From 3f44d16f5297a0f7d63f98e48eba46c1e2538a3e Mon Sep 17 00:00:00 2001
From: Anton Kling <anton@kling.gg>
Date: Mon, 23 Oct 2023 20:10:01 +0200
Subject: WindowServer/LibGUI: Add a eventloop

This can be used by any program does nothing until it gets user input.
---
 userland/libgui/libgui.c   | 27 +++++++++++++++++++++++++--
 userland/libgui/libgui.h   |  4 ++++
 userland/windowserver/ws.c | 23 +++++++++++++++--------
 userland/windowserver/ws.h |  3 +++
 4 files changed, 47 insertions(+), 10 deletions(-)

diff --git a/userland/libgui/libgui.c b/userland/libgui/libgui.c
index 5f5526d..a344778 100644
--- a/userland/libgui/libgui.c
+++ b/userland/libgui/libgui.c
@@ -2,6 +2,7 @@
 #include "font.h"
 #include <assert.h>
 #include <fcntl.h>
+#include <poll.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -155,7 +156,6 @@ char *random_string(void) {
   }
   close(fd);
   r[9] = '\0';
-  printf("r: %s\n", r);
   return r;
 }
 
@@ -230,7 +230,30 @@ typedef struct {
 
 void GUI_ClearScreen(GUI_Window *w, uint32_t color) {
   for (int i = 0; i < w->sx * w->sy; i++)
-    w->bitmap_ptr[i] =color;
+    w->bitmap_ptr[i] = color;
+}
+
+void GUI_EventLoop(GUI_Window *w, void (*event_handler)(WS_EVENT ev)) {
+  struct pollfd fds[1];
+  fds[0].fd = w->ws_socket;
+  fds[0].events = POLLIN;
+  fds[0].revents = 0;
+  for (;; fds[0].revents = 0) {
+    poll(fds, 1, 0);
+    if (!(fds[0].revents & POLLIN))
+      continue;
+
+    int rc;
+    WS_EVENT e;
+    if (0 >= (rc = read(w->ws_socket, &e, sizeof(e))))
+      continue;
+    if (event_handler) {
+      event_handler(e);
+      continue;
+    }
+    if (WINDOWSERVER_EVENT_WINDOW_EXIT == e.type)
+      exit(0);
+  }
 }
 
 GUI_Window *GUI_CreateWindow(uint32_t x, uint32_t y, uint32_t sx, uint32_t sy) {
diff --git a/userland/libgui/libgui.h b/userland/libgui/libgui.h
index d58c23c..07fd3db 100644
--- a/userland/libgui/libgui.h
+++ b/userland/libgui/libgui.h
@@ -3,6 +3,9 @@
 #include <stddef.h>
 #include <stdint.h>
 
+#define WINDOWSERVER_EVENT_KEYPRESS 0
+#define WINDOWSERVER_EVENT_WINDOW_EXIT 1
+
 typedef struct {
   int ws_socket;
   int bitmap_fd;
@@ -31,4 +34,5 @@ void GUI_UpdateWindow(GUI_Window *w);
 void GUI_OverwriteFont(GUI_Window *w, uint32_t px, uint32_t py,
                        const uint32_t color);
 void GUI_ClearScreen(GUI_Window *w, uint32_t color);
+void GUI_EventLoop(GUI_Window *w, void (*event_handler)(WS_EVENT ev));
 #endif
diff --git a/userland/windowserver/ws.c b/userland/windowserver/ws.c
index 2211b00..3d6e10f 100644
--- a/userland/windowserver/ws.c
+++ b/userland/windowserver/ws.c
@@ -1,13 +1,12 @@
-#include <fcntl.h>
-#include <poll.h>
-#include <stddef.h>
-#include <stdint.h>
-//#include <sys/mman.h>
+#include "ws.h"
 #include "draw.h"
 #include "font.h"
-#include "ws.h"
 #include <assert.h>
+#include <fcntl.h>
+#include <poll.h>
 #include <socket.h>
+#include <stddef.h>
+#include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/mman.h>
@@ -193,7 +192,7 @@ typedef struct {
   struct KEY_EVENT ev;
 } WS_EVENT;
 
-void send_to_window(struct KEY_EVENT ev) {
+void send_key_event_to_window(struct KEY_EVENT ev) {
   WS_EVENT e = {
       .type = 0,
       .ev = ev,
@@ -221,6 +220,13 @@ int windowserver_key_events(struct KEY_EVENT ev, int *redraw) {
     return 0;
   if (!(ev.mode & (1 << 1)))
     return 0;
+  if ('q' == ev.c) {
+    WS_EVENT e = {
+        .type = WINDOWSERVER_EVENT_WINDOW_EXIT,
+    };
+    write(main_display.active_window->fd, &e, sizeof(e));
+    return 1;
+  }
   if ('n' == ev.c) {
     // Create a new terminal
     int pid = fork();
@@ -230,6 +236,7 @@ int windowserver_key_events(struct KEY_EVENT ev, int *redraw) {
       execv("/term", argv);
       assert(0);
     }
+    return 1;
   }
   if (!main_display.active_window)
     return 0;
@@ -344,7 +351,7 @@ void parse_keyboard_event(int fd) {
         continue;
       if (!main_display.active_window)
         continue;
-      send_to_window(ev[i]);
+      send_key_event_to_window(ev[i]);
     }
   }
   if (redraw)
diff --git a/userland/windowserver/ws.h b/userland/windowserver/ws.h
index 9236e01..241c960 100644
--- a/userland/windowserver/ws.h
+++ b/userland/windowserver/ws.h
@@ -3,6 +3,9 @@
 #include <stddef.h>
 #include <stdint.h>
 
+#define WINDOWSERVER_EVENT_KEYPRESS 0
+#define WINDOWSERVER_EVENT_WINDOW_EXIT 1
+
 typedef struct {
   int fd;
   int bitmap_fd;
-- 
cgit v1.2.3