first pass at suspending

thomasballinger · thomasballinger · commit 4a43c116630a · 2014-10-18T02:17:40.000-04:00
Doesn't put the cursor back very well at all, but since we're
going to have no idea what has happened while Python
was suspended there's probably not much we can do.
diff --git a/bpython/curtsies.py b/bpython/curtsies.py
@@ -99,6 +99,14 @@ def event_or_refresh(timeout=None):
                         if starttime + timeout < time.time() or e is not None:
                             yield e
 
+            def on_suspend():
+                window.__exit__(None, None, None)
+                input_generator.__exit__(None, None, None)
+
+            def after_suspend():
+                input_generator.__enter__()
+                window.__enter__()
+
             global repl # global for easy introspection `from bpython.curtsies import repl`
             with Repl(config=config,
                       locals_=locals_,
@@ -109,7 +117,9 @@ def event_or_refresh(timeout=None):
                       banner=banner,
                       interp=interp,
                       interactive=interactive,
-                      orig_tcattrs=input_generator.original_stty) as repl:
+                      orig_tcattrs=input_generator.original_stty,
+                      on_suspend=on_suspend,
+                      after_suspend=after_suspend) as repl:
                 repl.height, repl.width = window.t.height, window.t.width
 
                 def process_event(e):
diff --git a/bpython/curtsiesfrontend/repl.py b/bpython/curtsiesfrontend/repl.py
@@ -219,7 +219,9 @@ def __init__(self,
                  banner=None,
                  interp=None,
                  interactive=True,
-                 orig_tcattrs=None):
+                 orig_tcattrs=None,
+                 on_suspend=lambda *args: None,
+                 after_suspend=lambda *args: None):
         """
         locals_ is a mapping of locals to pass into the interpreter
         config is a bpython config.Struct with config attributes
@@ -298,6 +300,8 @@ def smarter_request_reload(desc):
                                # because there wasn't room to display everything
         self._cursor_offset = 0 # from the left, 0 means first char
         self.orig_tcattrs = orig_tcattrs # useful for shelling out with normal terminal
+        self.on_suspend = on_suspend
+        self.after_suspend = after_suspend
 
         self.coderunner = CodeRunner(self.interp, self.request_refresh)
         self.stdout = FakeOutput(self.coderunner, self.send_to_stdout)
@@ -335,7 +339,9 @@ def __enter__(self):
         sys.stderr = self.stderr
         sys.stdin = self.stdin
         self.orig_sigwinch_handler = signal.getsignal(signal.SIGWINCH)
+        self.orig_sigtstp_handler = signal.getsignal(signal.SIGTSTP)
         signal.signal(signal.SIGWINCH, self.sigwinch_handler)
+        signal.signal(signal.SIGTSTP, self.sigtstp_handler)
 
         self.orig_import = __builtins__['__import__']
         if self.watcher:
@@ -369,6 +375,7 @@ def __exit__(self, *args):
         sys.stdout = self.orig_stdout
         sys.stderr = self.orig_stderr
         signal.signal(signal.SIGWINCH, self.orig_sigwinch_handler)
+        signal.signal(signal.SIGTSTP, self.orig_sigtstp_handler)
         __builtins__['__import__'] = self.orig_import
 
     def sigwinch_handler(self, signum, frame):
@@ -379,6 +386,13 @@ def sigwinch_handler(self, signum, frame):
         logger.info('sigwinch! Changed from %r to %r', (old_rows, old_columns), (self.height, self.width))
         logger.info('decreasing scroll offset by %d to %d', cursor_dy, self.scroll_offset)
 
+    def sigtstp_handler(self, signum, frame):
+        self.__exit__()
+        self.on_suspend()
+        os.kill(os.getpid(), signal.SIGTSTP)
+        self.after_suspend()
+        self.__enter__()
+
     def startup(self):
         """
         Execute PYTHONSTARTUP file if it exits. Call this after front
