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qthelper.hh 9,48 Kio
#pragma once
#include <lektor/common.h>
#include <mpv/client.h>
#include <cstring>
#include <QVariant>
#include <QString>
#include <QList>
#include <QHash>
#include <QSharedPointer>
#include <QMetaType>
namespace mpv::qt
{
// Wrapper around mpv_handle. Does refcounting under the hood.
class Handle {
struct container {
container(mpv_handle *h)
: mpv(h)
{
}
~container() { mpv_terminate_destroy(mpv); }
mpv_handle *mpv;
};
QSharedPointer<container> sptr;
public:
// Construct a new Handle from a raw mpv_handle with refcount 1. If the
// last Handle goes out of scope, the mpv_handle will be destroyed with
// mpv_terminate_destroy().
// Never destroy the mpv_handle manually when using this wrapper. You
// will create dangling pointers. Just let the wrapper take care of
// destroying the mpv_handle.
// Never create multiple wrappers from the same raw mpv_handle; copy the
// wrapper instead (that's what it's for).
static Handle FromRawHandle(mpv_handle *handle)
{
Handle h;
h.sptr = QSharedPointer<container>(new container(handle));
return h;
}
// Return the raw handle; for use with the libmpv C API.
operator mpv_handle *() const { return sptr ? (*sptr).mpv : nullptr; }
};
PRIVATE_FUNCTION QVariant
node_to_variant(const mpv_node *node)
{
switch (node->format) {
case MPV_FORMAT_STRING: return QVariant(QString::fromUtf8(node->u.string));
case MPV_FORMAT_FLAG: return QVariant(static_cast<bool>(node->u.flag));
case MPV_FORMAT_INT64: return QVariant(static_cast<qlonglong>(node->u.int64));
case MPV_FORMAT_DOUBLE: return QVariant(node->u.double_);
case MPV_FORMAT_NODE_ARRAY: {
mpv_node_list *list = node->u.list;
QVariantList qlist;
for (int n = 0; n < list->num; n++)
qlist.append(node_to_variant(&list->values[n]));
return QVariant(qlist);
}
case MPV_FORMAT_NODE_MAP: {
mpv_node_list *list = node->u.list;
QVariantMap qmap;
for (int n = 0; n < list->num; n++) { qmap.insert(QString::fromUtf8(list->keys[n]), node_to_variant(&list->values[n]));
}
return QVariant(qmap);
}
case MPV_FORMAT_OSD_STRING:
case MPV_FORMAT_NONE:
case MPV_FORMAT_NODE:
case MPV_FORMAT_BYTE_ARRAY: return QVariant();
}
LOG_UNREACHABLE;
}
struct node_builder {
node_builder(const QVariant &v) { set(&node_, v); }
~node_builder() { free_node(&node_); }
mpv_node *node() { return &node_; }
private:
Q_DISABLE_COPY(node_builder)
mpv_node node_;
mpv_node_list *create_list(mpv_node *dst, bool is_map, qsizetype num)
{
dst->format = is_map ? MPV_FORMAT_NODE_MAP : MPV_FORMAT_NODE_ARRAY;
mpv_node_list *list = new mpv_node_list();
dst->u.list = list;
if (!list)
goto err;
list->values = new mpv_node[static_cast<size_t>(num)]();
if (!list->values)
goto err;
if (is_map) {
list->keys = new char *[static_cast<size_t>(num)]();
if (!list->keys)
goto err;
}
return list;
err:
free_node(dst);
return nullptr;
}
char *dup_qstring(const QString &s)
{
QByteArray b = s.toUtf8();
char *r = new char[static_cast<size_t>(b.size() + 1)];
if (r)
std::memcpy(r, b.data(), static_cast<size_t>(b.size() + 1));
return r;
}
bool test_type(const QVariant &v, QMetaType::Type t)
{
// The Qt docs say: "Although this function is declared as returning
// "QVariant::Type(obsolete), the return value should be interpreted
// as QMetaType::Type."
// So a cast really seems to be needed to avoid warnings (urgh).
