From 4a8397433a7b6383e2341a87901b4c64b4f54f0a Mon Sep 17 00:00:00 2001
From: Greg Lucas <greg.m.lucas@gmail.com>
Date: Sun, 1 Oct 2023 17:27:43 -0600
Subject: [PATCH] FIX: Add PyOS_InputHook back to macos backend

The PyOS_InputHook is used to run our event loop while waiting
on standard input from the user. This means we should flush our
events while waiting for any input from the user so the figures
are responsive.
---
 src/_macosx.m | 63 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 63 insertions(+)

diff --git a/src/_macosx.m b/src/_macosx.m
index 8d92b75f6bfe..e9677a40e6b5 100755
--- a/src/_macosx.m
+++ b/src/_macosx.m
@@ -41,6 +41,66 @@
 static bool keyChangeCapsLock = false;
 /* Keep track of the current mouse up/down state for open/closed cursor hand */
 static bool leftMouseGrabbing = false;
+/* Keep track of whether stdin has been received */
+static bool stdin_received = false;
+static bool stdin_sigint = false;
+// Global variable to store the original SIGINT handler
+static struct sigaction originalSigintAction = {0};
+
+// Signal handler for SIGINT, only sets a flag to exit the run loop
+static void handleSigint(int signal) {
+    stdin_sigint = true;
+}
+
+static int wait_for_stdin() {
+    @autoreleasepool {
+        stdin_received = false;
+        stdin_sigint = false;
+
+        // Set up a SIGINT handler to interrupt the event loop if ctrl+c comes in too
+        struct sigaction customAction = {0};
+        customAction.sa_handler = handleSigint;
+        // Set the new handler and store the old one
+        sigaction(SIGINT, &customAction, &originalSigintAction);
+
+        // Create an NSFileHandle for standard input
+        NSFileHandle *stdinHandle = [NSFileHandle fileHandleWithStandardInput];
+
+        // Register for data available notifications on standard input
+        [[NSNotificationCenter defaultCenter] addObserverForName: NSFileHandleDataAvailableNotification
+                                                          object: stdinHandle
+                                                           queue: [NSOperationQueue mainQueue] // Use the main queue
+                                                      usingBlock: ^(NSNotification *notification) {
+                                                                    // Mark that input has been received
+                                                                    stdin_received = true;
+                                                                    }
+        ];
+
+        // Wait in the background for anything that happens to stdin
+        [stdinHandle waitForDataInBackgroundAndNotify];
+
+        // continuously run an event loop until the stdin_received flag is set to exit
+        while (!stdin_received && !stdin_sigint) {
+            while (true) {
+                NSEvent *event = [NSApp nextEventMatchingMask: NSEventMaskAny
+                                                    untilDate: [NSDate distantPast]
+                                                       inMode: NSDefaultRunLoopMode
+                                                      dequeue: YES];
+                if (!event) { break; }
+                [NSApp sendEvent: event];
+            }
+            // We need to run the run loop for a short time to allow the
+            // events to be processed and keep flushing them while we wait for stdin
+            [[NSRunLoop currentRunLoop] runUntilDate: [NSDate dateWithTimeIntervalSinceNow: 0.01]];
+        }
+        // Remove the input handler as an observer
+        [[NSNotificationCenter defaultCenter] removeObserver: stdinHandle];
+
+        // Restore the original SIGINT handler upon exiting the function
+        sigaction(SIGINT, &originalSigintAction, NULL);
+        return 1;
+    }
+}
 
 /* ---------------------------- Cocoa classes ---------------------------- */
 
@@ -139,6 +199,9 @@ static void lazy_init(void) {
     NSApp = [NSApplication sharedApplication];
     [NSApp setActivationPolicy:NSApplicationActivationPolicyRegular];
 
+    // Run our own event loop while waiting for stdin on the Python side
+    // this is needed to keep the application responsive while waiting for input
+    PyOS_InputHook = wait_for_stdin;
 }
 
 static PyObject*