Refine event handling

This commit adds a member function for event handling to the backend
interface, replacing the previous file-based system that relies on
poll(2). The new design addresses issues created by backends like SDL,
which do not expose underlying file descriptors.

Close #4

Makefile

@@ -23,7 +23,6 @@ libtwin.a_cflags-y :=
 
 libtwin.a_files-y = \
 	src/box.c \
-	src/file.c \
 	src/poly.c \
 	src/toplevel.c \
 	src/button.c \

apps/main.c

@@ -128,7 +128,7 @@ int main(void)
                          20);
 #endif
 
-    twin_dispatch();
+    twin_dispatch(tx);
 
     return 0;
 }

backend/linux_input.c

@@ -284,11 +284,6 @@ static void *twin_linux_evdev_thread(void *arg)
     return NULL;
 }
 
-static bool dummy(int file, twin_file_op_t ops, void *closure)
-{
-    return true;
-}
-
 void *twin_linux_input_create(twin_screen_t *screen)
 {
     /* Create object for handling Linux input system */
@@ -302,14 +297,6 @@ void *twin_linux_input_create(twin_screen_t *screen)
     tm->x = screen->width / 2;
     tm->y = screen->height / 2;
 
-#if 1
-    /* FIXME: Need to fix the unexpected termination of the program.
-     * Hooking a dummy function here is only a hack*/
-
-    /* Set file handler for reading input device file */
-    twin_set_file(dummy, tm->fd, TWIN_READ, tm);
-#endif
-
     /* Start event handling thread */
     if (pthread_create(&tm->evdev_thread, NULL, twin_linux_evdev_thread, tm)) {
         log_error("Failed to create evdev thread");

backend/sdl.c

@@ -72,55 +72,6 @@ static void twin_sdl_damage(twin_screen_t *screen, twin_sdl_t *tx)
     twin_screen_damage(screen, 0, 0, width, height);
 }
 
-static bool twin_sdl_read_events(int file maybe_unused,
-                                 twin_file_op_t ops maybe_unused,
-                                 void *closure)
-{
-    twin_screen_t *screen = SCREEN(closure);
-    twin_sdl_t *tx = PRIV(closure);
-
-    SDL_Event ev;
-    while (SDL_PollEvent(&ev)) {
-        twin_event_t tev;
-        switch (ev.type) {
-        case SDL_WINDOWEVENT:
-            if (ev.window.event == SDL_WINDOWEVENT_EXPOSED ||
-                ev.window.event == SDL_WINDOWEVENT_SHOWN) {
-                twin_sdl_damage(screen, tx);
-            }
-            break;
-        case SDL_QUIT:
-            _twin_sdl_destroy(screen, tx);
-            return false;
-        case SDL_MOUSEBUTTONDOWN:
-        case SDL_MOUSEBUTTONUP:
-            tev.u.pointer.screen_x = ev.button.x;
-            tev.u.pointer.screen_y = ev.button.y;
-            tev.u.pointer.button =
-                ((ev.button.state >> 8) | (1 << (ev.button.button - 1)));
-            tev.kind = ((ev.type == SDL_MOUSEBUTTONDOWN) ? TwinEventButtonDown
-                                                         : TwinEventButtonUp);
-            twin_screen_dispatch(screen, &tev);
-            break;
-        case SDL_KEYDOWN:
-        case SDL_KEYUP:
-            tev.u.key.key = ev.key.keysym.sym;
-            tev.kind = ((ev.key.type == SDL_KEYDOWN) ? TwinEventKeyDown
-                                                     : TwinEventKeyUp);
-            twin_screen_dispatch(screen, &tev);
-            break;
-        case SDL_MOUSEMOTION:
-            tev.u.pointer.screen_x = ev.motion.x;
-            tev.u.pointer.screen_y = ev.motion.y;
-            tev.kind = TwinEventMotion;
-            tev.u.pointer.button = ev.motion.state;
-            twin_screen_dispatch(screen, &tev);
-            break;
-        }
-    }
-    return true;
-}
-
 static bool twin_sdl_work(void *closure)
 {
     twin_screen_t *screen = SCREEN(closure);
@@ -174,8 +125,6 @@ twin_context_t *twin_sdl_init(int width, int height)
     ctx->screen = twin_screen_create(width, height, _twin_sdl_put_begin,
                                      _twin_sdl_put_span, ctx);
 