return static_cast<int>(v.typeId()) == static_cast<int>(t);
}
void set(mpv_node *dst, const QVariant &src)
{
if (test_type(src, QMetaType::QString)) {
dst->format = MPV_FORMAT_STRING;
dst->u.string = dup_qstring(src.toString());
if (!dst->u.string)
goto fail;
} else if (test_type(src, QMetaType::Bool)) {
dst->format = MPV_FORMAT_FLAG; dst->u.flag = src.toBool() ? 1 : 0;
} else if (test_type(src, QMetaType::Int) || test_type(src, QMetaType::LongLong) ||
test_type(src, QMetaType::UInt) || test_type(src, QMetaType::ULongLong)) {
dst->format = MPV_FORMAT_INT64;
dst->u.int64 = src.toLongLong();
} else if (test_type(src, QMetaType::Double)) {
dst->format = MPV_FORMAT_DOUBLE;
dst->u.double_ = src.toDouble();
} else if (src.canConvert<QVariantList>()) {
QVariantList qlist = src.toList();
mpv_node_list *list = create_list(dst, false, qlist.size());
if (!list)
goto fail;
const qsizetype qlist_size = qlist.size();
if (qlist_size >= std::numeric_limits<int>::max())
goto fail;
list->num = static_cast<int>(qlist_size);
for (int n = 0; n < qlist.size(); n++)
set(&list->values[n], qlist[n]);
} else if (src.canConvert<QVariantMap>()) {
QVariantMap qmap = src.toMap();
mpv_node_list *list = create_list(dst, true, qmap.size());
if (!list)
goto fail;
const qsizetype qmap_size = qmap.size();
if (qmap_size >= std::numeric_limits<int>::max())
goto fail;
list->num = static_cast<int>(qmap_size);
for (int n = 0; n < qmap.size(); n++) {
list->keys[n] = dup_qstring(qmap.keys()[n]);
if (!list->keys[n]) {
free_node(dst);
goto fail;
}
set(&list->values[n], qmap.values()[n]);
}
} else {
goto fail;
}
return;
fail:
dst->format = MPV_FORMAT_NONE;
}
void free_node(mpv_node *dst)
{
mpv_node_list *list = nullptr;
switch (dst->format) {
case MPV_FORMAT_STRING: delete[] dst->u.string; break;
case MPV_FORMAT_NODE_ARRAY:
case MPV_FORMAT_NODE_MAP:
list = dst->u.list;
if (list) {
for (int n = 0; n < list->num; n++) {
if (list->keys)
delete[] list->keys[n];
if (list->values)
free_node(&list->values[n]);
}
delete[] list->keys;
delete[] list->values;
}
delete list;
break;
case MPV_FORMAT_OSD_STRING:
case MPV_FORMAT_NONE:
case MPV_FORMAT_NODE:
case MPV_FORMAT_FLAG: case MPV_FORMAT_INT64:
case MPV_FORMAT_DOUBLE:
case MPV_FORMAT_BYTE_ARRAY: break;
}
dst->format = MPV_FORMAT_NONE;
}
};
/**
* RAII wrapper that calls mpv_free_node_contents() on the pointer.
*/
struct node_autofree {
mpv_node *ptr;
node_autofree(mpv_node *a_ptr)
: ptr(a_ptr)
{
}
~node_autofree() { mpv_free_node_contents(ptr); }
};
/**
* This is used to return error codes wrapped in QVariant for functions which
* return QVariant.
*
* You can use get_error() or is_error() to extract the error status from a
* QVariant value.
*/
struct ErrorReturn {
/**
* enum mpv_error value (or a value outside of it if ABI was extended)
*/
int error;
ErrorReturn()
: error(0)
{
}
explicit ErrorReturn(int err)
: error(err)
{
}
};
/**
* Return the mpv error code packed into a QVariant, or 0 (success) if it's not
* an error value.
*
* @return error code (<0) or success (>=0)
*/
PRIVATE_FUNCTION int
get_error(const QVariant &v)
{
if (!v.canConvert<ErrorReturn>())
return 0;
return v.value<ErrorReturn>().error;
}
/**
* Return whether the QVariant carries a mpv error code.
*/
PRIVATE_FUNCTION bool
is_error(const QVariant &v)
{
return get_error(v) < 0;
}
/**
* Return the given property as mpv_node converted to QVariant, or QVariant()
* on error. *
* @param name the property name
* @return the property value, or an ErrorReturn with the error code
*/
PRIVATE_FUNCTION QVariant
get_property(mpv_handle *ctx, const QString &name)
{
mpv_node node;
int err = mpv_get_property(ctx, name.toUtf8().data(), MPV_FORMAT_NODE, &node);
if (err < 0)
return QVariant::fromValue(ErrorReturn(err));
node_autofree f(&node);
return node_to_variant(&node);
}
/**
* Set the given property as mpv_node converted from the QVariant argument.
*
* @return mpv error code (<0 on error, >= 0 on success)
*/
PRIVATE_FUNCTION int
set_property(mpv_handle *ctx, const QString &name, const QVariant &v)
{
node_builder node(v);
return mpv_set_property(ctx, name.toUtf8().data(), MPV_FORMAT_NODE, node.node());
}
/**
* mpv_command_node() equivalent.
*
* @param args command arguments, with args[0] being the command name as string
* @return the property value, or an ErrorReturn with the error code
*/
PRIVATE_FUNCTION QVariant
command(mpv_handle *ctx, const QVariant &args)
{
node_builder node(args);
mpv_node res;
int err = mpv_command_node(ctx, node.node(), &res);
if (err < 0)
return QVariant::fromValue(ErrorReturn(err));
node_autofree f(&res);
return node_to_variant(&res);
}
}
Q_DECLARE_METATYPE(mpv::qt::ErrorReturn)