ui: add clipboard infrastructure

Add some infrastructure to manage the clipboard in qemu.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-id: 20210519053940.1888907-1-kraxel@redhat.com
Message-Id: <20210519053940.1888907-3-kraxel@redhat.com>

3 files changed, 155 insertions, 0 deletions

diff --git a/include/ui/clipboard.h b/include/ui/clipboard.h
new file mode 100644
index 0000000000..876de76219
--- /dev/null
+++ b/include/ui/clipboard.h
@@ -0,0 +1,62 @@
+#ifndef QEMU_CLIPBOARD_H
+#define QEMU_CLIPBOARD_H
+
+#include "qemu/notify.h"
+
+typedef enum QemuClipboardType QemuClipboardType;
+typedef enum QemuClipboardSelection QemuClipboardSelection;
+typedef struct QemuClipboardPeer QemuClipboardPeer;
+typedef struct QemuClipboardInfo QemuClipboardInfo;
+
+enum QemuClipboardType {
+    QEMU_CLIPBOARD_TYPE_TEXT,  /* text/plain; charset=utf-8 */
+    QEMU_CLIPBOARD_TYPE__COUNT,
+};
+
+/* same as VD_AGENT_CLIPBOARD_SELECTION_* */
+enum QemuClipboardSelection {
+    QEMU_CLIPBOARD_SELECTION_CLIPBOARD,
+    QEMU_CLIPBOARD_SELECTION_PRIMARY,
+    QEMU_CLIPBOARD_SELECTION_SECONDARY,
+    QEMU_CLIPBOARD_SELECTION__COUNT,
+};
+
+struct QemuClipboardPeer {
+    const char *name;
+    Notifier update;
+    void (*request)(QemuClipboardInfo *info,
+                    QemuClipboardType type);
+};
+
+struct QemuClipboardInfo {
+    uint32_t refcount;
+    QemuClipboardPeer *owner;
+    QemuClipboardSelection selection;
+    struct {
+        bool available;
+        bool requested;
+        size_t size;
+        void *data;
+    } types[QEMU_CLIPBOARD_TYPE__COUNT];
+};
+
+void qemu_clipboard_peer_register(QemuClipboardPeer *peer);
+void qemu_clipboard_peer_unregister(QemuClipboardPeer *peer);
+
+QemuClipboardInfo *qemu_clipboard_info_new(QemuClipboardPeer *owner,
+                                           QemuClipboardSelection selection);
+QemuClipboardInfo *qemu_clipboard_info_ref(QemuClipboardInfo *info);
+void qemu_clipboard_info_unref(QemuClipboardInfo *info);
+
+void qemu_clipboard_update(QemuClipboardInfo *info);
+void qemu_clipboard_request(QemuClipboardInfo *info,
+                            QemuClipboardType type);
+
+void qemu_clipboard_set_data(QemuClipboardPeer *peer,
+                             QemuClipboardInfo *info,
+                             QemuClipboardType type,
+                             uint32_t size,
+                             void *data,
+                             bool update);
+
+#endif /* QEMU_CLIPBOARD_H */
diff --git a/ui/clipboard.c b/ui/clipboard.c
new file mode 100644
index 0000000000..abf2b98f1f
--- /dev/null
+++ b/ui/clipboard.c
@@ -0,0 +1,92 @@
+#include "qemu/osdep.h"
+#include "ui/clipboard.h"
+
+static NotifierList clipboard_notifiers =
+    NOTIFIER_LIST_INITIALIZER(clipboard_notifiers);
+
+void qemu_clipboard_peer_register(QemuClipboardPeer *peer)
+{
+    notifier_list_add(&clipboard_notifiers, &peer->update);
+}
+
+void qemu_clipboard_peer_unregister(QemuClipboardPeer *peer)
+{
+    notifier_remove(&peer->update);
+}
+
+void qemu_clipboard_update(QemuClipboardInfo *info)
+{
+    notifier_list_notify(&clipboard_notifiers, info);
+}
+
+QemuClipboardInfo *qemu_clipboard_info_new(QemuClipboardPeer *owner,
+                                           QemuClipboardSelection selection)
+{
+    QemuClipboardInfo *info = g_new0(QemuClipboardInfo, 1);
+
+    info->owner = owner;
+    info->selection = selection;
+    info->refcount = 1;
+
+    return info;
+}
+
+QemuClipboardInfo *qemu_clipboard_info_ref(QemuClipboardInfo *info)
+{
+    info->refcount++;
+    return info;
+}
+
+void qemu_clipboard_info_unref(QemuClipboardInfo *info)
+{
+    uint32_t type;
+
+    if (!info) {
+        return;
+    }
+
+    info->refcount--;
+    if (info->refcount > 0) {
+        return;
+    }
+
+    for (type = 0; type < QEMU_CLIPBOARD_TYPE__COUNT; type++) {
+        g_free(info->types[type].data);
+    }
+    g_free(info);
+}
+
+void qemu_clipboard_request(QemuClipboardInfo *info,
+                            QemuClipboardType type)
+{
+    if (info->types[type].data ||
+        info->types[type].requested ||
+        !info->types[type].available ||
+        !info->owner)
+        return;
+
+    info->types[type].requested = true;
+    info->owner->request(info, type);
+}
+
+void qemu_clipboard_set_data(QemuClipboardPeer *peer,
+                             QemuClipboardInfo *info,
+                             QemuClipboardType type,
+                             uint32_t size,
+                             void *data,
+                             bool update)
+{
+    if (!info ||
+        info->owner != peer) {
+        return;
+    }
+
+    g_free(info->types[type].data);
+    info->types[type].data = g_memdup(data, size);
+    info->types[type].size = size;
+    info->types[type].available = true;
+
+    if (update) {
+        qemu_clipboard_update(info);
+    }
+}
diff --git a/ui/meson.build b/ui/meson.build
index e8d3ff41b9..fc4fb75c28 100644
--- a/ui/meson.build
+++ b/ui/meson.build
@@ -2,6 +2,7 @@ softmmu_ss.add(pixman)
 specific_ss.add(when: ['CONFIG_SOFTMMU'], if_true: pixman)   # for the include path
 
 softmmu_ss.add(files(
+  'clipboard.c',
   'console.c',
   'cursor.c',
   'input-keymap.c',