-    twin_set_file(twin_sdl_read_events, 0, TWIN_READ, ctx);
-
     twin_set_work(twin_sdl_work, TWIN_WORK_REDISPLAY, ctx);
 
     return ctx;
@@ -195,6 +144,53 @@ static void twin_sdl_configure(twin_context_t *ctx)
     twin_screen_resize(ctx->screen, width, height);
 }
 
+static bool twin_sdl_poll(twin_context_t *ctx)
+{
+    twin_screen_t *screen = SCREEN(ctx);
+    twin_sdl_t *tx = PRIV(ctx);
+
+    SDL_Event ev;
+    while (SDL_PollEvent(&ev)) {
+        twin_event_t tev;
+        switch (ev.type) {
+        case SDL_WINDOWEVENT:
+            if (ev.window.event == SDL_WINDOWEVENT_EXPOSED ||
+                ev.window.event == SDL_WINDOWEVENT_SHOWN) {
+                twin_sdl_damage(screen, tx);
+            }
+            break;
+        case SDL_QUIT:
+            _twin_sdl_destroy(screen, tx);
+            return false;
+        case SDL_MOUSEBUTTONDOWN:
+        case SDL_MOUSEBUTTONUP:
+            tev.u.pointer.screen_x = ev.button.x;
+            tev.u.pointer.screen_y = ev.button.y;
+            tev.u.pointer.button =
+                ((ev.button.state >> 8) | (1 << (ev.button.button - 1)));
+            tev.kind = ((ev.type == SDL_MOUSEBUTTONDOWN) ? TwinEventButtonDown
+                                                         : TwinEventButtonUp);
+            twin_screen_dispatch(screen, &tev);
+            break;
+        case SDL_KEYDOWN:
+        case SDL_KEYUP:
+            tev.u.key.key = ev.key.keysym.sym;
+            tev.kind = ((ev.key.type == SDL_KEYDOWN) ? TwinEventKeyDown
+                                                     : TwinEventKeyUp);
+            twin_screen_dispatch(screen, &tev);
+            break;
+        case SDL_MOUSEMOTION:
+            tev.u.pointer.screen_x = ev.motion.x;
+            tev.u.pointer.screen_y = ev.motion.y;
+            tev.kind = TwinEventMotion;
+            tev.u.pointer.button = ev.motion.state;
+            twin_screen_dispatch(screen, &tev);
+            break;
+        }
+    }
+    return true;
+}
+
 static void twin_sdl_exit(twin_context_t *ctx)
 {
     if (!ctx)
@@ -209,5 +205,6 @@ static void twin_sdl_exit(twin_context_t *ctx)
 const twin_backend_t g_twin_backend = {
     .init = twin_sdl_init,
     .configure = twin_sdl_configure,
+    .poll = twin_sdl_poll,
     .exit = twin_sdl_exit,
 };

backend/vnc.c

@@ -108,14 +108,6 @@ static void _twin_vnc_new_client(struct nvnc_client *client)
     nvnc_set_userdata(client, peer, NULL);
 }
 
