Implement page up and page down

1 files changed, 29 insertions, 6 deletions

diff --git a/ted.c b/ted.c
index a0d6492..4568719 100644
--- a/ted.c
+++ b/ted.c
@@ -35,7 +35,9 @@ enum editor_key {
   ARROW_LEFT  = 1000,
   ARROW_RIGHT,
   ARROW_UP,
-  ARROW_DOWN
+  ARROW_DOWN,
+  PAGE_UP,
+  PAGE_DOWN
 };
 
 typedef struct editor_config {
@@ -109,11 +111,23 @@ editor_read_key()
     }
 
     if (seq[0] == '[') {
-      switch (seq[1]) {
-        case 'A': return ARROW_UP;
-        case 'B': return ARROW_DOWN;
-        case 'C': return ARROW_RIGHT;
-        case 'D': return ARROW_LEFT;
+      if (seq[1] >= '0' && seq[1] <= '9') {
+        if (read(STDIN_FILENO, &seq[2], 1) != 1) {
+          return '\x1b';
+        }
+        if (seq[2] == '~') {
+          switch (seq[1]) {
+            case '5': return PAGE_UP;
+            case '6': return PAGE_DOWN;
+          }
+        }
+      } else {
+        switch (seq[1]) {
+          case 'A': return ARROW_UP;
+          case 'B': return ARROW_DOWN;
+          case 'C': return ARROW_RIGHT;
+          case 'D': return ARROW_LEFT;
+        }
       }
     }
     return '\x1b';
@@ -207,6 +221,15 @@ editor_process_key(editor_config_t *ec)
       editor_clear_screen();
       exit(EXIT_SUCCESS);
       break;
+    case PAGE_UP:
+    case PAGE_DOWN:
+      {
+        int times = ec->screen_rows;
+        while (times--) {
+          editor_move_cursor(ec, c == PAGE_UP ? ARROW_UP : ARROW_DOWN);
+        }
+      }
+      break;
     case ARROW_UP:
     case ARROW_DOWN:
     case ARROW_LEFT: