Separate multi-words filenames by '_'

Rename foobar.ext to foo_bar.ext.

<https://github.com/Genymobile/scrcpy/pull/226#discussion_r209454865>

app/src/control_event.h

@@ -0,0 +1,73 @@
+#ifndef CONTROLEVENT_H
+#define CONTROLEVENT_H
+
+#include <SDL2/SDL_mutex.h>
+#include <SDL2/SDL_stdinc.h>
+
+#include "android/input.h"
+#include "android/keycodes.h"
+#include "common.h"
+
+#define CONTROL_EVENT_QUEUE_SIZE 64
+#define TEXT_MAX_LENGTH 300
+#define SERIALIZED_EVENT_MAX_SIZE 3 + TEXT_MAX_LENGTH
+
+enum control_event_type {
+    CONTROL_EVENT_TYPE_KEYCODE,
+    CONTROL_EVENT_TYPE_TEXT,
+    CONTROL_EVENT_TYPE_MOUSE,
+    CONTROL_EVENT_TYPE_SCROLL,
+    CONTROL_EVENT_TYPE_COMMAND,
+};
+
+#define CONTROL_EVENT_COMMAND_BACK_OR_SCREEN_ON 0
+
+struct control_event {
+    enum control_event_type type;
+    union {
+        struct {
+            enum android_keyevent_action action;
+            enum android_keycode keycode;
+            enum android_metastate metastate;
+        } keycode_event;
+        struct {
+            char *text; // owned, to be freed by SDL_free()
+        } text_event;
+        struct {
+            enum android_motionevent_action action;
+            enum android_motionevent_buttons buttons;
+            struct position position;
+        } mouse_event;
+        struct {
+            struct position position;
+            Sint32 hscroll;
+            Sint32 vscroll;
+        } scroll_event;
+        struct {
+            int action;
+        } command_event;
+    };
+};
+
+struct control_event_queue {
+    struct control_event data[CONTROL_EVENT_QUEUE_SIZE];
+    int head;
+    int tail;
+};
+
+// buf size must be at least SERIALIZED_EVENT_MAX_SIZE
+int control_event_serialize(const struct control_event *event, unsigned char *buf);
+
+SDL_bool control_event_queue_init(struct control_event_queue *queue);
+void control_event_queue_destroy(struct control_event_queue *queue);
+
+SDL_bool control_event_queue_is_empty(const struct control_event_queue *queue);
+SDL_bool control_event_queue_is_full(const struct control_event_queue *queue);
+
+// event is copied, the queue does not use the event after the function returns
+SDL_bool control_event_queue_push(struct control_event_queue *queue, const struct control_event *event);
+SDL_bool control_event_queue_take(struct control_event_queue *queue, struct control_event *event);
+
+void control_event_destroy(struct control_event *event);
+
+#endif