Screen: More implementation details.

Only a single function is a stub now --- the actual drawing.

Signed-off-by: Ramūnas Mažeikis <ramunasnezinomas@gmail.com>

2 files changed, 45 insertions, 25 deletions

diff --git a/src/device/screen.c b/src/device/screen.c
index 6ad9a87..ac42076 100755
--- a/src/device/screen.c
+++ b/src/device/screen.c
@@ -1,10 +1,45 @@
 #include <time.h>
 #include <stdlib.h>
+#include <string.h>
 #include "screen.h"
 
 void draw_lines(struct display_status *status);
 void update_lines(struct display_status *status);
-char * get_line(struct display_status *status, size_t rline);
+void init_msg(char *msg, size_t size);
+
+void display_status_init(struct display_status *status, char *msg)
+{
+	status->delta = 2;	/* Currently default */
+	init_msg(msg, strlen(msg));
+	status->message = msg;
+	status->line_cursor = 0;
+	status->last_scroll_time = time(NULL);
+	update_lines(status);
+}
+
+/**
+ * Turns all whitespace into literal spaces to save screen real-estate.
+ */
+void init_msg(char *msg, size_t size)
+{
+	size_t i;
+
+	for (i = 0; i < size; i++) {
+		switch (msg[i]) {
+		case '\n':
+		case '\t':
+		case '\r':
+			msg[i] = ' ';
+			break;
+		case '\0':
+			goto end;
+		default:
+			break;
+		}
+	}
+end:
+	return;
+}
 
 void display_update_scroll(struct display_status *status)
 {
@@ -19,34 +54,11 @@ void display_update_scroll(struct display_status *status)
 
 void draw_lines(struct display_status *status)
 {
-
+	/* TODO */
 }
 
 void update_lines(struct display_status *status)
 {
 	status->first_line = get_line(status, status->line_cursor);
 	status->second_line = get_line(status, status->line_cursor + 1);
-}
-
-/**
- * Returns a pointer to the first charachter of requested line. If line does not
- * exist --- a null is returned.
- */
-char * get_line(struct display_status *status, size_t rline)
-{
-	size_t i;
-	size_t line_idx = 0;
-
-	for (i = 0; i < status->message_len; i++) {
-		if (rline == line_idx) {
-			return status->message + i;
-		}
-		if (status->message[i] == '\0') {
-			line_idx++;
-		}
-	}
-	/* The fact that we are here means that end of the message was reached.
-	 * In that case --- return null;
-	 */
-	return NULL;
 }
\ No newline at end of file
diff --git a/src/device/screen.h b/src/device/screen.h
index ec30cd5..7763bd2 100755
--- a/src/device/screen.h
+++ b/src/device/screen.h
@@ -3,6 +3,10 @@
 
 #include <time.h>
 
+#define SCREEN_WIDTH		(64)
+#define FONT_WIDTH		(8)
+#define SCREEN_MAX_CHARS	(SCREEN_WIDTH / FONT_WIDTH)
+
 /**
  * Struct that keeps track of the lines on the screen.
  */
@@ -16,7 +20,11 @@ struct display_status {
 	size_t line_cursor;		/* Index of the first line being displayed. */
 };
 
+/**
+ * Displays scrolling text on the screen.
+ */
 void display_update_scroll(struct display_status *status);
+
 void display_status_init(struct display_status *status, char *msg);
 
 #endif /* DEVICE_SCREEN_H */
\ No newline at end of file