src/plugins/platforms/wasm/qwasmoffscreensurface.cpp


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35

// Copyright (C) 2019 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only

#include "qwasmoffscreensurface.h"

QT_BEGIN_NAMESPACE

QWasmOffscreenSurface::QWasmOffscreenSurface(QOffscreenSurface *offscreenSurface)
    : QPlatformOffscreenSurface(offscreenSurface), m_offscreenCanvas(emscripten::val::undefined())
{
    const auto offscreenCanvasClass = emscripten::val::global("OffscreenCanvas");
    // The OffscreenCanvas is not supported on some browsers, most notably on Safari.
    if (!offscreenCanvasClass)
        return;

    m_offscreenCanvas = offscreenCanvasClass.new_(offscreenSurface->size().width(),
                                                  offscreenSurface->size().height());

    m_specialTargetId = std::string("!qtoffscreen_") + std::to_string(uintptr_t(this));

    emscripten::val::module_property("specialHTMLTargets")
            .set(m_specialTargetId, m_offscreenCanvas);
}

QWasmOffscreenSurface::~QWasmOffscreenSurface()
{
    emscripten::val::module_property("specialHTMLTargets").delete_(m_specialTargetId);
}

bool QWasmOffscreenSurface::isValid() const
{
    return !m_offscreenCanvas.isNull() && !m_offscreenCanvas.isUndefined();
}

QT_END_NAMESPACE