Add AVFCameraWindowControl as QVideoWindowControl_iid implementation

AVFCameraWindowControl is a renderer backend,
when QCamera viewfinder output set to QVideoWidget on macOS or iOS.
As it uses native API and lets the OS handle rendering pipeline,
it is an efficient alternative to default renderer backend.

Task-number: QTBUG-68779
Change-Id: I4d27022655a7d9f4ad7cf99c84b570a0c48cf10a
Reviewed-by: VaL Doroshchuk <valentyn.doroshchuk@qt.io>

1 files changed, 262 insertions, 0 deletions

diff --git a/src/plugins/avfoundation/camera/avfcamerawindowcontrol.mm b/src/plugins/avfoundation/camera/avfcamerawindowcontrol.mm
new file mode 100644
index 000000000..5154d0646
--- /dev/null
+++ b/src/plugins/avfoundation/camera/avfcamerawindowcontrol.mm
@@ -0,0 +1,262 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 The Qt Company Ltd and/or its subsidiary(-ies).
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "avfcamerawindowcontrol.h"
+
+#import <AVFoundation/AVFoundation.h>
+#import <QuartzCore/CATransaction.h>
+
+#if QT_HAS_INCLUDE(<AppKit/AppKit.h>)
+#import <AppKit/AppKit.h>
+#endif
+
+#if QT_HAS_INCLUDE(<UIKit/UIKit.h>)
+#import <UIKit/UIKit.h>
+#endif
+
+QT_USE_NAMESPACE
+
+AVFCameraWindowControl::AVFCameraWindowControl(QObject *parent)
+    : QVideoWindowControl(parent)
+{
+    setObjectName(QStringLiteral("AVFCameraWindowControl"));
+}
+
+AVFCameraWindowControl::~AVFCameraWindowControl()
+{
+    releaseNativeLayer();
+}
+
+WId AVFCameraWindowControl::winId() const
+{
+    return m_winId;
+}
+
+void AVFCameraWindowControl::setWinId(WId id)
+{
+    if (m_winId == id)
+        return;
+
+    m_winId = id;
+
+    detachNativeLayer();
+    m_nativeView = (NativeView*)m_winId;
+    attachNativeLayer();
+}
+
+QRect AVFCameraWindowControl::displayRect() const
+{
+    return m_displayRect;
+}
+
+void AVFCameraWindowControl::setDisplayRect(const QRect &rect)
+{
+    if (m_displayRect != rect) {
+        m_displayRect = rect;
+        updateCaptureLayerBounds();
+    }
+}
+
+bool AVFCameraWindowControl::isFullScreen() const
+{
+    return m_fullscreen;
+}
+
+void AVFCameraWindowControl::setFullScreen(bool fullscreen)
+{
+    if (m_fullscreen != fullscreen) {
+        m_fullscreen = fullscreen;
+        Q_EMIT fullScreenChanged(fullscreen);
+    }
+}
+
+void AVFCameraWindowControl::repaint()
+{
+    if (m_captureLayer)
+        [m_captureLayer setNeedsDisplay];
+}
+
+QSize AVFCameraWindowControl::nativeSize() const
+{
+    return m_nativeSize;
+}
+
+void AVFCameraWindowControl::setNativeSize(QSize size)
+{
+    if (m_nativeSize != size) {
+        m_nativeSize = size;
+        Q_EMIT nativeSizeChanged();
+    }
+}
+
+Qt::AspectRatioMode AVFCameraWindowControl::aspectRatioMode() const
+{
+    return m_aspectRatioMode;
+}
+
+void AVFCameraWindowControl::setAspectRatioMode(Qt::AspectRatioMode mode)
+{
+    if (m_aspectRatioMode != mode) {
+        m_aspectRatioMode = mode;
+        updateAspectRatio();
+    }
+}
+
+int AVFCameraWindowControl::brightness() const
+{
+    return 0;
+}
+
+void AVFCameraWindowControl::setBrightness(int brightness)
+{
+    if (0 != brightness)
+        qWarning("AVFCameraWindowControl doesn't support changing Brightness");
+}
+
+int AVFCameraWindowControl::contrast() const
+{
+    return 0;
+}
+
+void AVFCameraWindowControl::setContrast(int contrast)
+{
+    if (0 != contrast)
+        qWarning("AVFCameraWindowControl doesn't support changing Contrast");
+}
+
+int AVFCameraWindowControl::hue() const
+{
+    return 0;
+}
+
+void AVFCameraWindowControl::setHue(int hue)
+{
+    if (0 != hue)
+        qWarning("AVFCameraWindowControl doesn't support changing Hue");
+}
+
+int AVFCameraWindowControl::saturation() const
+{
+    return 0;
+}
+
+void AVFCameraWindowControl::setSaturation(int saturation)
+{
+    if (0 != saturation)
+        qWarning("AVFCameraWindowControl doesn't support changing Saturation");
+}
+
+void AVFCameraWindowControl::setLayer(AVCaptureVideoPreviewLayer *capturePreviewLayer)
+{
+    if (m_captureLayer == capturePreviewLayer)
+        return;
+
+    releaseNativeLayer();
+
+    m_captureLayer = capturePreviewLayer;
+
+    if (m_captureLayer)
+        retainNativeLayer();
+}
+
+void AVFCameraWindowControl::updateAspectRatio()
+{
+    if (m_captureLayer) {
+        switch (m_aspectRatioMode) {
+        case Qt::IgnoreAspectRatio:
+            [m_captureLayer setVideoGravity:AVLayerVideoGravityResize];
+            break;
+        case Qt::KeepAspectRatio:
+            [m_captureLayer setVideoGravity:AVLayerVideoGravityResizeAspect];
+            break;
+        case Qt::KeepAspectRatioByExpanding:
+            [m_captureLayer setVideoGravity:AVLayerVideoGravityResizeAspectFill];
+            break;
+        default:
+            break;
+        }
+    }
+}
+
+void AVFCameraWindowControl::updateCaptureLayerBounds()
+{
+    if (m_captureLayer && m_nativeView) {
+        [CATransaction begin];
+        [CATransaction setDisableActions: YES]; // disable animation/flicks
+        m_captureLayer.frame = m_displayRect.toCGRect();
+        [CATransaction commit];
+    }
+}
+
+void AVFCameraWindowControl::retainNativeLayer()
+{
+    [m_captureLayer retain];
+
+    updateAspectRatio();
+    attachNativeLayer();
+}
+
+void AVFCameraWindowControl::releaseNativeLayer()
+{
+    if (m_captureLayer) {
+        detachNativeLayer();
+        [m_captureLayer release];
+        m_captureLayer = nullptr;
+    }
+}
+
+void AVFCameraWindowControl::attachNativeLayer()
+{
+    if (m_captureLayer && m_nativeView) {
+#if defined(Q_OS_MACOS)
+        m_nativeView.wantsLayer = YES;
+#endif
+        CALayer *nativeLayer = m_nativeView.layer;
+        [nativeLayer addSublayer:m_captureLayer];
+        updateCaptureLayerBounds();
+    }
+}
+
+void AVFCameraWindowControl::detachNativeLayer()
+{
+    if (m_captureLayer && m_nativeView)
+        [m_captureLayer removeFromSuperlayer];
+}
+
+#include "moc_avfcamerawindowcontrol.cpp"