Add GET_CLIPBOARD device event

Add the first device event, used to forward the device clipboard to the
computer.

app/meson.build

@@ -6,6 +6,7 @@ src = [
     'src/convert.c',
     'src/decoder.c',
     'src/device.c',
+    'src/device_event.c',
     'src/file_handler.c',
     'src/fps_counter.c',
     'src/input_manager.c',
@@ -162,6 +163,10 @@ tests = [
         'src/control_event.c',
         'src/str_util.c'
     ]],
+    ['test_device_event_deserialize', [
+        'tests/test_device_event_deserialize.c',
+        'src/device_event.c'
+    ]],
     ['test_strutil', [
         'tests/test_strutil.c',
         'src/str_util.c'

app/src/device_event.c

@@ -0,0 +1,48 @@
+#include "device_event.h"
+
+#include <string.h>
+#include <SDL2/SDL_assert.h>
+
+#include "buffer_util.h"
+#include "log.h"
+
+ssize_t
+device_event_deserialize(const unsigned char *buf, size_t len,
+                         struct device_event *event) {
+    if (len < 3) {
+        // at least type + empty string length
+        return 0; // not available
+    }
+
+    event->type = buf[0];
+    switch (event->type) {
+        case DEVICE_EVENT_TYPE_GET_CLIPBOARD: {
+            uint16_t clipboard_len = buffer_read16be(&buf[1]);
+            if (clipboard_len > len - 3) {
+                return 0; // not available
+            }
+            char *text = SDL_malloc(clipboard_len + 1);
+            if (!text) {
+                LOGW("Could not allocate text for clipboard");
+                return -1;
+            }
+            if (clipboard_len) {
+                memcpy(text, &buf[3], clipboard_len);
+            }
+            text[clipboard_len] = '\0';
+
+            event->clipboard_event.text = text;
+            return 3 + clipboard_len;
+        }
+        default:
+            LOGW("Unsupported device event type: %d", (int) event->type);
+            return -1; // error, we cannot recover
+    }
+}
+
+void
+device_event_destroy(struct device_event *event) {
+    if (event->type == DEVICE_EVENT_TYPE_GET_CLIPBOARD) {
+        SDL_free(event->clipboard_event.text);
+    }
+}

app/src/device_event.h

@@ -0,0 +1,33 @@
+#ifndef DEVICEEVENT_H
+#define DEVICEEVENT_H
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <unistd.h>
+
+#define DEVICE_EVENT_QUEUE_SIZE 64
+#define DEVICE_EVENT_TEXT_MAX_LENGTH 4093
+#define DEVICE_EVENT_SERIALIZED_MAX_SIZE (3 + DEVICE_EVENT_TEXT_MAX_LENGTH)
+
+enum device_event_type {
+    DEVICE_EVENT_TYPE_GET_CLIPBOARD,
+};
+
+struct device_event {
+    enum device_event_type type;
+    union {
+        struct {
+            char *text; // owned, to be freed by SDL_free()
+        } clipboard_event;
+    };
+};
+
+// return the number of bytes consumed (0 for no event available, -1 on error)
+ssize_t
+device_event_deserialize(const unsigned char *buf, size_t len,
+                         struct device_event *event);
+
+void
+device_event_destroy(struct device_event *event);
+
+#endif

app/tests/test_device_event_deserialize.c

@@ -0,0 +1,28 @@
+#include <assert.h>
+#include <string.h>
+
+#include "device_event.h"
+
+#include <stdio.h>
+static void test_deserialize_clipboard_event(void) {
+    const unsigned char input[] = {
+        0x00, // DEVICE_EVENT_TYPE_CLIPBOARD
+        0x00, 0x03, // text length
+        0x41, 0x42, 0x43, // "ABC"
+    };
+
+    struct device_event event;
+    ssize_t r = device_event_deserialize(input, sizeof(input), &event);
+    assert(r == 6);
+
+    assert(event.type == DEVICE_EVENT_TYPE_GET_CLIPBOARD);
+    assert(event.clipboard_event.text);
+    assert(!strcmp("ABC", event.clipboard_event.text));
+
+    device_event_destroy(&event);
+}
+
+int main(void) {
+    test_deserialize_clipboard_event();
+    return 0;
+}

server/src/main/java/com/genymobile/scrcpy/DeviceEvent.java

@@ -0,0 +1,27 @@
+package com.genymobile.scrcpy;
+
+public final class DeviceEvent {
+
+    public static final int TYPE_GET_CLIPBOARD = 0;
+
+    private int type;
+    private String text;
+
+    private DeviceEvent() {
+    }
+
+    public static DeviceEvent createGetClipboardEvent(String text) {
+        DeviceEvent event = new DeviceEvent();
+        event.type = TYPE_GET_CLIPBOARD;
+        event.text = text;
+        return event;
+    }
+
+    public int getType() {
+        return type;
+    }
+
+    public String getText() {
+        return text;
+    }
+}