-static bool _twin_vnc_read_events(int fd, twin_file_op_t op, void *closure)
-{
-    (void) fd;
-    (void) op;
-    (void) closure;
-    return true;
-}
-
 static void _twin_vnc_pointer_event(struct nvnc_client *client,
                                     uint16_t x,
                                     uint16_t y,
@@ -240,8 +232,6 @@ twin_context_t *twin_vnc_init(int width, int height)
         log_error("Failed to init VNC framebuffer");
         goto bail_framebuffer;
     }
-    int aml_fd = aml_get_fd(tx->aml);
-    twin_set_file(_twin_vnc_read_events, aml_fd, TWIN_READ, tx);
 
     twin_set_work(_twin_vnc_work, TWIN_WORK_REDISPLAY, ctx);
     tx->screen = ctx->screen;

include/twin.h

@@ -455,15 +455,10 @@ typedef twin_time_t (*twin_timeout_proc_t)(twin_time_t now, void *closure);
 
 typedef bool (*twin_work_proc_t)(void *closure);
 
-typedef enum _twin_file_op { TWIN_READ = 1, TWIN_WRITE = 2 } twin_file_op_t;
-
-typedef bool (*twin_file_proc_t)(int file, twin_file_op_t ops, void *closure);
-
 #define twin_time_compare(a, op, b) (((a) - (b)) op 0)
 
 typedef struct _twin_timeout twin_timeout_t;
 typedef struct _twin_work twin_work_t;
-typedef struct _twin_file twin_file_t;
 
 /*
  * Widgets
@@ -585,6 +580,11 @@ struct _twin_scroll {
     twin_widget_t widget;
 };
 
+typedef struct _twin_context {
+    twin_screen_t *screen;
+    void *priv;
+} twin_context_t;
+
 /*
  * box.c
  */
@@ -619,7 +619,7 @@ twin_pixmap_t *twin_make_cursor(int *hx, int *hy);
  * dispatch.c
  */
 
-void twin_dispatch(void);
+void twin_dispatch(twin_context_t *ctx);
 
 /*
  * draw.c
@@ -654,17 +654,6 @@ void twin_premultiply_alpha(twin_pixmap_t *px);
 
 void twin_event_enqueue(const twin_event_t *event);
 
-/*
- * file.c
- */
-
-twin_file_t *twin_set_file(twin_file_proc_t file_proc,
-                           int file,
-                           twin_file_op_t ops,
-                           void *closure);
-
-void twin_clear_file(twin_file_t *file);
-
 /*
  * fixed.c
  */
@@ -1170,11 +1159,6 @@ void twin_clear_work(twin_work_t *work);
  * backend
  */
 
-typedef struct _twin_context {
-    twin_screen_t *screen;
-    void *priv;
-} twin_context_t;
-
 twin_context_t *twin_create(int width, int height);
 
 void twin_destroy(twin_context_t *ctx);

include/twin_private.h

@@ -472,14 +472,6 @@ struct _twin_work {
     void *closure;
 };
 
-struct _twin_file {
-    twin_queue_t queue;
-    int file;
-    twin_file_op_t ops;
-    twin_file_proc_t proc;
-    void *closure;
-};
-
 typedef enum _twin_order {
     TWIN_BEFORE = -1,
     TWIN_AT = 0,
@@ -504,8 +496,6 @@ twin_queue_t *_twin_queue_set_order(twin_queue_t **head);
 
 void _twin_queue_review_order(twin_queue_t *first);
 
-int _twin_run_file(twin_time_t delay);
-
 void _twin_run_timeout(void);
 
 twin_time_t _twin_timeout_delay(void);

src/dispatch.c

@@ -4,14 +4,21 @@
  * All rights reserved.
  */
 
+#include <unistd.h>
+
+#include "twin_backend.h"
 #include "twin_private.h"
 
-void twin_dispatch(void)
+extern twin_backend_t g_twin_backend;
+
+void twin_dispatch(twin_context_t *ctx)
 {
     for (;;) {
         _twin_run_timeout();
         _twin_run_work();
-        if (!_twin_run_file(_twin_timeout_delay()))
+        if (g_twin_backend.poll && !g_twin_backend.poll(ctx)) {
+            usleep(_twin_timeout_delay() * 1000);
             break;
+        }
     }
 }