Window improvements and first kernel terminal tests.

src/ppytty/kernel/window.py

@@ -106,7 +106,7 @@ def on_color(bg_color):
 
 class Window(object):
 
-    def __init__(self, left, top, width, height, bg=None):
+    def __init__(self, left, top, width, height, bg=None, no_cursor=True):
 
         self._left = left
         self._top = top
@@ -117,6 +117,7 @@ def __init__(self, left, top, width, height, bg=None):
         self._screen = pyte.Screen(width, height)
         self._stream = pyte.ByteStream(self._screen)
 
+        self._screen.cursor.hidden = no_cursor
 
     def __repr__(self):
 
@@ -187,11 +188,15 @@ def render(self, bt=_SelfBlessingsTerminal(), full=False, encoding='utf8'):
         bt_move = bt.move
         self_char_format = self._char_format
 
-        payload = [bt.hide_cursor]
+        payload = []
         payload_append = payload.append
 
         prev_char_format = ''
         line_numbers = range(height) if full else screen_dirty
+
+        if line_numbers and not screen_cursor.hidden:
+            payload_append(bt.hide_cursor)
+
         for line_no in line_numbers:
             line_data = screen_buffer[line_no]
             payload_append(bt_move(top+line_no, left))
@@ -206,10 +211,11 @@ def render(self, bt=_SelfBlessingsTerminal(), full=False, encoding='utf8'):
                     prev_char_format = char_format
                 payload_append(char_data)
 
-        payload_append(bt.normal)
-        payload_append(bt_move(top+screen_cursor.y, left+screen_cursor.x))
-        if not screen_cursor.hidden:
-            payload_append(bt.normal_cursor)
+        if line_numbers:
+            payload_append(bt.normal)
+            payload_append(bt_move(top+screen_cursor.y, left+screen_cursor.x))
+            if not screen_cursor.hidden:
+                payload_append(bt.normal_cursor)
         screen_dirty.clear()
         return ''.join(payload).encode(encoding)
 

tests/kernel/test_terminal.py

@@ -0,0 +1,71 @@
+# ----------------------------------------------------------------------------
+# ppytty
+# ----------------------------------------------------------------------------
+# Copyright (c) Tiago Montes.
+# See LICENSE for deatils.
+# ----------------------------------------------------------------------------
+
+from ppytty.kernel import terminal
+
+from . import io_bypass
+
+
+
+class Test(io_bypass.NoOutputTestCase):
+
+    def setUp(self):
+
+        self.t = terminal.Terminal()
+        self.os_write_mock = self.output_mocks['ppytty.kernel.hw.os_write']
+        self.os_write_mock.reset_mock()
+
+
+    def _get_written_bytes(self):
+
+        # c[0] is the call args tuple; c[0][1] is the 2nd arg to os.write
+        return b''.join(c[0][1] for c in self.os_write_mock.call_args_list)
+
+
+    def _assert_full_80x25_spaces(self, output_bytes):
+
+        # Strip possibly nested fake <tigetstr>/<tparm> calls and count b' '.
+        # The test output terminal is 80x25 so we should get 2000.
+        open_fake, close_fake, space = b'<> '
+        depth = 0
+        space_count = 0
+        for byte_value in output_bytes:
+            if byte_value == space and depth == 0:
+                space_count += 1
+            elif byte_value == open_fake:
+                depth += 1
+            elif byte_value == close_fake:
+                depth -=1
+        self.assertEqual(space_count, 2000, '# of spaces on terminal render')
+
+
+    def test_render(self):
+
+        self.t.render()
+        written_bytes = self._get_written_bytes()
+        self._assert_full_80x25_spaces(written_bytes)
+
+
+    def test_render_rerender(self):
+
+        self.t.render()
+        self.os_write_mock.reset_mock()
+        self.t.render()
+        written_bytes = self._get_written_bytes()
+        self.assertEqual(written_bytes, b'', 'no bytes written on re-render')
+
+
+    def test_render_rerender_full(self):
+
+        self.t.render()
+        self.os_write_mock.reset_mock()
+        self.t.render(full=True)
+        written_bytes = self._get_written_bytes()
+        self._assert_full_80x25_spaces(written_bytes)
+
+
+# ----------------------------------------------------------------------------