Rename "event" to "message"

After the recent refactorings, a "control event" is not necessarily an
"event" (it may be a "command"). Similarly, the unique "device event"
used to send the device clipboard content is more a "reponse" to the
request from the client than an "event".

Rename both to "message", and rename the message types to better
describe their intent.

app/meson.build

@@ -1,12 +1,12 @@
 src = [
     'src/main.c',
     'src/command.c',
-    'src/control_event.c',
+    'src/control_msg.c',
     'src/controller.c',
     'src/convert.c',
     'src/decoder.c',
     'src/device.c',
-    'src/device_event.c',
+    'src/device_msg.c',
     'src/file_handler.c',
     'src/fps_counter.c',
     'src/input_manager.c',
@@ -160,13 +160,13 @@ tests = [
         'tests/test_cbuf.c',
     ]],
     ['test_control_event_serialize', [
-        'tests/test_control_event_serialize.c',
-        'src/control_event.c',
+        'tests/test_control_msg_serialize.c',
+        'src/control_msg.c',
         'src/str_util.c'
     ]],
     ['test_device_event_deserialize', [
-        'tests/test_device_event_deserialize.c',
-        'src/device_event.c'
+        'tests/test_device_msg_deserialize.c',
+        'src/device_msg.c'
     ]],
     ['test_strutil', [
         'tests/test_strutil.c',

app/src/control_msg.c

@@ -0,0 +1,83 @@
+#include "control_msg.h"
+
+#include <string.h>
+
+#include "buffer_util.h"
+#include "log.h"
+#include "str_util.h"
+
+static void
+write_position(uint8_t *buf, const struct position *position) {
+    buffer_write32be(&buf[0], position->point.x);
+    buffer_write32be(&buf[4], position->point.y);
+    buffer_write16be(&buf[8], position->screen_size.width);
+    buffer_write16be(&buf[10], position->screen_size.height);
+}
+
+// write length (2 bytes) + string (non nul-terminated)
+static size_t
+write_string(const char *utf8, size_t max_len, unsigned char *buf) {
+    size_t len = utf8_truncation_index(utf8, max_len);
+    buffer_write16be(buf, (uint16_t) len);
+    memcpy(&buf[2], utf8, len);
+    return 2 + len;
+}
+
+size_t
+control_msg_serialize(const struct control_msg *msg, unsigned char *buf) {
+    buf[0] = msg->type;
+    switch (msg->type) {
+        case CONTROL_MSG_TYPE_INJECT_KEYCODE:
+            buf[1] = msg->inject_keycode.action;
+            buffer_write32be(&buf[2], msg->inject_keycode.keycode);
+            buffer_write32be(&buf[6], msg->inject_keycode.metastate);
+            return 10;
+        case CONTROL_MSG_TYPE_INJECT_TEXT: {
+            size_t len = write_string(msg->inject_text.text,
+                                      CONTROL_MSG_TEXT_MAX_LENGTH, &buf[1]);
+            return 1 + len;
+        }
+        case CONTROL_MSG_TYPE_INJECT_MOUSE_EVENT:
+            buf[1] = msg->inject_mouse_event.action;
+            buffer_write32be(&buf[2], msg->inject_mouse_event.buttons);
+            write_position(&buf[6], &msg->inject_mouse_event.position);
+            return 18;
+        case CONTROL_MSG_TYPE_INJECT_SCROLL_EVENT:
+            write_position(&buf[1], &msg->inject_scroll_event.position);
+            buffer_write32be(&buf[13],
+                             (uint32_t) msg->inject_scroll_event.hscroll);
+            buffer_write32be(&buf[17],
+                             (uint32_t) msg->inject_scroll_event.vscroll);
+            return 21;
+        case CONTROL_MSG_TYPE_SET_CLIPBOARD: {
+            size_t len = write_string(msg->inject_text.text,
+                                      CONTROL_MSG_CLIPBOARD_TEXT_MAX_LENGTH,
+                                      &buf[1]);
+            return 1 + len;
+        }
+        case CONTROL_MSG_TYPE_BACK_OR_SCREEN_ON:
+        case CONTROL_MSG_TYPE_EXPAND_NOTIFICATION_PANEL:
+        case CONTROL_MSG_TYPE_COLLAPSE_NOTIFICATION_PANEL:
+        case CONTROL_MSG_TYPE_GET_CLIPBOARD:
+            // no additional data
+            return 1;
+        default:
+            LOGW("Unknown message type: %u", (unsigned) msg->type);
+            return 0;
+    }
+}
+
+void
+control_msg_destroy(struct control_msg *msg) {
+    switch (msg->type) {
+        case CONTROL_MSG_TYPE_INJECT_TEXT:
+            SDL_free(msg->inject_text.text);
+            break;
+        case CONTROL_MSG_TYPE_SET_CLIPBOARD:
+            SDL_free(msg->set_clipboard.text);
+            break;
+        default:
+            // do nothing
+            break;
+    }
+}

app/src/control_msg.h

@@ -0,0 +1,64 @@
+#ifndef CONTROLMSG_H
+#define CONTROLMSG_H
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+#include "android/input.h"
+#include "android/keycodes.h"
+#include "common.h"
+
+#define CONTROL_MSG_TEXT_MAX_LENGTH 300
+#define CONTROL_MSG_CLIPBOARD_TEXT_MAX_LENGTH 4093
+#define CONTROL_MSG_SERIALIZED_MAX_SIZE \
+    (3 + CONTROL_MSG_CLIPBOARD_TEXT_MAX_LENGTH)
+
+enum control_msg_type {
+    CONTROL_MSG_TYPE_INJECT_KEYCODE,
+    CONTROL_MSG_TYPE_INJECT_TEXT,
+    CONTROL_MSG_TYPE_INJECT_MOUSE_EVENT,
+    CONTROL_MSG_TYPE_INJECT_SCROLL_EVENT,
+    CONTROL_MSG_TYPE_BACK_OR_SCREEN_ON,
+    CONTROL_MSG_TYPE_EXPAND_NOTIFICATION_PANEL,
+    CONTROL_MSG_TYPE_COLLAPSE_NOTIFICATION_PANEL,
+    CONTROL_MSG_TYPE_GET_CLIPBOARD,
+    CONTROL_MSG_TYPE_SET_CLIPBOARD,
+};
+
+struct control_msg {
+    enum control_msg_type type;
+    union {
+        struct {
+            enum android_keyevent_action action;
+            enum android_keycode keycode;
+            enum android_metastate metastate;
+        } inject_keycode;
+        struct {
+            char *text; // owned, to be freed by SDL_free()
+        } inject_text;
+        struct {
+            enum android_motionevent_action action;
+            enum android_motionevent_buttons buttons;
+            struct position position;
+        } inject_mouse_event;
+        struct {
+            struct position position;
+            int32_t hscroll;
+            int32_t vscroll;
+        } inject_scroll_event;
+        struct {
+            char *text; // owned, to be freed by SDL_free()
+        } set_clipboard;
+    };
+};
+
+// buf size must be at least CONTROL_MSG_SERIALIZED_MAX_SIZE
+// return the number of bytes written
+size_t
+control_msg_serialize(const struct control_msg *msg, unsigned char *buf);
+
+void
+control_msg_destroy(struct control_msg *msg);
+
+#endif