 +0000 (+0430)
Subject: fbpdf: align with the leftmost/rightmost character in the page
X-Git-Url: https://repo.or.cz/w/fbpdf.git/commitdiff_plain/8b5212e91baf6c14f6d34cd373e509e74d7060e3

fbpdf: align with the leftmost/rightmost character in the page

[ and ] commands align the screen with the leftmost and rightmost
characters on the page.  Very convenient especially for multi-column
pages.
---

diff --git a/README b/README
index 53cb050..66de094 100644
--- a/README
+++ b/README
@@ -38,6 +38,8 @@ j		scroll down
 k		scroll up
 h		scroll left
 l		scroll right
+[		align with the leftmost character on the page
+]		align with the rightmost character on the page
 H		show top
 M		show middle
 L		show bottom
diff --git a/fbpdf.c b/fbpdf.c
index 8cfc880..a6725e1 100644
--- a/fbpdf.c
+++ b/fbpdf.c
@@ -118,6 +118,38 @@ static void reload(void)
 	showpage(num, head);
 }
 
+static int rightmost(void)
+{
+	int ret = 0;
+	int i, j;
+	for (i = 0; i < prows; i++) {
+		j = PDFCOLS - 1;
+		while (j > ret && pbuf[i * PDFCOLS + j] == FB_VAL(0, 0, 0))
+			j--;
+		while (j > ret && pbuf[i * PDFCOLS + j] == FB_VAL(255, 255, 255))
+			j--;
+		if (ret < j)
+			ret = j;
+	}
+	return ret;
+}
+
+static int leftmost(void)
+{
+	int ret = PDFCOLS;
+	int i, j;
+	for (i = 0; i < prows; i++) {
+		j = 0;
+		while (j < ret && pbuf[i * PDFCOLS + j] == FB_VAL(0, 0, 0))
+			j++;
+		while (j < ret && pbuf[i * PDFCOLS + j] == FB_VAL(255, 255, 255))
+			j++;
+		if (ret > j)
+			ret = j;
+	}
+	return ret;
+}
+
 static void mainloop(void)
 {
 	int step = fb_rows() / PAGESTEPS;
@@ -211,6 +243,12 @@ static void mainloop(void)
 		case CTRL('u'):
 			head -= fb_rows() * getcount(1) - step;
 			break;
+		case '[':
+			left = leftmost() - hstep / 2;
+			break;
+		case ']':
+			left = rightmost() + hstep / 2 - fb_cols();
+			break;
 		case CTRLKEY('l'):
 			break;
 		default: