From f8c7213bb9bde9f6c25a705d4ac6c1ea3059f73f Mon Sep 17 00:00:00 2001
From: Oleksandr Nahnybida <oleksandr.nahnybida@gmail.com>
Date: Wed, 30 Aug 2023 22:48:10 +0300
Subject: [PATCH] Redirect program output to separate window

---
 gf2.cpp     | 10 ++++++++++
 windows.cpp | 57 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 67 insertions(+)

diff --git a/gf2.cpp b/gf2.cpp
index 8d5c3d1..e7e45a2 100644
--- a/gf2.cpp
+++ b/gf2.cpp
@@ -22,6 +22,7 @@
 #include <fcntl.h>
 #include <poll.h>
 #include <time.h>
+#include <pty.h>
 
 extern "C" {
 #define UI_FONT_PATH
@@ -33,6 +34,7 @@ extern "C" {
 #define MSG_RECEIVED_DATA ((UIMessage) (UI_MSG_USER + 1))
 #define MSG_RECEIVED_CONTROL ((UIMessage) (UI_MSG_USER + 2))
 #define MSG_RECEIVED_LOG ((UIMessage) (UI_MSG_USER + 3))
+#define MSG_RECEIVED_STDOUT ((UIMessage) (UI_MSG_USER + 4))
 
 // Data structures:
 
@@ -142,6 +144,9 @@ FILE *commandLog;
 char emptyString;
 bool programRunning = true;
 const char *vimServerName = "GVIM";
+
+char setPttyCMD[PATH_MAX];
+int pseudoTerminalMasterFD = -1;
 const char *logPipePath;
 const char *controlPipePath;
 Array<INIState> presetCommands;
@@ -558,6 +563,8 @@ void *DebuggerThread(void *) {
 	const char *setPrompt = "set prompt (gdb) \n";
 	write(pipeToGDB, setPrompt, strlen(setPrompt));
 
+	write(pipeToGDB, setPttyCMD, strlen(setPttyCMD));
+
 	char *catBuffer = NULL;
 	size_t catBufferUsed = 0;
 	size_t catBufferAllocated = 0;
@@ -1310,6 +1317,7 @@ void InterfaceAddBuiltinWindowsAndCommands() {
 	interfaceWindows.Add({ "Files", FilesWindowCreate, nullptr });
 	interfaceWindows.Add({ "Console", ConsoleWindowCreate, nullptr });
 	interfaceWindows.Add({ "Log", LogWindowCreate, nullptr });
+	interfaceWindows.Add({ "STDOUT", STDOUTWindowCreate, nullptr });
 	interfaceWindows.Add({ "Thread", ThreadWindowCreate, ThreadWindowUpdate });
 	interfaceWindows.Add({ "Exe", ExecutableWindowCreate, nullptr });
 
@@ -1482,6 +1490,8 @@ int WindowMessage(UIElement *, UIMessage message, int di, void *dp) {
 		free(input);
 	} else if (message == MSG_RECEIVED_LOG) {
 		LogReceived(dp);
+	} else if (message == MSG_RECEIVED_STDOUT) {
+		STDOUTReceived(dp);
 	} else if (message == UI_MSG_WINDOW_ACTIVATE) {
 		DisplaySetPosition(currentFileFull, currentLine, false);
 	}
diff --git a/windows.cpp b/windows.cpp
index 81bfabb..050cf8a 100644
--- a/windows.cpp
+++ b/windows.cpp
@@ -2521,6 +2521,63 @@ UIElement *CommandsWindowCreate(UIElement *parent) {
 	return &panel->e;
 }
 
+//////////////////////////////////////////////////////
+// STDOUT window:
+//////////////////////////////////////////////////////
+
+void *STDOUTWindowThread(void *context) {
+	if (pseudoTerminalMasterFD < 0) {
+		fprintf(stderr, "Warning: ptty fd invalid\n");
+		return nullptr;
+	}
+
+	struct pollfd p = { .fd = pseudoTerminalMasterFD, .events = POLLIN };
+
+	while (true) {
+		poll(&p, 1, 10000);
+
+		if (p.revents & POLLHUP) {
+			struct timespec t = { .tv_nsec = 10000000 };
+			nanosleep(&t, 0);
+		}
+
+		while (true) {
+			char input[16384];
+			int length = read(pseudoTerminalMasterFD, input, sizeof(input) - 1);
+			if (length <= 0) break;
+			input[length] = 0;
+			void *buffer = malloc(strlen(input) + sizeof(context) + 1);
+			memcpy(buffer, &context, sizeof(context));
+			strcpy((char *) buffer + sizeof(context), input);
+			UIWindowPostMessage(windowMain, MSG_RECEIVED_STDOUT, buffer);
+		}
+	}
+}
+
+void STDOUTReceived(void *buffer) {
+	UICodeInsertContent(*(UICode **) buffer, (char *) buffer + sizeof(void *), -1, false);
+	UIElementRefresh(*(UIElement **) buffer);
+	free(buffer);
+}
+
+UIElement *STDOUTWindowCreate(UIElement *parent) {
+	int master_tty, slave_tty;
+	char pseudoTerminalPath[PATH_MAX];
+	int ret = openpty(&master_tty, &slave_tty, pseudoTerminalPath, NULL, NULL);
+	if (ret < 0) {
+		fprintf(stderr, "Warning: cannot open pseudo tty");
+		/* TODO(Oleksandr): What should I do here, is it allowed to return NULL from window create? */
+	}
+	StringFormat(setPttyCMD, sizeof(setPttyCMD), "tty %s\n", pseudoTerminalPath);
+	pseudoTerminalMasterFD = master_tty;
+
+
+	UICode *code = UICodeCreate(parent, 0);
+	pthread_t thread;
+	pthread_create(&thread, nullptr, STDOUTWindowThread, code);
+	return &code->e;
+}
+
 //////////////////////////////////////////////////////
 // Log window:
 //////////////////////////////////////////////////////